C900 funny transmission sound in 3rd

Recently the '88 C900 (5 speed) gearbox has been making unhealthy sounds. I've noticed a slight whine in 5th, and then more recently when engine braking in 3rd it makes a somewhat rattly/grindy noise, not really nasty but not healthy either. Is this a common problem? I'm curious if the transmission is doomed to imminent failure, or if this is simply a nuisance that may not cause any real problems for years.

Reply to
James Sweet
Loading thread data ...

Yes, the pinion bearings were beefed up a year or three after '88.

Only if you don't drive it much. Get it fixed (pinion bearings at least, more if you've driven it much) or find another box. '90 I think is when it was improved, I'm sure someone can confirm or correct.

Dave

Reply to
Dave Hinz

in article snipped-for-privacy@individual.net, Dave Hinz at snipped-for-privacy@spamcop.net wrote on 13/03/2006 15:39:

I heard '89, but it may well depend on the market.

Once repaired, the older boxes can be "strengthened" by using a steel inspection cover plate. I think if you're getting grinding noises on over-run/engine braking then it may well be very close to failure and I'd be inclined to have the box looked at with a view to repair.

Of course, driving style will affect things so take it easy on the acceleration and perhaps use your brakes rather than the engine until you have it fixed. Thereafter, I can't see why engine braking will put any excessive strain on the box.

Paul

1989 900 Turbo S
formatting link
Reply to
Paul Halliday

What's involved in replacing these bearings? I'm quite adept and performing extensive repairs and have done a lot of engine work, I've never attempted to repair a gearbox though. I'm assuming it has to come out of the car and be disassembled?

Reply to
James Sweet

Have a look at the Twinsaab's manual transmission rebuilding guide at:

formatting link
to get an idea of what's involved in a home rebuild job if you want to attempt it yourself.

Uprated pinion bearings are sold by Swedish Dynamics I think for something like US$200 to 300.

Craig.

Reply to
Craig's Saab C900 Site

The car is almost 20 yrs old what do you expect?

Reply to
PAPAGENE4JACK

My Volvo Turbo is 22 years old, I regularly thrash it, and the transmission is holding up fine, so I guess that's what I've come to expect.

Needless to say, the Saab trannies obviously are a weak spot, I do still like the car though.

Reply to
James Sweet

Thanks for removing any question about the usefullness of your messages.

Reply to
Dave Hinz

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.