spenny_b

Hey guys, hoping to find somebody who can answer this query please...

In the middle of a complete suspension teardown and overhaul and noticed something on the front hub assembly.

The PET shows a "bearing seal" and circlip fitted onto the hub shaft, looking to install against the front wheel bearing retaining plate.....



In the description, it doesn't differentiate between models - it reads as though it's a common part for Carreras, Turbo's and RS/RSA's

Mine's a 1992 3.3 Turbo - but when I stripped it, there's no sign of these parts. It looks as though some parts of the suspension have been apart and reassembled by a previous owner/shop (signs of copper slip, rather than aluminium paste), so were these items forgotten? Of course you only really get one chance to install the shaft into the bearing, so it's conceivable they got forgotten, then consciously not fitted once they realised, rather than destroying a bearing.





There's definitely a step on the shaft for the collars to fit, and my guess is that the circlip is just used to apply tension to the mating face - there's no groove for them to install into.

Any help or insight greatly appreciated - I could potentially be rebuilding this (extended) weekend.

Cheers
Spencer

Goughary

Got your pm. I'm completely stumped. Haven't ever seen that one.

Someone will know. I'm sure there is just some version of the hub/bearing that used it and i just haven't come across that...

cobalt

There is a TSB 9405 which I have someplace although Bill V is kind enough to send me a copy shortly. There were changes made to the front hub and ABS gear (they call it shake proof washer) which was carried over to the 993. I believe the turbos had this done first and these parts were eliminated. The design of the hub seems to use the later style ABS gear which was the same design as on the 993 so I am assuming yours does not use these parts.

spenny_b

Hi Anthony,

Hmm, interesting, I'll Google for that TSB in a moment. Mine was a late '92 build, registered in early 1993, so perhaps one of the later models that used the changed design. I've just been going through the photo's I've been taking for my build thread. It's not the clearest, as I wasn't trying to capture this part specifically, but if you look at where the hub enters the bearing retainer plate, I don't think there would actually be enough room to accommodate this "seal" without fouling the flanged screws that hold the retainer plate in place....





The ABS gear I've got is what's labelled as items 14-17 in the diagram below....



...not sure if that would be the updated assembly or not - I'm guessing it is, anything that's been corrected via a TSB isn't going to remain in a current PET, surely?

Thanks again
Spencer

spenny_b

Ok, thanks Rob - with this and Anthony's reply above, I think that's enough to convince me that the car wasn't originally fitted with this sealing washer+circlip, it's probably a car built after the Tech Service Bulletin changed the assembly.

Cheers
S

cobalt

I am quite confused by all of this. Here is a picture of a spare hub assembly from my 90 C4. It doesn't show any signs of the circlip and bearing seal. If it exists it would ahve to mount to the upright itself under the plate.




The TSB doesn't address this as I thought it would. I will have to see if there is any other info I can find out. It doesn't appear they were installed on the 90 unless it is internal so it is possible this was changed. Not sure why a sealed bearing would need a bearing seal. What hub part number do you have? I am finding issues with the part numbers cast into the 993 Hub I have as well. PET and TSB state 964 341 065 03/04 yet as you can see the part clearly shows 964 341 605 --. So I will try to see if I can loosen the bearing retainer bolts and see if I see anything on the 90 hub. The bearing is in excellent condition and they split when you remove them so I don't want to press it apart but I might end up doing it anyhow. For now I would assume it was superseded or revised at one point the PET isn't showing. We have been finding more and more errors with the PET like this lately.

993 hub



993 (48 teeth) ABS ring gear on the right which is pressed and centered into the hub vs the 964 (45 teeth) ABS ring gear on left which is pressed into and centered by the bearing.

cobalt

So I grabbed this from a thread on Pelican showing a very nice job on a front suspension swapping over 964 hub and ABS gear to a 993 upright. I will see what else I can find out.

tjb616

That's me Anthony (same username as Pelican.) My build thread is actually here on RL just a few posts down the page. I was just over on Pelican looking for an answer to this semi-related question. Making another cup of coffee to overcome last night's whiskey and headed out to the garage to dig in. Will report back shortly.

tjb616

Ok here's what I got:

Anthony, to answer your question from Pelican, no that is not a rubber gasket and there is no circlip or seemingly a provision for one. It is just a metal lip cast into the hub. Detailed photo below. My car did not appear to come with #10 or #3 from the PET. It is a Nov '90 build MY91, but is a bit of an oddball as it had 2 piston (early) rear calipers with late rear struts.

