t-20 gear oil/atf

[LarryW]

My t-20 in my attex has gear oil in it. It drives good. No problems at all with it. I heard of others that say they have gear oil in theres also and never had any problems. Has anybody actually witness a problem or is that a myth? I hear about it all the time and have suggested to others to make sure you use atf even. Maybe its something only the new t-20 cant have? Modern bands made differently or something? I have no idea. Just thought I would ask for others opinions. Would you guys recommend I change it out for atf?

[racerone3]

Larry,
the T-20 in my Wild Wolf was full of gear oil (to the top plug) when i got it. i did 3 or 4 fluid changes with about 10 min of run time in between, and it has been working fine for a little over a year now. it is scheduled to get new bands sometime in the next month and a half, so i'll let you know what the old ones look like when i get it torn down. on another note, i just found a starter that looks like it would fit the reverse gear mount on the scrambler you used to have... day late and a dollar short!

[LarryW]

.......on another note, i just found a starter that looks like it would fit the reverse gear mount on the scrambler you used to have... day late and a dollar short!

lol, thanks for thinking of me!

I am real curious on the gear oil thing? I thought the oil reacted with the glue holding the friction materal on the bands? (I have never seen a band yet so maybe there isnt friction material on them?) Mine had new bands installed by Matt O. about 120 miles ago.(Well he didnt say he did it but that it was done at about 190miles when he owned it)

[jpswift1]

lol, thanks for thinking of me!

I am real curious on the gear oil thing? I thought the oil reacted with the glue holding the friction materal on the bands? (I have never seen a band yet so maybe there isnt friction material on them?) Mine had new bands installed by Matt O. about 120 miles ago.(Well he didnt say he did it but that it was done at about 190miles when he owned it)

Hey Larry, get the gear oil out of there ASAP and get a just a couple ounces of ATF type F in there along with about 4 ounces of limited slip differential additive to keep the bands from chattering. I've seen a few T-20s first hand lose the bands because of gear oil. Don't run it any more until you change it to ATF. It'll save you so many headaches down the road.

[hydromike]

I can't speak intelligently about the science behind what the gear oil actually does to the bands, but I know that one T-20 that I had a while back had a quart or so of gear oil in it. The bands were not pretty... There was minimal delamination of the friction material, but I don't know if it was in there for a week or 20 years. The T-20 was developed to specifically use ATF, and I would imagine there was a lot of research and development surrounding the choice to use it vs. another lubricant. Gear oil and ATF have markedly different lubricating properties, viscosities, temperature thresholds, what solvents they contain, etc. I'm not about to claim that I've done the research directly (i don't feel like risking bands and drums), but I like to play it safe and go with the recommended fluid. I know that there are hundreds of thousands of limited slip differentials out there that are running comparable friction material that call for gear oil, but it's quite a different application.

Your T-20 could quite possibly last a lifetime with gear oil. I certainly can't say with certainly what would happen... I've just heard horror stories about some trannys that have been taken apart, with burnt-up gear oil flowing from it's innards.
~m

[Roger S]

I can't imagine what gear oil in an atf application would be like. Would assume very like filling an engine with stp. I forgot there are wet clutches with gear oil, like my old harley. Water is the big danger with band and clutch lining in the automatic transmission world.. the glue is water based. A car driven into deep water and the trans takes on water.. well for the engine and tran's sake, you should shut it off before water gets in the air cleaner a cylinder gets a gulp of water.. anyway if an auto trans takes on water and continued to be driven, the atf and water turns into a milkshake. Then the temperature heats the water and there's a term, "steamed the lining off the clutches/bands". If a driver is smart enough to stop the engine before water is sucked up through the trans pump, it will stay separate like water/gas/oil does. I did this once, and towed my car to my shop. Pulled the trans pan and a quart of water poured out separatley fron the atf. If I drowned a t 20 I wouldn't drive it till it was drained.

[mark m.]

I should aso add that most gear oils that I am familiar with have sulfer added to it's chemistry and sulfer and bronze do not get along together well. In other words the sulfer will eat the bronze. I rebuilt the Borg Warner T20 that came in my Starcraft and that had gear oil in it from the previous owner. It was not a pretty sight when I pulled it apart. All the bronze bushings were wanged. Surprisingly the band material was still intact but just worn down. Go figure.

[Roger S]

On that subject, Mark, my nissan pathfinder forum discusses that GL4 gear oil will eat soft yellow metals, syncros, etc. GL5 is called for, but a lot of trans trouble was created when refilled with gl4. I wonder if this is the case on the argo reverse idler bushing wear..

[amphibious drew]

While at RI, one of the engineers informed me that gear oil may cause pad to delaminate from the band. It could act as a solvent to the adhesive, but he said it depends on what adhesive was used on the band at time of manufacture. Indicating that several glues have been used on the bands over the years, but he did not specify as to when the glue held up to gear oil. I would keep it safe with ATFIII myself. Yeah I can run my engine on started fluid alone, but how long it will last is questionable. Also, I believe it was JPSwift's father that informed me that the viscosity of gear oil is much thicker than ATFIII. This could cause increased wear on bearings, drums, and planetary gears due to the oil not fully penetrating all parts properly.

[LarryW]

Thanks for all the info guys. I'll swap it out and pretend it never was in there. No sense worrying until its broke!

[jpswift1]

You should be just fine once you get it out of there and get the ATF in. Just put just a few ounces less than a full quart in there of the ATF and about 4 ounces of anti slip differential additive and you'll be good to go.

[LarryW]

Thanks Jeff!

[jpswift1]

Glad to help, Larry. How has it been treating you? Did the pressure washer get anymore of the red paint off of it?

[LarryW]

I have about 75% of the paint off. Still working on rest. I did find something out I am going to change. The air cleaner intake in through the cooling fan on flywheel. When you dont have drain plugs and then climb a bank in the creek, the back fills with water above the flywheel and pumps the water into aircleaner. Motor dies. They tried to pull me out with a 2by quad but Bills attex(ex 5 wheeler, 6 wheels again) did pull me out. I plan on finishing my 208tt and then redoing the trainer and fixing the drain holes and crack.

[Toys4Me]

Good to hear the 5 wheeler has 6 wheels again. When I finally find a clutch and get the engine swap done we need to get together and go play in the mud by you.