How long do OE motor mounts usually last? - Page 2 - PeachParts Mercedes-Benz Forum

NJ300sdl · #16 08-29-2010, 05:23 AM

I had same problem. Found three bent wheels and a bad universal joint.

BodhiBenz1987 · #17 08-29-2010, 12:50 PM

Quote:

Originally Posted by NJ300sdl

I had same problem. Found three bent wheels and a bad universal joint.

Yikes. The U-joint would be a possibility; I wouldn't know how to tell if it was bad (I'd think the vibrations would be mostly under my butt, then, but I realize vibrations go wherever they feel like). As for the wheels, I recently had all four balanced and new tires put on the front ... if they were bent, do you think the tire shop would be able to detect that? That jumps out at me a bit because the tire shop I went to for years (including once a month ago) put the lugnuts on with way to much torque. I had another shop do the tires and put them on correctly, but I'm still worried the wheels or lugs were damaged. The vibrations came on gradually last winter, not at any time near having it at the tire shop, though.

vstech · #18 08-29-2010, 01:04 PM

Quote:

Originally Posted by BodhiBenz1987

Alright, I've searched for about an hour and can't find the torque specs for the 87 300D transmission mount anywhere. I found them in a thread this morning and didn't write them down (

) and can't find them now. They don't seem to be in my AllData discs and I don't have the print FSM with this job in it. Lots of good threads on the procedure, but ...
Can anyone please list the torque for the bolts to hold the trans mount in place? I promise I'll write it down this time.

pull on it till the threads strip, then back it off a hair...

sixto · #19 08-29-2010, 01:14 PM

For a 123 mount to crossmember is 25Nm and mount to transmission is 70Nm. Should be safe numbers for a 124.

Sixto
87 300D

BodhiBenz1987 · #20 08-29-2010, 01:48 PM

Quote:

Originally Posted by vstech

pull on it till the threads strip, then back it off a hair...

Thanks sixto.

BodhiBenz1987 · #21 08-29-2010, 10:03 PM

Can't get a wrench on the dang top nut. The box-end wrench won't fit between the nut and the flex disc and the open end isn't getting a good purchase. Hmmm. Think I will buy a 6-point box end or a flare wrench tomorrow.

vstech · #22 08-29-2010, 10:39 PM

hmmm I am sure I did it with open end wrench, what size are you trying? I don't think you can do it with a flare wrench, they are too wide. use a open end with 4 flats not two flats and a rounded butt.
it looks like I'm picking up a twin to your bodhi, only a tad more miles. 360K... I may wanna pick your brain for tweaks on her.

Billybob · #23 08-29-2010, 10:48 PM

Quote:

Originally Posted by BodhiBenz1987

Can't get a wrench on the dang top nut. The box-end wrench won't fit between the nut and the flex disc and the open end isn't getting a good purchase. Hmmm. Think I will buy a 6-point box end or a flare wrench tomorrow.

Are you referring to the top nut on the tranny mount? It probably won't help you at this time, but there is a wrench that's found in some older MB tool kits and many BMW tool kits.

It’s a “dog bone” Heyco No. 450 style with a 17 mm and a 19 mm ring that is perfect for that job. It’s a 12 point and the ring itself is quite thin and the wrench itself is quite thin, that makes it perfect for the tranny mount's top 19 mm nut in that confined space on the tranny tail.

It’s also the perfect wrench when you use the 17 mm ring for the nuts on the differential side of rear flex disk where there is very little room between the nut and the differential and there is very little space around the circumference of the nut. This wrench can get on the nut and prevent you from rounding it. If you're talking about the nuts on the front flex disk this is the answer for them also And even being thin as it is, being a Heyco it's of good quality in material and fit on the fastener. I always check the BMW trunks in the bone yard for these!

If you are referring to the tranny mount’s top nut, a six point tool may not work as you’ve only got a very short swing on the wrench there before you hit the vertical rib on the side of the tranny tail, if you can get the wrench on the nut you probably can’t turn it enough to allow it to get it on the nut for the next pull because you've got less than 60 degrees of arc to swing the wrench!

Fulcrum525 · #24 08-29-2010, 11:08 PM

Quote:

Originally Posted by Billybob

Are you referring to the top nut on the tranny mount? It probably won't help you at this time, but there is a wrench that's found in some older MB tool kits and many BMW tool kits.

It’s a “dog bone” Heyco No. 450 style with a 17 mm and a 19 mm ring that is perfect for that job. It’s a 12 point and the ring itself is quite thin and the wrench itself is quite thin, that makes it perfect for the tranny mount's top 19 mm nut in that confined space on the tranny tail.

It’s also the perfect wrench when you use the 17 mm ring for the nuts on the differential side of rear flex disk where there is very little room between the nut and the differential and there is very little space around the circumference of the nut. This wrench can get on the nut and prevent you from rounding it. If you're talking about the nuts on the front flex disk this is the answer for them also And even being thin as it is, being a Heyco it's of good quality in material and fit on the fastener. I always check the BMW trunks in the bone yard for these!

