We picked up a 1985 Cat 966D at auction and have been going through it replacing all fluids and filters and doing a re-paint. Its quite the machine, much larger than the old C model. Cat did a full rebuild on it in 2012, it has 6700 hrs on it currently. Its been a solid machine so far, we've been extremely happy with it, dont make them like this any more. After the re-paint a crack did appear tho....
We did end up having to stud the tires, as these particular rubbers are extremely slick on ice, especially in the afternoon. One of our guys slid off a little driveway below, no harm done fortunately.
Anyway after the first greasing of machine after paint job I noticed some old cracking shining through, on the main Lever 4E-3119 (4V8517) Cat wants $11,762 for said part. I did find a used one through Cat for 3100, shipped here. So they are available, which is nice to know. This isn't a production machine so I'm looking into the likely hood of having this welded up. I understand this is not a simple process being such a large chunk of steel and what appears to be cast steel potentially? So I thought i'd bring it here to the knowledge base as im sure someone has broken another one out there. Any luck repairing? Does cat have a procedure for such a thing? I marked the cracks vertically with knife as you can see, to see if they were growing, and they dont seem to be...yet
on the right side it appears to be stressing it somehow. Doesn't appear to be cracks, just stretch marks
Budget for a replacement tilt link. Those are cast and not repairable by welding with any success from everything I've seen. To do any sort of a job the link would have to be removed from the machine, got into a heated shop then preheated to around 150 DegC before anyone thinks of striking an arc on it. I would imagine an electrode with very high elongation (so not 7018 then) would give the best chance of success. After welding it would need to be stress-relieved for something like 48 hours at 250 DegC if my memory serves me correctly. Is there a welding shop round your way with an oven big enough to fit it into after the repair.? I have dozens of photos of tilt links broken in half that started as cracks like this. A lot of them originated from casting defects, the rest from operational abuse. Bear in mind that a used replacement could be in a similar shape to the one you have on the machine right now. Have you looked to see if there is anything obviously out of true in the loader linkage.? Are you ever going to be loading dirt with it on a production basis.?
Everything seems to be plumb and strait, nothing bent. This won't be a production machine no, just loading some gravel here and there, snowplowing in the winter. No there isn't an oven to fit it in unfortunately. There is a "new aftermarket" from Cat but I'm leary about that route as well
I think your are very wise to be leery of that option.
To give you an idea. This is a stress diagram of a typical tilt link. The lowest stresses are green, moving up through yellow to the highest stress areas in red. Your cracks are just on the boundary of the yellow/red area.
Here's a couple that failed with internal casting defects. In the frist one the little discolouration in the centre of the balck circle is the grain of foundry sand that started the internal crack. There was no sign of an external crack at all until the lever failed catastrophically. The second one it's more obvious and there was indication of an external crack before it failed.
TBH I think if I was in your position I'd just keep it under close observation, at least for now. It is possible that those cracks were started by an operator banging the bucket linkage against the dump stops in an attempt to dislodge sticky material from the bucket. Try and stay away from that type of operating practice and the tilt lever could give you long service without the cracks getting any bigger. Another suggestion. Are the dump stops on the lever and on the cross-tube of the lft arms nice and flat.? Do the stops come together even or can you see daylight through certain parts when the stops are touching.? Do they look like the photos below.? I sure hope not.
wow, thanks for that really cool diagram! Really puts it into perspective. The failures are quite interesting also, heck of a way to start your day. Do you think it would be worth trying to grind it out and metal glue it back up? or the chance for actual success is so low I should just monitor it? Its hard to say what previous operators were like, it does have a bent fork tip thats indicative of less than stellar operating techniques. But other than that everything seems in order. The bump stops are smooth and dont look beat up
That Cat cast steel is usually quite weldable. If you have a heated shop overnite and weld it on the machine. Take a grinder with a flap wheel and clean the paint and rust off. Use a regular grinding wheel to grind the crack out and leave a small V. Use a torch to preheat warm enough to drive off the water. You can weld with fresh 7018 and I weld stringer beads and slag with a needle scaler. Don't get it too hot. Grind the over weld off flush with the flap wheel and a lite coat of paint while warm. If you have any questions PM me for a phone #. Good luck Bob
Thanks for the reply and ideas, I think I'll budget for another one, then give it a go welding! I'll report back when it fails!
