Wet clutch purposely run without oil?

I have an HD6G dozer with a wet type clutch that I am adjusting. In the course of adjusting the clutch I see no oil in the clutch housing.

Upon further investigation it appears that there has not been oil in the system for a very long time - far longer than I have owned the tractor.

Here is the thing though. The prior owner was a machinist, welder, fabricator. He was well known to take good care of his things. Is it plausible that being unable to find or afford parts that he choose to run the wet clutch dry and be gentle with the machine?

He is deceased now so I cant ask him for clarification on what he was doing or why. What do you guys think?

Should i bite the bullet and fix the entire thing. Cant find the pumps anymore so you have an adapter, new pump, new lines and hoses, ect. The machine ran fine with it dry in there for the last two years!

Thanks,

Leo

Tom, there are two dipsticks on the left hand side of the tractor, one for the engine and the other descends down to the belly pan and terminates into what appears to be the aluminium sump for the wet clutch. Both have oil in them.

This is definetly a wet clutch machine in that the clutch is identical to the wet clutch drawing in the parts manual, the clutch housing has an oil filter, and there are hoses commin and going to what appears to be a hydraulic pump under the fuel injection pump.

And yet, not a drop of oil in the clutch housing or any of the hoses. It has been dry in there for a long time.

???????

Pump not working perhaps. They have the same mounting and drive as the fuel transfer pumps on Detroit 2 stroke engines. You can use one of those to get the oil circulating again if your pump is shot. The oil circulation serves a very important purpose, it cools the friction and spacer plates to prevent them warping. You DON'T want that to happen. The oil to use is a 10W trans fluid or 10W ATF.


Edited by Mactractor - 24 Oct 2019 at 1:37pm

If it was made to run in oil I would think no oil would be very bad. But how much different is the runs in oil clutch from the dry type. I know some inovative people used steering clutch plates and brake linings made to run in oil in Cat D6's that where built as dry steering machines. They did not add a pump just filled the compartment. So would dry clutch HD6 parts fit and work in a wet clutch HD6 compartment?

Ray, I was think that maybe he was running a dry clutch inside of oil bath wet clutch housing just because that might have been the only clutch housing he had.

However, I compared the clutch in the machine with the drawings in the parts manual and it looks exactly like the wet clutch in the manual and nothing like the two wet clutches.

As to whethere he made custom discs, or used dry disks in there or something else I cant say. Being a machinist, and not a rich man I would have to assume that he had to make what he could't find or afford.

Leo

Hmmm. Interesting idea with the throttle

I just finished repairing an old HD11 with the "first generation" wet clutch- it had a similar problem- run low on oil.  The problem with that is the wet clutch bearings are open roller bearings, depending on the oil circulation to lube them.  In this case, the pilot bearing in the flywheel failed, and also the needle bearings in the throw out assembly, where lever linkage attaches to the release bearing.  Then, one of the blocks fell off and got into the clutch.  After putting it all together with new bearings and seals, I was shocked to find that the oil pump was still operational!  No real major oil leaks, just seepage over time, and not checking the oil I think.  It was unfortunate that those early machines had relatively small reservoirs for steering, transmission and clutch- all separate.

To answer an earlier question, I am sure that the pump is not working because the return line to the cover of the clutch housing has tons of cracks in it, and is bone dry. I would have expected an oily mess all over the belly pan if the pump was trying to move oil through that hose!

In fact i was shocked that the sump still had oil in it. That's why i never caught the issue. I figured if the dipstick showed oil that I must be fine.

So it will take me some time to find a DD pump. Any opinions about just blocking off the drain back to the sump and then filling the clutch housing with oil up to the old level of the drain?

You better removed the pump first maybe the shaft or the coupling pump drive is brooked

Okay guys, you know better, so off it comes first thing tomorrow.

BTW, why did Allis Chalmers make everything so tight on these things? You would think that on a machine this size that they could have spared two inches between the frame and engine for a human hand and wrench to fit in. Add in the bucket in the down position, and this machine is just a bear to work on!

P.S. is it normal that the floor boards and body are metric fastners and everything else is imperial? My tractor was built befor the fiat purchase so its a bit puzzling (and a PITA) to deal with mixed hardware like that.

Thanks for the advice guys.

Leo

I know your post os old but I'm running into the same problem with getting my clutch ring to move how did u get yours moving

Thank u for the reply. I figured it out after looking at it in several directions. I had to lose the 2 nuts and use a chisel and big hammer and turn the inside ring. The notched ring it shows in the book to turn doesn't turn its bolted to the flywheel.