I bought a D8K for use on the farm. No operators manual of course, so still figuring things out. The temperature gauge has three overlapping bands, green, blue and yellow, all ending in red at the top end. I'm assuming the different colors represent different operating conditions? Fan forward vs reverse? Winter vs Summer? It does run much hotter with the fan pushing forward, even on a cold November day. Are there internal adjustments on the brakes, ( or clutches), or just the external linkages? This has the combined clutch and brakes on the levers. Which work fine, but brakes seem to be at the end of the stroke on the levers, and the left foot brake doesn't function at all. Any specific instructions for free play when adjusting them? What is the difference between Cat's Transmission Drive Train Oil, and the transmission hydraulic oils for tractors? Would any other oil not be compatible with the clutch linings, or not have enough EP additives? The TDTO oil ended up being hard to source locally, more expensive, and I already keep trans hydraulic on hand. By serial number, this is supposed to be a spacer plate engine, any way to confirm that visually? And do they require any special pampering to avoid the known issues? When shifting the powershift under load, it nearly comes to a stop before shifting, which can't be good for the powertrain. Is that normal, or are there accumulators that could need attention, or pressure needing checked? I mostly avoid shifting it under load, instead decellerating and changing the gear, letting the torque converter take the abuse instead. Are they intended to be like any other powershift, and designed to shift all day long under full load? It will coast on with the decellerator fully depressed, does that indicate it is idling too high, or is that typical? I can't access a parts book, but if i understood a previous thread correctly, does this have chain drive instead of gears in the final drives? My neighbor who is an Cat skinner from way back, but only ran 6's and 7's from the same era, thinks that the final drives are noisy/whiny compared to what he remembers. Nothing untoward in the oils, both sides make the same sound, don't really notice it from the seat. We have an old tractor with chain drive rear end, and it sounds much the same. Lots more questions, but that is more than enough for one post.
Hi Farmer. First thing you need to do is include the serial number of the machine. There are a couple of guys on here that have lots of experience and can access the cat SIS and pull information for you. But they need that number.
Operation & Maintenance Manual (covering all basic servicing) should be your first priority. Less than US$50 to download from Cat. As WW pointed out before, need a Serial Number to identify the correct one. Also in your case it might be a good idea to post the engine Serial number as well. For powertrain (trans & finals) you will need an oil that meets Cat TO-4 (TDTO) spec. Trans would typically be SAE30 and finals SAE50. Accept no substitutes ..........
Fan forward vs reverse? Winter vs Summer? It does run much hotter with the fan pushing forward, even on a cold November day. That sounds odd to me. It shouldn't run "much hotter" in either direction. Are there internal adjustments on the brakes, or just the external linkages? As suggested, get a shop manual on ebay and follow the brake adjustment procedure. Each band has an adjustment at the back top of the bevel gear compartment. This has the combined clutch and brakes on the levers. Which work fine, but brakes seem to be at the end of the stroke on the levers, and the left foot brake doesn't function at all. Any specific instructions for free play when adjusting them? The turning levers control both the brakes and the steering clutches on all K-s. You can disconnect the brakes if you want the controls to work like an H. If the linkage is hooked up, then the problem with your left brake is in the brake cover or below in the band or drum. Follow the manual for adjustment advice. What is the difference between Cat's Transmission Drive Train Oil, and the transmission hydraulic oils for tractors? The TDTO oil ended up being hard to source locally, more expensive, and I already keep trans hydraulic on hand. We used to use 30W engine oil in the transmissions, but that oil is no longer the same today. Best use a 30W transmission oil as suggested. Ask your local oil distributor who distributes a name brand oil for a TDTO substitute. Don't use one that's a "recommended" replacement. Use one that "meets or exceeds" Cat TDTO. By serial number, this is supposed to be a spacer plate engine, any way to confirm that visually? And do they require any special pampering to avoid the known issues? Take a look at the side of the engine block. If you see a 1/2" plate between the head and the block, you have a spacer plate. When shifting the powershift under load, it nearly comes to a stop before shifting, which can't be good for the powertrain. Is that normal, or