Axle Shaft\ C.V. Joint Questions?
 

Hi Folks,
I started getting a wierd noise from the driver's side rear. It is louder with the power applied & quiets down when coasting -there is little or no vibration. I've narrowed it down to the outer c.v. joint on the driver's side. (i think?) I'm looking for some thoughts& help........

With the 240d on the hoist, the left side axle shaft can be moved 1/2 to 1 inch in & out (towards the wheel & then towards the diff) All the "in & out" play is in area where the axle shaft meets the outer c.v. joint - no indication of leakage or ripped boots. Also noise appears to be coming from this area. If I move the axle shaft in & out & then drive the car, the noise disappears for a while.

My questions are:

1. Is it the outer cv joint?
2. Can I buy just a cv joint?
3. If I need to buy another axle shaft, what are my options? Any recommended sources?
4. How long should I drive my car with this problem? I use it right now for short local trips?

Thanks

Aivars

Axle shafts
 

Hi Aivars,you didn't mention what model you have.I have replaced both of my halfshafts,it's a fairly simple job.The noise that I had was a clicking noise at low speed,more pronounced in reverse.The shafts,as far as I know,are not rebuildable.Look for used ones,I paid $125Cdn each for mine.Maybe someone with more experience can jump in...

Hi Kyle,
My car is a 82 240d. I thought about looking for a used axle shaft. Although Parts America sells rebuilt ones for $120 US (this includes core price) - but I'm unsure of the quality??

I've read up on the R&R axle shaft posts, and it does seem simple. I just want to make sure I've reached the right conclusion & also try to get input on where to get my parts.

Aivars

Did you check the tightness of the bolt?

This bolt is on the end of the shaft at the wheel, you can see it if you take off the wheel, or the little "hub" cap.

Hi Ed,
I checked the bolt and it was tight.
Then I loosen the bolt to see if the splined end of the axle shaft was moving when I moved the shaft. But even with bolt out the splined end didn't move.

It looks like the "play" is located the on the outside cv joint. Where the axle shaft meets the cv joint. I'm not sure if this movement is normal?
Aivars

Yes, that movement would be normal because as the suspension (wheel) moves up and down, the "pumpkin" doesn't because it is fixed to the car. So the shaft changes length.

Could be a wheel bearing as a CV joint usually clicks instead of rumbles.

Hi Ed,

I didn't realize that movement was normal. Although there is a noisy clunk from the cv joint when I move the axle "in & out". I know the noise is coming from the driver's rear. When I spin the wheel you can hear it - I'm just not sure where it is coming from the joint or the bearing.

I thought since the sound went away (twice) after I jacked up the car - indicated that by varying the angle of the cv joint by jacking up the car & the sound going away indicated a problem with the joint.

After I jacked the car up & the noise went away I took the car for a high speed run on a couple of really bumpy roads to try to get the noise to start to start - but to no avail. Even doing circles in the local church parking lot (hoping for some devine intervention) didn't induce any noise.

Stumped in PEI! :confused:

Aivars

I haven't been on the forum this weekend much, but after reading your thread, I would bet on the CV joint rather than the bearing. Bearings usually roar, while CV joints can do many different things depending on failure modes. Bearings usually make a constant and relentless noise until failure, little can be done to eliminate the noise.

The real tip-off is moving the joint temporarily eliminates the noise. By moving the joint latterly you may be squeezing a little lubricant into the wear areas or causing it to run in a less worn position. This never lasts long and the problem returns.

The axle shafts are throw aways, it takes special tools to rebuild them. You can get replacements (most are rebuilt) from Advance Auto. Most other parts sources have them also. Used is a possibility, but is risky. I just changed one of mine - paid $150 from Advance Auto (82 240D). Mine lost a boot and began making a clicking noise. I repacked it with grease and put on a split boot. The noise stopped and it ran for another 50,000 miles, before the boot failed again.

Since the failure mode is usually loss of lubricant, you could take a stab at injecting some grease into the joints, if the boots are still good. You'd have to remove the boot clamps and slide the rubber back, so that it could be packed with grease. This is risky, because a 20 year old rubber boot is apt to be fragile. The lubricant they use is a heavy oil, but I have found grease works just fine. You may have to find some replacement clamps, if you can't save the old ones. It might work, if you are looking to save money.

Good luck.