Awesome job on the machine And the educational photos from Nige are great too
Well, made it through the summer! this crack may have grown a little bit, hard to say Or if the new paint just chipped more around it. I didnt attempt welding, sounded like mixed results locally, mostly failing.
I did have another question about an injection pump leak on this machine. Maybe I should start another thread but ill try here first. Its leaking right out of the throttle linkage. There is a plate there id like to take off and re-seal. But wanted to ask beforehand to a bunch of springs dont come flying back at me. We pressure washed it off real well to see where it was coming from, but it made a pretty good mess over the summer
As far as the cracks they can be welded but if the proper technique isn't followed can make it worse. Preheat around 300F would be ideal because it's a thick piece of cast steel. I'd use something a little stronger than 7018 like 8018C3. This is the most common 8018 that doesn't always list the C3 in the name. The fine print will show it though. It has 1% nickle for added toughness and good for low temperatures. It's commonly used on crane booms. You could use one of the high strength stainless based specialty rods but that would be overkill. Wraping it in a welding blanket after welding so it can slow cool would be beneficial. Peening with a needle scaler while it's hot from welding would help relieve stress. If you don't have a needle scaler even a blunt/dull chipping hammer to peen the welds would help. As far as the leak I don't know about a 966D but on my 931B track loader 2 seals could be installed on the throttle shaft cover if the 1st one was pushed in a little further.
Thanks for the info Dave, we are somewhat sorta remote, there aren't alot of pro welder options. I play around on the MIG quite a bit, but not fluent enough on stick to carry this out just yet. For the pump, thanks for that info too, I really want to pull that cover off and see whats behind door #1 haha
If you want to have a bash at welding it I'd suggest a rod with more than 1% nickel. Eutectic Xuper NucleoTec 2222 was our weapon of choice in an attempt to avoid re-cracking and have an advantage of being low heat input too. If they work with the levels of expansion & contraction on nuclear reactors then that's good enough for me. https://www.castolin.com/product/eutectrode-xuper-nucleotec-2222-welding-electrodes The price will make your eyes water though. Loads of pre-heat and post heat required plus beat the bejasus out of it with a needle gun after each pass to stress relieve the weld while it's still hot. What worries me if you start chasing that crack is how deep it might actually go. The problem at the moment where that realization dawns on you is that you've already gone to the point of no return and have to keep going. Here's a thought. Does anyone around your way have an ultra-sonic machine (similar to what's used to measure undercarriage wear) that could be run over the crack area in an attempt to determine how deep it is.?
Interesting Nige. I have not tried measuring cracks with my ultrasound gadget. I’ll have to read up on that.
It's not definitive but U/S can give you an idea. If there is access from the back side of the section then moving the U/S probe over that back side surface (you'd have to smooth/polish it first) then it should show a discontinuity appearing when it passes over the crack and then disappearing again. The measured distance from the back side surface to the discontinuity should give some idea of the location of the root of the crack. A bit of simple maths and you have the (very approximate) depth of the crack from the other side.
As wqs said previously, not letting the linkage hit stops would make so much of a difference. We had an exact unit to this one in Northern Ontario 25 years ago. It had the same type of crack. We watched it for quite a long time and did not seem to grow any more. Eventually we had enough budget to buy a spare and change it out. When I left that place that unit had 70000 hours or more. Last I heard it had over 90000 hours. Every 10000hours rebuilt motor torque and transmission. I did the rear oscillating axle in it, along with the front differential once..They use to grease the whole boom every 8 hours religiously. These units made a good name for Cat in the mining industry. You should get lots of years of use. Simon C
If you have any problem with starting the engine, and find the batteries down in charge, Don't just get a new alternator without first checking a special plug that is about 2 feet from the alternator output post. It is I recall red in colour and about 6 Gauge in size, and has a bullet style plug that will burn out in time. I had to cut this joiner out and put in a permanent butt connector instead. We had changed out 2 alternators before this without finding out that as soon as the machine would turn on the lights the old connection would not carry the current. We had that on our 966F model also I believe. Hope it helps. Simon C
Thanks for the tips Simon, I'll take a look at that alternator connection while were in there. Any advice on re-sealing the throttle linkage shaft on injection pump picture there?
Is it just the shaft leaking? or the plate also? if you can't tell, dry it off with brake cleaner and dust it with flour or other powder to see where it seeps out first. If it's just the shaft, I'd try to fish the seal out with a pick and replace it without removing the shaft. For the cat guys, is cracking in that location typical? I'd be looking at the pin and bushings in that end to make sure they're not putting outward pressure on that "forked" end. You're not going to weaken it by grinding the crack out. Welding with nickle or SS rod would at least let you see if it keeps cracking.
