G50 Shaft Upgrade + New Clutch : Change Fork? + T/O Bearing Guide?

[strictly]

I have been reading through as many old threads as i can. I can see the G50 shaft upgrade/replacement has been covered many times before.

Here is what im driving :

1988 911 3.2
G50
UNMODIFIED Clutch Shaft (orginal, 16mm)
Rubber Clutch (will be changed to spring type)
Old Style/Orginal G50 Fork (thinner arms)

I am going to upgrade the clutch shaft and bushes to the bronze type, and put a new clutch kit in (sach) with the springs in the disc,. The original needle bushes are available, but the shaft is not, and I dont want to repeat history lol (my shaft is galled)

My questions are :

1) I understand when i change the clutch i need to change the T/O bearing guide to the smaller one, as the clutch (sach) will have a new smaller T/O bearing with polyamide sleeve. The TB says to install the T/O bearing to sleeve DRY, which im going to do unless someone says other wise

My question is will I also need to change the fork? because the new T/O bearings require the later fork????

2) I am reading conflicting information on the bronze bushes being self lubricating, i think the best advice is a smear of grease anyway? Optimoly High Temp Grease?

3) PEDAL Cluster. I understand that there is no bronze bush kit for the G50, but i can buy most of them seperatly.

Out of curiosity, does anyone know if some of the bronze bushes from a 915 pedal cluster will fit the G50? If not i need one anyway for my 73, so will buy it and see what does and does not fit, and post the results. I imagine a few will.

[jlex]

Sorry I don't have any answers to your questions, but will be following your progress for advice for the future of my '88. It has the original clutch also. With only 35,000 miles on mine, I don't know when I'll need clutch work, but would like to be prepared. How many miles on yours?

[turbobrat930]

Contact Jim Patrick at Patrick Motorsports. Jim will provide you with any information you need, and any parts you may require. Stand up guy as well!!!

Patrick Motorsports By Patrick Motorsports Porsche & Mid Engine Performance Specialists

[KTL]

The aftermarket shaft assembly with the bronze bushings is a good way to go, especially since your transmission's bellhousing is original. In other words, if the updated shaft was available? Then you would have to drill the bellhousing to accept the larger diameter of the needle bearing cups.

I would use a dry lubricant on the shaft. Dry moly lube spray will work good. I wouldn't use anything "wet" because that attracts dirt and there's plenty of clutch dust dirt flying around inside the bellhousing.

Yes, no need for any lubricant on the guide tube or the T/O bearing. That plastic sleeve is the "lubricant" for sliding on the guide tube. You can continue using the original T/O bearing and guide tube in your new clutch. Then you'd not have to worry about the plastic or the size. But it's just good sense to replace the bearing and tube as part of a complete clutch overhaul. When you use the new T/O bearing, yes, you must replace the guide tube because their respective inside and outside diameters need to match. You can't mix new and old here.

Yes you will need to replace the release fork. The original release fork is sized to accept the troublesome needle bearings. The original fork actually has the needle bearing body pressed into it.

If you look at the parts diagrams for the '86 911 pedal cluster and the '87-up 911 pedals, some of the bushings are the same. You can download the PET diagrams from Porsche.com, looking under classic Porsche Classic Genuine Parts Catalog - Porsche Cars North America

The pedal cluster is found in group 7

[DRACO A5OG]

Originally Posted by KTL

Yes, no need for any lubricant on the guide tube or the T/O bearing. That plastic sleeve is the "lubricant" for sliding on the guide tube. You can continue using the original T/O bearing and guide tube in your new clutch.

Good to know! This applies to 915's too, right?

[KTL]

Actually no Master Jim. Only applies to the G50 release bearing with the plastic liner. I believe the older style of 915 release bearings are still typical metal on metal and a good extreme pressure grease should be used.

Here's the G50 tech bulletin



Here's the 915 release bearing

[strictly]

Originally Posted by KTL

The aftermarket shaft assembly with the bronze bushings is a good way to go, especially since your transmission's bellhousing is original. In other words, if the updated shaft was available? Then you would have to drill the bellhousing to accept the larger diameter of the needle bearing cups.

