Defender 90 brake and axle/transfer box problems

[DORISD90]

Hi,

I have a 1994 Defender 90 and a few days back I heard grinding, clunking, knocking noises coming from the rear of the truck. My guess is it's the rear axle maybe the diff or else the transfer box. The noises are not constant but quite regular. The grinding noise doesnt happen that often but the clunking and knocking noises are quite regular. I don't know what the problem is but need to get it sorted.

The noises happen when driving at any speed. The truck feels fine to drive with no notable decrease in power, speed, acceleratiion or handling. The gearbox feels fine with no problems. I havn't tryed to put it into low box or lock the diff since the noises happened as I fear doing more damage. There is some oil leaking from where the propshaft meets the rear axle.

The brakes have also had problems since the noises began. Generally, as you know, when you press the brake pedal it is firm. However, around the same time the noises began the brake pedal has not been firm and the pedal almost hits the floor and on occasion has. They are obviously not as effective but have not completely failed. when I'm driving and have to press the brake pedal sometimes it's fine and feels as normal and then a few minutes later you press the brakes and the pedal hits the floor. Don't know what problem is or whether it has anything to do with the noises I'm hearing.

Thanks for any help you can offer. If anyone has any questions please let me know. Sorry if the description is a bit vague but as I dont know what the problem is I don't know whats relevant and whats not.

Thanks again.

Andrew

[Briarston]

Loose wheel bearings causing brake pad "knock back" perhaps?

[Aragorn]

The brake symptoms are characteristic of loose wheel bearings, only takes a few minutes to jack the rear axle and have a wiggle at each wheel to see if theres any play.

[Mo Murphy]

Certainly a disintegrating wheel bearing. Not safe to drive as broken bits of bearing can lock the hub and stub axle together giving rather entertaining handling Expect to have to replace the stub axle too if the bearings have broken up.

My experience is that when one goes, the other on the axle isn't far behind.

HTH

Mo

[DORISD90]

Thanks for that.

Never thought of the wheel bearings so they'll be checked and hopefully that will sort the problem.

Mo, I think I'v expierienced that "entertaining handling" your talking about but luckily I was only doing 30kph and there was no traffic coming against me. I put it down to a faulty steering box though because the one in it is leaking oil by the gallon. Have a new one in the garage now so will have some fun fitting it at the weekend.

Thanks again

[Mo Murphy]

Good luck, enjoy

Mo

[Chrissyg]

I don't suppose you've checked the rear A-frame balljoint have you?

[Defender]

Might also be worth checking the rear diff as if the pin is broken this could cause a knocking noise as the two halfs of the pin fly outwards and knock against the casing.

The brake issue may be unrelated to the problem at the rear check the servo to see if it's cracked, tends to crack around the triangular bit where the bolts are, if air is getting in then the servo will be less effective but depending on whether the crack is open or closed (possibly heat or how hard you hit the pedal) may explain why it's intermittent. On the other hand I may be completely wrong but as you only need to open the bonnet to check its an easy one. If it is cracked as a temporray test you could use silicone sealer to fill the gap let it dry and if it works ok replace the servo.

[Hybrid_From_Hell]

Might also be worth checking the rear diff as if the pin is broken this could cause a knocking noise as the two halfs of the pin fly outwards and knock against the casing.

if the pin was broken the drive would fail at rear axle with c diff open

Nige