are there accumulators that could need attention, or pressure needing checked? I mostly avoid shifting it under load, instead decellerating and changing the gear, letting the torque converter take the abuse instead. Are they intended to be like any other powershift, and designed to shift all day long under full load? Sounds odd. Just run it in the same gear when under load, decelerating to shift between F and R. Did you pull your transmission filters and cut them open to see what's in them. Did you pull the screens. It will coast on with the decellerator fully depressed, does that indicate it is idling too high, or is that typical? Not sure what you mean by coast. If your're coasting, you're not in gear so yes it may move. If you meant you were in gear and didn't come to a stop when your decelerator was pushed through the floor, then that's not normal unless your blade is up and you're facing downhill. I can't access a parts book, but if i understood a previous thread correctly, does this have chain drive instead of gears in the final drives? Gear drive. My neighbor ... thinks the final drives are noisy/whiny compared to what he remembers. Nothing untoward in the oils, both sides make the same sound, don't really notice it from the seat. We have an old tractor with chain drive rear end, and it sounds much the same. Did you pull the filters and cut them open. No chunks when you drained the finals is a good thing. I hope you put a quality 50W back in. The filters are up on top and can be removed/replaced after an oil change. What you really need to know is whether the your oil pumps in the finals are working. Not sure of your serial number. Here's two cheap parts manuals in good condition. One of them matches your serial number. https://www.ebay.com/itm/CAT-Caterp...:cYgAAOSwxr1drhfc:sc:USPSPriority!95021!US!-1 https://www.ebay.com/itm/CAT-Caterp...:~6gAAOSwg8hdrg9D:sc:USPSPriority!95021!US!-1 There's good shop manuals on ebay also ranging from $70 to $200. You should be able to find one for around $100.
Shop and Parts Manual. $80. 77V5006 - Up. https://www.ebay.com/itm/CAT-Caterp...503204&hash=item56b7da1bee:g:16QAAOSwk3RbriJ8 Shop and Parts Manual. $80. 77V1 - 5005. https://www.ebay.com/itm/CAT-Caterp...503204&hash=item56b7da1454:g:zLUAAOSwPfBbriEa PICK YOUR SERIAL NUMBER. THIS IS A GOOD DEAL!!!
The water temp gauge has different ranges that go along with the water pressure gauge. most of the pressure gauges have been removed or are inoperable. if you have the pressure gauge, you will notice the colors match up with the temp.
Machine SN is 77V14093. Which is supposed to be a 1980, and well past the SN break for spacer plate engine. But I don't see any spacer plate from the side of this engine. Didn't check engine SN yet. Thanks Farmerlund, that would make sense, and no, there is no water pressure gauge. Only a fuel pressure gauge, and I'm not certain what I am supposed to do with that information either, just for monitoring fuel filter?
Look on top of head, if it has bolts it is a spacer plate. Bob
Bolts outside of the valve covers?
Service and parts manuals ordered, thanks for the link Check Break.
Machine SN is 77V14093. Which is supposed to be a 1980, and well past the SN break for spacer plate engine. But I don't see any spacer plate from the side of this engine. Didn't check engine SN yet. Engines got swapped all the time to cut down on rebuild time. You may have an early engine. Your parts book will tell you what you have from the block casting number.
If the engine is overheating..check fan belt tension and blades that they are angled the same. Is the radiator plugged externally..or internally?...like at engine oil cooler..are you losing coolant..check radiator relief and cap gasket. The steering clutches and brakes: adjust brakes tight and back off 8 clicks..if it doesn't steer after that..that clutch is not releasing. It might require assessment by a dealer field mechanic from Finning. Best of luck.
The transmission will use SAE30 oil that meets TO4 spec..but the final drives use gear oil like 85/90. Each final drive has a filter that needs to be checked as does the magnet/screen and filter for the transmission. The drain plugs magnets for those compartments need to be checked as well.
Today TO-4 would generally be used in both transmission and final drives. The only thing that changes is the viscosity. Although thinking about it for the OP's climate he could probably get away with SAE30 in both the transmission and the final drives. See below, extracted from the O&M Manual. "LO" in the table would be an engine service classification or TO-2.
New dozers nowadays would use TO4 oils in final drives that are planetary types but older ones with heavy spur gears would likely be better protected with heavier grades of oil. In Alberta where temperatures in winter can approach -40F it might be advisable to change oils to lighter grades if working under more severe operating conditions like land clearing or road building rather than plowing snow.
