Jackstand placement on the 380SL

I posted earlier about the purchase of an 82 380 SL with an engine problem. I have run compression tests: dry range 145-165 and wet range 160-175. Nothing there that would point a finger to which cylinder might be the one with the terrible noise which I assume to be a wrist pin or the rod bearing. This car has 134,000 original miles and while I don't have records with it it is apparent the car was not abused. It is perplexing that the engine should fail at such an early time on its clock. I was happy to see that it had been converted to the two row chain at some point in its life.

I received my newly purchased engine manuals today and it looks like it is time to fish or cut bait. I will be removing the engine and determining my next course of action once I find the source of the noise. Which brings me to my question. My workspace is limited to working on jackstands. While it appears that the front stands would be best placed on the frame-like rails molded into the body pan outboard of the front of the transmission I am at a loss as to where the rear set should be placed. I am unfamiliar with the rear suspension/ drive train setup on this car. For lack of a better/correct term I will refer to what looks like "rear A-arms" on this car. If I was winging it on my own I would probably place the rear jackstands somewhere to the outside reaches of those. Anyone concur or have suggestions on the safest or proper positioning of all four of the jackstands? Thanks for any insight.

Randy

[kip Foss]

I have worked on cars for nearly 50 years. Although I have never worked on a Mercedes (even though I have a 450 slc) I would say that you are safe to place jack stands on any portion of the rear suspension that is clearly well built, does have a brake line or rubber boot in the way, and that is as far outboard (more stability) as possible. My MB has jack points on the rocker panels which tells me that they are designed to carry the load of that portion of the car. I would check these panels for rust before I lowered the weight the car on them. If you are using a roll a round type floor jack be careful when you jack up back of the car after you have already put stands under the front. Floor jacks jack in an arc and they can pull the car off the front stands if the jack does not roll under the car as you are jacking it up. What ever you do, DO NOT scrimp on the money when you buy jack stands. Buy good quality. DO NOT buy the ones that are made from a pipe that is split into 3 legs. Wal-Mart has good, 4 leg ones for a reasonable price. I weld approx. 12 x 12 x 1/8in. plate on the bottom of my stands because I often use them on the gravel driveway.

While you have the engine out you should install a nice little 4 spd. manual trans. that I have for sale. It is out of a 350 slc and I am pretty sure would bolt up to your 380.

Good luck. Kip.

Thanks for the pointers. When I got serious about my car work I invested in a floor jack and a good set of jackstands. I had a set of the inexpensive jackstands you mention I used as a safety measure when changing tires years ago. Didn't take long to realize they were false security...

I ended up resting the car on the front and rear "A frames" as far outboard as possible. It is very stable.

The four speed would be fun, but for now at least I'll stick with the automatic and concentrate on getting it back on the road. Again thanks.

Randy