Clunking noise while reversing

[bunsen Member Find all posts View Profile Close bunsen]

Sadly, our Manual 120 has developed a clunking sound while reversing. Yesterday it was apparently fine, but this morning as I was reversing out of the garage I heard this dreaded sound.

It increases in tempo the faster the car is travelling (in reverse). Going forwards there is no noise. Changing gears is normal, it's just when the car moves. In reverse, with the clutch in, there is no noise when the car is stationary. When in reverse moving backward is when the noise is heard (both clutch in and out).

In first, with the clutch in, rolling backwards, there is no sound.

Looking at the driveline, all looks normal to me. There's no play in any of the drive shafts.

Any ideas gurus?
:? :cry:

[Schaffer Addicted PP Member Find all posts View Profile Close Schaffer]

Re: Clunking noise while reversing

There are a lot of posts about this issue already. There are two possibilities from memory. One is that the car has been wet and the bang is the brake calipers releasing while the other is to do with the tailshaft and I believe Toyota just apply a shit load of grease to resolve.

[MDSimpson Advanced Member Find all posts View Profile Close MDSimpson]

Re: Clunking noise while reversing

If it is only when the car is moving backwards, could be brake pad wear indicators?

[bunsen Member Find all posts View Profile Close bunsen]

Re: Clunking noise while reversing

The noise is only apparent when the reverse gear is selected. If the car is rolling backwards, in any gear but reverse, there is no noise.

I have done a search on PradoPoint, and using Google, and the symptoms indicated in the other partially related threads are different.

I have taken the car to a few places and have spoken to a few mechanically minded friends, and it's sounding like a busted tooth on the reverse gear, or a bearing problem. I've had the gearbox oil flushed this morning, and no tooth came out, but there were fine metal particles in the oil.

[bunsen Member Find all posts View Profile Close bunsen]

Re: Clunking noise while reversing

It was a cracked tooth on the reverse gear.

Got the gear cluster replaced, a new heavy duty clutch and all the appropriate jobs done while the transmission was out.

[scojohara Junior Member Find all posts View Profile Close scojohara]

sorry to drag up an old post, but mine is doing the same thing this morning. Was fine yesterday and now has a clonk noise in reveres when the clutch is out. The noise changes with speed. When rolling backwards with the clutch in it makes no noise. Bunsen, how much did the replacement of the gear cluster cost you?
Scott

[znelbok Member Find all posts View Profile Close znelbok]

Check your Uni joints as well. When not under load they wont make much noise, load them up and they will. Cheaper the check them than pull apart the gearbox.

If you do end up replacing them, put in greasable uni's

[johna Member Find all posts View Profile Close johna]

Check your Uni joints as well. When not under load they wont make much noise, load them up and they will. Cheaper the check them than pull apart the gearbox.

If you do end up replacing them, put in greasable uni's

The uni joints on the 120 kzj have 4 grease nipples plus 1 more per tail shaft slide.....

[scojohara Junior Member Find all posts View Profile Close scojohara]

Thanks for the replies. I have greased the two nipples on each end of both tail shafts but missed the one on the slides. Will have a look tomorrow. I understand how loading up the joints will make noises but I am a little confused why if uni joints, why they only make noise in reverse?
Scott

Edit...........
I have just gone out to have a look at the car, I greased a nipple on each end of each tail shaft plus a slider. Mine doesn't seem to have any more that I can see.

[scojohara Junior Member Find all posts View Profile Close scojohara]

I found the culprit of the reversing noise yesterday (well Toyota did). The reverse gear was buggered but other internal gear box parts. The result is a gear box rebuild. I am not sure on the cause of the damage but a bit pleased it happened now and not in 3 weeks time on the way to or at cape york. Thanks for the replies.
Scott

[bunsen Member Find all posts View Profile Close bunsen]

Apologies for not replying sooner. I'm not on the forum much these days. Scott, I'm glad you found the cause of the issue. I was told that a primary cause of the cracked tooth was putting the tranny into reverse while still rolling forward. I can't for the life of me remember doing this, but the missus was a bit sheepish when I asked her!

My next drama is either a buggered throwout bearing, or rattling clutch fork? I can't say I've enjoyed the experience of having a manual?

[BBB Junior Member Find all posts View Profile Close BBB]

I echo your sentiments regarding having a manual. My vehicle slips out of reverse gear but only when reversing up a steep hill… just wondering if it could be a broken cluster too? How much did yours cost to rebuild or did you install a reconditioned gearbox?
I also have problems with my thrust plate bearing. There is another post on this forum which talks at great length about a defect with the Toyota cover sleeve which keeps failing…
Cheers
Bryan