993turbo

The 928 Manual gearbox is made by GETRAG. Hence the G in the type name in the gearbox modeltype.

This goes for all the Porsche models, when you see a G in the gearbox description, its a GETRAG. Getrag also made the racing gearboxes for most Porsches. (The also make gearboxes for Mercedes, and BMW etc..etc..)

The rear locking diffs are ZF.

Cheburator

Getrag did not make the boxes... G comes from Getriebe - Deutsch for Gearbox Early boxes have Porsche synchros, which are bad at best and trully horrible in reality. The post 1985 boxes are Porsche made again, but with Borg-Warner synchros, which are actually quite good. Unfortunately Getrag did not get anywhere near our boxes... Thus they are so expensive from Porsche and even 2nd hand...

993turbo

Thanks for the language lesseon. Im fluent in German.

For the other Porsches, i.e 911, when it was a Porsche gearbox they used the Porsche projectnumbers, 901, 915 etc..etc.. as soon as they changed to the ''much better'' Getrag gearbox for the 911 for the 87 model year, the gearbox got a G ''prefix''. Thought this was for the 928 as well.

The Borg Warner syncros were added for the 85' model year strengthened gearbox, earlier it was the Porsche syncros.

Glenn Evans

The torque of the rear driveshaft coupling in the torque tube must be checked each year.If it loosens to the point of allowing play (as it will, over time), you will break the transmission input shaft. Red dust (rust) around the rear coupling is a sign that there is play and that you are living on borrowed time unless you retorque the bolt (best to replace it).

Other than that, the manuals, including the diff, are built like a truck transmission. You do not need to worry about yours.

heinrich

I don't see how you can take exception. You made a hugely incorrect statement and he corrected you.

Andre Hedrick

Colin,

Do you have a spare to take apart and prototype from?

Cheers,
Andre

Lizard928

Andre,

I am going to be using the early cases for my modifications as they have the slightly better LSD unit.....

Andre Hedrick

You are such a DOG!!!!!

Not doing the later gearbox and not doing the 16V cams!

Anyways, keep us up to date on your adventures

Lizard928

This unit would be able to be bolted in to the later cars.....
But it will not be a "street" box......

GregBBRD

[QUOTE=Glenn Evans;9015793]The torque of the rear driveshaft coupling in the torque tube must be checked each year.If it loosens to the point of allowing play (as it will, over time), you will break the transmission input shaft. Red dust (rust) around the rear coupling is a sign that there is play and that you are living on borrowed time unless you retorque the bolt (best to replace it).QUOTE]

Exactly.

The other very common problem for 5th gears is that people crack/break them when they remove the transmissions. Even a little "side" movement, when the gearbox is removed from the torque tube can/will damage the gear.

I always suggest that people remove the coupler bolt, but leave the actual coupler in place. This will add some support to the three separate "leaf" pieces of 5th gear, as the gearbox is removed.

depami

Can someone please elaborate on this? Soon I will be changing out the '82 5-spd and don't want to inadvertently do something stupid.

Thanks, Denny

Lizard928

Denny, remove the transmission and TT as a single unit to make it easier.

IcemanG17

just run the rogerbox..........................................

Seriously............how many HIGH hp 928's blow manuals....pretty much ALL OF THEM.... Here is a ?? Name 1 race 928 with STOCK or better HP that completes a full season (12 on track hours) on the same trans................................................................... ........................................................................ ........................................................................ ...

exactly...not even the mighty KIBORT can claim that.....his blew up last year....Anderson breaks them on a regular basis...same for Simard..
leave it stockish...the clutch fails....upgrade the clutch the trans fails

How many ORR cars run automatics with ZERO issues...even with boost....George and Bill have done it for YEARS with no issues....

I have 85.5 hours on track on a rogerbox....that was USED to start with...17 hours in 3 days a few weeks ago... I just changed the trans fluid and filter....and after looking at it + smelling it...it really was a WASTE...still red fluid and no burnt smell at all....I had a YEAR (40 HOURS) of track time on that fluid-filter (normal fluid, nothing special)....however I NEVER-EVER see more than 180F on my trans temps either...a good cooler helps

It really is the "poor mans sequential" for minimal cost....

Okay stepping off the soapbox with flame suit on

justaguy

Colin
If you can design it I can probably build it. I would be interested in helping if you decide to move foward.
I have the Widows old box here. Maybe I should open it up and look inside.

Dave928S

Denny ... have a look at the input shaft protruding from the front of your manual gearbox and you'll see where the drive shaft inserts. Sliding the driveshaft in to that (or out of it) with NO up/down/side misalignment is essential to avoid breaking that fragile end. Treat it like it's glass.

+1 on what GregBBRD said re leaving the coupler in place to support the relatively weak (for angular movement) end.