Cracking in those areas isn’t exactly unusual. It’s often related to banging the tilt link against the stops on the lift arm. Seeing as the crack was already there when the current owner got the machine it seems likely that it happened in a previous life.
My experience with welding Cat castings goes back to the old 245 s when they first came out. Brand new ,ran by shovel operators building logging road. Lots of breakage from boom foot mounts boom to stick to the house being torn off the carbody. We kept lots of Arctec 223 xc in stock and used it for all welding repairs on the 245 s .I did this work in less then perfect conditions on cast parts and the fabricated steel parts with good success . The winter weather in the Queen Charlottes was less then desireable for this work. Id have a go at digging those cracks out and run something like Arctec223 . I think youll get lots hours on them yet.
Tugger2. That Arc-Tec 223 is the rod I use also. It has great elasticity and has served me well. Small stringer beads and peened after every pass. Also grind back out the weld starting point.. Welded a crack on the barrel of a hitachi 200 Excavator stick cylinder. New operator was a little hard on the machine but it still lasted 63 full truck loads before it let go again. It gave the owner enough time to find a spare cylinder and keep his crew of workers going. Propane torch warmed the area before the weld and cooled down slowly. That was how I fixed that one that was leaking oil right out. Simon C
About your 966D Park Brake. We disconnected the grease line that feeds a steady bearing that is attached to the park brake drum. If someone decides to give 3 extra shots of grease to that line every day , eventually you will have a park brake drum with multiple tubes of grease in it. Just put in a grease nipple and give it 1 shot every week and all will be okay. We fixed 2 units to prevent this mess. Just to save you some aggravation. Simon C
Thanks for all the information, will be heading over there tomorrow and will check and implement these ideas. I'll try and find some of that ARCTEC 223 rod to at least have on hand if I find a competent welder. I imagine one of the contributing factors is the down lever is incredibly sensitive, when you have a full bucket if you're not really on your game and just push down on it, the bucket will come down almost like its in a "float" position. It can slam into the ground, or stop in such a fashion it will bring the back tires off the ground. It will really wake you up, you have to be ever so gentle with your down movement to operate correctly. Id image the forces involved out on that lever are unfathomable. Ive looked at adjustment, but doesn't seem to be any. Must be an internal valving issue? For the injection pump shaft, it is leaking out of the shaft only. The plate looks like it holds it on, or stabilizes the shaft. It doesn't look like I could remove seal without taking the plate off, but will take another look
Without a machine/engine S/N to work from this may or may not be the same as your FIP. #10 is a 5P-3272 Lip Seal, #11 is a 7N-8779 Gasket. If the existing seal has worn a groove/amrk in the shaft even a new seal might not fix the leak. Hopefully someone like pumpguy can give you some insight on what to expect if you try to remove the cover.
ooh, that will be very helpful. The new serial# after rebuild is 99y75580. I will get the engine number shortly. Attached is invoice from Cat to BP after work was completed. There are another mess of invoices totaling an additional $40,000, not including this $164,000 whopper
You're going to need an engine S/N, and preferably also anything off the FIP if it has a tag on it. The Certified Rebuild S/N for the machine does not show what the machine arrangement is - unless that is the S/N before the CR was 99Y05580, in which case details exist. The available details are from the original machine build in 1988 though, not from the CR. For the FIP on the original engine S/N 08Z43959 installed in the machine the cover gasket is the same P/N, the lip seal P/N changes to 8T-2604 which is a replacement for 5P-3272.
Even if you can't get the seal out, like welder dave said, a new seal might fit right on top, that would be on a different surface than the original if the shaft is worn. I wouldn't expect anything to fly out taking that cover off, maybe a linkage to line up, or some springs to pay attention to, I don't do pumps. If you want to slow down the bucket, a hydraulic orifice fitting in the "up" side of the cylinder will slow it down, or a needle valve even so you can crank it as slow as you want it.
You can easily take that cover off the pump if you want. Remove the throttle arm first. Remove the bolts in the cover. Hold in on the shaft a little while pulling the cover off the shaft. The only thing behind the cover is the detent for shutoff position on the throttle. As stated I quite often use 2 seals to get a new position on shaft.
That is amazing! Gotta love the amount of knowledge we have at our fingertips with youtube. thanks for sharing
Here is the new number and engine number.
