5 speed fluid/oil advice needed

[theripperman]

I have a ’99 Sonoma, 2.2 with a 5 speed. It was used when I got it and I don’t have an owners manual. It’s getting close to 200K and I’d like to drain the tranny but I don’t know what to put back in it, anybody know what they are supposed to have in there? I never think to ask the parts store guys when I’m in there. Thanks.

[Barnes888]

hey, so the book says to use 2.9qts (2.75 litres) of "Gm 9985648 Synchromesh transmission fluid and 12380672 friction modifier"

but i'm pretty sure you can just get away with 75w90 gear oil.

[theripperman]

Thanks for those numbers. I didn't find anything on the second one with I did on the first one. Looks like it's a 5W30 weight oil.

http://www.amsoil.com/storefront/mtf.aspx

Found some Pennzoil too. It didn't give the weight, but it wasn't a synthetic either. I'll have to pick some up. Thanks again.

[brandon200317]

if your curious about the part numbers just bring them to a GM dealership and they can look them up for you. but no synchro mesh is not 75w90 nor would i recomend that in that transmission. if you had a borg warner in it istead of the nvg1500 tranny you'd be running auto tranny fluid in it i believe. but go to a dealership and get their input. they work with these vehicles on a regular basis

[JoeSonoma]

I just got a new rebuilt 5 speed GM tranny in my 1991 4.3L Sonoma -- it requires the special GM Synchromesh fluid (which is synthetic), and if you use anything else you will loose the lining on the syncos and, well, then you're in big trouble!

I know with some trannys you can use auto tranny fluid, but if the book says yours requires the Synchromesh fluid, DON'T use anything else.

Use the part number that Barnes888 posted to find the right fluid, if that fits your specific tranny. The brand name of fluid doesn't really matter, but it MUST be synthetic and MUST say "Synchromesh" and list the GM part number somewhere.

Let us know how it works out.