C-81 eight speed filled with water

[Rob R 966]

Hi have a "barn find" C-81 I am in the process of restoring.... I drained the tranny and it contain at least a 1/2 quart of water and the rest was a light colored glop. The only plug I found to drain the tranny was the 1/4" drain/fill plug at the back ot the transmission, I tilted the tractor and flushed with kerosene then refilled with 80-90 weight gear oil ..... problem is that today I checked the oil and it is light brown color again much better then previous but still not healthy any suggestions..... is there a better way to drain and clean this puppy out?   Thanks

[rmaynard 15,417]

After filling it with 2 quarts of kerosene or diesel oil, run it around the yard for about 15 or 20 minutes, then drain it again as described above. You will never get it perfectly clean unless you open it up and clean it piece by piece, but it will certainly be much improved over the oil/water emulsion you had before.

[Sparky-(Admin) 21,300]

There is a drain plug on the botton of the tranny. It takes a 1/4" (I think) allen wrench to get out. Its very close to the trailer hitch tail that goes under the tranny. Usually its filled with gunk and needs to be cleaned/scapped out to get the allen wrench to go all the way in and prevent stripping it.

 With the kerosene method I think the guys who do it drive it around a bit to get it all mixed up thruout the tranny.

Mike...........

[sorekiwi 761]

What they said  ^^^^^^^^.

 

I usually drain it the first time (front raised as high as possible), replace the drain plug and fill it with Kerosene,  spin the axles and input shaft (by hand) and work the shifter a bit, drain it out again and refill with a 50/50 mix of Kero and engine oil.  Drive it round a bit (no hard work!) and drain it again.  Then fill it with gear oil.  If it was fairly clean with the last drain (the Kero/oil mix) I leave it as is.  Otherwise I'd use it for a week or two and change the oil one more time.

 

I'm not a fan of driving the tractor with pure kero, I think the bearings need some real oil to lubricate them.

Edited November 22, 2013 by sorekiwi

[nylyon-(Admin) 7,240]

And get a new shifter boot, it's likely cracked.  I always liked Peerless on Gillotti rd in New Fairfield.  They'll likely have to order it, but they're really nice folks there.

[boovuc 1,090]

If you go down to October 7th in this forum to the post "Transmission Flush" and read the tread, you'll see a tip on raising the tractor up in the front to drain more fluid that gets stuck behind a casting bolt mount.

Quoting SousaKerry: If you lift the front end of the tractor up to a 35-45 degree angle you will get a larger amount of fluid out. There is a hump inside the casting that the oil gets trapped behind.

If you can't get all your flush out, it will discolor your new gear oil and thin it out!

[Rob R 966]

All great suggestions thanks guys..... was thinking and wondering if shooting some air in the filler hole while tilting the tractor up might also help?

[stevasaurus 22,698]

No shooting air in the trans.  I would say that you need to drop the trans and split it and clean this one out the right way.  I think it is OK to flush transmissions that you know and have been using and maybe got some water in, but you say this is a barn find.  Know way of knowing how long it has been sitting and no way of knowing the history.  If you have a lot of rust in there, you may just be loosening it and it can and probably will get trapped in the bearings...especially the #1533 ball bearing carrying the differential. 

 

If you are going to just keep flushing it...put the horse on blocks (rather then driving it around).  Why you ask???  Because, if it starts making bad noises, you can just shut it off, and it will not be stuck in the middle of the yard.  Also, if the seals start leaking (and they might) with the thinner oil, you will not have the trail of oil in your grass.

[Rob R 966]

SUCCESS!   I raised the front all the way I could with a good garage jack, drained all the fluid out (had replaced a week ago but was almost as gloppy as the first dump). I then blew it out with air (set the pressure a 40lbs NO HIGHER) this blew at least another 1/2 qt of crap out of the transmission. I then lowered the tractor added 1 1/2 quarts of kerosene and drove the tractor up and down my hilly property for 10-15 mins., brought it back into the garage, jacked it up again, drained the kero and blew it out with 20lbs of air.

 

I then added new clean 80 weight oil lowered the tractor and drove it all over the place brought it back the oil remained crystal clear and it is purring like a kitten and the trans oil looks like trans oil .....ready to take the stress of plowing this winter........   

 

Thanks to all

[stevasaurus 22,698]

   good luck with that.

[Rob R 966]

Don't think luck has much of a calling card here, some excellent input, common sense and good ole American ingenuity..... prevailed.

[boovuc 1,090]

Boy! If we could just bottle that and send it to Washington, we may have hope!

[leeave96 487]

Also - don't forget to replace the shifter boots if they are dry-rotted/cracked.  Cheap and easy fix.

[Rob R 966]

10-4 will do....... txs

[jrc0528 20]

I bought a C-10? with a 8-speed this summer that had nearly a quart of water in the trans.  I split it open since it needed seals anyways.  None of the bearings showed any rust, but I was glad I opened it since one of the 1533 diff carrier bearings had shredded part of it's ball cage!  I ended up replacing all the major bearings in it and all the seals.  Funny part was the only internal rust was in the upper section of the castings, above the oil line; condensation I'm guessing.

[pfrederi 17,641]

I bought a C-10? with a 8-speed this summer that had nearly a quart of water in the trans.  I split it open since it needed seals anyways.  None of the bearings showed any rust, but I was glad I opened it since one of the 1533 diff carrier bearings had shredded part of it's ball cage!  I ended up replacing all the major bearings in it and all the seals.  Funny part was the only internal rust was in the upper section of the castings, above the oil line; condensation I'm guessing.

I believe you are correct.  I have seen that in trannys before...