107 subframe mount replacement - PeachParts Mercedes-Benz Forum

knarf · #1 05-16-2004, 09:56 PM

Greetings Forum Members,

I need to replace the front subframe mounts on my Euro 1985 280sl.
I've read the DIY article in the forum for 108 body replacement.
The proceedure detailed in the MB service manual is much more involved, i.e. special engine support, dropping the entire subframe , etc. .
Can the 107 mounts be replaced one side at a time simular to the proceedure in the forum's DIY post?

Thanks,

Knarf

DavidSoine · #2 05-17-2004, 03:23 PM

I did my 560sl one side at a time and had no problem...OTOH several things have to be disconnected in order to make it happen. I supported the engine with a jack.

best,

Dave

knarf · #3 05-17-2004, 09:01 PM

Dave,

Thank you for the reply.

It was just what I wanted to know.

I'll be replacing mine soon.

Knarf

RandyA · #4 05-17-2004, 10:10 PM

Replaced the fronts on my 560sl in a couple of hours. Did not disconnect anything. The only bolts I touched other than removing the wheel were the mount bolts themselves. You really don't have to remove the wheel.
One floor jack, two jack stands, and a small piece of 2x4 lumber. One side at a time, jack the car and support with a jack stand near the jack hole but further under. With the jack under the subframe, near the coil springs is a good spot, tension the subframe against the body. Remove the bolts from both mounts on this side. Paying attention to the brake line, lower the subframe as much as you dare. I had 4 inches easily. Place the other jack stand so as to hold the subframe here. Don't place it under the control arm or any 'sprung' area that would allow further drop! Insert the 2x4 between the body and subframe to maintain the gap. Move the jack under each mount and with a socket on a long extension as a push rod raise the jack pressing the mount out of its pocket.
Lube the new rubber well with silicone or KY jelly. Set each mount in its pocket one at a time. Lay the board on top of the mount and raise the subframe with the jack to press the mount into place. Insert the new bolts with new nut plates.
Repeat.

The rear axle mounts were twice as easy to remove but twice as hard to button back up. Getting the bolt to line up with the nut in rear was frustrating. When the rear axle drops away it moves inboard and aft. Getting it up, forward and out while trying to thread the bolt caused all small children in the neighborhood to run inside.

DavidSoine · #5 05-17-2004, 11:17 PM

RandyA:

How did you pull the rear subframe mounts? Did you need a puller or did you drive them out somehow...or did they fall out.

Dave
'87 560sl

RandyA · #6 05-18-2004, 12:22 AM

Quote:

Originally posted by DavidSoine
RandyA:

How did you pull the rear subframe mounts? Did you need a puller or did you drive them out somehow...or did they fall out.

Dave
'87 560sl

I was able to pry them out moving from side to side a little at a time. . There's a metal flange on the bottom that's just large enough to work against. Also, getting the new ones seated was troublesome. It took brushing the inside of the pockets with a wire wheel and a lot of lube and hammer to get them in fully. The rear of the car is so light that pressing with the jack did little. A section of all-thread with large washers rigged to press them in would have been a better way to go.

DavidSoine · #7 05-18-2004, 12:02 PM

In other words, a Snap-on universal puller kit would have done wonderfully. 2 or 3 jaw with the slide hammer...OK...

Thanks,

-ds

knarf · #8 05-18-2004, 09:05 PM

To All,

Thanks for answering.

RandyA, thanks for the detailed replacement proceedure reply.

Knarf

YuCrew · #9 04-16-2005, 08:03 PM

RandyA's 'piece 'o cake' writeup was so good, it prompted me to tackle this job on a 1984 380SL with 84,000 miles. I encountered a few differences but nothing major. Here's my experience.

1. Remove sway bar
2. Jack up the FRAME on one side of the car and support FRAME with jack stands
3. Tension the subframe and remove brake line (where steel line meets rubber line), plug it, catch the dripping fluid and unfasten shock mount BOTTOM end
4. Remove both subframe mount bolts
5. Remove engine mount bolt (10mm hex socket head bolt)
6. Lower subframe and pry out the mounts (mine were very easy to remove) Don't be disappointed if the mounts APPEAR to be in good shape. If you carefully compare them to each other and to the new ones, you will observe big differences
7. Install new mounts, raise subframe and install the bolts. Leave bolts very loose (engage 4-5 full threads)
8. Reattach shock mount BOTTOM and lower the subframe
9. GENTLY raise engine under the pan (as called for in the Service manual) It's hard to believe the pan can suport such weight/force. I used a 2x4 to distribute the force across the pan
10. Remove engine mount (two 6mm hex socket screws); right engine mount was so compressed (1/2" SHORTER than the new one) I thought the new one might be an incorrect part. Pay attention to right side and left side mounts. The look very similar to each other.
11. Install new engine mount and 2 screws and lower the engine; tighten all 4 subframe mount bolts and 2 engine mount bolts once the other side mounts are installed
12. Reattach brake lines and bleed.
13. Reattach sway bar
14. Enjoy the NEW ride and handling

Strife · #10 04-16-2005, 11:38 PM

Quote:

Originally Posted by YuCrew

Pay attention to right side and left side mounts. The look very similar to each other.

Could you describe the difference (other than a splot of paint??). Thanks.

BabyBlueBenz · #11 03-10-2009, 10:07 PM

I know this is an ancient thread, but I successfully replaced my '86 560SL front subframe bushings today using a hybrid of YuCrew's and RandyA's methods mentioned here.

I did disconnect the engine shock, torsion/sway bar link and shock absorber but did not disconnect my brake lines. I was able to drop the subframe about 3 inches without tensioning the brake lines (it helps to turn the steering fully in the direction of the side your working on). The old mounts came out with just a little screwdriver prying...I didn't need to push them out (or back in) with the jack. The new mounts took a little bit of jostling to get seated (lubricating them and the cups they rest in makes a huge difference).

I knew they probably needed replacing when I jacked the front end up and saw this substantial gap:

That, and an annoying rattle from the front end on bumpy surfaces.

Here are the driver's side mounts compared to a new one...

The worst of the old mounts was broken pretty badly, although the rubber didn't look too bad (MB OEM part).

New mounts were made by Febi in a kit including all four front mounts & hardware.

Thank you for sharing your experiences YuCrew & RandyA!
You have helped me alot today!

nobby · #12 03-11-2009, 12:14 AM

Quote:

Originally Posted by Strife

Could you describe the difference (other than a splot of paint??). Thanks.

I heard that the only difference was the compound of the rubber in the mount.

mbboy · #13 03-11-2009, 04:08 AM

Just curious: what symptoms led you guys to replace your subframe mounts, and what differences did you notice afterwards?

Thanks

BabyBlueBenz · #14 03-11-2009, 09:19 AM

Quote:

Originally Posted by mbboy

Just curious: what symptoms led you guys to replace your subframe mounts, and what differences did you notice afterwards?

In my case, I had a bad rattling sound from the front when driving on washboard-type road bumps. Combine that with loose steering, and I initially thought that the steering coupler was the cause of the noise. After replacing the worn coupler, the steering tightened but the rattle still persisted. With my car jacked up, it was easy to see the loose subframe mounts as shown in my first photo.

I haven't driven the car yet, but I am anticipating a quiet and much improved ride.

Update:

Oh yes!...very much improved. I now feel like I'm in contact with the road, and not just bouncing above it. Gonna check the rears again closely, they're probably due as well.