Hi All New to this (today) so, Rookie.... (and a very frustrated contractor) Anyway here's my problem - 2007 Cat D6N LGP, Bought a brand new complete undercarriage from Finning Cat here in Canada, to the tune of $46,000. Got it in the field, and 6 mins after working it, shut it down. The tech said they set Track tension at Cat and tested in yard, but as soon as I got pushing dirt on a slope, she wanted to start jumping on the sprockets. So i shut down and tightened them a bit, but not too tight. Stopped jumping, but the whole time I ran it, it would work fine going straight forward, but in a slight turn left or right, there was a constant clunk, clunk, clunk - which was- at about 11 oclock each revolution, the rails would crawl/hang up on the sprocket segments, and then flop back down at about 1 oclock. And both the rails and sprocket segments are scuffing- So obviously wearing out prematurely. (Keep in mind this is Brand New- everything) Cat sent someone out, and his comment was, "We want to look after this for you" - That was over a month ago. His other comment was- " Hmmm- looks like the rails aren't running true in relation to the sprockets' - as in they were somehow crooked and not engaging the sprockets right. I made the mistake of agreeing with him, but to me it looks like there is too much space between the width of the sprocket and the width of the insides of the rails, creating 'slop'. So it's not the sprockets (that are immovable) but the rails, that to me, are 'sloppy' when engaging the sprocket segments. He assured me the part #'s were checked, and the parts are all correct for this machine. If the bearings on the drive assembly were shot that bad, there would be oil gushing out everywhere, so i don't buy the comment. Cat wants me to haul it in, on my own dime, ($1000, then haul it back out to my unfinished job again- another $1000 ) saying we need to bring it in to diagnose it. I haven't ran it all winter, we're shut down- and I don't want to run it till it's rectified - the rails and sprockets will wear out twice as fast as they should My question is- Is there anyone out there having similar problems with Brand New Undercarriage from Cat?? Is there possibly a hidden recall on some parts?? Please help - Thanks Curtis
Can you supply some info..... Machine Serial Number. Part Numbers of the sprocket segments and the track groups that the dealer installed in your machine. I would imagine they should be on the invoice or in a document attached to it. Maybe even in the quote you approved before they did the work. Any other part numbers you might have available such as idlers, track rollers, carrier rollers, etc, might be useful.
Why wouldn't you let the dealer warranty it? Bob
Terexcat, Maybe you could take a picture(s) of the invoice and post it. So, we can see what Finning did. Block out your personal info, of course. Maybe some good pictures of the undercarriage, too.
$46,000 sounds like they did all the labour too. That's a big chunk of change that they should be responsible to figure out and any shipping if it has to go back to their shop.
Did they check for deflection in the pivot bar?
Well i of course want them to- but they don't want to truck it in and back out again on their dime- plus I wanted to see if anyone else had this issue to gather some intel before i went in and met with them
If its a redo that's their fault I would be sure they paid for the trucking. Bob
Undercarriage is basic and not rocket science so it shouldn’t be hard to figure out once you have their attention. Who quoted the job, a PSSR or the shop ? Tell them you want the PSSR to come out and measure/check everything and then a game plan can be figured out.
Sounds like an alignment issue of the track frame to the sprockets. There are shims that go on the ends of the pivot shaft that spaces the track frame so that the idlers are dead in line with the sprocket. The other issue has been stated already which is the condition of the equalizer bar. Are all three joints intact and not allowing the track frame to shift side to side and out of alignment with the rest of the machine. The issue of the freight is pretty normal now days. Dealers don't have the kind of people that can take care of the problem in the field and most have taken the position that warranty work is to be done in the shop so the owner's can't see what kind of stupid mistakes were made. Start climbing the management ladder to find someone who has the ability to say yes. They did the work, the person that came out there acknowledged that, so they should be negotiating some on the freight at a minimum if not paying the whole thing.
Hi Nige, 2007 ALY02934 6N LGP (8) SINGLE FLANGE 310-4912 (8) Double Flange 416-7050 (2) Carrier 229-5446 (10) Sprocket Segment 397-9556 (4) Idlers 396-4170 (2) Track Assemblies 416-7043 ** They sold me what they called GD (General duty, not Heavy Duty) MTO'S- (Made to order) which is rails and pads assembled at Factory- That's the part # ** -Also- Equalizer Bar Pins and Bushings done- In Spec Track frame pivot shafts and bores - LT and RT Bearings replaced Rt side minimal movement, LT side Substantial movement- was told will need machining in the next approx. 1000-1500 hrs thanks Curtis
A D6N is relatively easy to move and $46K is not pocket change. Did they tell you up front about the machining required or after they had put everything back together? With the money you were already spending why not just do the machining at the same time if it's going to need to be done in short order anyway. Sounds like they dropped the ball and want to sell you more undercarriage in 1000 hours.
