Gearbox interchangeability? [Archive] - SaabCentral Forums

: Gearbox interchangeability?

28th June 2007, 05:12 AM
hi guys....

both myself and my mother (she has a red c900 aero LPT - mum got style!!!:cool: ) have gearbox issues and need replacements.... im gonna get a full refurb on mine, but i think she will be best getting a good second hand one fitted

i have found a possible box for her, reasonably local, that i can have for free if i remove it, however it is on a N/A, not turbo... is there any particular issue with fitting a non turbo box to a turbo, or are they all one and the same?

thanks in advance chaps and chaplettes ;)


Albert Trout
28th June 2007, 05:16 AM
As far as swapability is concerned they're all the same. Different internals over the years but you'll be able to bolt it on nae bother. Being an N/A will be a good thing. Not as many horses trying to pull it to bits over the years.

28th June 2007, 05:18 AM
thought so, just checking

Albert is faster at posting than a westcoast mainline intercity!! :cool:


28th June 2007, 05:21 AM
I have read conflicting responses to that one G . would love to know the facts ,

have seen it said that the turbo box had heavier this that and the other comapred to n/a .

Also have read many times there is no difference , that the only variances come with the age of the box , that is the later the better ,, pinions etc . with I think about 88 startineg to be considered as Better and 90's as best .

Hopefully we may get an exact answer , Jim .. ??? RAUL ??? :lol:
My hunch is that Mum probally is a liitle more gentle on her Lpt than you may be . ( sexist and agist I know ) but only a hunch . If she isnt *hard* on the car the N/a box would probally serve her well .

Albert is quick ,,, and I am inclined to think spot on , Internals changed over years , but not a turbo v n/a box . (happy to stand corrected )
totally agree re one ex an n/a , every probability it has had an easier life . I am currently looking for a 5sp to convert an auto aero , N/a is top of list .

Albert Trout
28th June 2007, 05:38 AM
I'd not heard that the N/A internals were any different. I wouldn't have thought Saab had enough money to make boxes with different internals for N/A's & Turbo's but I can't say I'm certain. We'll have to wait until Jim gets out his bed before we know for sure :D

28th June 2007, 05:41 AM
know anyone that lives close to him albert ? lol.. JIM .. wake up already ..:D

28th June 2007, 05:46 AM
AFAIK all gearboxes bolt up to all engines.

28th June 2007, 05:48 AM
cool, so my only issue now is how good is the box that i think i have found for her.... cheers guys


Albert Trout
28th June 2007, 05:48 AM
They definitely bolt up but are they the same? ;)

Jim Mesthene
28th June 2007, 07:03 AM
Some turbos have different primary drive ratio and front mount.
Other than that, the stuff inside is the same.

Albert Trout
28th June 2007, 07:32 AM
Cheers Jim. I trust our chatter didn't wake you from your slumber.

28th June 2007, 08:11 AM
Morning Jim , and thanks , is what I had come to believe had read contradictory ,

Re the stones on your roof ,, I apologise on Alberts behalf , I said .. Dont wake him .. U know what hes like .,.. burning question ,,


28th June 2007, 08:24 AM
Inner drive shaft CV joints can be different - depending on the year some non turbo ones are slightly smaller. Maybe worth taking these as well if you source a used box.

28th June 2007, 08:51 AM
If I had to replace my box I would get a N/A one, just because they have had low power put throught them all their lifes, its still worth getting rebuilt and having a spare handy for the day its goes puff!

28th June 2007, 08:56 AM
Inner tripods , they changed in size based on year not turbo v n/a .
I had an 87 n/a original box , larger diameter drive shafts and tripods to match .
I think this happened around 86 ..87 . But yeah good point make sure re shaft diameters

29th June 2007, 01:51 AM
TwinSaabs has a good trans reference across yr/models here ( The ratios are different on '86 on up turbos.