Ferret erratic knocking from left hand side front.

[Grant Hopkins]

Sounds familiar, I had a bevel box go on my Ferret in the RH rear position. It started to clunk and got rapidly worse on the way back to park it, it even locked up a couple times and I had to move it in reverse briefly to unlock and continue ahead. I wouldn't recommend driving it until you figure out exactly what is wrong, it could become a very heavy and difficult to move roadblock.

[45jim]

Insect suspension ball joints, steering joints and wheel nuts to ensure tight and serviceable. If all OK, disconnect the driveshaft from the transfer box to the suspect bevel box. Drive the Ferret around a parking lot to see if the noise is related just to the suspect wheel station. If noise stops suspect u-joint on driveshaft or bearing on bevel box input or transfer box output or the transfer box itself. If still knocking from the wheel station you know your problem is the wheel station itself, remove the outer hub cover and remove the sun gear and replace the cover. Move the vehicle carefully in a straight line. The tracta joint and bevel box will be disengaged and should remain stationary. If the noise goes away your problem is there and you will have to remove the wheel station to further diagnose. If the noise is still there you will have to dig further into the hub itself as this may be a bearing failure or a broken gear in the reduction hub.

[Malcolm Towrie]

Originally Posted by 45jim

Insect suspension ball joints, steering joints and wheel nuts to ensure tight and serviceable. If all OK, disconnect the driveshaft from the transfer box to the suspect bevel box. Drive the Ferret around a parking lot to see if the noise is related just to the suspect wheel station. If noise stops suspect u-joint on driveshaft or bearing on bevel box input or transfer box output or the transfer box itself. If still knocking from the wheel station you know your problem is the wheel station itself, remove the outer hub cover and remove the sun gear and replace the cover. Move the vehicle carefully in a straight line. The tracta joint and bevel box will be disengaged and should remain stationary. If the noise goes away your problem is there and you will have to remove the wheel station to further diagnose. If the noise is still there you will have to dig further into the hub itself as this may be a bearing failure or a broken gear in the reduction hub.

Thanks, Jim. Good logical diagnosis. We've inspected brakes and suspension so far. All looks good.

Malcolm

[Robin Craig]

Malcolm the honest answer is I can not recall the sequence of noises during the failure.

As Jim said raise that side off the ground and you should quite quickly be able to diagnose the troublesome component by disconnecting various items in the drive train.

The cause of failure on the bevel box was a very nicely painted over breather for the bevel box. It had several layers of paint, it is something I warn about often and loudly to new and keen Ferret owners.

[Malcolm Towrie]

Robin,
Why would a plugged breather cause such a catastrophic failure?

Malcolm

[Richard Farrant]

Originally Posted by Malcolm Towrie

Robin,
Why would a plugged breather cause such a catastrophic failure?

Malcolm

Malcolm,
Failures are often due to lack of oil or low levels. With a blocked breather the pressure build up could force oil out of the bevelbox / inner tracta via the cork seal around the inner tracta housing, also it could well pass the seals in the challis and overfill the outer tracta and hub, seen this quite often. It pays to check the levels frequently.

[Robin Craig]

Malcolm,

Richard eloquently and precisely said what I would have replied.

[Malcolm Towrie]

Originally Posted by Grant Hopkins

Sounds familiar, I had a bevel box go on my Ferret in the RH rear position. It started to clunk and got rapidly worse on the way back to park it, it even locked up a couple times and I had to move it in reverse briefly to unlock and continue ahead. I wouldn't recommend driving it until you figure out exactly what is wrong, it could become a very heavy and difficult to move roadblock.

Grant, what had actually failed in the bevel box?

Malcolm