[breath2]

I just picked up my daughter after her 1995 Saab 900S broke down. She said the tach was only reading abut 1,000 RPM @ 50 mph which she thought was odd since it was typically around 3-4K RPM. Then the car started to shake so she pulled into a parking lot. When I went to pick her up the car starts fine but when it's put into reverse it jumps into gear and stalls out. The way the car was parked I didn't try any forward gears. The car has about 125,000 miles on it and we've only owned it for about 6 months. I checked and it has trans fluid, nothing apears to be draging undeneath the car. I've searched this forum and didn't see anything similar to this problem. I don't know if the RPM thing has anything to do with the transmission problem, but since I'm a motorcycle guy I do know my tach on my bike runs into the trans box. Any ideas?

 

[earthworm]

Mine reads at 50 mph 1,900 rpm
.....................60........ 2,100
.....................70........ 2,300
As I recall

The Aisin-Warner seems to be a very good unit,IMO..
But, in this case, the farm seems to have been purchased..
Of course, check the connections, fluids, maintenance items..

 

[Slaab4life]

When the attempt to reverse was made, was the engine warm? I have an issue where on cooler days if I attempt to go into reverse with a cold engine, it bogs itself, shakes semi-violently, and then stalls out. With a warm engine this never happens.

 

[breath2]

The engine was warm when I attempted to put it in reverse. The way it jumped and then quickly stalled out I'm not sure I would be able to give it enough gas pedal to stop it from stalling out and still control it. I'm having real negative thoughts that it's a serious transmission problem.

 

[earthworm]

I wonder if the 4 gear lock up solenoid is sticking or hanging , causing this unusually low RPM reading. Much as a manual transmission in 5th gear at 1,000 rpm would cause problems, an automatic may do the same under that unusual stress.

This may be fairly easy to repair if the solenoid is external and accessible..
It appears not to be....
Just assure that all is properly plugged in and that the shift control is adjusted..

 

[breath2]

Problem Solved

It turned out the problem was casued by broken motor mounts. Two of the three were broken. I had all 3 replaced and the transmission goes into gear smootly and all is fine.

 

[philosophicaldreamer]

It turned out the problem was casued by broken motor mounts. Two of the three were broken. I had all 3 replaced and the transmission goes into gear smootly and all is fine.

This is exactly what happened to me. It did not even occur to me that broken motor mounts can incapacitate the transmission. It was a sweet relieve, however, to know that instead of paying for having the transmission worked on, I had to pay for motor mounts.

Ta-ta, j.

 

[earthworm]

Indeed good news. And evidently you have found a good honest mechanic - and this is even better news...

Apparently rubber is a maintenance item, to be replaced little by little between 100 to 200K miles. Broken engine mounts have been known to cause run-a-way acceleration and the engine fan to chew up the radiator, among other things.
This all depends on the particular design of the power pack cradling system and the linkage set up...
During the big general services the technician is to try to move the engine and transmission; bad mounts are then revealed..