Agreed. The operating conditions in terms of both climate and type of work being performed would definitely have some bearing on the grade of oil selected.
The big difference of a D8k to newer D8s is that the D8K and older ones final drive compartments have their own oil and lubrication system and are separate from the bevel gear case which is shares the oil of the transmission. The other huge difference is track frame is attached to the structure of the final drive compartment which contains what is commonly referred to as the dead axle. The bull gear rotates on that axle the hub to which the track sprocket is pressed on.That hub is supported on the end through bearings which support the hub to which the track frame is attached to. On newer dozers the track frames are attached to the frame with a pivot shaft which supports the weight of the upper structure of the machine. The final drives are attached to the upper structure and thus are referred to as high drives. This has a few advantages in that repair of final drives and steering clutches is much simpler and wear of sprocket is less as it is out of the dirt. The problem of the older dozers is that a D8K that with a ripper weighs over 50 tons and if it is dozing at full power and the blade hits a boulder or 4 foot fir tree stump and can bend a dead axle. This and wear of the bearings on the bull gear hub can cause angular misalignment of bull gear teeth and pinion which will break off teeth. I have had the pleasure of having to do close to 50 for that reason. Also steering clutches and brakes are pretty challenging especially when its minus 30 Fahrenheit and owner wants to do it in the field.
D8K and H models called for 50 wt. engine oil and not gear oil. As I recall an 8K weighed in at around 80,000 with 4 barrel multi-shank ripper with two shanks installed and a U blade with full fluids. I've never seen a bent dead axle on an D8. I have seen them on D9G and H machines. It was attributed more to final drive failures than anything else.
Where I worked all D8 final drives had gear oil and failures were not attributed to the oil but likely lack of if due to sprocket seal failure.Chicken before the egg? I only recall SAE50 only came out for planetary final drives on loaders, high drives and haul trucks about 25 years ago which was nice because it didn't have that awful smell. As far as dead axle bending I would suspect that it would be momentary and contribute to bull gear failure. About weight..I find it hard to believe a D8K with U blade, cab, stump/rock guarding, rock guards, extreme service undercarriage and 4 barrel being less than 50 tons. Maybe in Mexico where they have no cab and have worn out undercarriage.
Construction equipment guide specs https://www.constructionequipmentguide.com/charts/crawler-dozers/caterpillar/d8k/7518 Operating weight with standard blade. Operating Weight 70503.9 lbs (31980.4 kg) Standard Blade Width 13.3 ft (4.05 m) I'll find the oils in a bit.
d8h like mine uses 30weight engine oil in finals or warm weather 50weight according to lube chart on top of dash
Here is a discussion on this forum for a few years back on the subject. HeavyEquipmentForums We never used gear oil in Cat finals.
my d8h tips the scales at about 79000lbs with 8a blade, front mount hyd, light canopy, 6 roller track frames and only a drawbar- therefore 8k with ripper is a lot heavier. I've had mine hauled a couple times and had to go across weigh scales. my parts book says dry weight basic machine is 47290lbs- no hyd, no hard nose etc
Ok...that chart is likely for a stripped down D8 for agricultural application where it pulls cultivators and seeders so it doesn't cause excessive ground compaction
In western Canada D8Ks built roads in mountains and hills. They pushed out rock, boulders and big stumps in logging and mines as well. To do that they had to be guarded and beefed up to do the job. If the D8K in Alberta came from some stockyard where it was used for just pushing animal waste or landfill it wouldn't need heavy guarding or reinforcement of blade and pusharms.
We have three K-s and a late model H. All 8S and 4BBL (2 shanks). All heavy guarded with pushblocks. The H with ROPS weighs 83.5K and the K-s (1) ROPS and (2) EROPS between 85 and 87K. 30w in the transmission. 50w in the finals.
Ok..maybe my information about weight is not accurate.I don't drive a low bed truck so cannot confirm from personal experience going across scales and doing the math. I vaguely recall a number of 120,000 lbs but maybe that was a gross weight which included the truck and trailer. The other thing is maybe the truckers exaggerated. I'll have to ask my older brother..he was a dealer mechanic for 38 years and two of his sons are excavator operators that also drive their low beds..their dozers are little D6Ns..
