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[tj924]

Heard a new sound from what seems like the rear right of the car last night. It is a definite "scrape, scrape" sound that happens at any speed, with the car in or out of gear, motor on or off & with the clutch in or out. Current thinking is:

1. Something has come loose on the Rear drum brake assembly
2. Rear wheel bearing
3. Something to do with the CV joints (as I recently removed & repacked the joints on that side)

Haven't yet got the car up on stands to check it out, but does anyone have a procedure for removing, checking & repacking the rear wheel bearings? Can't find much in my Haynes on how to do it? Does the 36mm nut have to come off?

Would it be worth removing & checking the CV joints on that side of the car again to make sure nothing has come loose (eg maybe a circlip has popped out & the CV joint assembly has come loose)?

Any other suggestion welcome.
_________________
TJ
Silver '82 924 NA 5-Speed Manual

[Ozzie]

To adequately remove and repack the RWB you would have to remove the CV joint closest to the wheel after removing the big nut.
You have to remove the entire rear axle to get to the inner bearing.

First just jack it up and rotate the wheel to find the noise, probably just a drum come loose.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[tj924]

[Ozzie]

You'd have to remove the CV joint and axle from inner and nut and hub from outer to get to the bearings.
Has a spacer tube between the bearings to remove and clean as well.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[Master Q]

I'd have thought the most likely culprit for a scrape-scrape noise would be the brake drum.... Being as it is a big resonant bell-like structure. bearings tend more towards a rumble or whine; sometimes changing pitch or becoming partcularly prominent at some speed....

All that banging around witht he CV could have left some loose material rattling around in there....

Personally I'd take the back brakes apart first; probably changing the shoes while I had it in biits....

[seanski44]

also, might be just worth checking that there isn't anything lodged in your tyre. I test drove a BMW once that made horrible noises, turned out to be a piece of wire had been embedded in one of the tyres and scraped past the wheelarch..

otherwise what the other guys said
_________________
1998 BMW Z3 2.8 arctic silver & red

1981 168HP 931 S2 blue/tan leather - SOLD
1985 121HP 924 2.0l na modded - SOLD!
1992 968 lux SOLD
1989 944 2.7 lux SOLD

[gohim]

When my left rear wheel was making a scraping noise, it truned out to be the wheel bearings. The exhaust running by the left side bearings and cv joints causes the bearing grease to break down over time.

There are grease seals (inner and outer) and a o-ring seal at each rear wheel, and you are going to want to replace all of them when you remove the axle bolt and cv axle to repack the rear wheel bearings. You may have to order the parts, so I suggest that you buy them in advance. They are all VW sourced parts. You should not have that much of a wait if your local Porsche Dealer does not have them, and a good VW Aftermarket Parts Supplier should have them in stock. It takes most of (2) 14oz grease tubs to repack the cv axles, and rear wheel bearings properly.

[tj924]

Jacked up the rear end & checked for the noise by rotating the wheel by hand. Definitely the rear-right making the noise. Popped the wheel off & it appears the noise is coming from behind the hub rather than inside it, which points to the bearings.

Now, the REALLY interesting part is that the 36mm castle nut was loose enough for me to undo BY HAND. Just had to hit it with WD40 to get it all the way off BY HAND (no spanners or any other tools used). The only thing holding that wheel together was the cotter pin, & I know there wasn't one on the car when I got it (ie I put the cotter pin on it)!

Hub wriggled off fairly easily as well. Under the hub (ie where the brake parts are located) was full of fine black dust, which I assume is "brake dust" & is to be expected. Brake drum & shoes appear to be in good order.

So, the plan now is to get some seals & O-rings as suggested by Gohim, repack the bearings & reassemble (oh, & clean out the brake dust as well). In terms of torquing the hub nut, I thought maybe I could get it done up as tight as I can with the tools I have, put in a new cotter pin, then take it around to a local garage (< 5 minutes from here) that has the capability of doing up the nut properly. Sound like a plan? Any pitfalls?
_________________
TJ
Silver '82 924 NA 5-Speed Manual

[Ozzie]

Sounds like a plan, should be no problem.
Just check the backing plate isn't rubbing on the brake hub.
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[5150]

tapping/rubbing noise from the back of mine recently turned out to be the fuel pump - the mount had broken away at the rubber at one end, I hadn't noticed until I started pulling everything apart thinking something inside the drum or the bearings....
_________________
Mars Red '78 Euro 924 n/a
http://www.cardomain.com/id/5150_uk

Graphite? Grey Metallic '85 (late model) 944 2.5

There are two kinds of pedestrians: the quick and the dead.

[tj924]

OK. Got the rear wheel shaft out fairly easily (hit it a few times with a rubber mallet). The inner spacer ring appears to be jammed on the shaft. Should I attempt to get this off?

Can't see a sealing ring (113 501 315H) on the inner side & couldn't see a circlip, but I didn't shine a light in there, so that is probably what is holding the inner bearing in place.

Got the outer spacer ring to slide out through the outside & I can see a sealing ring (also 113 501 315H) on the outer side but I can't for the life of me get it to come out. Would it just be jammed in there or possibly "glued" with gasket sealer or something?

Do I also need to take off the cover (PET diagram 501-05, part # 113 501 311) to get the rest of the assembly out?
_________________
TJ
Silver '82 924 NA 5-Speed Manual

[gohim]

There are two identical grease seals on each axle. One on the outside and one on the inside. The outside one is removed from the inside of the cover after the cover is removed from the trailing arm.

The o-ring will be found under the cover after the four bolts are removed from the cover and the cover removed.

Grease seals are almost always a press fit. I have found that the easiest way to remove them is usually a seal remover, which is a curved hook with a long handle for leverage.

[tj924]

Finally got everything apart & cleaned! The outer seal (113 501 315 H was the part number on it) is definitely rubber (green) & was well & truely jammed in. Took a significant amount of work to get out of the cover as I couldn't initially work out what was part of the seal & what was part of the cover. Turns out that seal is also part metal & I was expecting a rubber seal. Seal is now totalled & will require replacement

The inner seal (113 501 315 G is the part number on it) is the same dimensions as the outer, but looks to be made of urathine (black) rather than being rubber covered metal. That one came out somewhat easier & appears ot be undamaged & in good nick, so I'll probably not replace it.

There is a metal elasticated ring on the inside of the seals that was a firm fit on the outer seal but quite loose on the inner. There is a chance that I damaged it on removal, but I may not have & it may have been that causing the noise I was hearing. I have moved that ring to the seal I am keeping & will get 1 new, complete seal.

I'll need to check for the o-ring again 'cause I didn't find one at all!

Now to get a new seal & work out how it all goes together again . I am assuming I can use CV Joint grease to do the wheel bearings?
_________________
TJ
Silver '82 924 NA 5-Speed Manual

[gohim]

Trying to reuse seals after they have been removed is foolish.

They cost less than $5 each, and the time to disassemble and remove the old seal and whatever parts are damaged by the failed seal make trying to save the $5 a fool's errand.

It sounds to me like someone has been in there before, and failed to replace the o-ring after removing it.

[tj924]