VT928

Guys,


My 1980 Euro S has been getting a little loose at the rear end, whenever I give it gas or hit the brakes. We put the tail end up in the air and removed the wheels. What we found has me confused. The hub carrier moves about a quarter of an inch up and down when you tug on the caliper While the aft attachement point barely moves. It looks like the forward mounting part of the carrier that the long bolt goes through is elongated. Anybody ever see a problem like this? I know it is thirty years old and expect to have some issues but this I never expected. Thinking about removing the carrier and adding bushing both lower attachemant points to get it back in spec. The alternative of buying two new carriers and bearings is signigicantly more expensive. Will buy new long bolts and nuts. I am also wondering if the 295/35 17 inch rear tires I am running might have been the cause of the unusual wear on the carries

Paul

1980 Euro S Red/Blk Lea

mark kibort

there is a set of washers that could be missing, or you could be missing one.
mk

jon928se

As MK said - the conical washers 1 each side of the hub carrier could be missing. These locate the hub carrier on the pin - the hole in the aluminium hub carrier that the big pin goes through should not touch the pin.

Alternatively the Nuts on the big pin may have come loose - if this happens the conical washers don't locate in their respective concave surfaces in the hub carrier allowing movement of the hub carrier on the pin.

VT928

Hi Jon,

Both hub carriers are loose the same way and both wobble up and down only on the front side in other words if you grab the caliper it can move up and down about a quarter inch. We were in there last year to put on rear tie down brackets with sway bar attachments. The large pin was removed and reinstalled at that point. We didn't try to retorque today I guess we can try that next before looking at how to rebuild. Is there supposed to be preload on the nuts on the big pin so that it squishes the bushings into the hub carrier?

(coming to you live from the garage mahal here in the hippie highlands under the uberbeam)

Paul and Jay

AO

I gotta agree with these guys. Either the conical washesr are missing/not in the right locations, or you're nuts are loose. I would loosen up the nut, spread things out to be sure the washers are in their place, then re-torque. the 275 tires had nothing to do with it.

jon928se

IIRC All the bushings have crush tubes and the Nuts and Washers bottom out on the Shoulders on the pin - meaning that the components along the pin have to be a precise length otherwise you will get movement. There should be a big flat washer between the shock bush and the rear "A" arm bush. if you left this out would cause the same issues. PET doesn't show this washer but the WSM does (page 42-2 item 12)

If the hub carrier has got worn from being loose you could probably rectify the situation by adding washers between the crush tubes until the overall length became fractionally longer than the distance between shoulders on the pin.

VT928

Thanks guys,

I hope it is as simple a fix as you suggest, as experience tells me a simple cheap fix is a realitively rare thing for a 30 year old 928.

Paul

jon928se

Paul

My experience with these stems from two marathon 12 hour sessions removing the pins from my SE after 12 years of salty UK roads. I am intimate with them and with every piece of advice available 10 years ago.

Pull the pins (it'll be easy you had them out ;ast year) and verify you have all the parts as per the WSM in the correct place and correct order. Put the pin back in and put a nut on one end down to the shoulder on the pin. then put the other nut on loose leaving enough room for a prybar and pry the crush tube forwards against the nut. If the crush tube end goes beyond the shoulder you need to add a washer or washers with an ID bigger than the main body of the pin so that when you tightne the nut it compresses the all the crush tubes and washers together. Get Jay to call if it makes no sense - I'm much better at talking than typing.

Bill Ball

The conical washers are missing or could be installed in the wrong place. Seen it.

In this pic from the WSM, I labeled them "C" (for conical). When they are installed correctly you cannot see them as they nestle inside the concave areas of the hub carrier. Also, the nuts on the ends of the shaft need to be torqued to 103 ft lbs. With the washers in correctly and the nuts tight, the carrier should not move like this. Also, the other washer "F" needs to be on the other side of the shock mount.

Bill Ball

Here's one way to install them incorrectly in this pre-assembly mock-up by one of our members. The right conical washer is shown OK (it will be seated in the the hub carrier). The other is wrong, on the other side of the lower shock mount (not shown) instead of the hub carrier.

Bill Ball

Here's what it should look like assembled. Note there are some gaps or spaces, but they are occupied by center bushings on some of the components and things are locked tight lengthwise.

mark kibort

when Scots was assembled by the shop without a washer correctly oriented, the wheel would move under braking a visable amount. ( I could see it on the track following him) this might be what your issue is.

VT928

Problem Fixed

Thanks for all the advice, I tightened up the nut on both ends of the threaded pin and all the "slop" disappeared. I am still concerned that they loosened up in the first place so when the new pins and nuts arrive I will go ahead and replace them just to be sure. The car is back to being right and the handling is once again very controlled.

Paul

1980 Euro S Red/Blk Lea

Mrmerlin

be generous with a coat of anti seize on the new pins,
use thick grease to hold the conical washers in place

Bill Ball

Those nuts are locknuts and according to the WSM are single-use. I have reused them and not seen them come loose, but that is when they are torqued to 103 ft lbs. Mine are original and have been off many times.