And those are both engine crankcase service classification viscosity grades, not gear oil. An 50 on the SAE crankcase scale is in the same range viscosity-wise as a 90 on the SAE gear oil scale.
I vaguely recall a number of 120,000 lbs but maybe that was a gross weight which included the truck and trailer. That's where your number is coming from. The K-s weigh out a little over 126K on a Murray 5 axle, more on another brand trailer with another bump if your tractor is not optimally set up for heavy haul. Nige pointed out a little detail I'd forgotten, the oil being based on an engine service rating. Pretty important if you're out of oil and just looking for something to top off a system. We went with Mobil a long time ago and now I realize my brain focused on which product goes in which fill plug without remembering why. I only remember one occasion where we lost so much hydraulic fluid on a weekend that we bought everything Walmart had to get by. When that job ended, the hydraulic system was drained and whatever hoses replaced. The rest of the time I had the Mobil distributors mapped out. They treated us well and I remember some of them would open up after hours if we got in a bind.
Another thing to remember is the the additives in EP gear oils have been known to degrade the silicone rubber in Duo-Cone Toric Rings and cause premature leaks and/or seal failures Cat strongly advise against the use of EP oils in any compartment that has a Duo-Cone seal in it. The attached Service Mag for excavators is just one example.
That's not entirely true, cat tractor scrapers still use 90 wt. in diffs and final drives with duo cone seals. Bob
Interesting information..I didn't recall that service letter..but don't recall the sprocket seals being silicone...although methinks the input pinion from the steering clutches is. That explains why they fail and overfill the final drives with transmission oil..which could cause a failure of the sprocket seal. Although typically sprocket seal failure occurred from dirt forcing itself into the ramp of the toric ring and eroding it and the duocone rings..plus wire etc. that gets wrapped around it when a machine is used in a garbage dump. It is a good illustration of the benefits of a high drive.
That service letter refers to excavators with planetary drives..as do haul trucks which have silicone toric rings. Gear oils have a phosphorus additive which is a smelly lubricant enhancer which spur gears need because of extreme pressure as single gear teeth slide into each other. Planetary gears can get by without it because the force is spread over more teeth.
50 wt lube oil has been the recommended oil for D8H&Ks finals since at least the late 60,s so if you are using 90 wt you are causing the final drive seal failures. Bob
I’ll be honest and say that for big iron (yellow or otherwise) I personally detest EP oils with a passion. Cat generally stay away from EP so it’s not normally an issue, but I’ve seen plenty of cases on machinery from other OEMs where EP oils have been replaced very successfully with either SAE50 TO-4 or SAE60 FD-1 oil depending on the machine and the ambient temperature range. Currently we run the swing drives, pump drives, rotary heads, and finals of a fleet of Hitachi 3600’s and Atlas Copco DML drills on 60-weight FD-1. The OEM Manual recommended EP90 oil in every case. The improvement in the oil condition as shown by analysis is like night & day.
I've run EP oils in Hypoid and Amboid differentials forever. Cat runs bevel gears in their differentials on wheel loaders and as such never needed the smelly snot for lube. I've have used a lot of EP oils in line cranes. It always seemed to me that kind of oil was for applications that applied very high torque requirements across point loaded surfaces or in places that had extensive sliding surfaces under extreme stress like swing and traction drives in cranes.
Yes..that is why if it was my dozer I would use that oil in the final drives after maybe sourcing toric rings that were compatible with it. The main cause of seal failures in those machines is not the oil it's the dirt packing into the seal area. That's why when the sprockets are off...the seal protectors are replaced. In one area where the dump had lots of pulpmill bale wire we welded 1" blocks on the case and sprocket so it would cut the wire before it wrapped into the seal. It sort of worked.
Yes EP oil has a disgusting smell..particularly when a machine has caught fire and burned that oil.It would make a maggot gag.
correct me if i'm wrong but EP gear oil was designed for hypoid gearsets where the pinion is mounted below(or above) the centerline of the crown gear which results in a wiping action of the pinion teeth across the crown gear teeth. regular spiral bevel gearsets where the centerlines are in the same plane do not necessarily need EP oil although it may be used. cat kept it nice and simple-you could use engine oil anywhere and keep it running(especially out in the bush)
Methinks you are correct that in differentials it is very important but having seen a D8 final drive apart due to failure my feeling is it is critical to have the best lubricant possible. However if for some reason you have no lubricant like if someone forgets to tighten the drain plug and it falls out and all the oil is lost...Then engine oil is better than nothing if that was all you had and had to move the machine several miles. In all fairness engines have gears that rely on the lubricity and additives that might help a final drive from suffering damage if it was just being moved.
