Okay, 1996 GMC K2500 what tranny fluid?

[partsman]

I have a 1996 GMC K2500 4X4 7.4 litre 454CI with the 4L80E tranny, can I use Transynd in this tranny? And is it tranny fluid in the transfer case and with the rear diff which is a posi from what I gather do I need to use an additive when I put in diff fluid?

 

[unDummy]

Yes, you can use transynd. Dexron6 or any fullsynth dex-spec'd ATF would be perfect. If the xfer case calls for ATF, then use any full synth DexronIII there. I don't think that I would use an ATF in a tranfer case with a BB Chevy. I'd consider a 75w80 GL4 MTF/MTL/mesh-type fluid, With a 14 year old rearend, your posi, if it hasn't been replaced or rebuilt, is probably tired. Fill it with the gear oil you want to use. If there is no chatter, then no additive is needed. If there is, then add an ounce or 2(as needed).

 

[Mike_dup1]

Keep in mind that Dexron VI is only backward compatible for use in Automatic Transmission ONLY. It should not used in manual transmissions or transfer cases. While Transynd may be used, its very expensive compared to regular and synthetic ATF's and usually only available in bulk (5-gal+), it would not be economical IMO. Transynd is for HD trucks who follow the Allison Extended service changes.

 

[Donald]

You can look up your vehicle on the Amsoil website and they will list an Amsoil fluid for your transmission, transfer case, diff. etc., along with capacities so you know how much to get. Of course they will all be Amsoil products if they make the proper fluid otherwise they will list the OEM fluid. But you cannot go wrong with Amsoil fluids.