CV joint boot question - PeachParts Mercedes-Benz Forum

rickg · #1 02-11-2003, 06:38 PM

This is probably another one of my "wishful thinking" ponderings, but I'll toss it out here anyway.
before I took the little trip over the mountain pass last weekend, I checked the car over from one end to the other, and happily didn't find much that needed attention. Only tightened up the alternator belts a bit. But I did notice the CV joint boots are intact, but starting to look brittle and cracked. Anyone have any tricks to make 'em last a bit longer? Any kind of "dressing" that will soften them up and not bust open on me at a bad time? I plan on taking the axles off later this spring and re-booting them and replacing the diff seals, but just would like them to hold out till then.

#2 02-11-2003, 06:45 PM

Boots on the 123 cars started looking cracked in just a few years. I have never had a boot break on one of these cars, so I don't the cracks are a bad indication.

Boots on Hondas on the other hand tear up all the time. Of course, to be fair, those boots have to turn with the steering wheels, so they live a tougher life than those on the rear suspension of a Benz.

Good luck,

#3 02-11-2003, 06:58 PM

Well, cracks are not good. You don't want them to tear obviously. For if they tear, dirts and pebbles can get in, destroying your CV joints in the rear. Now, sure, you can get new shafts, however, from what I was told by a MB mechanic, you would then have to convert to the new "notched" shafts, which then require diff gear modification. ($$$$$$) Now, I'm not sure if my terms are correct, but it goes something along these lines. To shed any light further, my car had cracking/brittle boots for years till they fell apart in the shop while something else was being fixed. I then got replacement boots, but from what I understand, they are hard to find outside a dealership. I've heard of a lot of people speak of re-built shafts, but to fix the car with new parts, its an expensive and involved job. I would trust only a Mercedes mechanic with the right tools....

rwthomas1 · #4 02-11-2003, 10:23 PM

Hey if it ain't broke don't fix it!!! I have heard that coating rubber with petroleum jelly will help soften and preserve it but I can't vouch for this method. I like to spray rubber suspension bushings and such with silicone spray. I like to think it helps keep them from drying out. Reality is Carquest has the axles you need for $69.95 each. Wait until a boot lets go. When it does you still have at least a couple hundred miles before the CV gets boogered up, maybe more, then order the axles and replace them at your leisure. Why would you tear into something that ain't broke? RT

omegabenz · #5 02-12-2003, 12:12 AM

Put Black RTV on them, but smooth it very thin where it needs to be so its flexible.

Dont buy mercedes axles from napa, they are horrible, I had to buy all new clamps from mercedes, and also they rust.

Autozone has lifetime warantee, but I am going to buy benz ones next time.

samiam4 · #6 02-12-2003, 01:10 PM

Leave them alone- don't touch them!!!

Keep an eye on the cracks, until they break you are fine. I wipe down my new axle boots with silicone spray. Not sure if I would wipe on an old axle.

New axles *DO NOT REQUIRE DIFFERENTIAL MODS*. If I had a digital camera, I would show you. The MB parts catalog lists the axle and innner hub seperate. So, instead of one-piece assy, the inner flange stays with the diff(ala Porsche and VW/AUDI).

I purchased a new Lobro/GKN axle from the aftermarket($274) and it comes complete. IT was a drop in replacement for the orginal Homokinetic axle. DO NOT LISTENto suppliers selling you $250 rebuilt axles when you can have a new one for under $300. They just are trying to make more $$ on selling you an inferior part.

Many ppl on the list are going with Carquest axles for $69.95.

Michael

rickg · #7 02-12-2003, 02:52 PM

Thanks for all the input! I guess I'll just keep an eye on them for now. We're planning a long trip this summer, and i'm just a bit nervous about getting out in the middle of nowhere and having something decide to go away on me. I guess I'm just being a bit paranoid. Worst case is a boot will rip open. I'd still be ok until I could get somewhere to get it fixed.

rwthomas1 · #8 02-12-2003, 03:32 PM

When my boot split it leaked oil everywhere which sorta freaked me out so I jumped to replace both axles. The actual tear in the boot was only about an inch long and on one of the inner folds of the boot. Likely after all the oil leaked out I could have packed it with a greasegun and drove for another 1000miles if needed. Bottom line: don't be overly concerned about it. You could always buy the Carquest axles and stick them in the trunk. Since you really don't need any other parts to do the swap except gear oil any mechanic could handle the job with a little guidance from you.... Enjoy your trip! RT

Bill DeWitt · #9 02-12-2003, 09:56 PM

Duct tape will get you home if you catch the break
in time. Bill

#10 02-12-2003, 10:48 PM

Yeah, don't touch the boots, mere touch will break them, then you have a real problem.

#11 02-13-2003, 06:59 AM

My response referred to SURFACE CRACKS. If the cracks go all the way through, the boot will split. I have not seen one that did not have surface cracks.

As one of the previous posters in this thread indicated, "if it ain't broke, don't fix it!"

Good luck,

#12 02-13-2003, 12:51 PM

Well, obviously surface cracks will eventully errode to cracks. I was told that the rubber components on a Merc have a service life of 8 years until the rubber starts to decompose. Of course, this depends on conditions, etc.

leathermang · #13 02-13-2003, 01:35 PM

You can wash any rubber boot like these,,,, let them dry,,,, then take some open weaved cloth... like CheeseCloth.... and RED RTV ( room temperature vulcaninzing) gasket maker... and wrap the boot overlapping half the width of your gauze.....
You really have to work fast and it is really messy for most people.... it skins over in about 10 minutes depending on temp and humidity..

When starting start a little inside and go to the outside within a half revolution... so lock the starting end under the rest...

Very important not to touch it or move it for at least 24 hours...these are amazingly strong .... and may help your original rubber last longer due to keeping oxygen from it...ozone is a major problem for rubber....

GregS · #14 02-14-2003, 11:20 AM

Just work some petroleum jelly into the rubber. It really does rehydrate the rubber and make is swell up, helping prevent them from breaking open. You can do the same on rubber door trim that's old and squashed.

Greg
'84 300D, 173k
'90 300CE, 162k

pklarc · #15 02-17-2003, 11:47 PM

I replaced the boots on my 83 300d last year [ about 5k ago] with split boots. working fine no leaks