v8 disco auto clunk on downshift

Possibly misled? I'm not sure but do check the rear trailing arm bushings. I've heard this is a common problem.

Jack.

On or around Tue, 16 Sep 2003 11:40:45 +0100, "alanpbrown" enlightened us thusly:

check yer UJs in the propshafts, also check front axle.

The thing about cross-drilled gears most often applies to the LT77 type

5-speed manual, and also to early R380 5-speed manuals. Not sure if the same thing afflicts autos. Mine has the chain-driven transfer box from the Range Rover, so no info...

Like Austin says, I'd check the UJ's.

One of the problems with "clunks" is that they often come from somewhere completely unrelated to where they sound like they come from. If the UJ's are okay then I'd look at the suspension bushes before thinking about expensive bits like gearboxes.

AFAIK the ZF autobox does not suffer from the lack of lubrication problem associated with LT77 and R380 manual boxes - at least I've never heard of it with the ZF. There is a Land Rover Technical Bulletin for the manual boxes but I can't find anything for the ZF.

HTH Regards Steve G

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On or around Wed, 17 Sep 2003 16:22:17 GMT, "Richard" enlightened us thusly:

you ought to hear the 110.

most of the wear on mine is in the front axle; you can get some quite impressive clangs going from forward to reverse.

On or around Wed, 17 Sep 2003 20:12:18 GMT, SteveG enlightened us thusly:

all the oils are probably stiffer and damp things more. Including the oil in the axles.

There's quite a bit of slap in the Discovery drivetrain, no one place, just cumulative. Can the diffs be adjusted or somehow overhauled to take some of the play out? At 130K should I be thinking about replacing prop UJ's?

Tim Hobbs

'58 Series 2 '77 101FC Ambulance '95 Discovery V8i

On or around Wed, 17 Sep 2003 22:48:01 +0100, Tim Hobbs enlightened us thusly:

only if they're visibly slack.

The diff probably can be adjusted, in theory. There should be a defined setting for the CWP, normally done with shims. I was thinking about this the other day, WRT the 110 front axle, and whether to try and find a low mileage replacement or rebuild mine.

eliminate the gearbox as the clunk is not there with a small amount of hand brake applied thus slowing the rear prop earlier. With it applied fully at standstill there is no clunk at all going from D to R, all ujs are in good condition as is the sliding joint I haven't yet checked the A frame joint. Is it a case of a small amount of movement make lots of noise or am I looking for loads of play? Interestingly the clunk is not there when cold as noted in one of the replies,it has also been suggested that it could be spline wear on the halfshafts has anyone any experience of this?Also how common is it to get lots of play between the crown wheel an pinion the manual says between 0 .1-0.17mm ? I presume this is measured at the tooth and not at the outer edge of crown wheel . Thanks Alan

Ditto going into reverse on my 1988 3.5V8 RR currently showing 130K but with an Ashcroft refurbished autobox fitted approx. 15K ago. I have been told that it is wear on the i/p to the transfer box. I reduce it when engaging reverse by stopping at neutral, then taking my foor off the brakes for a few seconds and then re-applying them (hard) before enaging reverse.

It sometimes helps

Richard

Hi

I thought the clunk was normal? All auto's I've owned (including a 5 speed auto) have made this noise when changing quickly from D to R, or P to R. I usually go to N for a few seconds and then engage the relevant gear. It helps some times .......

Neil Founder

(Fun, Friendly and FREE)

On or around Mon, 22 Sep 2003 09:07:26 +0000 (UTC), "Neil Brownlee" enlightened us thusly:

auto) have made this noise when changing quickly from D to R, or P to R. I usually go to N for a few seconds and then engage the relevant gear. It helps some times .......

There's always *some* play in the transmission, and Landies have a lot more transmission to have play in it. Most often, play seems to be in the front end, where you have the following possibles:

splined joint in the propshaft, pinion/crownwheel clearance, planet and sun gear clearance in the diff, splined joint sun gear to inner half shaft, ditto half shaft to CV joint, play in the CV joint, splined joint between outer half shaft and hub driver.

in the back end, you lose 2 of those, viz. the one from the inner half shaft to the CV joint and the CV joint itself.

on older landies, you also don't always have the one at the hub end, depending on axle type.