After doing a little homework and reading the 99E description it is different from what I was told. The attached #12 oil clutch adjustment instructions recently supplied by "eddieb" describes it well. If the oil source is the engine sump there may not be a separate fill and dipstick. When I asked the owner of the 70D he stated it was under the floor plates??

CC, forgot to ask. How did you go about pinning the thrust bearings?

Techie and Magnet,

I can't find any mention of a seperate oil clutch in the parts or service manuals I have. CAT describes the flywheel clutch as being an automotive type, double plate oil type clutch. It's lubricated from the diesel engine but it does not run in oil. I am confused as to the starting engine controls being on the left side. They should be on the right side as you look forward. One lever engages the pinion and the other the compression. A petcock controls the gas to the starting engine. You will not have a pinion lever and a seperate starting engine lever like on other CATs of similar vintage. With the starting engine running, the tractor in neutral, you lift up on the lever and when the engine is turning good, you pull up the short compression lever. When the diesel engine is warmed up you step on the foot throttle and open the hand throttle. When the diesel fires you have to watch that the pinion lever returns to the down position and you close the gasoline petcock. To shut off the diesel engine you have to put the hand throttle in the idle postion and then pull up with your hand on the foot throttle.

Here is a scan of the operators manual .

Hi Doug,
Thanks for the response. Would agree, none of the oil clutches actually run in oil, just lubed and cooled by it. The dozers used the clutch housing for a collection sump and had their own pumps. The grader makes use of the engine as a sump and uses sections of the engine pump to supply and scavenge the clutch oil. Think we got it straight:D
CCJersey is the one to talk to about in the seat starting. I'm not all that familiar with the grader pony seat start setup. Do know the dozer and loader arrangement.

Back to my question....I have an 8T1-up manual but it only shows the regular dry type clutch. Does your 70D manual cover the details of the oil clutch? the supply and scavenge pump? How about in the parts manual? I have a 70D parts manual coming so I guess I will find out shortly.

Magnet,

From the manuals, I can't tell much difference between the 8T and the 70D as to the clutch. I am not the best at comparing Cross sectional diagrams. I once had to repair my 70D clutch because part of the in-cab starting linkage crystalized and broke-falling into the clutch; causing forks to break and other bad things. That particular part did not even show in the parts manuals. My great local CAT dealer found me the part and told me how to take the engine out and fix it. The operators manual merely says the clutch is lubricated from the engine and to drain the clutch housing when you change the oil. The clutch is very similar to my D4 7U. I assume that the oil does not return to the engine. I can't find any mention of any special maintence the clutch requires rather than adjustment.

Hi Doug,
Thanks again for your response. You sorta confirm my suspicions that info on the last series of #12's is pretty sparse, especially in the clutch area. I will continue some research and share findings if I can come up with anything significant.

PS, Do I recall correctly that you went through a direct start conversion on a grader recently. If so how did it go?

OM, our 12E grader has the direct electric start option, so no experience with the in-seat pony start controls. Parts book shows one of those buzz bomb side mount ponies on the D333, so I'm glad it's straight electric. In the parts book, the controls look to be similar to those posted by Doug for the 70D which would have a D318 and the horizontal pony, just with the pinion for the in-seat controls, I believe.

I haven't finished reassembling the engine, but did get the thrust bearing in and wondered what others thought about the result. I will update the original thread on that with pictures.

Sorry about the confusion, the controls for the pony motor are on the RH side as you face forward! Once I'm able to get the pony motor running I will work on spinning the diesel...

Thanks again for the direction... you guys are just too good!

Charles

Magnet,

I did the direct start conversion the easy way. I traded the my old 70D in on a 71D that had factory direct start. My old 70D had 16,000 hours on it and was a faithful but worn machine. It is now maintaining a motocross track. Techieguy could probably use the adjustment/ rebuild information for the carb on the pony motor so I will try and scan it. When I bought the 70D it belonged to a pipeline company that just pull started the tractor. I cleaned out the carb and it always ran well for me.

Techieguy,

Here is a little help from the CAT manual. Hope this is helpful.