G50 Pivot Shaft BOSS repair - HELP!

[cliyde]

What is the recommenced fix for G50 Trans BOSS repair? Is there anyone in surrounding NC, VA, or SC competent in fixing this issue?
Anyone have first hand experience with repairs and options? GREATLY appreciate your help and advice.

On my way back from the grocery store today, the clutch pedal in my '88 911 suddenly gave up and I was no longer able to shift between gears without grinding them. I noticed a slight metal rubbing sound now emanating from the trans when depressing the clutch, which oddly still maintained some pressure/resistance as I struggled to figure out what was happening... Luckily I was able to limp home, get it up in the air only to find this:

Retainer and clutch fork pivot BOSS broken. Ugh Must have been a larger issue for a while I wasn't aware of.

[rolfjahn]

LMN Motorsports in Virginia Beach, VA Lutzo is the owner.

[Cory M]

Out west California Motorsports (CMS) and Patrick both do this. Mine was done by CMS.

https://californiamotorsports.net/collections/porsche-g50-transmission/products/cms-g50-993-gt3-clutch-fork-pivot-shaft-boss-repair

[cliyde]

Thanks @rolfjahn and @Cory M, will look into both shops/solutions. Really hate having to ship my tranny across the country for a "fix", but I'll do it for the most reliable, long term solution.

[rolfjahn]

Lutzo has rebuilt 2 G50 transmissions for me along with Patrick Motorsports gearsets and limited slip differentials. Patrick Motorsports gearsets along with Wevo shifters make a huge transformation to the driving experience.

[cliyde]

@rolfjahn I will give him a call. Thankfully my trans is in good working order internally, but machining/welding will be required to the bell housing along with a new fork and shaft replacement.

[cliyde]

Has anyone had issues with the boss ear weld “fix” holding up long term? I’m pessimistic about the cast part integrity welds holding up from previous experience with a Carrera intake that I had repaired this way, but did not last.

California Motorsport solution looks great, but will be pricey it seems. Appreciate any other feedback from the pelican community.

[john walker's workshop]

If the broken piece still matches up nicely to the stubs on the housing, perhaps a good local welder guy can do a nice tig weld on it and add some extra beef. A brass bar the same size as the shaft could be used to keep the alignment.

[KTL]

CMS formerly welded billet blocks onto the bell housing for the repair. They’ve now switched to a machined adapter which is fastened to the bellhousing with screws

https://californiamotorsports.net/collections/porsche-g50-transmission/products/cms-g50-993-gt3-clutch-fork-pivot-shaft-boss-repair

[Cory M]

Mine was repaired with the welded blocks. This was 10+ years ago, but it's a racecar and doesn't get driven that much compared to street car. I've swapped engines a couple of times since and inspected the weld repair and it looks fine, no cracks or unusual wear.

[KTL]

I didn’t mean to imply CMS changed their approach due to the welding not being reliable. I think they just came up with a better way to tackle it with machining and no need to weld it?

[Marc Bixen]

We've used CMS with success. We had a client whose boss' had previously been welded, and broke again. The CMS solution is professional and the new style (bolted not welded) is serviceable in the future if necessary. That repair was 3+ years ago, and still going strong. The only issue is that the diff housing needs to be stripped completely, so usually, new pinion, mainshaft and diff bearings. Don't fool around with guys who "might" be able to repair it. This is not something that you want to do twice. Also, get rid of those garbage bronze bushings and do the proper update with the factory bearings, seals, and shaft.

[cliyde]

Thanks, guys. I greatly appreciate the insight.

Originally Posted by Marc Bixen

We've used CMS with success.

Originally Posted by KTL

...they just came up with a better way to tackle it with machining

[Matt Monson]

Originally Posted by KTL

I didn’t mean to imply CMS changed their approach due to the welding not being reliable. I think they just came up with a better way to tackle it with machining and no need to weld it?

Once they purchased their own CNC for their manufacturing operations a number of their old fixes for things were upgraded.

[cliyde]

Now the fun begins.
Should know more after the drop & trans pull. Will update the thread on direction I'm heading with repairs, but will say I'm already leaning CNC if shipping $$$ doesn't kill me.

[Matt Monson]

Have it stripped locally and just ship the bellhousing.

[Marc Bixen]

Originally Posted by Matt Monson

Have it stripped locally and just ship the bellhousing.

+1 for Matt. Have it stripped locally.

[cliyde]

Thanks @Marc Bixen & @Matt Monson

Anyone have a PDF copy of the G50 workshop manual I could borrow?

[KTL]

I have G50 in in pdf format. I’ve got two manuals- ‘84-‘89 911 workshop manual supplement and also a 993 manual. Give me an email address and I can share it with you via my google drive

[jlex]

Scary... what year was your car and how many miles were on it? Did it have the original clutch on it?