The 6NC engine S/N prefix replaced the 08Z prefix when it ran out of numbers @ 08Z99999. All tech info for 08Z applies equally to 6NC. Being a much later engine than the original there are updated parts on the governor. The cover has changed so the gasket updates to 150-3728 and the seal to 138-9507.
Arctec223 is basically 8018 with a much higher price. Eutectic has an equivalent to it as well. I deliberately botched an interview with Arctec. Head office is in Calgary and the boss was coming up to Edmonton and was supposed to do the interview after his other business but got tied up and couldn't do the interview. I said no problem just give me a few days notice when you come back to Edmonton. In the mean time I talked to people I knew in the industry and did a little research on Arctec. Arctec is a good product but very expensive. They do not make their own consumables though. One guy I worked with who's been in the industry since 1970 said Arctec sales people work on straight commission. Straight commission is great for established sales people with a built up clientele but not so great for someone just getting into outside sales that a big part of the job is trying to establish new customers. About a week later I get a call about 3pm while I'm at work. I go outside on my break and the boss is coming up tomorrow and can Interview me at 1pm. I said I can't just leave, I need a little more notice than that. Fast forward and the Edmonton manager agrees to meet at a hotel restaurant after work a couple days later. I go there and am waiting at a table. About 15 minutes later I get a call the guy is in the parking lot. Fine, come in the restaurant (I'm not doing an interview outside). He comes in and sits down. Tells me a little about the job and says they are trying to establish new territories in Central and northern Alberta. There is a lot of traveling and some staying in motels. He asks if I have a reliable vehicle? Yes. Then I start asking some questions. Do you get a company credit card for gas and motels and meals? No, you pay for the motel and get paid back. Is gas covered? No, you get paid per Km. Again you pay out of pocket 1st. How much per Km? It depends so he can't give me even a range! Do you pay anything for vehicle wear and tear? No. (I had said earlier I wouldn't be comfortable on straight commission but a base salary and lower commission would be OK.) About the 1st thing he asked is if I'd be OK with straight commission? Not really as I had previously stated several times. If I'm trying to get new customers do you have samples I can give? We like to hire welders so they can demo the product, we don't really like giving product away. What do you tell potential customers when they ask why your product is more expensive than other brands? Nickel is expensive no matter who you buy it from. (Yeah but your's is typically the highest and not every rod has nickel). Do you have a bunch of long term sales people? I've been with the company about 7 years and 1 of the salesmen has been here 14 years but the other sales people have been with us for 2 or 3 years. That's a big red flag. How much do your sales people typically make? It varies but our top salesman makes over $70K. He never said what newer sales people make. At this point I pretty much lost any interest in the job. He asked me how I handle difficult situations with an employer. I gave him an example of my experience at WEM where I quit because of a total idiot manager. My actual boss wanted me to stay. Many, many employee's quit because of the idiot manager my boss was too afraid to stand up to. The way I figured it, there was absolutely no risk for Arctec and I could be out money and have no idea how much income, if any, I would receive. Under the same circumstances I can't see any anyone let alone a qualified welder agreeing to the conditions. Maybe an established outside sales person who already has a good clientele but even then I think they'd want some kind of guaranteed minimum. At 1st it sounded like a great job and they were really interested in me. However once the fine print came out, I thought they were off their rocker.
Its sounds like a job offer i would run from to. I guess thats why we dont ever see an Arctec salesman running around the coast here.I buy what need from our welding supplier and use it sparingly as you said its pricy. They make 3 products i swear by for bush work .The 223 for crack repair ,the ecoface 60 for buildup finicky things like churn bits , (no one in thier right mind churns for piling anymore ) the hardcro 63 small high wear areas. Im no scientist on how this stuff works .The 223 seems to like those cracks that are impossible to clean out perfectly after air arcing . The ecoface 60 builds up very well when your trying to reshape a worn corner like on a churn bit ,the trick is to use your 4 lb hammer and pound it down to shape every few passes to work harden it. The hardcro 63 is single pass only ,really works after you have shaped your worn spot back to spec with the ecoface 60. try and pile the 63 on to build up and it cracks off ,single pass only wears really well. I would not use this stuff in the shop on major repairs when thing are clean and dry , but out on the job when things need to be running the next morning its the answer.
