a growing love affair, and now on to subframe

[Ed Fisher]

Well, as I continue picking away at this car it continues to show its appreciation with increasingly smooth behavior.  As you may remember, a couple of weeks ago we replaced motor mounts, engine support arms, and transmission mount.  Last weekend we put in the trunk mount to the differential and tweaked the transmission linkage.  The shifts are smooth, and the handling civilized and noise-free, at least from the back.  I know that this has all been said before, but dang, what a difference.

Now the sub-frame bushings are on tap for this weekend.  I have read the archives, secured parts from SL-Tech (thanks, Gernold), and lined up my helpers.  My question is:  will the alignment be changed so significantly that a 20-mile drive after subframe mount replacement will tear up my tires?  Are there steps that can be taken to get it very close for that post replacement drive?

By the way, a couple of significant things that I learned while reading/talking that may bear repeating:  Joe Alexander alerts against “hanging” the subframe in the air and stressing the mounts, as in a lift that supports only the body of the car.  Gernold seconded that opinion, and also extolled Joe’s expertise in this hobby.  Secondly, Gernold suggests getting the car on the ground and loading the mounts with the weight of the car for the final tightening of the leaf springs and mounting nuts to the bushing.  He used to stuff the mounts in there after prying things apart, but no longer does that after seeing wear that he attributes to not aligning/loading properly before final securing.  My intent here is to pass along some information that I hope helps anyone else in the future.

Lastly, as I risk beating a well-ridden horse, I wanted to say that this list is an amazing resource that I not only gladly support but also rely on as the tool that is most often used in the box.  The courteous exchanges, the freely given knowledge, and the support offered are invaluable.  I would not have undertaken any of these tasks without you.  My most sincere appreciation do I extend.

Ed Fisher
Dallas, Texas

[J. Huber]

Hey Ed, sounds like you are having fun! Only thing I can add about sub-frame mounts is that most swear by doing one side at a time. Also, when mine were done -- two summers ago -- it did not affect my alignment at all. I did motor mounts, shocks, sub-frame mounts, and sway-bar bushings all at once -- really improved things up front.

James
63 230SL

[George Davis]

Ed,

in theory, replacing the subframe mounts can affect toe and caster.  Toe could change slightly due to a different angle of the tie rods.  I wouldn't expect much change at all, really, certainly not enough to worry about for a few miles.

Caster could change if you don't get the subframe located fore-and-aft in the same place, but most instruction sets I've seen including marking the original positions of the leaf springs to be sure you get it back in the same place.

Thanks for the tips you included in your post, I violated both of them but will try to do better in the future!

George Davis
'69 280 SL Euro manual

[66andBlue]

quote:Originally posted by Ed Fisher
... Secondly, Gernold suggests getting the car on the ground and loading the mounts with the weight of the car for the final tightening of the leaf springs and mounting nuts to the bushing...  

Ed,
thanks for posting these tips. But please, could you flesh this out a bit more for the "technically challenged" like me.
Car on the ground .. but weight off, how?
With the car on the ground, can you get to the leaf springs?
Thanks for all the help!

Alfred
1966 blue 230SL automatic

[Ed Fisher]

Alfred:

Since I haven't done this yet I can't offer too much of an opinion other than what Gernold told me.  The idea was to settle the suspension fully before the final securing of bolts.  Gernold told me to pay attention on the left side and I would get a feel for it.  What I am envisioning is that there can be a binding or premature wearing of the new mounts if weight is applied after the final tightening sequence.  In other words, you want the mounts to be in their natural state, or close to it, when torquing them for the last time.  If there is no room under the car, I guess you could let the weight down with a 2x4 under the tire to allow a little access room.  It may not be too big of an issue though, as George has stated that he did not follow that procedure and all goes well for him.  I'll let you know more after this weekend I hope.

Ed Fisher
Dallas, Texas

[Ed Fisher]

I am back with an update after the installation this weekend.  The subframes had to be stuffed into place, and pried into position, just like y’all said.  The only thing that I could do to offer a settling reposition was to loosen the cap bolts after the car was on the ground and had been driven a mile or two.  I hope this will allow a little movement into a natural position.  Thanks to all the advice and help.  As it turns out the old mounts must have been done by the previous owner, because they came out not looking too bad, and the difference that the new genuine Mercedes parts made was not that noticeable.  Oh well, at least I know they are done now with good parts.

[merrill]

I read a post on the mercedes benz club site where a guy with a sedan used a sissors jack between the sub frame and the car to separate the halves.

'73 280se 4.5.Instead of using a crow-bar (or other prying bar) on the lip of the bottom frame support for these mounts, I used a sizzor-jack from my wife's Honda between the body and "A" frame with a piece of 2x4 cut-off for base support"

would this work on the sl?

[rhersberger]

I can't help any on the original question, put I recently had the entire front suspension completely rebuilt (plus rear shocks) on my '68 280 SL by a good professional and what a difference it makes.  Intellectually I knew the suspension was not in good shape. Only after driving with the rebuilt one did I realize how poor it had gotten over the years.  The car tracks and corners so well that the handling is quite remarkable.  I'll finish the rear suspension next year, but that is somewhat simpler.

[J. Huber]

Hey RHersberger, I know the feeling. Same was true for my car. I did about the same updating and it handles a lot better...


PS I see from the profile you reside in SB. Mind sharing which shop you use? Me and my car spent many years there.


James
63 230SL

[Khurram Darugar]

Ed,
   Did you replace the engine arms due to some sort of failing?  Or just a new set was at hand when you replaced the mounts.
Thanks
Kay

Kay
Euro 280sl LHD Auto.

[Ed Fisher]

Kay:

Here is a post that I had done on an earlier string.  HTH.  Ed

Well the motor mounts are in, as well as the transmission mount (which came out in 6 pieces). The job was a bear since the engine support arms had to be replaced as well. That is why I am posting. Had Gernold at SL Tech not warned me to look at the support arms I would not have known to check the part numbers and found that they were the incorrect parts that stayed with the motor out of a sedan. Fresh mounts would have only made the engine sit higher and made a mess. Thanks Gernold, for the wisdom and the correct parts. The difference is very subtle. Anyone not sure of their engine origin and looking to change motor mounts should get in touch with Gernold. All parts genuine Mercedes and top quality.

[rhersberger]

James:

I use Haik's German Automotive on Cota.  I've always had success with him.

Rod Hersberger
Santa Barbara

[al_lieffring]

The first clue that a SL has a set of sedan mount arms is often the front of the valve cover bumping against the hood. A set of worn sub frame mounts will reduce this clearance even more, new motor mounts even less hood clearance.

Al

113-042-10-014715
built 11 Jan 66
904/396 blue, Ivory Tex
condition- rust bucket

[J. Huber]

quote:Originally posted by rhersberger

James:

I use Haik's German Automotive on Cota.  I've always had success with him.

Rod Hersberger
Santa Barbara

Thanks Rod. I know the shop -- never used them though. My main guy from about 1980 to 1995 was Gunther, owner of Stuttgart Motors, but I also used the International Autohaus for basic stuff. Can't speak for recently but I recommend either to anyone out there, as they are familiar with our cars.

James
63 230SL