I scored a very nice World Class T5 today at the wrecking yard. The problem is that it has gear oil in it. I know that non-w/c used gear oil up to 87, and 88 and up used ATF. How much damage will it do to the trans to run it with gear oil, and should I just drain it, clean it out and refill it with ATF? What would you recommend to clean it out with if I have to go that route?

 

I've read that gear oil isnt bad for the trans....
Its better to use ATF in colder areas...
or in warmer areas...either is ok. (atf or oil)
If you wanna clean it..I'd take off the top cover and shoot it with brake clean or carb clean...and let it dry before filling it...
make sure to get RTV before taking it apart..cause there arent gaskets in that trans.

 

Okay, thanks for the info.

 

Starting in 1984, all 5 speed manual transmissions used ATF, according to my Haynes manual. My tranny guy tells me ATF was used because of the close tolerances involved.
The lone exception was 1987, when SAE 5w-30 manual transaxle fluid was specified.

Since the tranny's out, it shouldn't be too tough to clean it out, and go back to ATF.

My paranoid side wonders if the gear oil might have been an attempt to quiet a noisy trans... hope for your sake it was just a matter of ignorance!

Good Luck with it!

------------------
Zslug

May the road rise to meet your treads...

'84Z, 5sp, stock 305, Edelbrock intake, GTA wheels

 

My '84 Z28 T-5 had gear oil in it also...
I thought only WC T-5's used ATF?

 

zslug, I'm thinking it was just ignorance. The tranny mount wasn't bolted to the trans, there were only 3bolts holding the bellhousing to the motor, the wiring under the dash looked like a rat's nest. In general, the guy had a lot of half-baked stuff that he did.

I guess while I have it open, I'll look at it real close for any scoring or bad teeth or stuff like that.

My present T5 (non w/c) is an 87, so that uses motor oil. I think I'll use a 50/50 blend of mineral and synthetic ATF's inthe new one.

[This message has been edited by plain82 (edited October 20, 2001).]

 

Gear oil will eat the synchros in a WC T5, so definitely drain it and use ATF only.

------------------
1991 Camaro Z28
5.7L 5-Speed (originally 305)
317 RWHP, 418 RWTQ
13.23 @ 107.62 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Member: SoCal F-Bodies
-=ICON Motorsports=-

 

Camaroman, that info was according to Haynes, so I didn't take it as absolute Gospel. Before I did anything, I asked the Chevy dealer service dept. who verified ATF in my '84 is correct.

------------------
Zslug

May the road rise to meet your treads...

'84Z, 5sp, stock 305, Edelbrock intake, GTA wheels

 

That's odd. My 84 T5 absolutly hates ATF. It will grind the 2-3 and 3-4 almost everytime. I switched to gear oil and now it shifts as smooth as glass.

EDIT: IIRC the GM service manual states that gear oil should be used in 86 T5s (still not WC) but I am not 100% sure.

Dale

------------------
1986 FireBird
2.8L MPFI
1/2 CAI
Gutted Cat, No muffler
Was 700-R4 --> Now T5
**** Great cars aren't bought, they're built ****

[This message has been edited by 86Chicken (edited October 22, 2001).]

 

Plain82, here comes my paranoid side again...
Given all the screwed-up stuff in that area, transmount, bellhousing, etc., are you sure you got what you think you got?

Since I'm going to be doing this myself sometime in the not-too-faroff, how does one tell T-5s apart, W/C vs. non-W/C?
And while I'm at it, are ratios the same?

------------------
Zslug

May the road rise to meet your treads...

'84Z, 5sp, stock 305, Edelbrock intake, GTA wheels

 

I checked the tag on the tailhousing bolt, the number is 13 52 176. It also has the bearing on the face, down and to the left of the input shaft, says TIMKEN on it.

Go to www.5speeds.com and click on T5 on the left side. At the bottom is a place to look up tag numbers for T5's. That way you know what it actually came out of.

Edit: They also have a forum where you can ask questions. Not just about T5's either.

[This message has been edited by plain82 (edited October 22, 2001).]

 

Thanks for that link!

------------------
Zslug

May the road rise to meet your treads...

'84Z, 5sp, stock 305, Edelbrock intake, GTA wheels

 

n/p. It comes in handy.

 

I used redline gear oil in mine for 20000 miles. my synchros never felt better

------------------
1991 Firebird
350 L98 (was a 305 TBI),T-5,Edelbrock TES and cat back,Accel manifold
NOS,subframes,jegster torque arm,MSD Digital 6
AFPR,Lakewood lcas
Hurst linelock,SLP cam (206 212 .480 .486),relocated battery,cold air,Hypertech chip,centerforce df,clutch
poly bushings and mounts
AFR 190s
Harland sharp 1.5 rockers
autopower rollbar

12.33 @ 114.83 juiced uncorrected

13.510 @ 102 non juiced uncorrected

 

The WC T5 were first available in '88. There is a casting date on the housing, forget exactly where,but one on each housing. Borg-Warner would have supplied some in '87 for the '88 production year. If unsure, remove the shifting fork cover to inspect the guts. I recommend anyone buying a used T5, to have a quick look inside. Their weakest link, in my opinion, is the input/mainshaft bearing. Especially if thicker oil is used, as it is dificult to get lube in there to begin with. What was Borg-Warner thinking when they used loose needle bearings on fixed races? Almost every T5 I've had apart, has spalling (extreme pitting) on the races(bearing surfaces). The life of those shafts was limited. I am working on a mod to repair and reuse the damaged shafts, and will post the info. 1st gear being the strongest, after 4th ofcourse. 3rd is the weakest as the teeth are the thinnest and the main/counter shaft tend to spread with the torque. I've seen every tooth shear off flush to the gear base,on both 3rd gears. Back on topic... The WC will have carbon fiber syncros, with steel dog teeth, also much stronger than brass. The gears themselves are also much stronger in the '91, '92, years. The evolution of strength was similar to the 700r4. The T5 needs a thinner fluid to lube in the tight places/clearances. I don't like ATF. Try taking a bit between your thumb and forefinger to test the film strength. It sucks! The best thing you can do is to use a synthetic type ATF or a similar fluid. There is a company called SWEPCO. I was at a tranny shop once, and the Swepco rep showed up and I started chatting him up about different fluids. He had an ATF and Swepco ATF sample. I was really impressed with the synthetic or whatever it was, I couldn't really break the film with fingers, yet it was thin!! I have no affiliation with Swepco... They do provide Porsche with the fluid to use in their transaxles, I think they use them exclusively, and have not had problems since. I'm not saying these guys are the best, but do some research to get that regular ATF out of your T5!! Especially if you're running lots of power. This ended up being a little longer than I wanted,but hopefully it will help a couple people with the endurance of their T5. Ta...