Transmission fluid

[6wheeler 603]

I have a C-120, model#71-12K801. I am trying to rig up a hydraulic system on it so I took off the fender pan to get where I need to be. I checked the tranny juice and its milky. What type fluid should I use? It doesn't smell like 80w90 but, it is sticky like that. Also, it seems to be leaking behind the brake drum. That may be where its getting water(milky) and the fluid is orange colored, so maybe some rust inside. Is there a way to flush it? Apparently the PO did not check the fluid , I bent up the dipstick pretty good trying to get it out, but I can fix that. Is there a vent on this tranny? I ask because it seems to have other leaks as well, but not on the axle seals. I need a brake band as well, there is no brake pad left and it is almost rusted through. I would imagine the tranny leak sped up the pad deterioration. I don't know the year of this tractor. Are all the bands the same? Thanks for any help... Pat

[stevasaurus 22,863]

Pat...rmaynard here on Red Square sells the brake pads...send him a PM, I think he is in the vendor section. As for the trans...you can drain it and then put in kerosene to flush it out. Drive it around a little in each gear and then drain...do it 2 or 3 times depending on how it looks when you drain it. Then fill with 90wt. You can replace any of the seals without dropping the trans...check side to side play for bearing wear though...a new seal will leak if the bearings are shot. There really is no vent as such, but air, oil, water and dirt can get into the trans where the shifter is if the boot is not good. Hope that helps.

Just saw your other post on the mower deck...your tractor is a 1977 and it should have a wheel horse transmission #103907 8 speed. :thumbs:

[6wheeler 603]

Thanks Steve, it is an 8spd. It has oil all over it, so I really can't tell where it is leaking yet. There is fluid on the brake side and the drive side. Good call on the shift boot, it is cracked up pretty good. And it is a 77? Good to know as well? Thanks.....Pat

[sorekiwi 761]

Your tranny is probably leaking from one of the seals, but also obviously has some water in it.

Sometimes when they get water in them the level gets too high, and the mixture can "flood" the oil seals. Was the level high on the dipstick?

Flush the transmission as Steve said. Myself, I dont think I'd drive the tractor around with just Kerosene in the box, I'd probably prefer a mixture of 50/50 Kero/Auto trans fluid or engine oil. (I know Kerosene has some lubrication properties, but I'm not convinced that its enough for 50 year old bearings!!).

After the flushing mixture comes out clean, refill it with the correct amount of gear oil and see if it still leaks. If it does you'll have to replace some seals which can be done from outside the case.

[stevasaurus 22,863]

I agree with you Mike about driving it around, I don't like that idea either...may be put it on blocks and run the gears for a minute. I really am of the school that if it has had water in it...it is too easy to tear it down and clean it out right...that way you now for sure. I would really like to take his trans and run the kerosene through it and then tear it down to see if that is just a waste of time. I know some guys on here don't like it when you always suggest tearing down a transmission. I would just really like to be sure if running kerosene or diesel through a trans does anything a far as cleaning out the bearings. Maybe 10wt oil alone or mixed with kerosene is a better choice.

I know that the kerosene method would not have worked on my 702 trans.

any ideas guys? :thumbs:

[can whlvr 993]

i have had to tear into a few trannys and i tore into one that i cleaned with paint thinners and did the whole routine,run,change,run more thinners,do 2 80-90 oil changes,and there is NO replacing tearing it down and cleaning it piece by piece,yes the cleaning trick can get it fairlt clean but there is sour oil up high in the tranny and all the small places where it doesnt get cleaned and i dont like running them very long without proper lubrication,if the fluid is really contaminated it doesnt hurt to split her,and then one can see how the gears are and bearings,and then u can get her properly clean,i too have done the flushing trick with sucess too,it depends how bad it is inside

[sorekiwi 761]

I hear you Steve, kero wouldnt have worked on this one either...

I've never looked at the chemistry to work out why, but ATF is a really good cleaner (and penetrating oil as well). It doesnt work as quickly as kerosene does, but it does supply some lubrication if you are going to drive the tractor around, and I think it does a more thorough job of cleaning than kero does.

Some boxes you just know that you are going to have to split them, but others I think you can get away with a few good flushes. Of course if its your only tractor then you need to fix it properly, if you have a back-up (or three!) I think that sometimes you can take the chance, flush it and see what happens.

[stevasaurus 22,863]

You know Mike and Don, I think it is time to experiment and do an investigation for this flushing out thingy. I have a trans that I have been wanting to tear into. Maybe open it and inspect and put it back together...flush until clean...open back up and check it out. I'm just concerned that as parts become harder to find and more expensive, guys will be sorry that they took the easy way out. Doing it right will give you a trans that will be good for another 50 years. No Worries Mate... aye :thumbs:

[can whlvr 993]

sorry guys i didnt proof read my last post,the tranny that i tore into after the flush was not completly clean and thats why i think if u have milky tranny oil its best to do a split and clean piece by piece,if its not real milky and not like the trannys u guys showed maybe a flush is good enough

[repairman 7]

I just flushed an 8 speed trans today that had some water in it I used ATF mixed with diesel I had the trans out I filled the trans full top to bottom turn it over and jostled back and forth also all bolt were reinstalled during this process I then return the trans back in it normal direction placed a floor jack under it used a large C-clamp to secure it to the jack I have a small 110 v electric motor with 1/2 pulley on it I set it on the trans using another clamp attached a belt to the trans plugged in the motor and let it turn stopping periodically to change gears and repeat this was a crude setup but worked I drained it after about 30 mins and repeated this step after the second drain it looked much better

I re-installed trans filled with 85/140 this is what the manual calls for I will run and recheck for about a week then drain and refill ATF is a good cleaner along with diesel.

:thumbs:

[6wheeler 603]

Thanks for all the info guys. I went with the diesel fuel and ATF. I put her up on stands and let her run. I put it through all the gears for three flushes and I filled it through the dipstick on the second one all she could hold and put a pan under it so it could force it out through the top. It was messy but I think it cleaned out well. I put a fourth flush in of only ATF all the way to the top again and let it overflow again. I let it drain for two days and refilled with 80-90. I'll run that a couple of days and drain it again and refill. The last flush came out pretty clean so I hope it worked. Thanks again Pat

[stevasaurus 22,863]

Pat...now that is what I am talking about...yours is the trany that I would love to open up and see just how clean it is now. Great thread. :thumbs: