Thanks

My authorised MB Motor shop in Aug replace only 1 mount because when reversing (gear on Reverse), the car vibrates badly. But he check when on Drive, it do not vibrate.
So only 1 mount was replaced in Aug'05.

Yesterday the other motor shop who replace the water tank & Radiator, spotted both mounts broken.

The question is either he presume 2 need to replace at same time without realising the other shop had replaced last yr or previous Shop had done something to stop the vibrating?

Currently on Drive i dont notice much vibration even on stationary. I suspect its the right mount which was replaced, am i right?

Some 1 mention if not replace it may cause stress upon other parts of engine, what are those possibilities??


Kind Regards

If you open your hood (bonnet) and rev the engine in Neutral (hand brake on), you will see that the engine lifts and kicks to the left when facing the engine from the front of the vehicle under revs. Same under heavy acceleration in gear, In reverse gear the torque forces the engine the oposite direction! So sounds right, they replaced the right hand engine mount(left looking from the front of the vehicle) as this loads in reverse and if broken would cause the shuddering. If your shop says both are broken it could be correct. Jack the engine up and you will soon see if either or both mounts are broken. Or have the shop hand you the broken mounts after they have replaced them, normally the rubber shears. If your mounts are broken, your gearbox and it's mount are the only thing stopping lateral movement and holding your engine relatively in place! Don't do an emergency braking or you may find your Fan starts trying to chew it's way through your radiator core!

Hope that helps.
Brian
280SL

Thanks

Confirm from your post that the right mount was the one replaced (looking from drivers seat). I will open the plastic base to have a better view today. I do not seem to be able to view the left mount from the bonnet? Is it exactly opposite side of the right mount?

Will the gearbox & its mounts be place with tremandous stress, over a long period? What are the signs of this?

How could the right mount be broken when it was replaced in Aug'05? The shop only had a rough look, could he be wrong, that its not only 1 mount need replacing? How much are they, do they come a set upon ordering?

Kind Regards

Confirming viewing from drivers seat, when I put the Reverse gear with brake on, the engine slightly lowers on left side & on Drive gear, it rises slightly on left mount. The Right Mount look pretty stable throughout this. This must prove that the left mount require replacement, right?

Also confirm that right mount had been replaced in aug'05 & dont need replacelement.

I like to check in the MB invoice it says L/H Engine Mount replaced, is that viewing from drivers seat or fron of car?

Kind Regards

Reference to "left" and "right" should be based on viewing the engine from the driver's seat ... similar to doors, windows, headlights, etc.

__________________
Fred Hoelzle

Ferdman is right, however It is difficult to view engine movement from the drivers seat, as well as standing in front of the engine. Another problem is in Australia the trade refer to the left side as Nearside and drivers side as Offside, as you drive/steer on the opposite side of the road, left and right and nearside offside are opposite. Now I've confused you and me!

If the shop has had a rough look, wait until they inspect thoroughly. The fact the mount is 12 months old does not preclude failure. Either have them inspect them thoroughly or check yourself, any signs of swelling/cracking or deterioration will indicate replacement if not actually broken. Regarding replacement, Phil at Fastlane, this site provider can sell you the parts, check this site. Re Gearbox, these are sturdy suckers and due to design of box and rear gearbox mount can withstand heaps, you won't damage it. The mount however is not designed for lateral front-rear movement to the same extent. If you have two broken engine mounts the gearbox/engine assembly can in extreme circumstances - ie emergency braking, move forward and damage the radiator. Besides that, it won't be a problem.

Manner of driving, oil contamination can cause a mount to fail, your best bet is examine and replace if necessary. If you intend keeping the vehicle for some time it is worth replacing as a pair, but thats my opinion, so be guided by what you find or the shop by inspection. Hope that helps.

Brian.
280SL

Thanks

Correction, the L/H mount is the one seen rise& lower during the Reverse & drive gear (with brake on). Whereas the R/H mount hardly any movement, meaning its collapse, correct?

You mention oil contamination, can damage the mount? How is that?

Also I notice in my radiator/water pump leak previously the colour of the coolant by the previous authorised MB service shop is green colour. Some post mention that MB engine dont like green coolant. Now with the new Raidator/water pump in place, I notice coolant in reservouir is not green, look like lemon colour I guess.

Kind Regards

i would think the one with more movement is the bad one.

but at the cost of them, i would prob do both. while you're there.

be sure to pb blast the allen screws well cause they can break off on you.

tom w

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

If your engine is a geasy oily mess underneath, good chance the oil has had an opportunity to soak into the rubber parts of the engine mounts. Oil tends to degrade the integrity of the rubber causing swelling and as the rubber fatigues it literally tears itself apart when placed under load, voila! Busted mounts and nice clean shiny breaks in the rubber mount. The underside of your floorpans will shown if the vehicle has suffered any long term leaks even if the engine has been steam cleaned prior to your purchase, they don't tend to clean too far back.

Your right about coolant, should not be green and yes Merc coolant looks like cats piss in colour. If you do find atomised oil over the gearbox and on the underside of the floorpans, have a good look at your rear gearbox mount, flex disk and diff mount. If your replacing mounts you may as well see what the rest of the drive train is sitting/spinning on while she is up on the hoist. Just may save you having future failures with rubber parts. It's not hard to tell, they go all gooey looking and start to swell out the sides of the mounts, generally spongy soft, not firm and perky like a 17 year old females finer bits!

Hope that helps and follow the last post about shearing bolts.

My engine been quite clean & hardly any grease or oil beneath.

I will have the mounts check to ascertain it true condition.

In the previous MB service shop indicate that there is an issue with the tailshaft coupling? Is this a bit issue & what are the symptom of this part needing replacement?

Can't Believe A Competent Shop Would Only Change "one" Mount.
That Is Like Replacing "one" Shock!
John1

Change all 3 of them at the same time.