G50/52 main gear selector shaft relacement

[steve.sammut]

Has anyone had this shaft break on them? I cant believe that a 16m hardend steel selector shaft can break on the knuckle. Is it possible that the box has had a knock in a car park or is the heavy linkage supporting all that weight!
regards
Steve

[steve_d]

Are you saying the selector shaft has broken where it exits the 'box?
Or are we talking about the various shafts external to the box?

Steve

[steve.sammut]

no the shaft broke internally on the 2 knucke joints.
The shaft is 16mm thoughout exept in two points where the shaft selects neutral

[GT4T]

The shift forks on the G50 family (and Porsche gearboxes in general) are a known weak point. There are several companies in the US which make billet replacements for them. PowerHaus II is one company that comes readily to mind and is VERY popular with the Ultima and GT40s crowd for their work with the G50 family of transaxles. You might want to have a look in the Porsche section here at PH as I just noticed a topic where good Porsche gearbox techs in the UK were being listed and recommended.

In addition to the shift forks, the side plates are often replaced with stronger pieces as well. For a discussion of gear oils in the G50 family as used in GT40s (basically the same stresses as you Ultima guys) have a look at www.GT40s.com in the engine/transaxle tech section.

Regards,
Lynn

[X8Matt]

So a bit of thread resurrection...

Long story short - my G50 gearbox is now a single speed (5th I think!). It seems that the selector shaft that hangs out the back of the gearbox is goosed. Is it a specialist job to repair the box or can that part somehow be replaced more easily?

If the box does need to come out then I will take the opportunity to change the ratios. LuckyP (I think!) lowered them significantly, so it is only geared for about 140 leptons at 6000 rpm. It makes for noisy motorway cruising!

Any recommendations for a workshop to do it?

Thanks

[Storer]

I used this chap to do my G50/52 new diff.

http://www.sportsandclassic.com/index.php?page=ser...

A rebuild is not cheap and takes a while. Bearing are very expensive (about £250 each!!!) but I am happy with the work Mike did on my box.


Paul