Attached also is a photo of a spare 993 upright and hub I have on hand, it doesn't appears to have these parts either, which makes sense as they're not noted in the 993 PET. It has new bearings so Id prefer not to take it apart.

Possibly worth noting, the bearings each have 2 seals on the face, shown separated. When I pulled the bearing "lid," the outer one came with it on one side. Attached is a photo of where it would rest on the hub.



1990 964 hub

993 hub + upright

cobalt

Should have realized. I have been drinking too much myself with all this isolation. I didn't put 2 & 2 together. Keeping busy during the day is fine but the evenings get long.

Thanks for posting and it is looking great. I am considering having the 993 hubs turned down to work with the 964 ABS gear. Not sure I want to chance the 964 hub with a 265 upfront. Unfortunately the bearings do that when removing the hub. No way to salvage them. keep up the good work.

spenny_b

Thanks for the info both....as it happens, the chap at my local OPC must be bored over a public holiday (lockdown) weekend, and replied back to me this morning, saying he can't access workshop manuals at the moment, nor can he find TSB 9405, but he did find this >>




It's all kind of related, but not entirely sure it answers anything on this specific question...

Cheers
Spencer

tjb616

No worries. 265 up front seems like quite the adventure. Have you driven a 964 with that much tire up front? The RWB guys who have tried it have gone back to smaller ties citing poor handling, unwanted tracking, and difficulty aligning. Granted, maybe not the best source of info, but I don't recall even seeing a race car set up with more than 245 up front.

Thanks Spencer. My takeaway is simply that the TSB you shared from 1992 doesn't show the circlip or seal at all.

spenny_b

From my limited experience on suspension setups on 964's I'd say that what I've heard agrees entirely. There's a company here in the UK and on YouTube called "DriftWorks", the owner Phil has an RWB 964 Turbo which he imported from Japan. The last few episodes they've released are of him swapping rear spring plates in an attempt to cure EXACTLY the symptoms you describe above - in fact from his descriptions it sounds pretty hairy (and although I don't know him, I have seen plenty of his videos driving various cars; I think he's pretty handy and comfortable with being un-straight)...I don't necessarily agree with what he's trying to achieve - an absolute steadfast refusal to increase the ride height, loves that stance and crazy camber - but he has now said that the trailing arms made little difference, and that he was now turning his attention to swapping the inner barrels of his front split rims. Can't remember the size he's currently running but am sure it's >265.

cobalt

Thanks that was the TSB I was looking for, I knew there was another but it has been years since i looked at them. My backup drive is giving me problems and the paper copies are buried in one of 10 bankers boxes in my attic. Unfortunately it doesn't allow me to do what I am considering, so it looks like I use the 964 hubs or machine the 993 hub to make it work.

I am currently running 9's with 245's although the front suspension is pushed out 12.5mm wider per side over WB settings or 42.5mm wider than NB settings vs the standard WB 30mm's. This with the evo uprights should keep the scrub radius and ackerman angles in check. Unlike the RWB builds I have seen which just use wider + offset wheels to fill the wheel wells which messes with the scrub radius giving them more of a 0 scrub radius vs negative. A 0 scrub radius would give them the poor handling they are experiencing. I am looking for as much up front mechanical grip as i can get for track driving. All work in progress. The car won't be street driven only track. I also installed a cup car power steering pump and rack since I found the manual rack to take too much effort for wide sweeping turns like the carousel at the glen. I guess we will see one day if the tracks ever open again.

tjb616

For what it's worth, the RWB with the issue mentioned above had BBI uprights.