I no longer have all the reference materials, but I do know CAT loved to make all sorts of different bushing sizes, first thing I would check is the OD of the track bushings against the part number of the segments, may be something as simple as a mismatch.
Thanks for the Part Number info. Could you please take a look at the LH & RH outer track links and find the Part Number that is cast on them. It should be right underneath the shoe mounting surface.
The machine is two hours away from me but I had a couple pictures on my phone the right side rail number was 417–3595
MTO simply means that the Track Gp is not kept in Cat Parts Stock. If a dealer orders a pair of that P/N the factory will manufacture them - keeps inventory down. This took a bit of tracking down. First up, General Duty track is grease-lubricated, not the oil lubrication used in Heavy Duty (SALT) tracks. It's somewhat like an excavator track in a lot of respects. The 397-9556 Segments were the clue. They are only used in two Undercarriage Arrgts, 433-0303, & 433-0304. You have the 433-0303 installed in your machine. There is no documentation that I can see anywhere regarding these two Arrgts except the parts listing below. The only difference is the single flange rollers are listed as 417-3770 compared to your 310-4912 and I can find no apparent relationship between the two part Numbers. I wonder if it's sold as a "set" for the HD to General Duty undercarriage conversion.? So on the face of it everything appears to match up correctly Part Number-wise, or at least very close to it, so back to an alignment issue. Can you run the tractor on an area of hard level ground (concrete if possible). Run the tractor flat out in 1st gear forward then flick the gear selector into neutral and let the tractor stop on it's own without touching the brakes. Set the park brake but don't drop the blade/ripper. Take a look at whether the track links are running tight against the inside or the outside of the sprocket on both LH & RH sides. Also take a look to see if there is any difference in the wear pattern on the inside and outside surfaces of both sprockets, idlers, & carrier rollers.
Grease lubed tracks on a dozer? I hadn't heard that and now I know why it is so much cheaper. Unless they made the bushings over size, those chains will need a pin and bushing turn to maximize the undercarriage life. They are essentially the same thing that was used fifty years ago. Do they have a master pin as well?
I won't swear to it but I heard they used the same grease seals as excavator tracks?
Being able to do a pin/bush turn is one of the selling points. 4 year/3000 hour warranty is another. https://www.clevelandbrothers.com/content/uploads/2018/08/General-Duty-Brochure-Medium-TTT.pdf https://www.toromontcat.com/parts/undercarriage/cat-general-duty Croc-type master link John.
A question for the OP. What type of ground conditions are you working in that requires 34"-wide track shoes on a D6N.? A bog..?
There is no selling point in a pin and bushing turn anymore. Three thousand hours and more was a normal life for undercarriage in 1965. It's actually kind of funny that Cat is marketing this.
Should be oil lubricated. Curious if I missed it but where did you find they are calling it grease lubricated tracks ? Nope. Exact same seals as the HD std track
FYI - You can get from D11 down in general duty UC for dozers now. Cat does not sell any repair parts for general duty tracks (HEX or TTT). They are the exact same fit and size as STD/HD. That way Cat has 2 (plus more but we won’t get into that) product lines in GD and HD but only has to stock 1 part number repair parts. So you break a link on this D6 and just order up the readily available D6 HD link and away you go. The difference is in the metal - heat treat and such on links and pins. This competes with the ITR, Berco, ACE etc of the world.
As well the GD links are not polished/coated in the seal area like HD so GD bushing turns are possible but not always worth it for the extra you would get. It’s meant to be run to destruction like all the aftermarket brands they compete with.
The part about grease lubrication was in one of the links I looked at. I tried to find it again but couldn’t. There are a number of links for GD specifically related to excavator undercarriage so maybe it could’ve been in one of them and related only to excavator U/C. Certainly looking at the link group the plugs & stoppers in the ends of the pins are the same part numbers as used on SALT links.
