Slight clunk under floor
 

Getting a small clunk on my 75 diesel almost under my feet or around the accelerator pedal assembly.
Car drives fine, no clunk, knocks etc when driving, even quiet over speed bumps
Before everyone says it’s worn lower wishbone bushes or lower engine mount, just done both thinking it was one of those but the issue still remains
The issue seems to occur when decelerating and the auto is coming back down through the gears and you feel a small clunk in the floor area.
Dosn’t seem to have any relationship when braking nor when accelerating just when there is some sort of torque on the motor changing back down
I have also replaced the hydramount and top engine mount a few months ago so they should be fine?
Ideas ?

Exhaust hangers getting a bit tired?

Hi, change ATF perhaps..

The auto appears to be working fine, changes all smooth, fluid changed a couple of months ago.
As said, i only feel the small clunk in the floor pan area when the auto is going down back into second gear (decelerating)
Fine when taking off and accelerating and braking.
As for exhaust brackets, I’ll have a look, that is a good point to look at .

Had that myself, the exhaust dropped just enough to bring the tunnel cross braces within range of normal movement.

This would be my bet too

Got the car up on ramps today, had a look at the exhaust hangers, all seemed fine, plenty of clearance all around the heat shield , cross braces, rubbers looked fine etc.
Checked steering rack , all tight.
Think the only way I might be able to see what’s going on would be up on a hoist
and start the engine, foot on brake and shift from park to drive and have someone underneath.
Unfortunately I don’t have a hoist so unless the tiny noise gets worse probably not worth the effort !!
Only thing that has a bit of give in it is the flexible joint before the cat but looked fine.

Took the car to a local suspension specialist re the slight noise on braking and take off and they could not locate the source of the noise.
Everything they tested seemed fine.
There suggestion was to see if it gets worse as the car is driving fine and nothing obvious seems worn. Gotta love these cars little quirks !!

Still had the small clunk on acceleration and deceleration.
Taken to my local mechanic who reckons they have traced it to tge hydramount.
I stated i had put a new one in under 12 months ago so should be ok.
No sign of any leakage ftom the hydramount and the rubber looks fine but ive asked them to have a look anyway.
Im wondering if it has worked loose and on the diesels theres an aluminium spacer which sits under the mount and lifts the mount up so it fits the duesel engine.
Hoping that the spacer might have worked loose and is moving?

Sounds like it could be in the drive train somewhere, drive shaft, CV joint? Do they have a bearing supporting the os drive shaft?