I have a vibration that is linked to the wheel rotation RPM under braking.

Easy. Warped rotors. Only not so.

Normal driving along, nothing. Smooth sailing.

Every press of the brake has vibration through the pedal and steering wheel.

I was so convinced it was rotors, i very nearly ordered a set before checking it out.

I checked them by clamping clamps to the fixed parts, and having a bar just touch the rotor on the face, at the edge. I couldnt detect even 0.25mm out of true when spinning them.

Whats next? what could be feeding back like that? Drive shaft? Front diff?

 

If not warped rotors, which I would have gone for first, it may be an axle seal leaking oil/grease onto the rotors which would cause similar symptoms.

Alternatively it may be CV joints or top and bottom ball joints snatching under braking. Another possible is wheel bearings may be loose causing a brake snatching effect.

Do you have a magblock and dial gauge? and if so check the rotors on the worn areas whilst rotating them and see what run out you have.

Résultats Google Recherche d'images correspondant à http://i.ebayimg.com/images/i/120985547302-0-1/s-l1000.jpg

Before spending your hard earned cash check out all the possibilities first.

Good luck

 

I used a redneck version of a magblock and dial gauge. Two G clamps, with the handle of one of them just resting on the outside worn bit. I couldn't detect anything at all. The vibration feels like much more than a very small rotor warp.

Ooh, i like your idea of a seal leaking onto the rotor. This would create a slippery bit that would be a small amount of ineffective braking on each rotation. I can check that out quite easy.

 

Check out your drag link or LR's nomenclature. Have had several vehicles with same symptoms.
......

 

Thanks number9.

After a bit of reading around, and as a thought I installed a 2" MD TF lift about 18-24 months ago. Should I have aligned something differently when I did that?

 

I have the front end off the ground now, and cant spot anything amiss.

Drag link, 20, seems tight. Nothing wobbles other than what I would expect. There is flexibility in the drag link end ball joints, but only what I would expect to see to allow it to operate, nothing 'linear'.

The steering itself is solid from steering wheel to road wheel, no 'lag'. My Heep ZJ had about 4" of movement at the steering wheel before the car responded, was more like sailing than driving.

The only anomaly I see are the rubber inserts each end of the damper, 6, are cracked, but again, no linear movement which i can see would cause a wobble under braking.

Im back to square one.

Wobble under braking that is in time with the wheel rotation. Not rotors. Cant detect any grease on the rotors.

Can it be caliper related somehow?

Ive never changed the brake fluid, or bled them. One thing on my list of to-do's.

I'm open to offers or suggestions here. Labor day weekend road trip coming up and i'd rather know what it is and not have it fixed than not know..

 

Was rotors.



The back of the rotors were all messed up. Couldn't see from the front and didn't think to look with the fronts being fine.

These puppies were very well stuck on there. Had to go to my biggest hammer! The sledge.

2nd one soaking in PB now.

 

Glad you've cracked it Cappedup. I had a sneaking feeling it may be oil on the rotors or crappy rotors. Checkout the caliper slider pins as they don't appear to be working OK.

 

I scratched my head so much I just bought new rotors and changed them anyway, thinking the problem would present itself when things were in bits.

Should of thought to double check the back of the rotors in the first place. Stupid really.

I already swapped the guide pins and re lubed along with new Akebonos last year, so the pads are practically new.

Ah, your saying the slides are duff, which is why the rotors got damaged? Hopefully I'm all good now, with new pins, pads, rotors.

Bleeding is next, getting new fluid in there. But I'll wait til I've got more time. Never had any fun with brake fluid. But it certainly needs doing.

Cheers.

 

When you come to brake bleeding try lay your hands on one of these Lynx plus a Windows 10 tab and do a power bleed to ensure the modulator A and B lines and long brake lines are fully bled through and all the calipers operate correctly. You should be good to go for many years then.

Lynx Diagnostics Interface | Single Model Home User Version | Britpart