Yes Equalizer bar is good Wondering if they forgot/ wrongly installed the pivot shaft shims
Does that have to do with making sure the shims are correct concerning the track alignment?
The salesman quoted the undercarriage (if that’s the same thing as PSSR) he has mysteriously “moved to another area”-and so has the guy they sent out to look at it after I told them something was wrong.
The rep they sent out did this,but I was running the dozer so I didn’t see what he looked at- but I am heading out there tomorrow I will find level ground and do that and maybe take some pictures. as far as 34 inch pads I specifically asked them before hand if I need them or could I get away with something narrower- I asked if the wider pads was harder on the undercarriage and if I would get more life out of it with a narrower pad- he said no and they recommended staying with 34 I am on hard ground 80% of the time other than pushing pads across water and sloughs the other part of the time Thank you for your time on this I want you to know it’s much appreciated
This does seem suspicious. I would be talking to someone higher up. Maybe Finning knew there was problem and wants to make it difficult for you to find out what happened? I had a lawyer write a letter and give me advice. At a pre-trial meeting (she wasn't present) a judge made very condescending comments and even racist comments about her. It was a large law firm and all of a sudden she's moved to a different area and wouldn't take my calls. I wanted to inform her what the old judge said about her. I went to trial and won my case. The comments the judge made after reading the letter she sent to the other party... I don't know who this Dina Pred** is but she looks to be Italian. On a different matter I told another lawyer about it and he said it was definitely out of line and should have been reported to the law society.
IMO you have been sold a direct replacement (forget the GD/HD differences for the moment) to what was installed when your tractor originally left the factory. It was shod with 34" shoes back in 2006 when it was built and therefore it's a "like for like" replacement as regards ground pressure. Your machine ALY02934 was originally built as a Low Ground Pressure (LGP) machine which only lists 28" & 34" track shoe width options. The track frames on most LGP tractors are set further away from the chassis to accomodate the wider shoes to prevent them rubbing on the chassis. The track shoe width options available for a non-LGP D6N tractor are 22" or 24". I have no experience of "re-shoeing" an LGP machine to operate on a narrower width of track shoe than the factory lists in the Parts Manua (28" in your case)l. On the face of it I can't think of an obvious reason why it couldn't be done. I'd like to hear other members' thoughts on that though. When it comes to track shoe width this thread may interest you. FWIW I'd be looking at possibly 28"-wide shoes on the D6N for your application as described, possibly you could even go down as far as 24". Whether shoe width is anything related to your problem is debatable but I certainly wouldn't rule it out at this point. HeavyEquipmentForums Some typical photos of the 20% of the time where the tractor is not on hard ground might be useful. Also a question. When you are operating on the "sloppiest" ground you have, what sort of marks do the track shoes leave in the ground.? In other words how far does the machine sink.? Again photos might be useful, along with something in the shoe imprints to give an idea of scale.
Wider track shoes can be the death of undercarriage in harder ground conditions. The dictum is to always use the narrowest shoe width that will give adequate flotation.
Dave did you help write the scrip for " my cousin Vinny" ? Bob
No, just shocked when the old geezer said that.
So what exactly needed machine work? Is the pivot shaft worn, frame bores worn? Did you decline to have machine work done before it was assembled? It doesn't seem likely that the dealer would go to the work of installing new bushings in a worn out bore and then bring up that fact after the machine was fully assembled. Especially if the bores or shaft are worn enough to cause what you say is going on. There are no shims on the pivot shaft. Just one spacer that sets the depth of the frame on the pivot shaft. The track rails don't fit tight on the sprockets, there is supposed to be room between them to allow movement. Did the sprocket segments get installed correctly? Sounds like you need to get someone out to look at this that knows what they are looking at and has actually seen an undercarriage on a D6 Bob
That's what I questioned earlier. If you spend 46K on D6 undercarriage a couple thousand more for machining doesn't seem like it would/should be a deal breaker. The people involved suddenly moved to different area's does seem suspicious. I wouldn't think running narrower shoes on an LGP would hurt anything. I would imagine the rails are the same. Have heard of some operations having 2 sets of tracks for different conditions.
We have swapped out wide pads for narrower ones on a D6M without any issue. Helped prevent shoe breakage.
My D6H was built as an LGP dozer and was switched over to 20 inch tracks before I bought it. I can't see any issues with the narrower tracks, those are the ones I wanted. An advantage is, I can get between the tracks and the engine compartment to work on things there. Otherwise you have to lay on the tracks if it was an LGP, or if it came from the factory as a narrow track machine. My.02.
