Hi I am new to this forum. Just wondering if anyone has replace a final drive pinion. I have tracks separated and final drive removed. The drive pinion has 2 gears that are chewed up. It run fine but I found pieces of gear when I changed my final drive oil. A local mechanic say's put it back together and run it. I am concerned that the tooth will bust off and cause more damage. I understand that the steering clutch and bevel gear shaft needs to be removed. I have a service manual and was wondering how long it would take to remove the clutch and gear assembly being as I seem to be half way their. Any help would be appreciated. Thanks, Hank
Yair . . . mcknight19 . I think you mean the pinion has two teeth chewed up? Either way teeth or gears it would be a very bad move to run it, given time it will destroy the final. You were very lucky to find it at a stage where it may have caused minimal damage. I don't know the machine and don't quite understand your comment that you have the final "removed". The steering clutch will certainly have to come out but unless the machine is quite different to conventional design I think it unlikely you would have remove the cross shaft to service a final. HOWEVER. Old machines are a can of worms and once you get in there it is often found there are other problems that need attention. All the best with it, I am sure some knowledgeable folks will chip in with more definite advise. Cheers.
Thanks for the reply. I am going to try to do most of the work myself and just looking for someone that might have done this to know what I am in for. Your right I meant 2 teeth not gears there are just the pinion and the main drive gear. On this machine the final main drive gear separates from the rear case. Thanks Again, Hank
Be patient Hank, I'm sure one of our resident experts on this generation of machine (tctractors would be your man) will be along shortly to help you with your final drive issue.
Well funny enough, is the shovel peddle steer or Long Lever? anyhow you will need a bit of tooling to get things stripped correctly, a few photos of how things look would be handy? tctractors
Its pedal steer. I will put a couple pictures on tomorrow evening. I do have manuals and a mechanic that will work for a fee. I just had a complete engine rebuild with only about 12 hours of run time. I think I bought a lemon the person that said the machine was good I found out he does not know as much a I thought about them. All in all it seem like a good machine just had some bad luck. After the money that I spent to purchase machine last fall and the cost of the engine rebuild I am trying to do most of the work myself to save my wallet and marriage. Wife not real happy ran 25Hrs. then complete engine rebuild 12Hrs final drive pinion. I think the pinion was bad when I purchased the machine because I have not ran it hard and if I would not have changed my final drive oil and just added oil I still would be running and wouldn't know any different. Sorry about the rambling, Thanks, Hank
If it has 2 gears loosing metal by all means park that machine. I had a similar situation on a 943 and it caused a catastrophic failure. Look back thru post for pics. If I had caught it before it combusted I might have saved a couple thousand dollars. I can pm you some connections on parts.
I wanted to edit my original post but for some reason I must not have access to the edit feature. "I said 2 gears I meant 2 teeth." I have pictures i am going to upload now.
holy metal-eating chipmunks Batman ....... That could have been an extremely expensive failure if you hadn't found it. Take some pics of the teeth on the bull gear that the pinion mates with. I would be amazed if there was no damage at all on it. Those pieces that are missing from the pinion must have been meshed in between the two gears at some point, just cross your fingers they haven't started a crack in the root of a tooth on the bull gear. You "local mechanic" should have had that pinion rammed up his *** sideways for even suggesting that you should continue to run the machine - IMHO of course.
Yair . . . As pointed out by Nige , with that amount of damage to the pinion the bull gear has taken a pizzling and, if at all possible I would be hesitant to reuse, there is every chance it will start shedding teeth. Cheers.
