v8 auto box-slight clunk on downshift

phil said:
I have found my car clunks at very low speeds for example if I take my foot off the throttle at less than 25mph it goes into third with a clunk.. Is this avoidable?
Click to expand...

If you release the throttle fully to prompt the upshift, you shouldn't get a clonk. I'd look for a cause in the drivetrain such as worn u/j's or diff mountings, especially if you have a similar clonk when engaging DRIVE or REVERSE. If you don't find anything there then look to see if the kickdown cable is sticking, which would keep the pressures artificially high when you are lifting off.
You really need to get it test driven by someone who knows the boxes, or trawl through the roadtest procedure in the WM, but even that won't help you if you don't know what you're looking for.
 
adjusted kickdown to instructions given by people here and a gearbosx specialist
he reckons its got a pressure valve fault,,
started clunking on up changes now--bummox :(
 
Well if you've come to the end of what you are able to do yourself you need to get it roadtested by someone who knows what they are looking at/for.
 
harveyp6 said:
phil said:
I have found my car clunks at very low speeds for example if I take my foot off the throttle at less than 25mph it goes into third with a clunk.. Is this avoidable?
Click to expand...

If you release the throttle fully to prompt the upshift, you shouldn't get a clonk. I'd look for a cause in the drivetrain such as worn u/j's or diff mountings, especially if you have a similar clonk when engaging DRIVE or REVERSE. If you don't find anything there then look to see if the kickdown cable is sticking, which would keep the pressures artificially high when you are lifting off.
You really need to get it test driven by someone who knows the boxes, or trawl through the roadtest procedure in the WM, but even that won't help you if you don't know what you're looking for.
Click to expand...

I found the two 1/2 inch bolts on the diff mounting were loose. That has 99% cured it. I know I need throttle shaft bushes too which I think, once replaced will cure.

Cheers.
 
A good result then. Poor old BW35 getting all the flack when all the time it was those naughty diff mounts!
 
well................
my diff mounts are good,uj joints are good
looks like my box is fubar-
got a 76k mile one in staorage-fluid nis clean-is it worth chuckin it in?????
 
If the problem is only the clunk on the downshift you should be able to adjust the kickdown cable to cure it. (See "stina"s thread, she has similar problems, and all the info needed to cure it is there.)

Autoboxes don't like prolonged periods of storage, so fitting a used one could see you with more problems than you have already.
 
Brook, just a thought, my throttle shaft bushes are missing. I have been trying, unsuccessfully to order replacements but as I am struggling to do so I cut some petrol hose and slipped it over the shaft through the support brackets. Now I can take my foot off the throttle as merrily as I like and the clunk has gone. It used to let out an almighty clunk as it selected third. I am referring to the shaft that goes directly onto the left hand carburettor. My shaft was very wobbly.
 
everything seems ok
guess the box is "cabbaged"
ill have to fit the box from the other v8...
its gave enough bits for my car already,,mite as well use the box too
 
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