Rumble from the rear

[barker_001]

The Excel's rear, not mine!

While out on Sunday, I noticed a rumble from the rear of the car, which seemed to pulse at about the same speed as wheel rotation, and caused a noticeable vibration through the car. It only occurred at 70mph or slightly over that. I think I've felt the beginnings of this before, but it has always gone away after a mile or two at speed, as everything has warmed up. This time it didn't go away, so whatever is causing it is getting worse.

I am thinking wheel bearing(s) but wondered if if could be something else? Is there any way of confirming wear / damage in the wheel bearings without taking everything apart? The rear wheels were balanced fairly recently, and when I've experienced balance problems in the past, they have not had the same sound to accompany the vibration.

Changing the wheel bearings looks quite involved, has anyone done it at home with standard tools? Thanks for your thoughts...

[richardw]

Could well be wheel bearings. The rear bearings are not simple - they need to fit either side of a crush washer which is no longer available, with the correct preload. Lotusbits re-use the crush washers using shims to achieve the same preload. It is a question of torquing up the bearings then backing off a little, I think.

Cheers, Richard

[bash]

The nose bearing on the diff can give a similar rumble, one went on me that fooled me for a while.
Bash
Ps, having done both wheel bearings and a diff pinion they both a pain to do but doable at home. The wheel bearings will need you to have a big vice mounted to a very solid bench though.

[Pete Boole]

Wheel bearing noise tends not to pulse much. Have you checked the propshaft yet?

Pete

[bash]

When it comes to checking the rear wheel bearings the standard test of wobbling the wheel can show up play and of course spinning the wheel off the ground can reveal a noisy bearing, but when mine went I found that it showed more play when I took the driveshaft off and got someone else to wiggle the wheel while I looked at the inside of the bearing assembly. Check to see if there is any lift/play in the nose of the diff first, its easier to spot.
If you dont want to tackle either bearing I would strip the diff or rear hub off, cos thats just spannering, and take them to mike taylor cos they both can be a pain to do, that will save you some labour money.
Bash
You can still get the crush sleeves new from the States but mikes shim kits work just as well.
https://justdifferentials.com/7-5-toyot ... inion.html

[bash]

It could of course be the tyres they can develop faults, front to rear change just to see if the vibration disappears, it might make the steering feel odd cos tyres wear differently front to rear but it would eliminate another possibility.
Bash

[Marten]

The Excel's rear, not mine!

While out on Sunday, I noticed a rumble from the rear of the car, which seemed to pulse at about the same speed as wheel rotation, and caused a noticeable vibration through the car. It only occurred at 70mph or slightly over that. I think I've felt the beginnings of this before, but it has always gone away after a mile or two at speed, as everything has warmed up. This time it didn't go away, so whatever is causing it is getting worse.

I am thinking wheel bearing(s) but wondered if if could be something else? Is there any way of confirming wear / damage in the wheel bearings without taking everything apart? The rear wheels were balanced fairly recently, and when I've experienced balance problems in the past, they have not had the same sound to accompany the vibration.

check that the rims are straight, a they seem to be made out of cheese
check that the yokes of the propshaft are still in line, and that the rubber hasn't let go

[barker_001]

Thank you gents for your thoughts, lots of things to check there. Will try to get onto it this weekend.

Bash, I must admit I hadn't thought of uneven tyre wear, hopefully that's something easy to check by swapping them around. I had a Mazda 3 which used to "50p" the rear tyres quite rapidly, the sound was similar but more noticeable at low speed.

[AndrewWebber]

Maria and I hope it wasn't our fault from our lift to and back from the meal in the rear last year! Although the set up is of course a little different and different parts, I'm changing all of the bearings etc. in the Elite to hopefully solve my slight rumble. Should know if it has worked next month.....hope you get it sorted okay.

Andy

[bash]

I misdiagnosed my fatherinlaws skoda as a failing rear bearing when I drove his car, that was a tyre when it was examined.
Bash

[Tanz]

Bryan - I had exactly the same symptoms as you describe and thought it was wheel bearings. Felt like the rear wheel was shaped like a fifty pence piece. It wasn't constant - came and went. Turned out to be a sticking calliper - piston was seized. Changed callipers and discs as they were at minimum thickness and all is well now.

[barker_001]

Bryan - I had exactly the same symptoms as you describe and thought it was wheel bearings. Felt like the rear wheel was shaped like a fifty pence piece. It wasn't constant - came and went. Turned out to be a sticking calliper - piston was seized. Changed callipers and discs as they were at minimum thickness and all is well now.

Thank you - It's funny you should say that Phil, when I jacked the car up on Sunday the right hand rear wheel rotated quite freely, the left hand wheel rotated but the pads were dragging slightly on it. I didn't think it was excessive - I've felt worse in the past on other cars - but perhaps that's a contributing factor. Also I couldn't feel any play in the rear wheel bearings. I would far rather overhaul the calipers than change the wheel bearings, and I don't think they've ever been done.

[barker_001]

Problem solved...

Phil was right, the problem turned out to be quite badly seized rear calipers. My specialist, Andy at Qmech, commented that it was amazing that they worked at all, let alone passed the MOT...

I had bought overhaul kits and pistons previously, with the intention of overhauling the rear calipers myself, but as tends to happen with these things, never got round to it. So Andy and Chris overhauled the calipers and fitted braided hoses all round while the system was open. They also checked all the wheel bearings and brake runout, but found nothing else wrong. The time taken and hence the labour bill was somewhat more than expected. Andy commented that if he'd known they were that bad before disassembly, he would have suggested replacement calipers instead. When I checked afterwards, they are available for around £100 each. Worth remembering if you find yourself in a similar situation... But now there is no vibration or rumbling at motorway speeds, which is a good result.

Phil, thank you, I owe you one!