Landcruiser Drivetrain Backlash

chris.f, Dec 21, 9:47am
A friend has a '94 80 series manual and coming on and off the throttle results in loud sounding clunks from drivetrain backlash.

When under the caryou can rotate the front driveshaft about an inch, in both directions and this is what I think is causing the clunk. UJ's are tight.

A number of transmission and driveline "specialists" haveinsisted this was normal for the fulltime 4wd especially in the cruisers. It is backlash in the front diff which is the cause. The backlash can be removed, however what it then does is wind up the front diff to a point where it will want to keep driving in a straight line.

As the advice has been repeated in much the same words on 3 different occasions by 3 independent 'experts", I have a tendency to go along with it. When I asked if it was something I should be worried about, the unequivocal response was nah mate, I've heard worse than this and it still wasn't a problem.

Am interested in others experiences though as I would hate to be misinformed.

a.woodrow, Dec 21, 10:15am
I would check that the splines on the ends of the front cvs are ok and where they slide through the hub isn't worn. Have struck this many times and they can contribute to the clunk considerably. I have seen a couple get so bad that the cv ended up spinning in the hub!

carmad50, Dec 21, 10:30am
autohubs bud they have 2 springs ones out ve alignment hitting the spline as it turns , had this on my terrano , pull the shafts check the end bearing shud be a dry bearing with grease inside itbrass or copper worn other maybe cause or cvs as above

andrewph, Dec 21, 10:34am
Yes they do make some noise on deceleration. Try taking the rear driveshaft off and check the nut on the pinion and the flange on the box as they can wear on the splines and the flange and nut comes loose on the shaft. Check the sliding joint for rotational movement. This can be done by putting the shaft in a vice gently and trying to rotate the other shaft with a pipe wrench or polygrips. Good luck

gadgit3, Dec 21, 6:12pm
Front cv spline and drive flange it goes into. We replace them a lot to reduce the backlash in 80 series.

bwg11, Dec 21, 8:40pm
Very common. Before buying, I test drove three. They all had the on throttle - off throtle "clunk" to a greater or lesser extent. I bought one at 31,000 kms and ran it to 110,000 kms and over that period the "clunk" never changed.

chris.f, Dec 21, 10:37pm
Thanks for you opinions/advice people. If it is a "problem" then it hasn't got worse, so maybe it is more normal than I thought. We'll check and monitor. Cheers