W126 Spring Compressor help...

[Proctor750]

I got one of the ebay units which mimics the factory tool for my W126 front springs.
Everything looks great but I notice that the key ways on the bottom plate and the keys on the bottom of the shaft don't have much lateral tolerance.


So as long as you are almost perfectly level then the shaft easily passes through.



The problem is that the plate doesn't rest perfectly level on the spring so I can only ever get the shaft halfway through the bottom plate.



I had all wheels off the ground but lowered the rear back onto the ground and have tried jacking the lower control arm, prying with a pry bar etc.


I do not want to modify the tool to make it easier to pass through...


Could the orientation of the plate make a difference?



I tried a rubber mallet while the jack was keeping the spring as straight as it could but it just got stuck halfway again.

[Diesel911]

I have one of the generic springs compressors and when I took it apart, I found that the bearing was assembled wrong inside of it.

It is here.
Inside Of A Cheap Coil Spring Compressor

[Proctor750]

Originally Posted by Diesel911

I have one of the generic springs compressors and when I took it apart, I found that the bearing was assembled wrong inside of it.

It is here.
Inside Of A Cheap Coil Spring Compressor

Very interesting. I did get it to work finally and it worked very well.

My issue instead of the rod portion of the kit was actually the plates themselves.
They are a tad too thick and the cutout slightly too small.



Since the spring is never completely vertical when relaxed (and the plates rest on a coil which isn't level to begin with) I could never get the rod perfectly lined up with the bottom plate cutout and it would get stuck halfway through the plate. This is due to the slightly canted angle of the plate vs completely vertical rod.

Jacking up the control arm to straighten the spring didn't really help either.


SO I ended up putting the plate right in the middle of the spring a few coils apart so the rod would easily pass through both. Then came the battle to rotate the plates ALL THE WAY BACK to the top and bottom so I had 8 coils between them.



Once they were fully separated I had a new problem of not being able to turn the shaft without the bottom plate joining it.

This meant I couldn't index the foot of the shaft to the plates recesses.


Much hammering and chiseling later I FINALLY got the rod to seat into the recesses.



Then it compressed like a dream boat.



I chalk it up to the manufacturing tolerance telephone game.
The good news is I get to do it all over again on the driver side.

[Diesel911]

Originally Posted by Proctor750

Very interesting. I did get it to work finally and it worked very well.

My issue instead of the rod portion of the kit was actually the plates themselves.
They are a tad too thick and the cutout slightly too small.



Since the spring is never completely vertical when relaxed (and the plates rest on a coil which isn't level to begin with) I could never get the rod perfectly lined up with the bottom plate cutout and it would get stuck halfway through the plate. This is due to the slightly canted angle of the plate vs completely vertical rod.

Jacking up the control arm to straighten the spring didn't really help either.


SO I ended up putting the plate right in the middle of the spring a few coils apart so the rod would easily pass through both. Then came the battle to rotate the plates ALL THE WAY BACK to the top and bottom so I had 8 coils between them.



Once they were fully separated I had a new problem of not being able to turn the shaft without the bottom plate joining it.

This meant I couldn't index the foot of the shaft to the plates recesses.


Much hammering and chiseling later I FINALLY got the rod to seat into the recesses.



Then it compressed like a dream boat.



I chalk it up to the manufacturing tolerance telephone game.
The good news is I get to do it all over again on the driver side.

Cool.

[vstech]

I do have the official spring compressor in the tool rental section...

[Proctor750]

Originally Posted by vstech

I do have the official spring compressor in the tool rental section...

I browsed the tool rental section briefly and for some reason couldn't find or figure out what the heck I was doing. User error on my end.


I'm curious what the official tool plates measure to in thickness and cutout diameter. Kind of besides the point I suppose- DOH

[Proctor750]

Quick question for those who already contributed here:

The lower control arm bushing "flats" are supposed to line up with the top flat plane of the lower control arm no?

[Diesel911]

Originally Posted by Proctor750

Quick question for those who already contributed here:

The lower control arm bushing "flats" are supposed to line up with the top flat plane of the lower control arm no?

What year W126 do you have?

There I believe is a wika on it somewhere in the forum.

I tried locating a drawing I posted long ago on the W123. What I remember is there is a flat machined area on the control arm that the sheet metal lower spring perch bolts to on top of the control arm. One of the bushing flats is supposed be inline or parallel with that flat. Harder to explain in words.
Even if it is just a piece of cardboard lay a straight edge across that flat on over to the bore of the control arm bushing and make it with a felt marker on both sides of the bore and use that to reference where the flats go. And yes, the flats are on the top and bottom.

Only the W123 lower control arm bushing replacement is listed.

http://www.peachparts.com/Wikka/DoItYourSelf

[vstech]

Originally Posted by Proctor750

I browsed the tool rental section briefly and for some reason couldn't find or figure out what the heck I was doing. User error on my end.


I'm curious what the official tool plates measure to in thickness and cutout diameter. Kind of besides the point I suppose- DOH

They are THIN!
The difference in diameter of the screw assembly is the biggie… barely visible, but the difference is there.

[Junkman]

Please be sure to grease the threads of the compressor. The inexpensive tools can be damaged if run dry. I don't know about the factory tools. I've only used the cheap ones. I forgot to grease one time and the difference in torq required made it so I'll never again forget the grease.

[Proctor750]

Originally Posted by Diesel911

What year W126 do you have?

There I believe is a wika on it somewhere in the forum.

I tried locating a drawing I posted long ago on the W123. What I remember is there is a flat machined area on the control arm that the sheet metal lower spring perch bolts to on top of the control arm. One of the bushing flats is supposed be inline or parallel with that flat. Harder to explain in words.
Even if it is just a piece of cardboard lay a straight edge across that flat on over to the bore of the control arm bushing and make it with a felt marker on both sides of the bore and use that to reference where the flats go. And yes, the flats are on the top and bottom.

Only the W123 lower control arm bushing replacement is listed.

PeachPartsWiki: Do It Yourself Articles - Mercedes Vehicles

That's what I thought - thanks for confirming. Makes since that it's inline with where the lower spring perch attaches.


I always use antiseize on threaded tools for sure.


I had a feeling the genuine tool would have thinner plates

[Clemson88]

I wouldn't try to make a living with a cheap spring compressor but I bought one and it worked fine. I plan on changing the springs off the gas 126 and replacing them with the springs off the diesel car after the paint is finished on my project car. The gas body (v8) front end rides higher than it should with a 5 cyl diesel engine mounted in the engine bay.

When that change is made I'll retire that cheap piece of junk.

[vstech]

Originally Posted by Clemson88

I wouldn't try to make a living with a cheap spring compressor but I bought one and it worked fine. I plan on changing the springs off the gas 126 and replacing them with the springs off the diesel car after the paint is finished on my project car. The gas body (v8) front end rides higher than it should with a 5 cyl diesel engine mounted in the engine bay.

When that change is made I'll retire that cheap piece of junk.

The blaum eBay tool is fine for a few springs on the 126, I’d want to clean and regrease the screw after each use, but it’s a robust tool.

The klan. I have is smoother, and of a higher grade of steel, also, it comes with a long and a short screw assembly, for clearance in 124’s etc. But for the 126, here are no issues with the Baum.

[Proctor750]

Just an FYI - my chinese ones are from "8milelake" on ebay. They worked but I wouldn't recommend them based on my struggles.