EBay Spring Compressor tube diameter - PeachParts Mercedes-Benz Forum

Graham · #1 06-15-2020, 07:50 PM

A friend has ordered a Chinese spring compressor off eBay. He is helping me with some jobs on my 300D.

While we wait for tool to be delivered, I would like to get a start and if needed, open up the engine bay access holes that the compressor shaft goes through.

Does anyone have a compressor that they could measure? I would like to know the max diameter of the center shaft.

BTW, I read about removing a couple of mm, but my springs were changed before and I would like to check diameter before grinding away more!

Graham · #2 06-16-2020, 08:37 PM

49 reads. I guess nobody has one of these handy to measure. We will have one soon, but it would have been nice to get those holes opened up ahead of time. I even emailed the vendor, but no dice there either. Oh well....

Rogviler · #3 06-16-2020, 08:52 PM

No, all my specialty tools are in storage. But the holes on my car measure 44mm. You'll want it a little bigger than the tool or it will get stuck.

Graham · #4 06-16-2020, 09:29 PM

Quote:

Originally Posted by Rogviler

No, all my specialty tools are in storage. But the holes on my car measure 44mm. You'll want it a little bigger than the tool or it will get stuck.

Thanks for measuring. Only 44mm? I measured my 85 300D and the holes measure about 48.9mm. Maybe already opened up? Or different model?

Do you have one of the eBay spring compressors? And does it fit through the 44mm holes?

Rogviler · #5 06-16-2020, 09:52 PM

Yes, I have the one in a red case with all black parts. I remembered the I did open the passenger side larger after struggling a little. This is with the calipers opened up to 46mm, which looks about what that one is:

If you have ~49mm holes that's plenty.

Graham · #6 06-16-2020, 09:57 PM

Great! Thanks for that Rogviler. One less thing to worry about!

Graham · #7 06-25-2020, 09:25 PM

Quote:

Originally Posted by Rogviler

Yes, I have the one in a red case with all black parts. I remembered the I did open the passenger side larger after struggling a little. This is with the calipers opened up to 46mm, which looks about what that one is:

If you have ~49mm holes that's plenty.

The compressor fitted fine. The holes on my car must have been opened up, because we checked another 85 300D and the holes were too small.

Thanks.

Rogviler · #8 06-25-2020, 09:56 PM

Nice! Always good when the annoying work is already done.

ROLLGUY · #9 06-28-2020, 04:15 PM

I don't have a photo, but I had a machinist friend of mine take off a mm or so from my compressor, and it fits in the hole without making them larger. He had to TIG weld the bearing retainer on top, as the snap ring groove was no longer holding. No big deal, it is only there to hold the bearing in while loosening the screw.

Graham · #10 06-28-2020, 05:14 PM

I saw a youtube video this morning. If you don't want to watch the whole thing, start at about 9:20. https://www.youtube.com/watch?v=dLVvS6CuNlQ

Looks like the plates slipped out after they had compressed the spring! Anyone else had that happen? Or is there something they forgot to do? That is a W210 with access from underside. But presume same problem could occur from topside. They held one plate in place with vicegrips when re-installing

Has anyone replaced springs? The plates are about 5.1" diameter. Too big for many vices. How best to hold spring to prevent turning while removing tension and then tensioning new spring?

When handling compressed springs, I see some just using their hands. Would it help to wrap with piece of carpet or something?

Rogviler · #11 06-28-2020, 05:42 PM

I've replaced springs several times on the 123, and using that tool correctly it's pretty much impossible for that to happen. There are 3 little tabs that fit into 3 slots in such a way that once they're locked in and there's tension on the tool the only way you would get the plate to slip off is if you were able to get tension off the spring and then move the plate up AND rotate it. I think what probably happened in the case of that video is that the tabs simply weren't in the slots so the plate was able to rotate itself.

So, my best advice is to check and re-check constantly that the tabs are snugly in the slots. You'll need a flashlight for sure, but I wouldn't proceed with removing the compressed spring until I was sure that everything was lined up correctly.

As far as taking the compressor off and then compressing the new spring, I feel the most safe with it flat on the ground and then holding in place from the top with my foot (like if you were cutting a log). Remember the law of equal and opposite reaction, you don't want either end stuck against anything or all that force is going one way like a bullet instead of just sort of flopping apart like a cut rope. And if the tool is properly lubricated it's not that hard to turn, even fully compressed.

Graham · #12 06-28-2020, 06:08 PM

Thanks. I am not actually going to do it myself. The friend who bought the compressor will do it. (he and his family have about 5 123s!) I just want to be sure he is as safe as possible, seeing he is doing it on my car.

I see your point about putting foot in middle of spring on ground when applying or releasing tension.

ROLLGUY · #13 06-28-2020, 07:01 PM

Quote:

Originally Posted by Rogviler

I've replaced springs several times on the 123, and using that tool correctly it's pretty much impossible for that to happen. There are 3 little tabs that fit into 3 slots in such a way that once they're locked in and there's tension on the tool the only way you would get the plate to slip off is if you were able to get tension off the spring and then move the plate up AND rotate it. I think what probably happened in the case of that video is that the tabs simply weren't in the slots so the plate was able to rotate itself.

So, my best advice is to check and re-check constantly that the tabs are snugly in the slots. You'll need a flashlight for sure, but I wouldn't proceed with removing the compressed spring until I was sure that everything was lined up correctly.

As far as taking the compressor off and then compressing the new spring, I feel the most safe with it flat on the ground and then holding in place from the top with my foot (like if you were cutting a log). Remember the law of equal and opposite reaction, you don't want either end stuck against anything or all that force is going one way like a bullet instead of just sort of flopping apart like a cut rope. And if the tool is properly lubricated it's not that hard to turn, even fully compressed.

The compressor in the video is different than the one I have. It has a horseshoe shaped lower plate that slides into a slot in the lower part of the shaft. Mine is like yours, it has the three slots. I don't care for the style compressor the guys were using in the video.

I also agree that the compressor should be compressed like you suggest, and then handled like a sweaty stick of dynamite.

Rogviler · #14 06-28-2020, 07:24 PM

Ooooh, I see the horseshoe plate now. I thought they were both the same. I feel way more comfortable using the disc with a hole style, which most of them are.

It's honestly another one of those things where if you use it correctly it's safe. And not only that but if you keep yourself out of the line of danger if something goes wrong that you can't foresee then you'll be good. Like a chainsaw, you never know when it could hit something and kick back, so you keep yourself out of the path of the chain at all times. Be cautious but no reason to be so scared you throw up either.

Graham · #15 06-28-2020, 08:07 PM

Quote:

Originally Posted by ROLLGUY

The compressor in the video is different than the one I have. It has a horseshoe shaped lower plate that slides into a slot in the lower part of the shaft.

Thanks! I hadn't noticed that either! The cheap eBay ones with hole in center are no doubt safer.