I would use a dry lubricant on the shaft. Dry moly lube spray will work good. I wouldn't use anything "wet" because that attracts dirt and there's plenty of clutch dust dirt flying around inside the bellhousing.

Yes, no need for any lubricant on the guide tube or the T/O bearing. That plastic sleeve is the "lubricant" for sliding on the guide tube. You can continue using the original T/O bearing and guide tube in your new clutch. Then you'd not have to worry about the plastic or the size. But it's just good sense to replace the bearing and tube as part of a complete clutch overhaul. When you use the new T/O bearing, yes, you must replace the guide tube because their respective inside and outside diameters need to match. You can't mix new and old here.

Yes you will need to replace the release fork. The original release fork is sized to accept the troublesome needle bearings. The original fork actually has the needle bearing body pressed into it.

If you look at the parts diagrams for the '86 911 pedal cluster and the '87-up 911 pedals, some of the bushings are the same. You can download the PET diagrams from Porsche.com, looking under classic Porsche Classic Genuine Parts Catalog - Porsche Cars North America

The pedal cluster is found in group 7

KTL,

thanks for that buddy. Okay noted on the lubricant. I also have my 915 clutch shaft bushes to do,and while they are not as exposed, it would make sense to use such a lubricant. Ive never heard of a dry lubricant, so its cool to read. Can you suggest a brand? I can then use it on the 915 TOB guide as well.

Good to know i could keep and use the old TOB, but like you said better to replace now, and use the upgraded guide tube

the fork, ah annoying as i thought. So to upgrade to the bronze bushes, i need the fork as well (starting toa dd up!). They state (various vendors) that it will fit both modified and unmodified bell housings, but only one has mentioned that a fork was recommended, hence the confusion on it, and the question

pedal bushes, ive seen the PET, and ive seen i can order them indvidually, i was just wondering if any one has had any success using the earlier bronze kit that is readily available. I actaually have one in a box, so i'll just take it alll apart and try it.

[strictly]

P.S

KTL,

furter to the above, i have i just reread some of your older posts, which i had allready read. So in summary i dont have to change the fork from a shaft perspective, if i upgrade to the bronze bushes as the bronze upgrade kit will work with any fork, but i most likely need to upgrade the fork for it to match the TOB with the polyamide (plastic liner).

Or and its not recommended, but okay if i plan to drop the engine again, just fix the current shaft problem, and reuse the old TOB, TOB guide, and old Fork, either with the old clutch/pressure plate,or with the new kit.

I havent decided any which way yet, the orginal TOB/Fork/Clutch all look okay, but i always err on the side of replacement

p.p.s JLEX, mileage is 75,000 it had a replaement clutch back in 2000, or so the service history says!!

[DRACO A5OG]

Originally Posted by KTL

I believe the older style of 915 release bearings are still typical metal on metal and a good extreme pressure grease should be used.

Master Kevin,

Once again, to my rescue sowwy for the HI-Jack OP

A Thousand Thanks! Yes, 915 is metal to metal, I wish it has the G50 style TOB/Guide, makes so much more sense. Maybe you CNC guys that work on Derlin can make one???

So I have my Kendal Super Blue L-427 Bearing Grease, I use on my wheel bearings. It states "Extreme Pressure" and 500F dropping point. I think this will do for the TOB/Guide Tube, maybe tip of the New Fork, No?

Tony Callas at Callas Rennsport, turned me on to this product 8 years ago and still using it.

I also picked up some CRC Dry Moly Lubricant Aerosol Can for the shaft. I will use this for the Omega Spring/Helper Arm Post.

[KTL]

Yeah the dry film lube is a type like DRACO mentioned, CRC brand is probably available at a local auto parts store or check your local industrial supply like Grainger? Dow Corning, LPS, CRC, Loctite, ........ all sorts of brands. Stuff works great for applications like this where we don't want something especially sticky that will gather dirt. I've found that it works best if you cure it by heating after you spray it on. Heat it with a heat gun or hair dryer and it'll stick much better.

The way the aftermarket shaft setup works for both original and modified bellhousings, is it includes some additional bushings that you put on the ends of the shaft if the bellhousing bores have been drilled out for the factory bearing cups.

