Re-boot CV joint or replace axel?
 

I have an 82 300D with 200,000+ miles. The rear CV boots are cracked (probably old age cracks) but have not broken and probably still have the original oil that was put in at the factory. As far as I know, the axels are fine and I have no rear end noise (from the car). :D

:confused: Is it better to replace the entire axel (with re-built) or to simply replace the four CV boots? I am leaning toward just the boots. From other threads, it looks like a toss-up between replacing the lubricant with gear oil or the grease that comes with the new boots: I will probably use gear oil. Either way, how difficult is the job from 1 to 5, with 1 being changing a tire? And an estimate of time from start to finish (then I double it for myself).

I have read the DIY from DMorrison and want to thank him for the effort he put in and the pictures so I can even consider tackling this job. Also the one from tobybul, thanks to him also.

Any suggestions on how to make the job easier will be appreaciated. I have access to a lift so won't have to do it lying on my back.

I am assuming that I will need the annular boots because that is what the car looks like.

Well from what I have found out it will work fine if you can get that HIGH dollar tool that streches the boot enough to fit over the can--and if they have never started knocking on a long trip.-And would be better than chinesium.

I agree 110% on the purchase of chinese products. I willingly pay a little more for US products, or things made OTC (other than china).

Just do the boots. The rebuilt axles are of a lower standard quality and they get polished down. If you have no noises, I say just re-boot them...

I need a new axle badly for 84 500sel. MB says I need a flange that costs almost 300.00 because i have homokinteics on now. Please someone who has done this switch... help me out here. What do i really need????

An Axle with no leaks and no noise are the prime canidates for just changing the Boots.

Lots of threads on changing the Boots. With some using the ATF Funnel to stretch the boots over the Axle has proven difficult.

Several Members own that Astoria Flexx Gun to stretch the boots (you also need to have an Air Compressor) and there may be one in our tool rental section.

There is also a Plastic Cone that is made by Dorman and Astorea that may work.

If your Axles are not making noise maybe your originals can be rebooted.

If you have another car to drive while the Axles are out you could call that Axle rebuilder in Colorado that is often mentioned in the threads (CVJ or CJV?) and see if they have exchanges or can rebuild your originals.

yes. rebooting is 100X better than a rebuild. if yours are not broken through, astoria boots can be installed, and new grease is included, but oil may be a better choice. it just depends on what you choose to use.
the gun is in the rental program, but I have it at the moment... I'm rebooting SEVERAL sets of good axles.

I have a chimanese axle and a stock axle. The chimanese one hasn't given me any trouble albeit its only 4 months old. We shall see.

I had to put a new axle on when my trailing arm crumbled.

Thanks all. It looks like the general consensus in to reboot as long as the current boots have not broken through so the oil/grease leaks out and dust/dirt leaks in. I checked prices and think I can do it for less than a couple of hundred dollars, assuming I can get the flex gun reasonably. I will check on that with vstech or the peach parts rental. Since the boots are not broken, I don't see any real hurry to fix them, but realize they will have to be fixed soon as the cracks are getting deep. I am convinced the ones on the car are the original. Imagine CV boots on an american car lasting close to 30 years and over 200,000 miles. I guess quality is worth the price.

Again, a very big Thank You to all who replied.

I'd put a layer of duct tape on if you want it to last any significant time. it could fail any day. the boots are about 15.00 each and come with grease, and collars. correct pliers are needed to crimp the collar, but you can accomplish the deed with pliers. I just bought 12 boots, and a set of pliers. I'm not going to use the grease unless someone wants me to. I'm putting in Mobile1 75W140 gear oil.

When i did the ones on my 240D, I used the entire contents of the grease packet that came with the boots and then filled in the remaining space with about a cup of 75w90 or 85w90 (can't remember which) gear oil. Figured that I'd gamble a set of axles on there not being any chemical interaction, and figured further that as long as it all eventually sort of mixed into a lubricative slurry, I didn't really care what its properties were.

