Opinions please? Transmission issue or something else.

[Andrew1320]

I have a 1997 Z71. The issue I'm having is sometimes when the truck is in reverse and you start to reverse there is a loud hard thud followed by a high pitched grinding sound, throw it in park and it will stop. It doesn't do this everytime. People have told me its the sun shell in the trans. Going out. I looked that up and when that happens you completely lose reverse and 2 other gears. I have every single gear, reverse still works and when driving it shifts beautifully. Goes into every gear just fine. I have a parts truck I am getting tomorrow and the guy says it has a good trans. So I have a good one to swap in. I just want to get opinions and see if it actually is the transmission. Any and all help is appreciated. Thank you!

 

[poncho62]

I would check your "U" joints and transmission and engine mounts first.

 

[kennythewelder]

could be transmission, could be transfer case, or what Ponch62 said.

 

[Andrew1320]

Im ruling out mounts because of the grunding noise. Im kinda wandering if it isn't the Tcase trying to engage when it shouldn't. Anyway to check that?

 

[SkyHighColorado]

Wouldn't be t-case. The symptoms you describe point to the sunshell being cracked.