I think you're correct that the kit works in such a way that you replace the bushings in the fork with those that come in the kit. So you're correct that you should be able to use your original fork, despite it having the needle bearings in it. You'll just have to drive those old crusty bearings out.

But keep in mind the fork is independent of the TOB. Fork doesn't care if you have old or new TOB with the plastic liner. Fork will work fine with either TOB. The updated fork has its upgrade in the pivot point and while it may have reinforced contact fingers with the TOB (not sure on that belief), the fingers are not a fault of the fork and either old or new fingers will engage the old or new TOB the same. In terms of failure, i've not seen many, if any, G50 forks break at the fingers or at the shaft pivot points or at the point where the slave cylinder pushes on it. The forks that break are the 915 forks because they're pretty dainty the fingers, right where they connect to the pivot tube, compared to the beefy looking G50 fork. Here's where a 915 fork breaks




Regarding the pedal bushings, I guess you'd use what fits from the bronze kit for the earlier cars. If you need new bushings for others not in the bronze kit, you'll have to use new plastic ones. I've heard of a few people having difficulty with the fitment of the bronze bushes. So you may end up having to lightly file them on the inside diameter if they fit too tight. Even though bronze are said to be self-lubricating, it doesn't hurt to put a bit of lube in them too. I'd also use dry lube here. Because the pedal area surprisingly collects a LOT of dirt & crap, despite it being well shielded by the carpet and floorboard.

Jim,

I think you're fine using that Kendall Super Blue if you want to. I hear that goop is some really good stuff. Just use it very sparingly on the guide tube.

[r-mm]

While youre in there can I suggest replacing the rubber hose and slave? Kevin helped me diagnose a really trickey clutch OVER disengagement that was from an internally swollen yet visually fine rubber line. Stickey slave didnt help.

[Bob Gruen]

Originally Posted by jlex

Sorry I don't have any answers to your questions, but will be following your progress for advice for the future of my '88. It has the original clutch also. With only 35,000 miles on mine, I don't know when I'll need clutch work, but would like to be prepared. How many miles on yours?

I think I was one of Pelican Parts guinea pigs on this upgrade some years ago. I read about it somewhere and called and discussed it with them and ended up sending parts back and fourth till we got it right. About a year later it was all grouped together on one comprehensive page; makes life easy.

I think the thing to understand is that it is a big chunk of vulcanized rubber that ages just like rubber lines or tires. My car lives in the South East (hot) and I blew the rubber clutch probably more than ten years ago. I would guess that even a babied clutch at 30 years of age is ready to fail. When it fails there are three metal tabs that will engage for limp-home mode, but your trans is then metal on metal with the engine, and I wouldn't want to drive any distance like that.

Also, any NOS rubber clutch is probably 30 years old as well, and sitting around in some warehouse is not much better than in your garage. Spring centered turbo clutch disk is the ONLY way to go.

Bob

[KTL]

I agree with Bob on the clutch disc. With only 35,000 miles, the clutch itself should be in good shape (but you really want to make sure that clutch release fork shaft issue is sorted out) and you can just throw a new disc in there. The rubber damped G50 disc is not as failure prone as the notorious SC discs were. But they still do fail with age

The simple solution that is a straight drop-in, with no modifications whatsoever, is to use a '75-'77 930 clutch disc. Pelican has a few choices

1988 Porsche 911 Carrera Coupe - Clutch & Flywheel - Page 1

Clutchnet also makes some nice products and their basic '75-'77 930 disc is a great value.

Clutch Discs Clutch Kits | Clutch Discs | Pressure Plates | Flywheels by Clutchnet (626) 448-7432

[Roger at Pelican Parts]

Sounds like you got plenty of great advice already, but just in case you haven't seen this tech article, it might help out: Porsche 911 Clutch Replacement | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article

[strictly]

Thanks for the details. I decided on changing the fork and T/O guide tube anyway (after reading the post).

Good info on the dry film lubricant, I have found many brands that do it, from WD40 brand to Wurth, all seem to have PTFE, i'll get some.

Luke