Not recommending this to anyone, but it's what I've done to a set that have got a few thousand miles on them since, and it's what I'm getting ready to do to the ones in my w126's.

gear oil??!!??
 

I've never before in my life heard of replacing CV joint grease with gear oil. CVJ grease is specially designed high-pressure stuff, plus the boot seal isn't designed to retain liquid oil.

Gear oil just ain't gonna cut for any serious length of time.

I await experience=based reports to the contrary, but expect none.

I re-booted maybe a couple of dozen joints over its 825K miles on my '85 Golf and I would never ever EVER consider using a liquid gear oil for that application.

Boot kits come with a tube containing the correct amount of grease for the joint, why on earth would anyone bother to 'improve' on what the manufacturer provides and requires?

------------

By the way, one 'trick' I used repeatedly was to swap a set of joints side to side so that the worn forward-driven ball tracks became the reverse-driven side, giving me double the mileage from a set of joints. I even did this with some very badly chewed-up joints and got 100K miles and more out of joints most folks would have tossed. Sure they sometimes clicked in reverse but to me that was the sound of thrifty success!

I haven't done MB axles, but for my 126 the part numbers appear the same side to side, so I can't imagine there's any problem doing the same here.

In fact, I'd strongly prefer to swap joints side-to-side and reboot with high quality boots than buy _ANY_ new axle (other than OEM of course.) It'd cost much less and serve just as long.

dan k

The original MB axel boots are filled from the factory with oil. I put grease in when I rebooted with the Astoria boots and had a knocking on the drivers side, I then removed the clamp and put in gear oil and the knocking has gone away for over 5K miles. If I do a reboot again I will just go with the oil method.;)

I'm willing to assume that the M-B engineers knew what they were doing when they filled their factory original boots with liquid oil. Just because an aftermarket manufacturer thinks they have a better idea doesn't mean I am obliged to use it. Their rubber boot doesn't care what I put in it, and the M-B CV joint came from the factory with oil swimming around it. So, that's what I've put back. The grease in there is just... because we had it.

I don't deny that most manufacturers including NEW M-B now use grease. But I'm going with what was good enough for the first 30 years for the next 30.

EDIT:

That came out sounding a little snappier than I meant it to. Long week. All I'm trying to say is that the "experience-based reports to the contrary" are essentially every M-B that the factory ever made in the 1980s whose axles worked for 20+ years before failing.

If Brian Carlton recommends, it I'll do it!
Gear Oil!
all the way.
Mobil1 75W90 for that extra oomph of protection and longevity!

One persons choice:
http://boostnbenz.1baddsm.com/DIY/CVboots/

nice DIY!
I've got serious parts washer, and I'm getting everything spic-n-span! I'm not taking the joints apart, just cleaning them and rebooting. should be fun I'll take plenty of pictures!

OK, this is what I get for assuming things.
 

Well, my experience with CV joints has been in VWs/Audis and BMWs, so I guess I blew it when I extrapolated to include MBs, where I've never touched any joints, CV or otherwise.

:eek:

dan k

vstech, I agree with your comment on Brian. He has given me advice before and I have not gone wrong by following it.

I am not sure what gear oil I will use; possibly synthetic (I have it in my transmission and it works well). If you get a chance, please PM me about the availability and cost of the flex gun. I expect to order the parts this week. I am also going to get the differential oil seal in case I need it. If not used, I can send it back.
FYI part numbers: (Inner boot - 1263500337, outer boot - 1263500237, oil differential seal - 0039978347)

I assume the flex gun you are using is a rental from peachparts.

Hello Nomorehurry,
I read in your last post the part numbers that you listed, those sound like MB part numbers based on the prefix of 126. If you are ordering those boots YOU WILL have trouble installing them. The flex gun will not work with the MB boots you HAVE to use after market boots. The difference is in the flexability and thickness of the boots. Be careful here and use the after market boots from Dorman or Astoria. Just a word of advise from someone who has been there done that. Get an extra set just in case you tear one of the boots.