Haven't personally been into MB joints, but have done several on smaller cars. Usually you can take them apart, clean them up, and inspect the balls and ball tracks to tell if they're really worn to the point of needing replacement. They look mysterious to the novice, but are not really that difficult. Any good repair book can step you through the process.

As far as replacements, definitely rebuilt! I suspect that the increase in the front wheel drive auto population of the last decade has spawned a HUGE c/v joint rebuild industry. I think they just re-grind the races and put in oversized balls. (I have a mental image of this minimum-wage person sorting through a 20-foot high pile of used axles, throwing them in bins: GKN, NTN, etc...) Point is, price is relatively low and quality high, because this is a well-established industry.

My two cents on rebuilts vs. new. I had vibration problems and decided to purchase rebuilt shafts......six months later I began to hear the famous clicking and never did completely remove the original vibration. Ended up trading the rebuilts in for new ones.

Probably just a bad experience but over the years I've learned the hard way that savings can be defined differently. I don't think I've ever spent more for a higher quality item and regretted it later....on the other hand, I have often tried to save by buying down and then wished otherwise later.

I'm going to keep my car for a long time and am busy making sure that each upgrade lasts as long as possible.

Nic
'85 300CD

Same sound, same problem with the only exception being I replaced both my axels (had them rebuilt) about 9 months ago. I will follow this post to see if you end up replacing your shafts and cure the problem. After giving up and taking my car to the shop last week where nothing was found wrong the noise has not come back.

I'm going to say that it's a bearing problem. When bearings go bad it's not always a constant sound. The sound from bad bearings depends on how the load is applied to them. For example, a bad bearing unit could make noise only when turning in one direction, or only when braking; when a particularly heavy load is on them. Ok, I'm not saying that it's definitely bad bearings, but this is my experience from bad bearings in my Volvo, 300D and Landcruiser. Oh, and when a CV joint went bad in my Volvo 850, it made a clicking sound.

Alex

Just an update on my cv/axle noise. It has disappeared!!...... at least for now. I still suspect that it is the outer driver's side cv joint.

My plan of attack is to try to lube it up and see how long it will be "noiseless". Any suggestions on lubricants. I plan to loosen the axle shaft side of the boot - but can't really grease up the joint. How about some gear oil poured in instead?

Keep the help& advice coming - that's why I like this board so much!!

Aivars

Again...intermitten noise is very indicative of CV joints early failure. I have spent several years as a rotating equipment specialist working for BP in chemical plants. I have analyzed and witnessed tear downs of hundreds of ball and tapered roller bearings. I've never ever seen a bad bearing in failure mode quiet down without intervention (a squirt of grease or tightening of float)... they always gets progressively worse. They also are generally independent of the throttle. About the only thing that will change the noise is reversal of direction, or change load (cornering or adding weight to the vehicle). A wheel bearing's purpose is to provide radial and axial support to rolling shafts.

CV joints on the other hand are very throttle sensitive, because they transmit the power to the rear wheels. They are very big (relative to bearings) and have less constraint than bearings (inches of end play as opposed to a few thousandths), which allows them to find different running areas. In certain positions they can make noise and in others they run fine. Most noisey joints are being starved for lubrication, and moving them laterally tends to temporarily redistribute lubricant to needed areas. At very advanced stages of failing the noise will become more consistent. That is why I suggested getting some lubricant into them could solve your porblem. I also suspect that even though you don't see failure of the boots, you may very well have lost a substantial portion of the lubricant - possibly through a loose clamp or even a small crack. The oil that is used is much like gear oil, which you may be able re-inject somehow??? (a big scringe??). I suggested grease as replacement, because it is easier to contain than a liquid.

Good luck.

Aivars - You might have trouble. I have had this problem with my Alfa, but thankfully not the MB...yet.
CV Joint repairs for the Alfa GTV were a wee bit over $500 Cdn.
Ouch! I have been told that this same repair on my 300 would be as expensive. Thankfully, there are a lot of these cars in the wreckers around here, and it doesn't seem to be too difficult a job. (But they never do, do they, at least until you get into it, or you find that you don't have all the right tools...or it starts to rain for a solid two weeks...or...).
If the CV joint is going, you can't do it any more harm. It has got to be replaced anyway. I'd just make sure my CAA card was paid up in the event it let go suddenly & needed a tow.