hi all: When I slow to a stop and drop down to first gear I get a clunking noise in the rear end. I'm not sure if it's a u joint or something worse. Any suggestions would be greatly appreciated. '85 XJ6

 

check all rear suspension bushings, and the transmission mounts, there's two, one on each side of the transmission.

 

Also, release the transmission kickdown cable about 1/2 a turn. If it is just that bit too tight the trans will cause a "clunk" as it goes into 1st gear on the over-run.

The 4 bolts that hold the centre section (some call it the pumpkin) in place are known to loosen with age. Access is NOT good, but with patience is do-able, and they WILL cause a clunk, but it is usually on take up as well as backoff.

Centre bearing worn, however a vibration is usually an associated feeling.

 

what centre bearing Francis? do you have a drawing?

 

Item #6

Tandem Propshaft - Parts For Series III Saloon | Jaguar Heritage Parts UK

Cheers
DD

 

All great suggestions so far .

What's your idle speed? If too high you'll get a downshift clunk as you roll to a stop.

How many miles on the car?

With miles you can get a 'stack up' of wear-induced free play in the transmission output section, driveshaft splines, and differential. Not necessarily anything to worry about but it *can* make for some clunks. The fact that the old BW trans is not known for being glass smooth contributes.


Cheers
DD

 

Doug:


Not like the Dynaflows of decades past, huh?


Carl

 

Nope



Cheers
DD

 

By releasing, do you mean shortening or lengthening the outer cable?

 

Shorten, as in turn the nuts "clockwise", so 3 flats = 1/2 turn in my language.

 

U-joints can be tested by; at a stop go forward a few feet then backward a few feet. a couple times. If there is a clunk at the beginning of each then it's a u-joint. if not then chances of u-joint are slim to none. This works about 95% of the time.

 

How does this method differentiate the U-joints from any of the other things, mentioned above, that can cause a clunk?

Cheers
DD

 

I would think that it would narrow it down. if a bolt got loose then it would usually only be noticable in one or the other way. the u-joint souds both ways. like I said.. most of the time... there are exceptions of coarse.

 

idle speed 5 in gear 8 to9 at idle tried the u joint test it passed. ill have to get under it to check bushings and mounts