Well that would make sense, other than the fact that the Machining quote was over $20,000-( yes that's another zero!) I couldnt believe it- and couldn't afford it to be honest. I'm working on pics and a response to Nige
I went back and looked at your OP, especially the part where you said "..........but the whole time I ran it, it would work fine going straight forward, but in a slight turn left or right, there was a constant clunk, clunk, clunk - which was at about 11 oclock each revolution, the rails would crawl/hang up on the sprocket segments, and then flop back down at about 1 oclock." Is there any chance you can take a video of the above and post it up to YouTube.? You can then link it direct to here and everyone can see what it's doing. Also why not take a photo from each side and let's all have a look what the track tension looks like.
These 3 pics were in the summer. More to come
i ll have to get my wife So you can’t post/upload videos here? I’m definitely NOT a computer guy it might take me a while or I might have to get my wife to do this
You can't upload videos direct, but if they are hosted on another site such as YouTube you can copy & paste the YT url and the video will play on here. Track tension photos shouldn't be too hard though.
I'm going to go with sprocket segments are put on backwards. Bob
I was going to say the same, until I saw one of the photos. The machined pad on the end of the sprocket segment that is intended to sit on the rim of the final drive and make the sprocket group run in a true circle is visible. Those pads are only on one side of the segment IIRC. That would mean that at least that one segment is installed correctly, I can't speak for the others.
Seems to be catching on both insides of the rail. I’d say the track frame is moving side to side.
Don't ya think the paint wear on the rails is from the rollers and the idlers? Look at the wear on the bushings and the top of the links. Track is running hard on inside of sprocket. Bob
Your second picture kinda shoots the single pad theory in the ass, any sprocket segments I've ever put on contacted the flange about 100%. Keeps the bolts tight. Bob
Yes looking up higher in the link near the pin I see what you’re saying. It’s only wearing on one side.
Another illustration and an extract from the text back from when they were first introduced. IIRC they are on everything high drive from D11 down to D6. Each segment has two small locator pads (7) on the underside, as shown. Place segment with the flange against the inside of the rim of the hub. Make sure that the two locator pads (7) on each sprocket segment are hard down on top of hub.
The weak link on the D6N's and others is the track frame pivot housing. Controls alignment and alignment position. Is that the machining that was passed on? Probably aggrevated by extra wide grousers.
The term General Duty Undercarriage was mentioned so I wanted to post some information I have from a Caterpillar brochure that explains it’s purpose. “Designed for use in low-to moderate-impact applications where the value of Cat Heavy Duty Undercarriage is not fully needed. Note: General Duty Undercarriage is not designed for forestry or waste applications. General Duty is built to Caterpillar specification for fit and performance on you Cat machines. While General Duty is built to different specifications than Heavy Duty, it’s design makes General Duty and Heavy Duty components interchangeable, eliminating any need for retrofitting and keeping downtime to a minimum.” If you read between the lines Caterpillar had some other company manufacture the undercarriage for them. That’s what they did with the Classic line and the Nexus line of parts they offered. The company I work for produced some of the Classic undercarriage parts about 15 years ago. Caterpillar supplied all the technical data as to how they wanted the track made. The Caterpillar chains were not sold to any other company. When the contract expired Cat moved on to someone else. This is common for Caterpillar they just don’t want you to know this. We do manufacture undercarriage for other OEM and aftermarket also. The OP shows to be in Canada so his pricing of $46k is probably Canadian dollars which is about 30% higher than U.S. dollars as the exchange rate is right now is 1.28 to 1. You can do a search for General Duty Undercarriage for medium track type tractors and find the complete brochure. There is also a GD brochure for 312/320/336 sized excavator.
It is possible to put the segments on inside out as I managed it last week. After fitting a set of D9 segments,I managed to put one on wrong briefly near the end of the day.I put this down to suffering with my testicles battling for head space with my eyeballs. Those bolts were 675 lb plus some 2 flat extra welly that made my eyes bulge a fair bit. Of course,I immediately realised the error of my ways,and took the opertunity to laugh at myself. A torque multiplier was on hand,but it didn’t sit nice at all with the track on. It wasn’t until I finished,that it would probably fit quite well at the bottom segment rather than the one in the gap. As for your D6 problem,your track frames are wiggling about I reakon. Good thread