Hot Rods What fluid for S-10 T-5?

Like the ***le says, I've read 70 weight and I've heard automatic transmission fluid. Which is correct?

 

put atf in mine...

 

Dextron/mercon (spelling?) is what the computer told me to put in my T-5 from a Mustang, though I don't know if the S10 is different or not? I went to Kragens and they checked it in their system and it says which kind of **** to use.

 

ATF is for the "World Cl***" T-5's that came behind V-8's. The others used gear oil.

 

I ran ATF in mine. 30,000 miles....never had a problem.

 

You guys are confusing me.....

 

I believe that is correct but would have to check.

I did some search and there seems to be some controversy as to which fluid goes in which year model of transmission and if it is an nwc or wc transmission.

It might be worth it to figure out what year and model of trans you have and go ask at the Chev garage closest to you which goes in it.

If you put gear oil in one that requires atf you will probably looking for a new trans before long. Model Id info here http://www.flatheadv8.org/t5-swap.htm

 

World Cl*** was the stronger T5, made after '86 or so. I had a non-world cl*** in an OT car and it still spec'd ATF

 

My S-10 T5 had ATF in it when I bought it so thats what I refilled it with. Got about 1,800 miles on it behind my 350 and it's still in one piece

 

Which T5 do you have? Non world cl*** or a world cl***.

 

Non-world cl***. S-10 with a mechanical speedo.

 

Here is a clip from Ernie's post on T5's:

[SIZE=+1]Oil[/SIZE][SIZE=+1][/SIZE]
[SIZE=+1]All NWC T-5 use 70WT Gear Oil or Redline MTL.
ALL WC T-5 use ATF.
Do not use gear oil in a WC T-5. Use a quality synthetic oil (regardless of which type you need to use) & change it frequently (every 15-20K). Fill to the fill plug – about 5-1/2 pints or 2-1/2 quarts[/SIZE]

 

A tech at a big trans rebuilder and parts shop in OR told me "do yourself a favor and use a good 10w30 motor oil".
Because prevention is so difficult to prove I can't tell you if the 10w30 I put in mine is doing me (or him) a favor.

 

for the last freakin' time, ALL GM T5's spec ATF, and all but the first year of Mustangs spec ATF. All you guys have to do is look at a shop manual or call the dealership, or go to a parts store if you want more info.

It would be best to run a Dextron compatable synthetic ATF like Syncromesh. It runs quieter and shifts smoother.
http://www.summitracing.com/parts/NAL-12345349/

 

Good, aftermarket MTF will do you wonders. I've used it all. Pennzoil Synchromesh, RP, Redline, Amsoil, I've ran it, and never had any complaints.

For the record, the T5 in my Sonoma has Pennzoil Synchromesh in it right now with almost 10K miles on it. And actually helped alleviate the rough second gear synchro issue it had.

 

Definitely ATF, some of the blocking rings use glued on clutch material.

 

What did it have in it when you looked inside it? Mine is a non-world cl*** T-5 but when I pulled it out of the S-10 blazer it had ATF in it. I put it back together with ATF. You should be able to tell what it had in it from the factory just by the smell if it's empty now. Gear oil has a distinctive smell unlike ATF.

 

REALLY BAD idea - motor oils do not have the correct polymer's for the shear strength that is needed in transmissions. Not a good suggestion.

 

I run a NWC T-5 It was built by long time Trans builder, Richie Mulligan of Streetwise Perfomance N.J ...........He insisted on 70W gear oil. I went with Redline MTL as outlined here at Modern Driveline (70w is not easy to find) at least around here..................scroll to the bottom of the page. http://www.moderndriveline.com/Technical_Bits/t5_history.htm You can tell which trans you have by looking at the bearing race (read the tech bit on the same page.

Note: Do not use Royal Purple 75/90 apparently it eats br***..................not good for the Synchros !!!

 

I have an 1989 S10 that I bought new and still have it. I had shifting problems when new and the dealer said to use syncro shift which they sold in the parts dept. I put it in and with 2 changes of this stuff everything is PERFECT!! 175,000 miles later. And I do speed shift it once in a while . If U need a part # let me know JB

 

The early NWC T5 specified 70wt gear oil, but everything since, including NWC, has been ATF. I used to adhere to the gear oil in NWC religiously, but for a few years now, I've run Synthetic ATF in everything and don't have any issues.

I've heard of folks running just about anything you can think of and get away with it...

 

IIRC some gear lubes have chlorine in them.