I have an 1989 T5 gearbox from an 89 Chevy S10. I've just repaired it an need it filling with the correct grade of oil. It's a Non World Class transmission and I am getting loads of conflicting advice on what Oil I should use.
Is there any help out there?
ATF.
I've owned a '89 GM T5 in the past - the case had an OEM lube decal affixed that specified ATF
https://forums.hybridz.org/topic/17575-borg-warner-t5-recommended-fluid/
Good info for future searches that talks about some differences and reasons for the ATF.
I've done a little more research today. Looks like that when early T5's came out they werefilled with gear oil, but it would seem that since the late 80's the manuals for both NWC and WC state ATF to DexronII.
I'm a little worried about the brass synchro rings because my 1st ring was worn to excess which contributed to the 1-2 sliding gear reverse splines getting damaged meaning I kept throwing 1st. So I want a GL4 spec which is better for brass syncros, GL4 spec is used in gear oil but not in ATF.
I did however find a Redline product called D4 ATF, which meets and exceeds DexronII and provides a GL-4 level of gear protection. Even quoting suitable for T5 transmissions.
Unless I find anything more suitable in the coming days I will be giving this a go.
Quote....1989 T5 gearbox from an 89 Chevy S10. It's a Non World Class transmission..
...so it's a NWC....so, it's not an '89 xsmn?
"GM started using WC boxes as early as 1988 in the Camaro / Firebird line but still kept NWC boxes in S-10's and Astro Vans. By the mid 1990's most of the GM T5 installations were all World Class."
https://www.5speeds.com/t5/