The driven gears in an engine do not typically have a very heavy torque load but when they are driving an accessory that exceeds 75 horsepower then it can be problematic.
Shame on you. Hitachi and AC did extensive planning on the breakdown of those machines. Someone else is going to have to pay more for their parts now that you've violated the Prime Directive.
Garbage dumps will destroy any machine. On the construction side, most sprocket seals leak because the duo cone seal between the pinion and final fails and the final fills with 30w. Cat changed the composition of the pinion seal toric ring but it's been too long for me to remember how. All I remember is it went from blue to black. Have to revisit that one of these days.
In the case of Hitachi we were told "You can't use TO-4/FD-1 oil to replace EP90, we haven't tested it". My reply - "We'll happily volunteer to be the guinea pigs, because our machines are out of warranty anyway, and we'll share our oil analysis information with you". No response - so we went ahead and did it anyway and ***k 'em.........
This kinda sums it ups .....
That attitude isn't a good idea to apply to maintaining equipment or perhaps any other pursuit because it can lead to injury,death or financial ruin. The issue in question is the use of correct oils. We have to be very careful if we don't follow manufacturer recommendations. They usually set forth those for various reasons which may not be that obvious like if a compartment has brake pistons which use brake fluid the seals are very sensitive to mineral oils. I have seen in some areas a practice is to lubricate toric rings with grease or brakeclean to make duocones easier to install.That is wrong to do as it can guarantee seal failure when it can chemically affect the seal composition and cause the seal rubber to swell, soften or harden. In a personal case I once bought a vehicle that the previous owner had put synthetic oils in the axles and transfer case: the seals were leaking.I drained all compartments and replaced all seals and put recommended oils in them : end of problem. It is not a good idea to mix brands of oil either if they come from different areas their chemical compositions might vary: stick with the devil you know rather than the devil you don't. I have seen one place where the master mechanic didn't believe in changing oils because he said the new oils have sharp molecules and will cause cause wear. That bizarre idea likely helped cause that company to insolvency and sixty people to be without jobs
I understand and agree with what you’re saying up to a point. In my case I have a tribology qualification as well as an engineering one. I wouldn’t go down a road to propose a lubricant change without thoroughly researching it first. In every case mentioned above the drive box is a planetary transmission equipped with rolling element bearings, not a hypoid gear set in sight. I have improved oil analysis (and component life) to back up every lubricant change that I’ve been involved in.
I like it. That acronym should go on our company logo as it sums up our secret to success. When we discovered the Allison transmission would enable our trucks to keep up city traffic (made every light) and didn't need a new clutch when the driver's brain shorted, we were laughed at, but eventually everyone stopped laughing as we became the Allison poster child for our industry on the West Coast. Allison was very good to us, but in reality, we were doing them a big favor. When it came time to service the first trucks we got a shock. The manual said to use Castrol Transynd at $9/Qt. This was around 2001-2002. We bought a few drums before buying a couple of used crushing plants in 2003. The plants came with oil analysis going back to 1995 and you could see the transition between the current lube (Schaeffer) and the prior lube. Post Schaeffer failures took longer to occur because better lube can't correct damage already done, but as components were rebuilt, failure ceased. One day I asked our Schaeffer rep (shortly after receipt of the last barrel of Transynd) if he had a substitute. He didn't have an approved oil because the approval process was onerous and essentially closed to anyone but Castrol but his lab guy said their 204A would do everything Transynd would, and more. We never buy warranties and our company motto is similar to Mr. Wilson's so we rolled the dice and switched to 204A at about half price and never looked back. We've lost 4 transmissions in 19 years, one snap ring (replaced by Allison), two with valve body issues and one that failed because it wasn't serviced for four years. I have a Ford F150 that started to experience transmission failure at 50,000. It slipped between 2 and 3 all the way to 80,000 as I waited for failure. At 80,000 I filled it with 204A. If I pull a trailer the fluid starts to change color but it currently has 243,000 and I'm looking forward to the day it gasps it's last so I can see what the 204A has not done to it all these years. Your switch to TO-4 and our switch to 204A x3 or 4 is sometimes the difference between a thriving competitive business and one teetering on the brink of failure when times get tough. Now, if only we could figure out how to quantify the savings (for $h*t that never happened) and submit a request for reimbursement.
