I have a 96 3500 5 speed, It has 220K miles, I just bought it and didnt nitice this, when im in 5th gear its a little noisey compated to the other gears. also when your driving in 5th you let of the gas it gos thump, and get back on the gas tump again, i beleve theres a lot of play in the tranny,
Is it time for a rebulid or what??

 

sounds like a loose nut.... check this out

https://www.dieseltruckresource.com/...v4500+nut+weld

 

Do you thank so?? will that make it has all that shaft play??
fifth gear has some noise to it also. Mostly mesh noise, Non of the other gears have any noise,

The tranny has so much slop"" When i go to shift i push in the clutch and you can fell/ hear it thump. weird, any help is very very much app>

 

Here's a update, most of the play is coming from the rear end. The other 1/4 of the issue is the tranny, It moves about 3/8 to 1/2 inch ( tranny )
the rear ins is major! 2" probably