'08 Tahoe 4x4 Motor Mount Education

[donjetman]

So when you handled the front driveshaft you got movement or noise?

easy movement at the bushings of the front differential mounts.

 

[donjetman]

So when you handled the front driveshaft you got movement or noise?

twist the driveshafts back and forth to see how much slop is in the transfer case

 

[Geotrash]

Quick question...going in that way from the top/side, were you able to get to the two 10mm bolts that hold the cooler line block to the side of the pan above the filter without dropping the front driveshaft?

I replaced the cooler line gasket about a year ago and did it from underneath but I unbolted the front U joint and let the driveshaft rest on the swaybar.

This summer when I replace my cooler lines I plan on doing it like you did by removing the motor mount and I'll also be removing the exhaust manifold to remove the broken rear bolt.

Yes, I was. In fact I had to get a helicoil into one of the cooler line bolt holes from underneath, previously. Never dropped the front driveshaft.

 

[EddieC]

twist the driveshafts back and forth to see how much slop is in the transfer case

A bit confusing. I thought you were describing diagnosis of the differential mounts, not the transfer case.

 

[donjetman]

A bit confusing. I thought you were describing diagnosis of the differential mounts, not the transfer case.

with the front tires off the ground, get under the vehicle and pull/push up and down on the front pinion and see if there is any movement at the front differential mount bushings.

 

[EddieC]

Well, we've chased this sound around and finally found it. It is a suspension issue after all and not motor mount.
The sound changed from occasional to always when backing and braking and as a mild clunk.
Having someone watch the driver's side top control arm while doing that it turned out that the 20,000 mile old top control arm bushings had enough play to allow the bolts to move enough to make noise.
New control arm and no more noise.

 

[petethepug]

Nice follow up & follow through. Add Solved or Fixed to the title and watch the likes go crazy

 

[jrobie79]

The next task I'll do to reduce the clunk/klunk will be rebuilding the transfer case, a <$300 DIY job.

Have a writeup for this?

 

[donjetman]

Have a writeup for this?

No, I might tackle this project this summer if it floats to the top of my lists