Wheel bearing adjustment/front suspension play

[amrbose14]

This query follows a combination of a). front suspension play flagged on the mot b). vibration during recent track day (this was probably just bits of rubber stuck to the tyres but ...). As a result I've been checking the front suspension and also front wheel bearings.

Q1: How does one disambiguate (properly) front suspension play and wheel bearing slack? The car is on stands, and I wobble the wheel vertically (hands top and bottom). I jack the wishbone up a little to presumably support the suspension and I wobble again. Not much difference. Is that suspension play? I don't think so (see below). Is there a better test?

Q2: How tight do people adjust the front wheel bearings? The workshop manual says you should be able to shift the pressure plate with a screw driver by hand. Does this mean 'easily by hand' or 'it is a bit tight but it can be moved without applying leverage etc.'. After adjusting the wheel bearing, interpretting the workshop manual as the latter, much of the 'suspension play' mentioned above has disappeared. Since I can still rotate the wheel, and the pressure plate, so this seems overall like a good thing right? There is less play in the wheel bearing.

Presmably the consequence of either too slack or tight wheel bearings is to shorten the life through increased friction. I'm probably worrying over nothing, but this post track day check over seemed prudent (and wheel bearings were suggested after my last post - which was a while ago but I just had a baby!). Lacking mechanical aptitute, I always find these 'matters of judgement' tricky.

cheers,
Chris
87 220T

 

[robwright]

You should be able to move the thrust washer not too easily but without leverage as you said. In fact the manual tells you not to lever against any surface. As long as you have done it roughly to that standard it should be OK mate. It's not an exact science.

 

[omigod]

To differentiate suspension componant play from wheel bearing play just get an assistant to apply the footbrake. This will lock the disc/hub assy to the caliper/strut assy leaving only the suspension ball joint/bushes to move.

 

[amrbose14]

Ta. Helpful answers to both questions. My two year old loves sitting in my car... so in a few years she can help!

Chris

 

[robwright]

I thought that until my seven year old daughter said that she would paint it pink!!!!

 

[amrbose14]

If it means I can retain 'our daughter likes it' on the list of reasons to keep the car........

ORIGINAL: robwright

I thought that until my seven year old daughter said that she would paint it pink!!!!

 

[amrbose14]

Thanks - that seems to work (with my wife on the brake - not the toddler). It makes little difference (after adjusting the bearings) whether the brake is on or not. There is a little play (most visible as a little movement of the tyre - small numbers of millimetres at the edge of the tyre), but I guess that's normal.

It certainly seems like there's less slack overall since adjusting the bearings.

cheers,
Chris

ORIGINAL: omigod

To differentiate suspension componant play from wheel bearing play just get an assistant to apply the footbrake. This will lock the disc/hub assy to the caliper/strut assy leaving only the suspension ball joint/bushes to move.

 

[Bonzo]

Hi Chris,
strangely at it's recent MoT, my car attracted an 'advisory' on play in the front bearings.

I think these cars should have just a bit... I've never had any luck with the method of tightening until you can just move the washer etc. What I normally do with all taper-roller setups is to settle the bearing first with a quater or half turn, then back off the adjuster until the merest hint of movement is felt when grabbing the roadwheel at 12 and 6 'o clock.

I'll be doing the job at the weekend, may remove and repack the bearings if I'm feeling enthusiastic.

Incidentally, go easy with the small cap that covers the hub- it's venomously expensive from an OPC !!

 

[amrbose14]

The mot seems to raise suspension play every other year!

The process described in the workshop manual is pretty simple.
Although I don't have an Allen key socket ling enough to torque it properly.

How do you get the hub cap off? I gently worked if off with a chisel, as described in the Hayes manual.

ORIGINAL: Bonzo

Hi Chris,
strangely at it's recent MoT, my car attracted an 'advisory' on play in the front bearings.

I think these cars should have just a bit... I've never had any luck with the method of tightening until you can just move the washer etc. What I normally do with all taper-roller setups is to settle the bearing first with a quater or half turn, then back off the adjuster until the merest hint of movement is felt when grabbing the roadwheel at 12 and 6 'o clock.

I'll be doing the job at the weekend, may remove and repack the bearings if I'm feeling enthusiastic.

Incidentally, go easy with the small cap that covers the hub- it's venomously expensive from an OPC !!

 

[Northern924]

Mine had a play advisary seems to be standard fare on these! As a side I'm suspecting mine needs the same work done but can I hijack slightly by asking what will be causing play with the wheel on the ground when pulling the top of the wheel? Also when reversing on close to full lock it sounds/feels like the front wheels are bragging across the tarmac?

 

[robwright]

When was the last time it had 4 wheel alignment mate? Mine never used to like being on lock in reverse at all. Or when not in reverse eiher to be honest. Had 4 wheel computer alignment done and it now drives and reverses like a dream.

 

[944Turbo]

When the car is jacked up it is not uncommon to have some play in the fully drooped strut so ensure diagonal and horizontal wobbling when checking the wheel bearing.
Tony

 

[Bonzo]

Re the front wheels dragging/ scuffing when reversing on lock- mine has always done that too, I've had 4-wheel alignment done and it didn't change at all. I don't think it's a sign of any problems..

 

[Bonzo]

Sorry to hijack your thread amrbose, but I discovered today that the 'play in front wheel bearings' advisory at the MoT is infact movement in the strut top-mounting, just as Tony points out above.
I would check your car carefully in this area. Also, I can't seem to find anyhting wrong with the top mount, it's rubber or the bearing, so may be just something to keep an eye on.

 

[amrbose14]

No problem.

On mine the movement that remains when the brake is applied appears to be the insert moving around in the strut housing. Is that what you mean?

Or do you mean that looking at the mounting from inside the engine bay you can see movement?

Chris (ambrose)

 

[Bonzo]

It's very deceptive where the play actually is!

Mine is right at the top, disappearing right under the inner wing itself. You can't see any play anywhere really. Rope in the help of an assistant and, while rocking the wheel at the top and bottom, get someone to lift up the rubber/ plastic cover to expose the actual damper shaft itself. Feel for movement here between the damper (insert) and strut body. If there's none, it must be moving at the very top, somewhere in the top mount/ bearing assembly. Seems like a very common complaint.

 

[944Turbo]

Mine was in the top of the strut body between the body and the damper rod, but much worse when 'dangling'
Tony

 

[amrbose14]

Is this actually likely to result in enough movement to affect suspension geometry?

Bloody ABS warning light was on today... for a bit...
Chris

 

[Bonzo]

I don't think you'd notice much on a road car tbh.. a perfectly set up track weapon, maybe- but the slack is not close enough to the wheel mounting points/ unsprung weight to affect things drastically. (imo of course!)

What you will probably notice is tapping/ knocking over bumps and maybe a little vibration through the steering.

 

[amrbose14]

Well it seems to handle pretty fine (once Promax set it up nice) despite the 23 year old dampers...