80 series drivetrain clunking.

Brett, i have a 95 80 series 4.5L auto and it has the same clunk every now nd then. In the autos it is apparently worse than the manuals. I have spoken to a 4x4 mechanic about this and it is common on the 80 series, as to a fix i don't know.

Brad.

Brett,

Have a look at the uni's. Also the play in the spline of the front and rear tail shaft. These will have to be removed to check properly.

Wayne

Hi Brett
The most common cause of excess backlash is the front c/v joints and more correctly, the drive plates that the c/v drives on the outside of the hub.
To check them, you only need to remove the dust caps in the middle of the front wheels and look for movement forward and bakward in the spline of each.
When this wear gets bad enough, drive will be lost altogether.
Now, the 80 series constants were never too good with backlash, so use this as a guide only...they might be ok
Manuals are far worse than autos, as autos always keep the torque forward when changing gears....when you change gears in manuals, you can sometimes let off to early and get the backlash wip happening.....
Check out the tech pages of this site
www.lcool.org

i have a 92 model with the same sort of noise i am geting the cv jionts done on thursday and new hubs i will let you know if it is fixed on friday


geoff

G'day Big Woody,
I have a '92 model 80. I have a similar noise and the symptoms are the same, rapid jabs on and off the throttle induces loud scary sounding clunks.

I went to a number of transmission and driveline "specialists" and they all insisted 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. (not too sure of the full technical blurb) but apparently when going in a straight line, the slack is not important as both front wheels are travelling at the same speed in the same direction.

Now, when cornering, and the tighter the corner the bigger the affect, the wheels are turning at different rates. Again Diffs are designed for this, but apparently there needs to be a little give somewhere to allow for the marginal difference in rotational speeds. Without the give, the diff would want to keep driving the wjeels at the same speed and hence force the car to want to keep going in a straight line.

This all may be just a lot of well rehearsed waffle, but as it has been repeated in much the same words on 3 different occasions by 3 independant 'spurts, I have a tendancy to go along with it. When I asked if it was something I should be worried about, the unequivocable response was nah mate, I've heard worse than this and it still wasn't a problem. Which keeps catching me by surprise because my concern over being stranded can quite easily be converted to easy cash by them.

This was all 40,000 k's ago and the clunks are still there, no worse and no better. Am interested in others experiences though as I would hate to be misinformed and be out in the middle of no-where with something broken and the prospect of expensive towing.

cheers

Peter

driveline lash is common on most full time 4wd vehicles when they have done some km. Centre diff seems to be a large component.

Mine even has it on a part time 4wd system, but it has done a 'few' km now.

dave

how u doing brett
i have had the work done [ c.v joints front hubs wheel bearings swivel housings and replace front drive flanges] a lot of work and cost me $1400 Im happy and some what relieved to say its fixed its always a worry to pay so much money and its no better. Im heading to the otway rangers in the morning to give it a good test theirs been plenty of rain down this way im in warrnambool [vic] hope ive been a bit of help to you
cheers
geoff