This may be a stupid question but is it easier to pull the lower control arm with the engine out or in? I have already pulled the engine in my '72 250 and I was thinking all along that now would be the best time to change out the subframe mounts and to replace the right bent LCA, but without the weight of the engine, can I compress the spring enough to get it out?

Can I just remove the subframe? Any suggestions?

Ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Definitely do it while the engine is out. The weight of the engine is irrelevant since you need a spring compressor anyway.

Check those subframe bushing mounting sockets closely. I don't know why the 250C's seem to be more prone to rust than other models of the 114/115 but they are. Maybe because the M130's dont leak as much oil, errr, I mean "self lubricate" the lower chassis area as do the diesels and 220's?

Since I don't have a spring compressor I was going to use another procedure where you jack the car up and place on stands along the frame and then use a floor jack under the control arm. Can I use any spring compressor and can they be rented from local auto parts store?

Ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Negative on the floor jack idea. You can get the spring out (remember this sound, "sproing" followed by "Oh crap"!) but it takes two men and a team of dogs to get it back in and we ain't talking common ordinary dogs either!

It takes a special spring compressor. The compressor goes INSIDE the spring through the opening at the top of the spring perch. External compressors wont work. At least not any I've seen.

So where do I get this spring compressor?

I am copying the link where the floor jack approach was discussed - what do you think?

72 250 - replacing lower control arm


Ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Tom's a braver man than I! I wouldn't attempt THAT process for all the tea in China!

I have all ten fingers and toes. I have been a mechanic for 34 years professionally and there is a reason why I have managed to keep them. Safety first! If that jack rolls or the spring slips while you are trying to fit those pivot bolts you are hamburger!

I can get the part number for the compressor Monday. Check on the "tool" section here on the board and see if they have a listing for it.

Let me just clarify and make sure we are talking about the same car - I have a W114 chassis and I can not find a specific spring compressor for that model anywhere. I have the 114/115 Chassis Service Manual from Mercedes and it does mention using a spring compressor. It uses a special jack with a cradle that attaches to the lower control arm - you unbolt the lower shock absorber nut, the torsion bar linkage, and the cam bolts and then lower the jack - and the control arm - slowly.

My concern was doing this without the weight of the engine... ?

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Torsion bar linkage? What torsion bar?

W114/115 uses a spring loaded lower control arm. No torsion bar. Are you talking about the stabilizer bar linkage?

I can see using a cradle to do the job. It would lock onto the control arm and prevent slipping.

The weight of the engine shouldn't have much effect. Remember, this is a sub-frame you are dealing with. You should have sufficient body weight to compress the spring. I have never done it this way without the engine in so take this paragraph with a grain of salt.

I think it is the same compressor for the 107 chassis. It consists of a screw mechanism and two circular plates. The screw mechanism slips down the center of the spring perch and is tightened from the top. The plates are grooved for the spring. They slip in between the coils and lock onto two flanges of the screw mechanism. You trap 5 coils between the plates and compress. It's still scary to have that much potential energy coiled up in front of you but it minimizes the slippage factor.

Again, just to clarify, in my previous post I misspoke - I said the manual DID mention using a compressor and that is wrong - the manual does NOT mention using a spring compressor.

And, the Mercedes manual clearly calls the bar that connects to the LCA a 'torsion bar connecting linkage', the Haynes manual calls it a stabilizer bar drop link. Just FYI...

None of this really helps me much though, because I also don't have this cradle for my jack...I could probably rig something, but...

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Go to "Tool Rental Program" I've rented one for $30.00 plus shipping and It was the "right" tool for the job. Good luck on your project.

I have already checked - none listed. I don't think there is one for a W114 chassis, unless you use the same one listed for a W116, W123, etc.

ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

Can anyone confirm that this spring compressor - from the Samstag web page will work for a W114 chassis? There are several of these available in the tool rental program, but the specs do NOT mention the 114 chassis???

http://www.samstagsales.com/klann_spring.htm

Thanks, Ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE

I've used that style and also another version of the compressor which instead of the locking lugs has an octagonal locking lip.

As noted, do NOT use an air impact on them. Check the lugs and their receiving areas closely for wear. The reason for not using an impact is because you can over-tighten the compressor and crack the plates or "wallow" out the lug receiving slots.

I believe on that style you can SLIGHTLY enlarge the hole in the lower control arm with a die-grinder and insert it from below. The preferred method is still from above but sometimes you have to loosen the subframe mounts to get clearance.

I use an Ordinary spring compressor for doing the W111 and W114 springs.Just buy a reasonable quality set from Pep boys ( or who ever has stuff like that in your area) You need 2 to squash a front spring enough to get the lower arm off ,they're almost 2' long when out. The 'mercedes book 'way of utilising the engine weight and a jack won't work for you because you have'nt got the engine in place.

OK, now I'm in a little bit of a bind.

I decided to wait until I reinstall my engine to try and replace the lower control arm - unless I can get my hands on a spring compressor. I thought while the engine was out though, I would go ahead and replace the front subframe mounts. Psfred had posted a procedure where you just removed the subframe bolts and you could pry the subframe down far enough to get to the mounts - well, that didn't work and I'm assuming that it did not work because I did not have the weight of the engine. So, I loosened the stabilizer arm and removed the shock absorber lower nuts and that worked (basically following Mike D's procedure).

Well, I got the mounts replaced but now I can't get the shock absorber down far enough - as I jack the lower control arm up the entire car goes up, so I am really missing the weight of the motor! Probably should have just waited...not really sure what to do short of finding someone (preferably someone who doesn't skip too many meals) to sit on my fender!!

May just have to wait until I reinstall the engine...


ryan

__________________
RG Newell

1984 300D
1972 250
1986 560SL
1991 300CE