That attitude isn't a good idea to apply to maintaining equipment or perhaps any other pursuit because it can lead to injury,death or financial ruin. The issue in question is the use of correct oils. We have to be very careful if we don't follow manufacturer recommendations. They usually set forth those for various reasons which may not be that obvious like if a compartment has brake pistons which use brake fluid the seals are very sensitive to mineral oils. There's a big difference between a well reasoned decision and stupidity. In this situation, we had/have access to some very bright engineers at Schaeffer who have spent their lifetimes engineering lube products. They do more than make suggestions, they warrant what they sell if they recommend it for a particular purpose. I see this as making additional effort to locate a cheaper and often better substitute rather than being lazy and taking the easy way out, a concept that applies throughout an entire business, not just in the shop.
It seems I may have overlooked finding a viable alternative to a manufacturer recommended lubricant by simply following their suggestion. It would then seem that they have a vested interest in not promoting the best lubricant because their core business is actually selling the parts to maintain and overhaul their machines. That is very similar to Gillette shaver business in which the profit is actually in selling the blades.Their seems to be a moral dilemma in question.
Machines are designed within a time frame that may have a finite amount of materials available. But time marches on as does technology. The machines built twenty, thirty or forty years ago did not have the advantages of new formulations in lubricants or material science. Manufacturers likely also don't want to recommend lubes that they would have to provide expensive testing and analysis for on machines that no longer resemble what they made all those years ago. As for the moral dilemma, how long would a manufacturer stay in business if they made a machine that never wore out?
D8 and D9 F/Drives at first used 30 C,C,Oil this being upgraded to the 50 grade T,O, 2 series oil when it was developed, this was said to reduce gear "Scuff", both the D8 and the D9 tractors use an oil pump that pumps oil through the Dead Shaft to feed the outer hub bearings, the use of to thick an oil will cause the oil pumps to fail or reduce their life in cold weather, some old style tractor Men want the 90 gear oil but the 50w is plenty good enough and should be the 1 to use, the Duo-Cone rubber rings thing is, black standard, blue high temp, the rubber rings with the steel facings are fitted dry into the casings, then you can put a lick of oil or light grease on the steel face to ensure ease of movement within the 2 steel facings. tctractors
Just as an added bit of script, Caterpillar were the first people to blend oil making the first detergent oils used in Diesel engines, they also used to build single cylinder oil test engines to improve and understand the lubricating requirements of the products that they built. tctractors
Wow. An interesting spectrum of observations. I have myself witnessed the marvelous and ingenious mechanical engineering of early Caterpillar dozers starting with Diesel Thirty or RD6: The brilliant work of those engineers of works of art 80 years ago are still capable of doing work today. The many iterations that have since followed cannot necessarily be considered as technical advancements but merely mostly changes that appease the need of perpetrating the business. There are some improvements to operator comfort and more recently some lessening of perceived atmospheric degradation (carbon neutral) which has dubious benefit....In short : Necessity is the mother of invention...or build it and they will come.
The lubrication pump in each final drive is obviously critical to the outer hub bearings. I vaguely remember a test for it is to pull the plug on the filter cover and operate the machine in both directions. It should squirt oil out if it's working.It is driven by a gear that it engaged to one of the reduction pinions.
The newer dozers with planetary final drives can use TO-4 oils and multigrades like TMS...which is synthetic which also might keep the older spur gear type final drives lube pumps from being damaged in extreme cold. That would keep sprocket hub outer bearings lubricated.
The oil pumps only work going forward, just thought I would say. tctractors
Which is one of the reasons that old-school tractor drivers were discouraged from tracking long distances in reverse, even though the ground speed of the tractor was slightly higher in 3rd reverse than it was in forward. It was almost a sacking offence in some big earthmoving companies.
Plus back blading is hard on the frog and hardware that hold the cutting edges on.
And on the sprocket and bushings by the way they release from the sprocket in reverse. Wear is greatly increased.