Knackered engine mounts on an auto?

[Toe]

Keep reading that its dodgy getting gears on a manual may be down to the mounts but is there just as easy way to check them on an auto? Thinking as it changes itself it'll never show on changes....
I have an annoying squeak/resonance at low revs when getting warm, know its the bolt holding brace onto turbo but the exhaust sure does shake when looking at it from underneath!!
Exhaust isn't exactly very healthy but with that shake was thinking maybe mounts, the torque arm? near the power steering tank is split so could be a pointer but beginning to think the mounts are knackered, it has done 126,000............ 

[Saabman]

Is there not a hydraulic mount on the 9k that fails??

[chengny]

A quick check on the overall condition of the motor mounts is simple:

Put the transmision in park (or 1st gear if it's a manual) - do not set the e-brake.

Get out and open the hood

Grab a good solid part of the frame (radiator support e.g.) and rock the entire car back and forth.

Because the wheels are free to move (due to the released e-brake), the energy will be transfered through the axles, then up through the transmission. The inherent play in the axles and trans will allow you to get a little rythm going. Note the relative displacement of the motor. It should not move much in relation to the frame/unibody. New mounts barely allow any slap/play at all.

I find that the upper mount is the most critical and it's demise causes the lowers to fail quickly after. It is easy to change. Do a check to determine whether changing just it alone might tighten everything else up. Jam a piece of wood (or a screwdriver, wedge,...) in the rubber web. This will simulate a new mount and if (after another rock and roll session) the engine doesn't slap around so much as before, you might try renewing just that one.

Or you can skip all this and have a helper rock the car (drive to reverse) while you just lean over the engine compartment. Watch the play and try to look deep in thought - you know- like an expert.

Seriously, things can get a little confusing using the running engine to check mounts. It is usually better to rock the vehicle by hand.

After re-reading the OP, I now realize Toe was asking about the transmision mount. Sorry.

[Kev_Mc]

Welcome to STT chengny 

[Mark B]

If I remember correctly, the old engine mounts on my car made themselves known by allowing unseemly vibrations into the car.

[Toe]

Hey no I was querying the whole engine and gearbox, looking at the engine from underneath, or the exhaust to be sure it does vibrate quite a bit, specially when cold (expected I guess), this is what causes the exhaust to resonate.

Will try the ideas though, cheers fellas, hopefully may even partly solve the vibration when in gear but stationary though to be honest having never had an auto before I'm not sure how much vibration you're meant to have when brakes are on and in D!

[danilo]

 Upper TQ arm (dogbone :-) Rubbers fail with time and as mentioned above, if not soon replaced, cause the front lower Hyd engine mount to fail... first. Rearward motor rocking under power (allowed by iffy dogbone rubbers) creates upward forces which tears the forward mount.
 Trans mounts seem to only 'drop' a bit as they age. I've yet to see a torn one in 27 (yikes!) years of fooling with Saabs.
 First step is to repair or rplace the upper mount rubbers. (inserting strips of heater hose into the rubber voids works surprisingly well. Yes! it's Hillbilly but nonetheless, quite effective :-)
 Avoid the urethane mounts as in my experiences they cause more issues than they solve.

[lizard]

have a look for oil around the mounts as thay are hydraulic ther will be oil around the mount depending how long ther being gone for

[zebthecat]

Has the engine mount go on mine.

Top ones had gone and both front and rear bottom ones torn through as well.

Had a little vibration at idle but not much but what was obvious was a distinct back and forward lurch when the car changed gear as the engine was heaving around like a drunk. Having previously had a manual 9K i thought this was normal behaviour for the auto.

[chrisw]

Abbott Racing do a poly gearbox replacment bush (as well as the top bushes)- its comes with the correct mounting sleave -other simular aftermarket ones dont. - I know I went down that route and it cost me a lot more than buying the abbott kit in the end.
The hydrolic bottom mounts are pretty robust but will break if the others arnt replaced when required.

[Mark B]

I don't think Abbott do a gearbox mount for an auto, at least they didn't when I wanted one.  The engine mounts are fluid filled and rely on the fluid properties to provide damping.  So when the fluid gets old, they can cease to function properly even without leaking.

[chrisw]

Mark B
They did do one, check with thier "chief mechanic" its a polybush with thier "made for it metal sleeve" that fits nicely in the mouting. Without that sleeve the polybush flexes too much and doesnt fit properly. I wish I had bought thier one instead of all the hassle i had bodging the aftermarket non-abbot poly bush to get it to fit, but one lives and learns as they say.

chris