Arctec is a good product. It better be for the price. Eutectic Eutectrode 966 is equivalent to Artec 223, 86,000 tensile, 36% elongation. One of the properties it's listed for is problematic and dirty steels in addition to superior resistance to impact as well as hot and cold cracking. When I worked at Acklands (who used to sell Arctec) customers asking for an equivalent to 223 was pretty common. I got along great with the Canadian manager of Eutectic. He came to Acklands once. He asked if I wanted to stay in the welding field and to call him once the Acklands job was eliminated. I wasn't really sure what I wanted to do. After the Arctec debacle I was kind of turned off regarding outside sales. I should have called him but as fate would have it, I ended up getting diagnosed with multiple myeloma and am now on disability.
If the OP is still interested in having a bash at that cast tilt link I’d still recommend the 2222 electrode despite the price. TBH I prefer Simon C’s suggestion of leave it well alone and budget for an eventual replacement, especially considering that the crack has apparently not grown at all over the course of a year that he can measure.
Sorry to hear your not 100 percent Dave, but rest assured there are a lot of young folks who can benefit from yours as well as many other good members experience here. Its hard to find 40 years experience in a 25 year old body. Learned a lot from a guy that was 30 years senior to me when I was 25. January coming up will be 40 years in the trade for me. You will still have lots of opportunites to help out some newbees, who will be grateful for any help they receive. Good night, sleep tight. Simon C
Thanks Simon! I try to help when I can especially wih welding. I've seen people I could drastically help with 5 minutes of showing them how to improve. I had a few apprentices tell me they appreciated that not only did I help them but also explained why you do it that way. It was kind of funny one time when someone asked why I always carried a tip cleaner and later in the day asked me how I did such nice cutting. Duh.
Looking at the spec. sheet for Eutectic 2222 it wouldn't be required for welding a crack in a known cast steel like the tilt link. If it was joining 2 different unknown steels used in extremely cold temperatures would be more of an application for it. The Arctec 223, Eutectrode 966 or just 8018C3 that has 1% nickel would be sufficient. Preheat, peening and slow cooling would help to insure maximum strength. If you really wanted to insure the repair was as good or better than new, you could have it stress relieved. A little costly but a lot cheaper than a new link. Could probably be done by induction heating using ceramic blankets like they use on pipe. Personally I'd preheat, peen after welding, put a weed burner torch on it for a few minutes right after welding and wrap in a welding blanket. Several hours later after it cooled could be ground flat so the repair wasn't noticeable (if desired). It would be paramount to make sure the crack was completely ground out and make sure there are no stray arc strikes. They did some bend tests on plate with stray arc strikes and in almost every case caused a larger crack.
Shaft cleaned up nice, we pressed it too the bottom of housing which gave us about an 1/8" off of the previous shaft grove. looks good so far. I removed the grease zerk that fills up the parking brake drum and placed it underneath so it can be greased with u-joints which is less frequent than the bucket. We found that alternator butt connector, but it was in perfect condition. decided to leave it until a problem arises. Didnt grind out the crack, probably just going to keep monitoring it. Still havn't diagnosed why the bucket drops so fast, any ideas on that one?
We got some new tires for her this summer, they were very difficult to find (covid excuses) we ended up with 2 yokahama and 2 Maxam. After they were installed this summer we noticed there is an entire 3" hieght difference between the two brands. So today we swapped the taller ones around to the back as they wear faster. Might run a little less air pressure than the front as well. Not an ideal situation, I know.
I think I'd put the taller tires on the front because they will have to hold more weight when the bucket if full and deflect more. On the back the tires only hold the machine weight and it can be less with a loaded bucket.
We wear out rear tires much faster than the front, this has just been our experience. Maybe because the majority of machine weight is on the rear for all the other operations, When you dont have a full bucket.
What does a bucket of snow weigh? I'm not making fun, I'm a South Carolinian.
Haha, guess it depends on the operator
If you want to check that you're "within spec" as regards physical tyre size, do this. Get the machine just like it's shown in the photo. Measure from the exact centre of the front axle to the ground on both sides and take the average. Then do the same on the rear. The front and rear axle averages should not differ by more than 3% - SAE standard J2204 applies. https://www.sae.org/standards/content/j2204_201911/
So... what does that pile weigh? Surely not 1 ton...5? 10? I have honestly never picked up a shovelfull of snow in my life.
That bucket load could be one ton or less. Snow is extremely variable in weight. I'd guess that's drifted but not otherwise packed, and around two tons. If that machine was clearing snow in the Midwest, it would have a snow bucket and a pusher 12-20' wide.
