Transmission mount 19mm top nut on 4Speed 240D will not come out - PeachParts Mercedes-Benz Forum

MyOld240D · #1 10-31-2015, 08:27 PM

I am at the end of my rope with this nut, exhausted tired dirty and I smell like coolant, oil and diesel fuel after replacing my head gasket today.

I have tried with all the strength I have to get this nut to turn. I've even removed my transmission support to let the transmission hang down but, it still doesn't give me enough room to get a ratchet on it.

Other than sawzall-ing through the mount and then trying to find a new nut tomorrow, what are my options?

I have tried PB Blaster... a sledge hammer on the wrench... oh that nut is not rounded... the wrench snapped in 2 though...

Please help.

And no, I don't know why I decided to tackle this after doing a head gasket. I just want that old mangled mount out of there.. it is the original mount and it is cracked and rotted and sludgy..

Frank Reiner · #2 10-31-2015, 08:50 PM

Since the stud, and the nut that is screwed onto the stud, are pointed away from you when you are under them, there is the possibility that you are turning the nut in the direction of tightening, rather than loosening.

MyOld240D · #3 10-31-2015, 09:08 PM

I thought the same thing and tried it both ways. It will not budge, period. Imgur: The most awesome images on the Internet

barry12345 · #4 10-31-2015, 09:11 PM

If it is a nut borrow a nut splitter. That's if there is room to get it on but they are not large and work fine. They come in different sizes. It looks like you have enough room in your attachment picture to get one in there. Actually they are not expensive and a tool box can use them.

I live where you must have ox/acc and a lot of other things to deal with removal issues. Or you probably would lose your mind.

charmalu · #5 10-31-2015, 09:38 PM

It is not a Bolt and Nut. The Stud is part of the mount.
If you want to use a Sawz All, cut under the Transmission,
through the top of the mount and cut through the Stud.

or soak it down with kroil

Charlie

sent from my pos computer

MyOld240D · #6 11-01-2015, 01:01 AM

Well. I tried heat, that didn't work out. I have resigned myself to the fact that I am going to have to cut the mount off, and then try to find a replacement nut. I shouldn't have to do it this way. The damn nut should move. If I find threadlocker, I'm going to have words with whoever installed this mount.

A sledgehammer won't even move the damn thing.

leathermang · #7 11-01-2015, 01:09 AM

Thread locker is not at fault.... in fact most of the time thread locker acts like an antiseize compound with regards to protecting from corrosion.... I have used RED locktite for 40 years.... on a regular sized nut it only adds about 5 ft lbs to the torque required to break it loose..... but it keeps it from becoming totally loose after a couple of turns like a ' lock washer' does... and the RED is technically listed as ' stud and bearing mount'... I love the stuff.
I know it has been mentioned... but are you really really sure you are trying to turn it in the proper direction ? Something basic is wrong for this to require this much torque with no movement....

MyOld240D · #8 11-01-2015, 01:22 AM

Huh. And yes, I am turning it in the right direction. I'll admit that spatial orientation is a bit difficult for me. I've done this job multiple times and never had a problem.

I had thought multiple times that I was turning it in the wrong direction and changed directions. I've got the car up on ramps and I'm able to get under it from the driver's side and I have a clear view of the bolt. From that side I am pushing on the wrench towards the right which should turn the bolt left...

I picked up a metal sawzall blade at Walmart and am going to tackle this when the sun comes up.

TopKnot · #9 11-01-2015, 01:45 AM

Before I started surgery I would remove the tranny cross member after removing the two bolts that attach the mount to the cross member.

Then I would get a 6 point wrench on the nut, there is very little room to swing the wrench on the nut because it sits in a space boxed on three sides. Good! Instead of turning that very difficult to turn nut, use a big wrench adjustable or otherwise as long as it fits maybe even with a cheater bar to turn the upper section of the steel mount that the stud is welded as part of. You can even cut the mount apart if it hasn't come apart already, getting the lower part out of the mix altogether. Maybe stick a small piece of wood or something along side the 19 mm wrench if and where it might make contact with the aluminum sides of the space where the nut is being held by the wrench. If there is a helper he could use a 2X4 braced up along the driveshaft and the wrench handle to prevent the 19 mm wrench from swinging too far or hard. having a couple foot of tool handle to apply torque to the mount should make short work of getting the stud and nut apart.

The steel plate along the top of the mount that the stud is welded to is in direct contact with the bottom of the aluminum tail piece of the tranny, might be difficult to separate that plate from the stud without taking at least a Sawzall blade kerf's thickness off the underside of that aluminum tail piece.

On a side note I thought I saw Carbide tipped Sawzall blades at Home Depot, Diablo Brand I think.

leathermang · #10 11-01-2015, 09:56 AM

Quote:

Originally Posted by TopKnot

...... On a side note I thought I saw Carbide tipped Sawzall blades at Home Depot, Diablo Brand I think.

Diablo is a good brand.. so are these..
RemGrit 6 in. x 3/4 in. x 0.032 in. Carbide Grit Reciprocating Saw Blade-E0406122 - The Home Depot

MyOld240D · #11 11-01-2015, 01:41 PM

Well, cutting the part out was a success. I installed the new trans mount and actually have more vibration vs. the non-mangled trans mount. The engine is vibrating more too, so I'll definitely be getting those motor mounts done sometime soon. I found a rounded out bolt on the right motor mount, so it'll need to be drilled out.