Clunking Noise when I'm shifting

[kevboost7]

Recently, i noticed there is a clunking noise when i shift gears. It dosent matter which gear, but unless i match the revs perfectly, there is a clunk sound coming from the rear. For example, when i shift from 1 to 2, if i dont feather the throttle to match the revs perfectly, there is a clunk noise. What could this be? It didn't do this before. 

[GTSBoy]

It's called driveline lash and it could be caused by absolutely any mechanical connection in the driveline. Diff gears. tailshaft centre bearing, CV joints, driveshaft splines.

[BK]

To add to this list above it could also be the actual rear diff housing moving and clunking from stuffed rear diff bushes. Just had this on the white 32 - the forward horizontal rear diff bushes were worn and created and crazy clunk.

[blind_elk]

Stuffed diff bushes is also my preferred guess. Get some SuperPro urethane replacements (and have fun getting the diff out and back in!).

[kevboost7]

How would you diagnose this? I'm assuming put the car on jack stands? And how big of a job is it to replace the diff bushes? 

[Duncan]

Best to take it to a shop. Diff bushes are a pain in the arse to change, it can be easier to drop the whole subframe (one of those jobs you can't do on a quickjack....) They need to be cut or pressed out, and pressed back in again at the rear, the fronts are easier to get to. 

You should be able to diagnose diff bush issues by jacking up the car, supporting with stands and getting a big pry bar between the diff and the chassis...it should not move noticeably.

[BK]

Rear diff rear vertical mounts are the shittiest job ever if you dont remove the whole subframe. Rear diff front horizontal mounts are better and can be done on car.