Wow.
Seen a 966D with 4 chains on it plowing to make a new road with 4 feet of snow on it and it could run in 2nd gear all the time. Amazing to see. Simon C
We ended up putting 40psi in the rear and 60 psi in the front and got them within 1/4" of eachother! was pretty happy about that. It really varies on density, this was moving a packed snowpile so I was really able to get under it a get a big chunk. Probably couple thousand lbs here
With aggressive chains a wheel loader would be a beast clearing snow. My track loader pushes through snow pretty good unless it's frozen in a pile with street pads. 4 wheels with studded chains would push a like a D9 in dirt.
They use a lot of wheel loaders in The Upper Peninsula of Michigan along Lake Superior. The Keweenaw Penenisula gets a lot of lake effect snow (200"+). The city of Houghton uses loaders and Bobcats to push snow into the center of the road, and then a truck mounted snowblower loads it into trucks. They have wheel loaders that clear roads with adjustable angle blades, some use their buckets and a couple are fitted with a snowblower. I lived in Dollar Bay for 4 years, not far from Houghton. The county used a motor grader to plow our neighborhood. They can move a lot of snow fast as well.
If that was with the bucket empty be aware that when you fill the bucket the front end will squat down and the back end will lift up a bit, thus changing your measurements.
Thats not a bucket of snow ,its a friggin ice berg in there lol.Good operator! The thing id be wary of on different tire diameter would be would the the stress on drive train between front and rear especially on hard dry ground. Not unlike a 4X4 pickup when your in 4 wheel drive and you try steering on dry pavement .i know it wouldnt be an issue in snow ice or mud.
By swapping tires to back they are the same size now. (Well, 1/4” overall) The tires now on the rear are more of the round tread pattern as the front have more of a squared off look. I believe the round ones are squishing more, skewing measurements some. For the record here, I agree with everyone and mismatched tire/tread designs isn’t ideal. That being said, I have to make the best of the situation and I believe this is it. Next, is figuring out why the bucket drops at a free fall if placed in the down position? Would it help if I got a video to explain better?
I dont know much about those newer machines ,but on my old Cat 910 theres a float position if you shove the lever right forward. Maybe needs adjustment between lowering and float?
That’s why the SAE J2204 standard exists. See Post #52 on the previous page….
66 1/2 on the back 66 1/4 on the front Should work aye?
If one is taller but squatting more, I'd measure from the top or bottom of the rim for rolling radius rather than rolling radius plus unloaded radius.
That makes sense, looks like 3/8”s difference that way
You're doing it wrong dude........ Measure the rolling radius from the CENTRE of the axle to the ground. Because of the weight of the machine this measurement will always be less than from the centre to the top of the tyre. As I said before you really need to do the measurements with the bucket loaded beacuse the front tyres will squat more, and the rear ones will tend to lift a bit, but if what you are moving isn't too heavy I guess it would work either way. Delmer has the right idea as well.
That's why I suggested putting the tall tires on the front. They will take more weight than the back ever will.
What did you do with your old tires?? I have a set of barely used L4’s (rock tires) that I would like to trade for a set of used GP L-2 or L-3 tires. These are showing some cracks between the lugs but really aren’t a problem. The sidewalls are nice. These are in Kenai.
I would very closely check that you don’t have a snow bucket which is much larger than the GP bucket from Cat - I worked on the BP field crew many years and all we had was snow buckets and if a new guy went and loaded up a full scoop of gravel heaped up - it would break the “dog bone” every time. I think you got our old D model that was high time and went away for a rebuild?! We ran Case 821B’s most of the time and we’re always happy to get in the Cat and feel what real loader was like. Lol. On another note in my shop I have welded up many cast steel parts with some stick electrodes called “super missle weld” that a Russian welder left behind from an old oilfield compressor plant project. I have used it all up over the years and none of those welds ever failed. Rear axle housings under a heavy rough terrain forklift was the last job, and it’s still going. I wouldn’t be afraid to clean that cracked looking spots up real good and just put some light primer on them and mark across the ends of the cracks with a sharpie so you can be 100% they are getting worse until you can repair it or replace it.
There should be 2 available positions on the bucket lift control lever if it is moved forward from the HOLD position (3), LOWER (2) & FLOAT (1). Pushing the lever slightly forward from Hold should give you power lower, pushing it all the way forward will engage float and make it drop like a stone. A problem in either the pilot control valve or the linkage underneath the armrest.?