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MG MGF Technical - Third, Forth and Fifth Opinions

Gentlemen,

Last weekish, I shared my woes with what I *thought* was a shot rear nearside bearing... the old metal-on-metal grind, particularly when cornering or on uneven road surfaces.

Despite valiant efforts to remove the hub nut, I ended up leaving it into a (non MGR)garage... who promptly told me the bearing was fine, but one of the bushes was worn. Upon further investigation, the lower shock bush has virtually disintegrated.

So, based on Rob/Tim's advice, I've awaiting the shock kit (and rear compliance washers) from B&G:

http://www.mgf.ultimatemg.com/chassis_and_handling/shock_bush_replacement.htm

So, what's the problem? Well, can anyone explain how the heck a worn lower shock bush can cause pretty consistent (five/ten seconds at a time) grinding noises (it's *exactly* like totally worn pads).

Or could it be something *else*? Cha-ching!

In anticipation,
Col
Colin McIlwaine

The shocker bushes on mine perished as well and the bottom of the rear drivers side shockers was just flapping about on the bolt that holds it in place.

It certainly wasnt making a grinding sound though. I had some rather loud clunks as I was going over bumps.

Bob Millar

Bob,

Yeah, that's what I would've thought, a clunking noise. This is *definitely* a noise produced by rotation. Damned if I can work out what it is though.

A pal told me he used to have a Renault 5 years ago which produced a similar noise... turned out it was non-Renualt pads he'd installed which warped with heat (!). MGR pads in my F though.

Confused,
Col
Colin McIlwaine

could it be a foreign object caught betwixt disc and backplate? I mention the possibility 'cos I suffered this on a ZS last week - amazing variety of screeching noises for a couple of days; could not get through to dealer by phone - so fixed it myself at the weekend by levering the backplates away from the discs a few mm with a large screwdriver. HTH
David S

David,

Couldn't see the wood for the trees, huh?

Popping out to check now... if that's what it is, I'll be really, really annoyed.

Back in 30 mins,
Col
Colin McIlwaine

Are there backplates on the rear discs on the F????
Bob Millar

Okay, an hour.

Nope, no foreign objects. On the other hand, hardly any inner pad either. The outer pad is fine (wear-wise) which'd lead me to believe that the piston is doing a damn sight more pushing than pulling. (Now, why didn't I check the *inner* pad before now?)

Still confused though. There's no evidence (yet) of inner disc scoring and the noise cannot be consistently reproduced during braking.

That said, what looks like the inner pad retaining clip (to the rear of the car) is riding *very* close to the disc. I guess there must be some lateral or rotational 'give' in the brake carrier in relation to the disc, so maybe this clip (or what's left of the inner pad) is hitting the disc at times of high vibration (potholes, etc)?

Still confused,
Col
Colin McIlwaine

Had a leaking piston on a car once which was causing a grumbling sound.

Have you check the brake fluid level? If it's leaking then you will have lost fluid.
Bob Millar

I believe (but stand to be corrected) that most Rover and MG pads are designed to make a rubbing noise when they are at or past the point of replacement.

I hope that Will Munns may be able to back me up on this. Certainly my daughters R400 stated that in the book.

JohnP

Bob, fluid is fine. At least something is ;-)

JohnP. Interesting... pity they (MGR)didn't design it with something other than a 'Crap, my wheel is about to fall off' noise.

I've ordered new pads in any case.

Col
Colin McIlwaine

Colin, I've just had a look at the web page that you put a link to up above. I would not use the technique for inserting the lower bushes as shown in the picture for item 8.

When I did my bushes I only replaced the lower ones, partly because the upper ones were okay and partly because I didn't have any metric spanners to undo the top. I inserted the blue bush by itself first and then once the bush was in the loop of the shock absorber I inserter the metal tube.

No vice or press was involved in doing this. All that is required are two of the washers that are removed from the lower suspension and a suitable bolt. Place one washer against the loop of the shock absorber with the bolt running through it. Place the new bush (coated in the grease) on the other side followed by the second washer and the nut for the bolt. Now simply tighten the nut up - the bush will be forced through the loop with the minimum of effort.

Ralph
Ralph

Colin,
The rear brake pads have a metal piece on each side inside pad which is like a tuning fork and makes a screeching noise when the pad wears down by rubbing on the disc.Your pads don't need to be completely worn out for this to occur, worth checking out.
Robert
R J Hemphill

Confirmation as hoped.
JohnP

Colin McI. WROTE:

>>Still confused though. There's no evidence (yet) of inner disc scoring and the noise cannot be consistently reproduced during braking.

That said, what looks like the inner pad retaining clip (to the rear of the car) is riding *very* close to the disc.<<

When that occasional screeching noise first appeared on my Rover 220 Coupe Turbo, I was at a total loss as to what it could be. I had been used to a nice big VISIBLE brake warning light intermittently coming on and finally staying on. This happens when the worn pads reached that level when the electrical contact within the brake pads made contact with the disc thus making a circuit which illuminates the brake warning light on the instrument panel.

An AUDIBLE warning I was not aware of but, that's exactly what happens when those looped metal parts built into the coupe's brake pads come into contact with the brake disc. Those loops are on all four brakes as I discovered when replacing them. A crudely audible gramaphone disc/needle (stylus?) effect ... in effect ...:O)) Works though. Had not realised they're fitted to the MG Fs though...... is that the case?

By the way, I replaced the worn EBC pads fitted by the previous owner all round with standard OEM Unipart pads from my local MG-R spares dept.(Why are the rear pads the same price as fronts when only half the size? ..lol.) Before fitting the new pads, I removed each caliper and thoroughly cleaned each one, paying particular attention to the sliders. I used fresh copper grease on the sliders. The brakes improved noticeably thereafter. After about 500 miles of not too harsh bedding in the new pads, I started to use the brakes more aggresively. The braking on the car was transformed, partly due to the new pads settling in of course, but, I suspect even moreso as a result of the servicing I gave each caliper and sliders. Those turbo brakes are now superb.

HTH

JMcF.
John McFeely

Everyone,

Thanks for the various bits of advice!

I've got her booked into my F man on 16/03 for the shock bush replacement, rear compliance washer installation and rear disc replacement. If none of those solve the problem, I'll let y'all know.

Thanks again,
Col
Colin McIlwaine

Good luck Colin - fingers crossed you'll get this annoying noise nailed!
Rob Bell

Colin I think I have the same problem as you ! can you please send me your moblie number off line so we can have a quick chat
Cheers..... Jon
Jon (NSE 81V)

Jon,

I'm in Tokyo until the weekend... back Sunday 9/3. Mail me at:

colin_mcilwaineNOSPAN@ie.ibm.com
(Remove the NOSPAM)

Ta,
Col
Colin McIlwaine

This thread was discussed between 02/03/2004 and 09/03/2004

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