Did 90' GMC have the SM465? I have a 90 GMC with Granny Low and have some back lash when I let off the gas. Wondering if it's the U joints or the tranny.

Thanks

Could be U joints, or the splined shaft inside the adapter that interconnects the tranny output shaft to the xfer case input shaft....
I don't think 90's had SM465's but I'm not completely sure....
Could be a NV4500 to a NP208...... :skull:

SM465's were offered up to and including 1991 models. Only way to be sure though is to get underneath it and have a look see.

There are a few sites that have pictures of SM465's and NV4500's so you can tell the difference. See AdvancedAdapters website.

Chris

Well let me think about this for a sec...:beer: :beer:
Ok If you have 5 foward gears it is a 4500.
Unless you shift gears from under the rig you should be able to tell sitting in the driver seat.
A 465 has 3 foward gears that are normaly used.
By back lash are you refering to a clunk?

OMG backlash in granny? That is way normal! Up until this year I've always had a 465 in my trucks, and backlash in Low is normal. That being said, you could have a worn drivesleeve, but I think in 1990 they didn't use the 10-spline one.

Squash