CHEVY GETRAG 290 TRANS HELP!!

[Lonepit]

I got a 91 K2500 4x4 with a getrag 290, and funny thing is i work at a parts store and i cant find which fluid to put into the trans and i even called the dealer and they dont know as well.. Ive heard from ATF which makes it whine and then 80-90, then manual trans 10-30, so which sounds the best to you guys?? I was gonna spend the money and drop in some Royal Purple Max-Gear 75w-90.. But i dont wanna waste the money if i shouldnt use it.... Little help would be awesome..... Considering i wanna play with it and take her in the mud soon.. and its gonna be my DD... Thanks Guys!!!

[Bo Duke]

They take Syncromesh fluid, its about 8 bucks a quart for I think penzoil brand at Oreily's...... I'll be rebuilding my 290 here soon, makes a lil noise and my reverse lights only work when I load the trans.

[Bo Duke]

They take Syncromesh fluid, its about 8 bucks a quart for I think penzoil brand at Oreily's...... I'll be rebuilding my 290 here soon, makes a lil noise and my reverse lights only work when I load the trans.

Ohhh and dont use a regular gear oil, the 1-2 syncro blocker ring isnt a normal brass blocker ring its actually a cone shaped ring with clutch material on it. 

[Lonepit]

ok Bo Duke, thanks man i appreciate it. Its just about ready to go lol.

[Bo Duke]

ok Bo Duke, thanks man i appreciate it. Its just about ready to go lol.

I hope not, I dont have the money for the rebuild kit yet.  Plus the T-case needs a chain to, so im looking at about 500 bucks in rebuild kits and a chain and one really long weekend....

[Lonepit]

well if you werent so far away i could help with the saving money part. i work at an auto parts store so i get parts pretty cheap.. and which tcase do you got? The 241c?

[RIP_K52007]

Tricky one to answer... its on the borderline year just like my s10 is. The Borg Warner T5 in my truck has T5 non world class that takes just ATF, and a T5 world class that you have to use syncromesh in. The syncromesh won't hurt the older trans but running ATF in the newer one will destroy it.
If you work at a parts store you should beable to get royal purple syncromesh for about $13 a quart it takes 2-3 to fill up a T5. Or you can go to a dealership and pay around $30 a quart. upto you. lol

[Lonepit]

Yeah just threw some royal purple syncromesh in it. Then had to go and run it at rizzos. Its in a few of the youtube vids from carwarz..