To get that Bad Boy out is going to be fun for you as you need to remove the top cover then undo the brake drum bolts and lift out the cross shaft, mark the case so you know the side the bevel gear sits on and undo the pre load adjusters well back as its easy to damage the bevel gear on lifting out, when you do lift out the cross shaft do it very slowly and help things plenty to avoid this damage, the next snag is removing the drum flange, all I can say is look at my posts in Shop Talk Caterpillar Sprocket Removal, the F/Drive outer case needs checking in the bearing location, don't use a cutting torch to remove any failed bearings, if you have to use a welder with the earth clipped on the bearing not the case, it takes me about 2 days to strip and rebuild 1 side on a good shovel with frame bolts that undo, up to a week if the frames are welded on. tctractors
Here are a couple pictures of bull gear it looks pretty good to me but I am going to have my mechanic verify before this machine is put back together. (Not the Mechanic that said put it back together and run it) I included a picture from the back of the machine of the steering clutch cover case. The manual shows this coming out the back. I was wondering what attaches this to the clutches. Looks like it just slides out the back. Thanks everyone for your input Hank
I can't tell from the photos, but it looks marginal? New pinion is about $200 CAT Classic or $150 aftermarket, the bull gear about $600 CAT Classic, $300-$500 aftermarket depending on serial number and/or changes in your final. I would split the difference, replace everything with aftermarket. Offroadeq.com is your friend.
The surface has a little wear about 1/4 inch from the far edge. It is still smooth and not through the outer coating. Are the aftermarket parts ok. I haven't heard of anyone having problems with the aftermarket and the price is definitely allot better.
Thanks for the link lantraxco their prices are very good just need to find out about shipping. Not going to order til I get the pinion out. Bearings look good should they be replaced also?
From an old gear head, change the both of them. There will be stress cracks in the hard surface of the bull gear, it may not fail for years and yet with a new pinion could detonate like a grenade. Been there done that with those having to work on the cheap such as old quarries where we robbed donor machines to keep borderline machines working for a time.
I'll leave the quality reports to some of the wrenches with current knowledge, I just peddle stuff now, haven't done any CAT repairs in a couple decades sadly. I haven't heard any nightmare stories from my customers and contacts though.
Yair . . . mcknight19 Absolutely! Cheers.
I was going to suggest Offroad Equipment for parts but lantraxco beat me to it. Apparently they are even better on the phone than dealing with them over the web. When doing a job like this one all bearings should always be replaced. You do not want to take a chance that a small speck of hardened tooth from the spalled pinion has passed through a bearing on its way to the bottom of the case. It would be a shame to spend hundreds of $ on new gears then experience a bearing failure soon after you got it all back together.
Thanks for the input. I will definitely replace all bearings. I will be starting the rest of the tear down in about 10 day. Had a death in the family and have been pulled away from this project for a while. If anyone knows about the steering clutch cover case that I have pictured. I guess there is nothing that holds it in other than the bolts. Manual shows it coming right out the back of the machine through the opening under the fuel tank. I will keep you guy's posted when there is some progress. Thanks again, Hank
I am of the belief that something complex, heavy, hard labor is taken apart it become wise to replace things (bearings-seals-whatever) that are easy to get to with the component opened up. Why go cheap for a $50 part that could end up costing thousands in repair and labor later? Nothing like having to winch a dead machine off a half finished project either.
The top pinion bearings I always change, the lower Bull gear bearings usually need the inner bearing replaced with the outer 1 still fit to run, if I am doing both sides I swap Bull gears left to right, otherwise I just stuff the Bull gear back to work after a look at the teeth, CAT Classic Parts are After Market bits and not made by CAT and can be good value, the parts are dear enough so I only change what is knackered, but I do this type of work constantly and have the tooling to tackle the job, you have a workshop repair book it gives good detail on the top cover removal, it will be thick in crud so give this area a good clean before undoing any bolts. tctractors p.s. the brake band on pedal steer 951's is the 720 deg item you need to consider the wear life of them once you are in to things.
Just thought it might be work a verb on the fact 941B and 951C's have lots of common parts, the 9 tooth pinion is 1 also the 52 tooth Bull gear is another, so is the hub the sprocket fits on, the 941 and 951B have a different tooth count on these gears with the pinion having 10 teeth and the Bull gear having 58 teeth, the lever steer shovels have the 320 degree brake band, so the parts are common to find and should be low cost non O.E. the bearings as long as they are name branded will be fine but the pinion bearings are pin locked in the casings to stop movement. tctractors