For the stick shift guys-ATF or Gear oil

[5speed91]

I bought a 1991 Chevrolet Silverado ext cab 1500 2WD with short bed. 5.0L (LO3) TBI V8 and a 5 speed. All the research i have done so far shows there were 4 manual transmissions available in 1991. 2 were four speeds and 2 were five speeds. Im guessing the 4 speeds came in the old body crew cab/one tons in 91. Does anybody else have a similar truck and know which 5 speed transmission it is. The first gear is not a "granny". shifter says 1,2,3,4,Overdrive

Also can you just use any GL5 gear oil such as 75W90 in the transmission or do they use ATF like alot of the newer manual transmissions. Thanks in advance. This looks like a great site!

 

[Tempted]

Look at the owners manual but I think it uses ATF.

 

[5speed91]

I don't have one. But your right, better to be safe than sorry. Ill see if I can buy and owners manual on Ebay.

 

[bluex]

It should be an nv3500 and will use syncromesh for fluid. You can get it at any dealership or get the penzoil brand at advance or auto zone

Also instead of buying a manual just call the dealership parts dept with the last 8 digits of your vin and they can tell you what it needs....

 

[bowtie-till-i-die]

I believe ATF in the newer trans like 4L60E, but gear oil in the older 700r4

 

[5speed91]

Thanks!

 

[Tempted]

I just snapped this from my owners manual. Picture is fuzzy but you can still make out what it says.

You must be registered for see images attach

 

[MOBS]

Yerp, it's the GM Synchromesh....AMSoil has some that's perfect for it....but you better haz a deep wallet there boi!!!

 

[Tempted]

Is the NV3500 all helical or only 1st?

 

[woody80z28]

You can get GM Syncromesh from Summit cheaper than GM. Pennzoil also has an equivalent for cheaper.

I put the Amsoil nv4500 stuff in mine, but havent heard of a Syncromesh type by Amsoil for the nv3500.