RCorney17

I've got a 2001 ML 430 (AT) with 181k miles that has that distinctive thump when under load usually in 1st gear only when accelerating from a stop. No thump if slowly accellerating from a stop. Took it to the dealer and they said my motor mounts are shot. I looked under the car and have located them both. One is in plain view, but I'm afraid I don't know what a good mount looks like to compare. The car doesn't idle rough or lift more than I would expect when you blip the gas while in park.

Both a dealer and an indy shop quote about $600 to replace. I trust both shops. Being that the parts are only about $80, I'd like to know if any of you have DIY. I have wrenched before on my 03 bimmer an 03 MINI and am fairly comfy doing it. My friend has a hoist in his garage and I plan to get his help with the job.

Thanks!

Maj. Dundee

If you have access to a lift there is no problem whatsoever. Replacing these mounts are no different than any other car or truck.

bbearden

I replaced both motor mounts and the transmission mount in my garage today using nothing more than jack stands and a floor jack. The transmission mount took less than 30 minutes as did the passenger side motor mount. The driver's side is a different story as I had to remove the power steering pump and loosen the AC compressor to get to one of the torx bolts. It was a pretty straightforward process, though I have heard this is a bit less room to work in the ML 430.

RCorney17

YES! Very tight with the V8 in there. While I didn't change the tranny mounts I can see how they would be a quick replacement. I also concur that the pass side was simple. The driver side was nearly impossible to remove/ replace. (wish I would have read this post before starting the job, I would have gone ahead and done the removals you talked about)

Sounds like we were doing the same job at the same time. I worked all Saturday and we got to a point where we could not lift any more of the engine for removal and started looking at parts to remove to gain access to the driver's side top nut. We ended up taking turns using an open ended wrench turning about 1/8 inch at a time and finally getting it off.

I guess using a floor jac to push the engine up negated the need for using the flimsy hooks at the back of the engine huh? Those things look to be a little stronger than pot metal.

Regardless, the new ones are in. Driver's side was totally shot. Pass side was smashed. Result= saved $$ in labor, no more thump on accelleration.

RCorney17

For those interested in doing this one yourselves, here are my lessons learned and thoughts on the process:
-This is a DIY with the right tools, patience and decent mechanic skills
-If you have the means ($) and don't want to get under your car, take it to a shop
-top nut is an 18mm, botomm two nuts are 16mm.
-Removal of the fan shroud is recommended unless you guide each fan blade past the shroud as the engine is raised
-Passengers side is a breeze; easy access from under car
-Removal of some brackets holding P/S hoses is helpful to access drivers side
-Removing P/S pump gains more access to driver's side
-Loosen A/C allows yet more access.
-having a wratcheting 18mm wrench would have sped my process
-Be sure engine lifts out equally (this may seem automatic, but I made the slightest adjustment and gained more access thinking it was equal)
-having a bar span the two back lift brackets should keep the brackets from bending inward toward the engine.

All-in-all, I'm glad I did it, but as always with ones first attempt at trying something new; it was hard work.

jbecke2

Just want to add my 2 cents (just did all 3 mounts on my 55)...


For the drivers side just remove the fender liner and use a "Gear Wrench" on the top 18mm bolt. I did not have to touch the PS or AC.

bbearden

I wasn't able to lift the engine enough to get clearance for the top motor mount bolt that secures the aluminum arm that secures to the motor. I take it you took both mounts out at once to get more lift when jacking up the motor?

jbecke2

Nope did them one side at a time, otherwise you'll never get them back in the holes. I did mine on a lift and supported the motor with a screw jack. Had to pry up on the alum. arm when taking the old mount out, kind of tricky but it came out and the new one slid in.

vr4boy

did this last summer on our 02 ml500...
2 jackstands on the truck frame and a floor jack with a piece of 2x4 on the oil pan corner (did one mount at a time).
the drivers side was hardest...didnt have to remove the ps or engine arm just raised that side high enough to wiggle the motor mount in.
one thing you have to do and is a "must" is to leave the tranny in neutral.
if its in park,raising the engine to install the motor mounts could bend the shift arm on the gear selector.
all in all pretty straight forward job...just take your time

gl..

NYCFIXMYPC.COM

I love this site.
I feel like I can pinpoint any issue I am having here.
I have a thump when accelerating from zero only. seems to be on the drivers side. I will have my mech. take a look and see. Do you guys think it makes sense to replace both motor mounts and the tranny mount while we have her open?

Maj. Dundee

Being that you have to raise the engine anyway, you might as well do both. They are fairly cheap at $35 ea.

NYCFIXMYPC.COM

Thanks for the insight. I'll make sure both are replaced. How about the tranny mount? Do you think it's worth replacing it just for the heck of its while the motor is raised?

Maj. Dundee

Of course.

Amopower

Hi all,The WIS instructions say to fit the engine on an engine supporting frame, and then to lift the engine by the front lifting eye. I have access to an engine hoist, but now am wondering if I need to also get this engine support frame that seems to go from one fender to the other?

NYCFIXMYPC.COM

had all mounts replaced and she runs like a champ!!

barijan

Could you believe that I got a pair of mounts recently and one of these was marked "front" at the WRONG side!

A friend of mine got similar mounts where the manufacturer obviously had corrected wrong markings just scraping these "front" marks at the wrong side and stamping new marks at the the correct side.

Well, to make this short, I have changed engine mounts for a long time and I know the smaller side is always the front side, for sure.
So, depending on where you get your mounts, do not believe blindly on the marks.

Installing it incorrectly will reduce the life span of the mounts and will put stress on the transmission mount and even on the driveshafts.
To dismiss any doubts, check the image attached.
Best regards!

Silicone

I'm looking forward to doing this soon and hope some experienced person can confirm something. In my travels reading so much information of late to acquaint myself with my new ride it was suggested that the motor mounts for the '02 ML500 and ML320 are the same dimensions or close enough to be interchangeable. It was suggested to buy the ML500 mounts for only a small amount extra gaining extra durability and strength. I can't find the reference so before I make a mistake hopefully someone here knows for sure. I've searched for this info but can't find it anywhere. Thank you.

khomer2

Vince,

Welcome.

More info.

Here are the MM for our 02 ML500 - part #11 - A1632400317

For an 01 ML320 - part # A1632400217

You can put in your vin# to verify the part # and compare.

Silicone

Thank for the welcome - great to be here and thanks to all for this amazing compendium of shared knowledge.

I couldn't find the answer to my question in those links however -- are they physically the same size and truly interchangeable or are the exactly the same part with just different numbers? If they have different rubber compound leading them to be more durable which I was led to believe, would there be any drawbacks to opting for the ML500 mounts?

khomer2

I cant confirm interchangeability, however, if you do a search with those part #s on ebay (as an example), they show that both part #s are for their respective model and are not interchangeable.
If they were interchangebale, I would imagine they would have the same part # (dont quote me on this).

I would recommend you stay with oem part # that is specific to your model. AND do not go with non-oem - there are not so good comments on the forums for those who installed generic MMs with not so good longevity results.

If some other members have first-hand knowledge of these 2 part number and interchangeability, they can chime in.