3.91 Diff noise after install

[Son of Marty]

How are the shifter mounting blocks, heat, oil and vibration tent to turn the rubber to goo after a while and the bolts to the trans case have been know to back out any of which will cause the shift tower to droop.

[2002iii]

Check your motor mounts they can throw the whole drivetrain alignment off.

 

Might need to use washers to adjust the height of the engine and/or transmission and/or center bearing. Make sure your driveshaft is level with transmission so it doesn't put stress on the guibo.

[Leucadian]

This seems like too many washers at the tranny mount?  I had the driveshaft rebuilt a few years ago, and I remember the mechanic saying that he thought the tranny was too low, so he added washers.  I never noticed until now.

 

Seems counterintuitive though, if the diff is higher, because of the new bushings, wouldn't I have to raise the tranny too to account for the higher diff?  I may pull half the washers and see if that helps.

 

 

And there is a very very small amount of clearance between guibo and selector rod, not sure about under load though.

 

Otherwise, shifter mounting blocks look fine.  

 

Edit: I also realized that when I replaced my radiator a couple years back (after the washers were installed) the engine was tipped too far forward, and I had to shave my radiator fan down so it would clear.  Couldn't figure out why at the time...now I know 

Edited December 5, 2021 by Leucadian

[Buckeye]

Is that 5 speed trans that you had installed? I ask because I see welded shifting arm. As mentioned above, check your engine mount. Replace them if age is unknown. make sure passenger engine mount limiter is set to specs. Then check/ replace trans mount. There is no reason to have multiple washers there. You may want to disconnect driveshaft to examine shifting arm and examine supporting blocks for shifting arm

[jgerock]

Please take another picture showing how compressed (or not) the foam donut is above the shifter platform. If the platform is too low, the shifter mechanism (“dog bone”) may contact the driveshaft, especially under acceleration.