I went for CVJ re-manufactured axles last January.

They're still holding up very well right now. I just got remans and plopped them in. No need to screw around with that crazy boot gun.

there's no need to "screw around with that crazy boot gun" if you order a set from me either...
and they'll be MB original axles, not rebuild ones. rebooted UNDAMAGED axles!

OK everybody. I had thought it was a fairly simple project to put the boots on with the flex gun. The effort to remove and re-install the axels will be the same regardless of whether they are origianal, rebuilt, rebooted, or whatever. Most of the thread has said I would be better off putting new boots on the existing axels and re-installing them. (My mechanical skills are not those of a professional, but not near as poor as they were when I started on this thing.)

Bluebird recommends aftermarket boots due to the thickness of the rubber, but I thought that was the reason for using a flex gun. I can easily understand MB putting on a stronger boot than needed, and I don't expect the car to last another 30 years, so a softer boot would be OK. Alternatively, since the boots on the car are not broken through, perhaps I should just use a rubber glue to fill in the cracks (like goop) and then Duck Tape or Gorilla Tape to hold everything together and just keep an eye on it. (This is starting to sound better and better all the time.)

If Astoria or Dorman are better, where can I find them? My usual mail order store only listed "viaco and GKN Loebro" for the boots and "DPH" for the seals.

As for getting new or rebuilt axels in stead of re-booting, how does the cost compare. The parts I was about to order come to just over $100. I intend to replace the gear oil in the differential anyway, since it is probably the original stuff also.

ok, the original MB specified boots are slipped on before the steel cage is crimped into place. removing and replacing with original boots, requires grinding off that connection, disassembling the joint then rebooting and then crimping a new cage into place... not really possible for the amature rebuilder. the aftermarket soft boots, stretch over the joint preventing damage to the cage.
I ordered my boots from http://www.astoria2000.com/main.html called the number,and they called me back and took my order.
dorman boots can be bought from amazon.com along with a dorman flexx type installer!

Thank you! That is an explanation that makes sense.

I checked the astoria.com website and the one I found sells coffee machines for espresso. Good stuff, but not what I need. :D I also searched for doorman and found their site (doormanproducts.com). The CV boots they sell are the universal type - one size fits all or maybe none.

So I bought some rubber sealer and will probably use that in the boot cracks as a preventative (and as a salve to my conscience). I may put some gorilla or duck tape on the boots, but I doubt it. This project started as something to fix before it breaks, but they have been cracked for a couple of years so I guess immediate repair may not be needed. Eventual repair is a certainty.

it's astoria2000.com, sorry.
I searched for astoria and flexx on google and found them!

FWIW, I took the car to a MB dealership and talked to a MB mechanic with 35 years experience. He said that the CV boots crack ater a few months on the car, and then continue to stay cracked without breaking form 30+ years. He also said that if they are changed, to use the grease that comes with the new boot, (but I am sure he was talking about MB supplied boots).

I put some silicone sealant in the cracks so I would feel better, and am going to watch and see if anything changes. I may wind up buying new axels by doing it this way, but I am tired of replacing good parts because I don't know any better.

I've pulled a lot of axles lately, and there are surface cracks, and there are serious cracks. it's hard to tell the difference, but when the serious cracks are squeezed, the boot disintigrates!
if you can squeeze your boot and it does not open up, or break, it's likely in decent shape. but when it fails, dirt gets in there, and renders the axle un-rebootable.

Thanks. I think the ones on mine are surface cracks even tho the rubber seems a little dry. I did fill the cracks with a silicone sealer as a preventative measure (probably won't work) and will keep an eye on them. I realize there is some risk, but between the cost and work required for new boots I think it is acceptable. That said, if one does break I will contact you then because I will be replacing the complete axels on both sides.