Turbo gearbox replacement

kpharo · Sep 4, 2004

We have a 220bhp '87 Turbo with LSD gearbox. It has what sounds like a whiny diff. We are thinking of replacing it with a secondhand gearbox, but the one we have been offered comes from an '89 250bhp, which has an oil cooler.

Two questions - do all 944 Turbo gearboxes all have oil coolers? And, would the gearbox be a straight swap for our original - are there any differences between the two? Clutch, ratios etc. etc.?

Guest · Sep 4, 2004

ORIGINAL: kpharo

We have a 220bhp '87 Turbo with LSD gearbox. It has what sounds like a whiny diff. We are thinking of replacing it with a secondhand gearbox, but the one we have been offered comes from an '89 250bhp, which has an oil cooler.

Two questions - do all 944 Turbo gearboxes all have oil coolers? And, would the gearbox be a straight swap for our original - are there any differences between the two? Clutch, ratios etc. etc.?

Dont quote me but i think there is a slight diff in gearing, and i understand the 250 diffs are stronger too.
No doubt someone will be a long to correct me on this.

Cheers

944Turbo · Sep 5, 2004

250Bhp cars have a LSD, cooler (220's didn't afaik), hardened 1st and 2nd gears, and IIRC different (slightly longer) ratios.
Tony

Guest · Sep 6, 2004

Tony is mostly correct, although a lot of 220hp 951 cars did have coolers and LSD, particularly 1986 models are commonly found with these options. The 250hp cars do indeed have hardened 1st and 2nd gears.

By "whining", do you mean the normal mechanical gear-mesh type sound, or something more severe? Can you hear it worse on decelleration? You could have a pinion bearing going out, which, if caught and replaced early, is repairable. Let it get to the point where you have gear lash and teeth braking, and it will be time for a complete overhaul, or another transmission (cheaper to do that honestly).

If you do have to swap transmissions, it is a fairly straightforward affair. With a helper, you should be able to do the job over a weekend with standard tools and a good jack. For reference, I did a trans swap in my car under duress 2 weeks ago, and with the help of two other friends we had it done in about 3.5 hours. There is a good tutorial on the Paragon products site that covers a swap in depth, here it is:

http://www.tech-session.com/kb/index.php?page=index_v2&id=65&c=4

Hope that helps!