The 2nd and 3rd gear synchros in my original 930 gearbox are going south, and the rubber centered clutch plate is pretty shot as well. So, I'm looking at a full rebuild, with a a new clutch package (press. plate, disc, throw out, etc.) when it warms up. I can get the box out myself, but I will let some else do the rebuild. This is a street car that will see little or no track time.

Faced with this and the associated costs, I'm wondering if I should swap to a 5 speed. I don't hate the 4 speed but would prefer a 5 speed. I will not cut and weld the car to install, so I guess that means the shortened G50, right?

I know what's involved (switching to hyd clutch, etc.) My question is - what are the REAL costs of both options - from those who've actually done this pls....

 

I have my '79 at the shop for the same trans repair right now - 2nd and 3rd sychros and dog teeth being replaced. While the powertrain was out the 15k major maint. is being done also - plugs, cap,rotor,filters, valve adjust, etc. My clutch was replaced with a steel center one about 15,000 miles ago so I'm ok there, but will replace the throwout bearing since it's apart.

I thought about converting to a 5 spd, but the cost was about twice the cost to rebuild the 4 spd. With no other work done, the trans repair would have been about $3,000 , I got estimates to convert to a 5 spd of over $6,000. So for me, 4 spds it is.

 

Don't rebuild. But one already rebuilt. There are lots of mechanics that rebuild them in their spare time and sell them for a fraction of what it will cost you.

Try Gary Fairbanks at 203-866 2466. I bought an LSD from him and his prices was excellent. He advertises in the back of Panorama.

Forget the G50. There is way too much modification to the car to get it to fit. It's not worth the $$$. If your motor is stock you can use a 915 but it's no where near as strong as a 930.

Mine is a Ruf 5 speed (930 4 speed + 1 extra gear). Great if you can find one. But I had to rebuild it...

 

I purchased my 78 930 with a fully rebuilt 86 915 box in it. The 915 lasted 17K miles before it sounded like ball bearings were flying around inside of it. I made the choice to jump to a G50 .... had the bell housing shortened, steel Porsche Motorsport synchros installed, billet shifter forks, G-50/50 LSD, factory G50 5th gear and plumbed it for an external oil cooler. It is expensive. With the linkage; hydraulics etc ... over $8000. I sold both the 930 tranny and 915 along with other parts I no longer needed and so it will net out costing me around $5K.

 

Is there any difference in the gear shift pattern between the G50/915 5 speeds, assuming a 915 is a 5 speed?

 

Reverse in the G50 is left and forward, 915s are right and back.

Also; different shifter mechanism and hydraulic operation, necessitating different pedals and master cylinder reservoir.

 

I have a 930 -76 with a G50 installed, You need to modify the suspension and usually it means coilovers... The G50 is good but the effort and money..? Mine had the G50 installed when I bought it.

 

Yes!!!!!!!!!!!

It is left and forward of 1st gear. That would explain the coilover suspension already on the car.

 

So you got a G50!

 

I have not had an opportunity to drive a 930 w/ G50 tranny. What is the "experience" like besides having the ability to "cruise" on highways?

The vehicle in question is an '86 w/ K27, long neck i/c, blah, blah, blah.

 

Shifting is easier. I autocross the car and like the quick and smooth gear changes . The first gear feels a little short , especially when accelerating..

Driving downtown is also more effortless than with the 930 or 915 gearbox.

 

Any thoughts on this tranny w/ RSR flywheel/ clutch package?

 

If you want to convert from CIS to a Porsche Motronic setup I have a refinished and balanced 87 G50 flywheel with the trigger on it. It's for sale because I no longer need it. If you want to use a new factory lightened 930 flywheel [balanced] on your CIS setup I also have this available for sale, never used or mounted.

With a shortened G50 you do not need to convert to coilovers on the rear setup. The shortened G50 will slip right in place of the 930 tranny.

 

I'm a little late to this thread, but will offer that if you're handy enough to drop the tranny you're probably handy enough to rebuild a 930 gearbox. They are probably the easiest Porsche tranny to work on. Big, beefy, and strong, too!

 

I know you can shorten a g50 trans, but did any of them come that way from the factory, or is this a completely aftermarket mod to the trans? Id like to do this one day and im trying to research it a little more.