Crawls Backward (When Alarmed)

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SAAB c900 Front Motor/Engine Mount Replacement, Pt 1

I mentioned in the last post that I had a list of things to do on Gröna (aka Greeny). This is another item.

The car has that (typical?) c900 movement in the shifter - i.e. a fair amount of vibration at idle and backwards flex/movement under acceleration. So as a first attempt to cure it, I'm going to replace the front - gearbox - engine mount.

To digress a bit on nomenclature: you'll hear people say "motor" instead of "engine." A "motor" is an electrical device. Unless you have a hybrid or an electric car, you don't have a 'motor' under your hood. You have an engine. I'm not ranting here, just being more precise.

Also, I tend to say 'gearbox' because it's a pretty accurate description of what is also called a transmission. Although in the case of a SAAB c900 (and a lot of front-wheel drive cars), it's a transaxle, since the gearb... transmission and the final drive are in the same housing.


First thing is to remove the skid plate from under the gearbox. The front bolts are 12mm, the rear nuts are 13mm.

The plate removed.

Twenty-five years of grime on the engine side of it - I'm going to clean it off later.

Also note the grommet/bushing that fell down on it. I wonder how long that's been there?

I'll need to remove the intercooler pipe and the rubber bellows on the ends of it.

The mount is under there, just can't see it very well yet.

Removed the bracket holding the boost control valve and the connector that runs from the Trionic harness to the valve. You can see the screw that held the bracket in on the radiator rail.

I really like those slide/clip connectors SAAB used. Simple and effective design.

The right-hand side fan will need to be removed to get at the mount.

We use a T20 Torx driver to get the two mounting screws off.

After the fasteners are removed, the fan can be lifted up out of the way without disconnecting its wiring.

Now we undo the clamps that hold the intercooler pipe bellows on. Two clamps on each end.

This is the compressor end - the compressed charge goes from here to the intercooler, then out of the intercooler to the intake.

Here's the pipe removed from the car.

I'll clean it up and polish it a bit while it's off.


Now
Now the mount is visible.

There's a limiter bracket (arrow) that has to be removed first.

Note the open compressor outlet. I'll put something in there momentarily.

A better view of the mount. Easy to access now that the pipe is removed. The bolts holding the limiter bracket need to come off now.

Removing the 13mm bolt on the left side of the bracket.

These bolts should be easy to remove - they don't have a lot of torque on them.

And remove the right side bolt. I just put the ratchet under the radiator hose to get at the bolt.

I've read some comments on the Interwebs that indicate both fans and the radiator need to be removed - this isn't the case.

Note that I stuffed a clean rag into the compressor outlet. Don't want to get dirt or even worse - a fastener dropped down there!

I shudder at the thought.

This is one of the bracket bolts - along with its washer and spacer. Keep these in a safe place so they can go back in just as they came out.

And here's the bracket itself.

When the mount flexes upward, as it would under hard acceleration, the it contacts the bracket which limits its movement.

There is a known 'mod' to the bracket involving putting a piece of radiator or AC hose under the top of the bracket to limit motion even more.

I had a piece of hose cut and flattened, but it was too thick - it would contact the top of the mount, so I decided against putting it in.

With the bracket removed, the rubber bump stop over the mount's center bolt is visible.

The bump stop just comes right out.

It's even shaped in such a way as to only fit one way. Those clever SAAB engineers!

And now we can see the main nut that goes on the mount's center bolt. It's bolted to the gearbox bracket.

Note the height of the bolt in this picture in relation to the bracket.

There is a lot of torque on the nut.

I soaked it with PB Blaster penetrating oil, and tried a breaker bar, but couldn't budge it, so I used my trusty Ridgid cordless impact wrench, armed with a 6 inch extension and a 19mm socket.

Five seconds later the nut was loose.

The gearbox bracket needs to be raised up so the mount can slide out from under it.

So I put a block of wood under the gearbox and jacked the front of the engine up with a floor jack.

Jack it up until the bolt clears the gearbox mount.

I had read about this online and had some trepidation about doing it, but there is enough flex in the other 2 mounts that this works fine.

Note that the bolt is now clear - compare this shot with the earlier one I referenced.

I'd guess I raised the engine up maybe 30-35mm, or about 1.75 inches or so.

The finagle the engine mount out.

In practice, I raised the engine a bit, tried the bracket, raised it another bit, etc., until the mount was clear.

You can see it lying at the bottom near the electrical connector.

Success!

Here we have the old mount on the left and the new replacement on the right. Yes, it's shot. Look at how badly the rubber is torn.

You'll also note the washer on the workbench - we need to make sure that's in place on the new mount when it gets installed. That will happen in the next post.


 
 
 
 

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