D6 8U clutch problem

Found more problems with clutch went to change out fiber links and one bolt came out by hand but still had threaded part attached from what I can tell 2 of the links had broke and fliped over draging on the bellhousing causing the yoke that bolt goes through to bend apart and back side of pin to jump out of hole. so now I need 2 sets of yokes (don't know what they are called for sure) has anyone seen this kind of damage or am I just a lucky one. May have a leed on some used ones. will try to post pics.
Russell

Is it just my computer or is there a problem with the forum.

Here are some pics of my mess.

As you can maybe see from the pics I have more problems than first thought busted main plate, clutch lining missing in places, some bolts heads have been welded (to lock from turning ?), 2 Link holders bent.
Now do I repair or just find another clutch?
I have located new plate assy and link holders.
Russell

Good to see the fourm working again!

Might be just as well if you can find some good used parts & could be a little cheaper I think.

Found another small problem I think it is called the clutch brake. The lining has broke out around some of the rivets and someone has welded around the outside of it.
I think I can chuck it in my lathe and clean up the outside where it is welded.

Anyone know how hard it is to rivet these linings back on, do I need special tools?

It would be easier with a riveting press, but since there are relatively few rivets in the clutch brake I bet you could use a good round ended punch and clench the rivets against the flattened end of a bolt clamped into a vise as mandrel. Hit it too hard and you can probably crush the lining material or almost cut the rivet off on the sharp edge of the hole in the backing plate. You will have to make sure the lining is always tight against the backing plate as you clench the rivet. That's a lot easier on a flat surface than it is on a curved brake shoe or band.

Don't you have to do the main clutch as well? You might want to find someone who has a press to do the whole job. The cluch brake won't matter as much if it's not perfect, it won't chatter etc like the main clutch might, but for the money, I would do the main ones the best way possible.

Linings and rivets should be available from CAT or aftermarket. I wouldn't bother with reattaching that lining.

For what you have and what you are finding I think you'd be wise to go shopping for a good used clutch assembly even though I believe all but the return leaf spring assemblies are still available from Cat. If you post the serial number I can scan the parts diagram from the 9U parts manual for the same time frame as I don't have any 8U manuals. Not unusual to have the disintegrating link assemblies tear things up in the housing.
If your up to it, the oil clutch conversion for the D6 is well worthwhile but it is a bit of a project.
The rivets will require a setting tool or most any clutch/brake shop that can handle rebuilds should be able to fix you up.

I think it is a 1952 serial # 6D8U5132
Russell

8U5132 would be equivalent to 9U9359-12,417 and here is the parts breakdown:

Thanks for the parts break down this will help big time.
I want to get this dozer back running right, my dad used to run this dozer right after it was bought new, (deep plowing to get some top soil back to the top), right after the 1951 flood west of Topeka Ks.

Where did the oil come from, looks like all the parts are coated, friction material looks dry though.


Talk about a mess, I have a D7 that apparently never saw any grease in the pilot bearing long before I got it, 15 hours later on the meter, the drive links that connect the main flywheel and clutch assembly could not take the strain anymore, the thick driven plate in between the 2 clutch plates was wobbling around when the clutch was not engaged and I assume when the clutch was engaged it grabbed the plate wherever it landed, lot of vibration, fenders were flapping, I knew something was up, and then the smoke started coming out of that compartment, the links let loose and the material left in there was like a big mouse nest, the links rubbed off on the upper bellhousing, so I shut it down, eventually removed the clutch assembly, and found that the pilot bearing was disintegrated, the bore eggshaped. Mind you, I realize the later oil clutch is far more durable, but the fact that this thing held on for as long as it did is amazing, if you keep an eye on things, and knew it needed some work, you certainly had enough time to get the tractor out of the field etc.
This clutch original, the tractor was owned by the corps of engineers until 1970, so I can see what happened, they kept the O.D. green paint up to date on it, probably ran it every so often, but was never used, until bought by a farmer, I think I'm the 3rd owner. There is a metal data plate rivetted to the inspection cover, that says, grease daily, (pilot bearing) ironically, that never occurred, LOL !


I was a bit intimidated or a little confused about what to do with this assembly, luckily I found a good used complete clutch assembly from a dismantler, from a running tractor. The friction linings were useable, but I decided I won't reinstall the clutch until the linings are replaced, both clutch brake and clutch plates. I was aware that the friction material, (segments) are available, but wondered if the holes were drilled in them, that would be a pain in the arse to drill them from a template of the old segments, then counterbore the holes for the rivets, then do all the rivets and attach the segments, you can get the hand tools from Cat, it's in the tools and supplies catalog, the old catalog from the 50's even shows the rivet press.

It did not make much sense to do this work, when you should probably be able to utilize an outfit that manufactures/installs friction materials, I had found a couple of places that does this work, over 100-150 miles away, nothing local yet although I've yet to call some of the crane outfits to see if they have anyone local that does friction work, should be a done deal then.

The only issue I had was about the thickness of the friction segments, wondered if anyone knew how thick they are, and what type of friction material is best, the outfits that do this work would probably be able to recommend the correct material, but how do they know how thick the material is supposed to be on one of these when it was new?

In the interim I've been turning the motors over by hand monthly to make sure they don't seize up, been sidetracked on other projects sitting in the yard, but I think I'll get to finally get the clutch done before winter.