Judder on Takeoff/ Driveshaft Carrier Bearing/ Mounts

[ngoma]

Trying to troubleshoot a judder in reverse (M46).

Some is probably attributable to the cracked front crossmember but I just checked the driveshaft and found the center carrier looked suspect. Isn't that rubber collar supposed to be further forward? Set into the bearing sleeve?

Also, the driveshaft appeared to be able to move too easily in the center carrier. Should I be able to move the driveshaft around there with finger pressure?

(photos from the rear)

[745 TurboGreasel]

They are supposed to be soft, I tried shimming one up solid, and almost broke teeth on the test drive it vibrated so bad.

[anders]

I would check the rear axle bushings. Really worn bushings would cause a shudder.

[BKelly]

Just as stated above, the bushing should be soft to the touch. The drive shaft should move around in the bushing, almost like there is to much play in it. There should also be a spring in the bushing.

[ngoma]

Made good progress in solving reverse judder (M46).

Removed driveshaft to replace suspected center U-joint. BUT: U-joints tested good. Smooth movement, no binding, no play, so I removed the plugs and greased them (temporarily installing 1/4" x 28 zerk fittings), and reinstalled driveshaft.

Rear of car appears to sag, springs look tired. Rear spring replacement planned for the future. Meantime I raised the position of the center bearing carrier 1/4" by inserting three 5/16" washers per side, between the chassis bracket and the brg carrier, bolt thru.

This lessened the reverse judder by approx. 50%. Might try shimming more (for 1/2" total) but first want to try replacing the soft panhard rod bushing, and trans mount.

[745 TurboGreasel]

I spent a lot of time and energy fixing rear sag before I figured out my front springs were actually elongated.
If you park next to other similar cars,and your nose is consistently an inch or two higher, it's the front you need to work on.