92 Saab 900S auto tranny trouble

[esky]

My dad drives the 92 900s, and has trouble with the automatic transmision shifting from 2nd to 3rd... from what he says, the car will start fine, drives from 1st to 2nd, then at 2nd just stays on as he accelerates into high RPMs without shifting... he'll have to slow down and drop RPMs or manually shift the car from 1st - 2nd - automatic for it to finally engage 3rd.

Our mechanic said he doesn't know much about the Saab automatic trannys and that we should find someone who does to look at it... but just curious if anyone has any clue what this might be... looking at replacing the entire transmission possibly? The car has a lotta miles on it already, so I wouldn't be surprised (100k +, maybe ~150 even, I forget). Any other ideas, or estimates on how much such a transmission would cost?

Just out of curiousity, if a new transmision is needed, would swaping in a manual be risky / much more expensive (or even cheaper)?

Anybody know a good SAAB mechanic / shop in Philly, PA?

[cdaly]

Brake band adjustment. It's a fairly simple procedure but you need to take off the bottom pans to do so. Look at http://www.thesaabsite.com/900old/c9...ionservice.htm for a guide.

[ProfZ]

It's definitely a front band adjustment that's needed--happens to them all at about 100k miles. Any competent transmission shop should be able to do this.

Also, replace the trans filter at the same time.

The link given above to thesaabsite's DIY page is very helpful, BUT their instructions for band adjustment are NOT accurate. Adjustment specs depend on serial number of trans; I have a rebuilder's manual which has all this info.

[cdaly]

Care to post the figures? Or are there too many?

[ProfZ]

Originally Posted by cdaly

Care to post the figures?

My pleasure Here goes:

Only the earliest trans used the spacer as called for in the instructions from "thesaabsite". If you have a Turbo car and the trans serial number is 001-1700 or lower, or if your non-turbo trans has serial number 002-2800 or lower, then use a 1/4-inch (6.4 mm) spacer. Tighten the adjuster stud to 11 inch-pounds (one foot-pound is close enough), then back it off one turn. While preventing stud from turning, tighten its locknut.

Many of these older trans were upgraded by Borg-Warner, and will have a number beginning with the letters RS. For these, and for ALL OTHER trans with serial numbers greater than quoted above, the adjustment procedure is this:

Use a spacer of 8.9 mm thickness. Tighten adjuster stud to 11 inch-pounds (for all practical purposes, one foot-pound) and DO NOT back it off. Tighten its locknut.

Some practical advice from my own experience:

(1) Make your spacer from a cut-down bolt (or other stock) from 1/2-inch to 3/4-inch in diameter. Hacksaw and file it to the correct thickness. Try to get it as precise as possible, but a 10% error is acceptable.

(2) Measuring one foot-pound takes either a micro-torque wrench or a torque screwdriver: Both are hard to find and expensive. (I nailed a torque screwdriver on eBay a year ago for $20, but this was a fluke. And...I had already done my band adjustment by feel, as described below.)

Here's an approximation if you don't have the torque-measuring tool: For the early trans, finger-tighten the adjuster stud then give it a 1/2-turn with a wrench. For the later trans, again finger-tighten the stud but give it 1 and 1/2 turns with the wrench.

Now change the fluid and filter, and cruise on for at least another 100k miles...

[abekus]

I have looked at my x-mission serial # which is 0130006729 (borg-warner). Is this the later serial # you refer to. It didn't have any dashes in it. Call back soon as I'm slowly draining the x-mission by loosening pan bolts. (Stupid drain plug refused to come out.)

[abekus]

I have taken off both pans, and have found only one nut that could be adjsted. (myself excluded) I have read the terms front band and brake band, are the two one and the same? Tranny serial # is 0130006729. In addition, I can't get the drain plug out. I have sprayed it with penetrant, I have beat on it with a chisel, it won't budge.

[ProfZ]

Yes, yours is a later serial number, 013-, so use those figures.

