Transfer case Rattle

[nuclear944]

Take the rubber cap off and give it a thump with your hand. It might free it up.

Tried that, and it worked. However, whenever I go over a bump or make a sudden turn, the needle goes crazy. This made me think that perhaps something is making intermittent contact inside the sending unit, which means SPARK! I disconnected it and am going to swap out the one from my sedan. I think the sedan might quickly become a donor for the SPG. I am very sad indeed to see it go. Anyone in colorado for a rust free sedan shell?

[nuclear944]

Work goes on. It's starting to feel like a new car now.
We did some work on the rear end, primed, and installed the first coat of black.
I swapped in the sending unit from the other car and it works perfectly now. I also swapped the bumpers. Looks great now.
I took apart the front end and tackled any rust that was starting to form. I took off the carpet, searched in seams, and thoroughly checked the underbody for rust, but there wasn't any.

Everything is going well, but there is one thing that I can't seem to find a replacement for: the front seats. They are cracked and worn from neglect and the driver's seat is collapsed.

[nuclear944]

Well, this is what the transfer case rattle developed into:



Needless to say, I have a load of work on my hands. How the heck could this happen at 95,000 miles? I've never used anything more than base boost in 1st and 2nd, never burned out or abused the transmission, and I've never shifted hard!

Well, this is what you get for trying to modify the APC and adding a 3 bar FPR.

[nuclear944]

Supposedly, there are a couple of c900's at local pick and pull yards, some of them with manual transaxles. I'll try to get a 89+ from a n/a.

[euromobile900]

It sounds to me like you're missing teeth on a gear, since you say it only really happened in third. It should be interesting to see what the box looks like on teardown. I kind of wonder though. I certainly hope it wasn't the transfer case--that'll be the first gearbox I've ever heard of destroying itself this way.

[nuclear944]

It sounds to me like you're missing teeth on a gear, since you say it only really happened in third. It should be interesting to see what the box looks like on teardown. I kind of wonder though. I certainly hope it wasn't the transfer case--that'll be the first gearbox I've ever heard of destroying itself this way.

Got some good news. I found a 900S at scrapyard with a manual transaxle. It's 1993, meaning beefed up box.

I think the synchro hub disintegrated and everything else went downhill from there. What annoys me is that I only have 95K on this transmission. I always drove it as carefully as I could.



I removed the reverse cover, and it seems to be gouged on the inside from flying debris:





I think I'll start disconnecting stuff from the engine step by step and once I get the new box and hoist, I can just undo the motor mounts and it's out!
Of course, I'll have to find someplace to work...Can't do this in a parking lot at 40F.

[peva]

I think the synchro hub disintegrated and everything else went downhill from there. What annoys me is that I only have 95K on this transmission. I always drove it as carefully as I could.

Do you have any evidence that the car once had a tow bar and pulled a trailer or caravan? This use kills 900 transmissions.

[euromobile900]

Well you've definitely lost a synchro spring! That may have gotten into the works and mucked things up a lot! It's unusual for a synchro hub to disintegrate, but I can see that happening to a synchro muff. It was possibly a combination of bad luck, hard shifting (previous owner!), and bad lubrication that caused the problem. I'm interested to see what else is in store!

[nuclear944]

Do you have any evidence that the car once had a tow bar and pulled a trailer or caravan? This use kills 900 transmissions.

Nope. Everything in the rear bumper area seems to be original.

The previous owner was a high school student and didn't give a snot about the car. He probably learned to drive on it.
If you remember, the reason I bought this car so cheap was because the slave cylinder was inoperative. He said it was getting harder and harder to shift until he had to force the car into gear.
At the same time though, the gearbox shifted reasonably well before the failure. In fact, while the hammering noise in 3rd was present, I could still shift in all gears (including 3rd) very smoothly and effortlessly.

..bad lubrication that caused the problem. I'm interested to see what else is in store!

That can't be since I replaced the oil not even five months ago. When I took the reverse cover off, oil spewed out.

[nuclear944]

Mid December:

I replaced the gearbox successfully with a low mile unit from a junkyard (1989 non turbo) and the car drove like new afterwards with no problems. It was a properly big job, but not difficult or painful at all given that you have enough time and a comfortable workspace.
I had to work in negative temperatures and had to finish the whole thing in 2 days. I'd never done something like this before but it went reasonably well. I didn't break anything surprisingly. You can imagine the look on my face when I took it on it's first drive.


















It was a matter of a few recalibrations and adjustments to get the car working 100%. It really did drive like new. I took into the mountains a few times and had one of the best drives to date.

On new year's eve, things went a bit downhill for me with the Saab addiction. Some health problems had developed and I had forgotten to insure the car (since it was out of comission for months). They pulled me over for no reason and fined me heavily for multiple things. I was forced to sell the SPG and many other "toys" due to lack of time and money. Looking back, I should have never even gotten into this but I learned practically all there is to learn about these cars. It's very heartbreaking to have to part with your best friend after you've spent so much time and work on it.

Saab Central DELETED my project thread in which I had invaluable information about first time gearbox replacement and other rare issues. Some people (user b202nut) got into a fight and they decided the best thing to do is delete my thread.

I just sold the SPG for 3,200$ after replacing the front seats, wheel bearings, and other miscellaneous parts. I had bought the car for 200$ two or so years ago, had invested around 700$ in parts into it up to that point. It did really drive like new though.

I am tempted to take apart the old box and post some pictures of the carnage for you guys.