If you are referring to the tranny mount’s top nut, a six point tool may not work as you’ve only got a very short swing on the wrench there before you hit the vertical rib on the side of the tranny tail, if you can get the wrench on the nut you probably can’t turn it enough to allow it to get it on the nut for the next pull because you've got less than 60 degrees of arc to swing the wrench!

I used a similar wrench the other day when working on the 280CE. Although in my case I don't seem to have any 19mm wrench so it was actually a 3/4 inch wrench...still seemed to fit perfectly.

BodhiBenz1987 · #25 08-29-2010, 11:17 PM

Quote:

Originally Posted by Billybob

Are you referring to the top nut on the tranny mount? It probably won't help you at this time, but there is a wrench that's found in some older MB tool kits and many BMW tool kits.

It’s a “dog bone” Heyco No. 450 style with a 17 mm and a 19 mm ring that is perfect for that job. It’s a 12 point and the ring itself is quite thin and the wrench itself is quite thin, that makes it perfect for the tranny mount's top 19 mm nut in that confined space on the tranny tail.

It’s also the perfect wrench when you use the 17 mm ring for the nuts on the differential side of rear flex disk where there is very little room between the nut and the differential and there is very little space around the circumference of the nut. This wrench can get on the nut and prevent you from rounding it. If you're talking about the nuts on the front flex disk this is the answer for them also And even being thin as it is, being a Heyco it's of good quality in material and fit on the fastener. I always check the BMW trunks in the bone yard for these!

If you are referring to the tranny mount’s top nut, a six point tool may not work as you’ve only got a very short swing on the wrench there before you hit the vertical rib on the side of the tranny tail, if you can get the wrench on the nut you probably can’t turn it enough to allow it to get it on the nut for the next pull because you've got less than 60 degrees of arc to swing the wrench!

Oh that wrench would have been perfect! However, the goods news is, with a bit of patience, an open-end wrench and a move I can't even describe (I managed to get a foot on the end of the wrench), the nut came loose. From there, the job was pretty easy.

The old mount was a little shorter than the new one, but it wasn't broken. We'll see how it drives tomorrow.

Wanted to double check on the torque, though. The top nut is 70nm, the small nuts underneath are 25nm ... but what about the 17mm nuts that hold the bracket (crossmember) to the chassi? There are four of them. They seem important to get right as they hold the trans up.

vstech, sounds great! Post some pictures as soon as you get her. I of course am very fond of the white w124s.

Billybob · #26 08-29-2010, 11:35 PM

Quote:

Originally Posted by BodhiBenz1987

Oh that wrench would have been perfect! However, the goods news is, with a bit of patience, an open-end wrench and a move I can't even describe (I managed to get a foot on the end of the wrench), the nut came loose. From there, the job was pretty easy.

The old mount was a little shorter than the new one, but it wasn't broken. We'll see how it drives tomorrow.

Wanted to double check on the torque, though. The top nut is 70nm, the small nuts underneath are 25nm ... but what about the 17mm nuts that hold the bracket (crossmember) to the chassi? There are four of them. They seem important to get right as they hold the trans up.

vstech, sounds great! Post some pictures as soon as you get her. I of course am very fond of the white w124s.

The 19 mm tranny mount top nut to 70 Nm, the four cross member securing 17 mm to 45 Nm, and the two 13 mm tranny mount bottom adjusting bolts 30 Nm.

BodhiBenz1987 · #27 08-29-2010, 11:47 PM

Quote:

Originally Posted by Billybob

The 19 mm tranny mount top nut to 70 Nm, the four cross member securing 17 mm to 45 Nm, and the two 13 mm tranny mount bottom adjusting bolts 30 Nm.

Thank you!!! I was close, I had guessed 40nm on the four ... I'll tighten 'em another 5nm and should be good to go.

Billybob · #28 08-30-2010, 12:14 AM

Quote:

Originally Posted by BodhiBenz1987

Thank you!!! I was close, I had guessed 40nm on the four ... I'll tighten 'em another 5nm and should be good to go.

Have fun and good luck!

BodhiBenz1987 · #29 08-30-2010, 01:45 AM

Here's a picture of the old and new mounts:

Not sure if it will make a difference or not. I took it for a short test drive but at 1 a.m. didn't feel like going out on the highway. Up to 60 it seemed like no vibration, though I'll consider that inconclusive since the vibration has been intermittent. We'll see after tomorrow when I drive it to work.

I did notice it seems to have a slight vibration when at idle in drive now, though ...

. I'll update tomorrow or the next day when I give it a proper drive.

BodhiBenz1987 · #30 08-30-2010, 02:56 PM

It didn't really help.

Acceleration seems a little smoother between 40-60, but other than that, same story. Certainly didn't hurt to replace it, though.
Trying to decide what to do next ... bit discouraged at this point. Guess I should probably take care of what I know is bad in the rear and then start looking at the front again. For all I know I'm getting vibrations traveling up the car from the back. It certainly does dive back and forth on the highway a lot, like a drunken gazelle.