[ProfZ]

Originally Posted by abekus

I have read the terms front band and brake band, are the two one and the same?

No; the front band operates when in forward gears while the rear band only operates when you shift into reverse.

The rear band is adjustable from outside the trans. But because it gets so little use (how many miles do we drive in reverse?), I've never seen one that needed adjusting. It's irrelevant to your problem, anyway.

The adjuster for the front band is in the forward right-hand corner of the trans housing (not the converter housing).

In addition, I can't get the drain plug out.

The plug has a slotted head, like a large screw. If the slot is too damaged to use a (large!) screwdriver, shape it with a small file and try the screwdriver. Clamp vise-grips on the screwdriver's shaft to give you leverage.

[abekus]

I finally got the screw out of the converter pan. I had to heat the pan uo with a propane torch to do it. Now I'd like to replace the thing with a real drain plug you know one with a hex head instead of a slotted screw. I haven't been abel to find anyone who stocks 9mm bolts to take its place. Any suggestions?

[alan forsyth]

try saab

[spgeed]

Hardware store? Some of them stock drain plugs.
Oil change place?

[cdaly]

You'd be better to stick with the slotted screw and just tighten it properly. It should not be tightened too much. Just enough to pinch the seal washer and then a bit. The torque wrench setting is only 5 Nm {44 in-lb {4 ft-lb}}. Having a hex head is just too much temptation to overtighten it...

9mm bolts

9mm is an odd size. Given that it's a Borg-Warner trans, chances are that's a 3/8" AF bolt instead...

[Matthew]

Is it possible that the bands requie adjustment due to stretching, and not actual wear?

[abekus]

Did the band adjustment on the tranny, is shifting fine now. Unfortunately the the return hose from the tranny is leaking (coolant) looks like a mess to get to. Hope I can manage it by swinging the A/C compressor out of the way. I don't have to remove the intake manifold.

[abekus]

Help! My car won't go in reverse. It was going into reverse any steadily got worse taking longer and longer to engage. It also won't go into 3rd anymore. It shifted after I got the car to about 50 mph. Could this be the controller referred to in Bentley's? I even tried disconnecting the accelerator cable to see if it would shift into 3rd any sooner, but to no avail.

[shamasi1968]

I'm new to saabs too, but I had a 1985 toyota pickup that slowly refused to shift into gears turned out that the linkage was going bad.worth a try. good luck.and welcome to the site.

[Matt88S]

I even tried disconnecting the accelerator cable to see if it would shift into 3rd any sooner,

Dude, if your trans is a autobox then you just did some very, very bad mojo to it. Never disconnect or losen a throttle valve cable on an automatic. Thats probably not something you wanted to hear though.

If we are talking about an auto here then it might be as simple as the cable going to the gear selector being out of adjustment. I had that problem on my S, its an auto.
There is a cable going to the selector and a allen screw that clamps it in. Over time this will get a little slack and when you select D or R it is not fully engaging or engaging at all.

The other posibility is a worn band.

Profz is a genius as all professors should be, lets see what he has to say about the matter.

[jetman]

There is a crimp on the kickdown cable around where it comes out of the casing on its way to the throttle body. The cable should be set up so that the crimp is about 2mm from the casing.

[ProfZ]

As "Matt88S" said, you should never disturb the kickdown cable. If you disconnect it, the end inside the trans could fall out of its cam--which means going into the trans to reattach it. Unfortunately, I fear this is a moot point...

From the information you gave, my first guess is that the rear clutch is (almost) gone; it is the only element used by both reverse and 3rd gears. This means a trans rebuild or replacement is on the cards

Because I don't feel comfortable making such a grim diagnosis on a car I've never seen, I recommend that you take it to a trans shop which specializes in imports--or a trusted SAAB dealership--for a "hands-on" opinion.

Please report back to us with what you find out--then we can (hopefully) give you some advice on options for getting your car on the road again.