98 V70 Inject grease into CV axle boot

[98v70dad]

This probably a bad idea but I'm sure someone here will point that out if it is.

I have a 6 year old aftermarket passenger side cv axle that is probably worn out but it still is functioning OK - no clicking. I get some wobble vibration and low growling noise at higher speeds on acceleration from something. I can feel it in the accelerator pedal. ALL of the motor mounts have been replaced. Everything in the front suspension has been replaced. New wheels. Tires balanced and re-balanced. Fresh alignment.

I have an OEM axle from the junkyard that I'm going to rebuild and install when I get time.

I'm planning a "grand" upgrade on the front end - all the suspension parts are new and the drivers side axle is new. I'm thinking of replacing the front rotors (nearly at minimum thickness), wheel bearings and passenger side axle all on a long weekend. I have not been able to isolate the wheel bearings as being bad. I've done high speed s-curves, jacking the car and spinning the wheels, etc. I dont want to replace the bearings if they're OK because they are fairly expensive and the job looks like a pain. My daughter abused the car learning to drive so the bearings probably took a beating and are therefore suspect but the car has only 156,000 miles on it. Bearings usually dont fail that soon.

So I'm wondering if I could inject some grease into the CV axle boot and see if it quiets the growl ...just a thought. I dont know much about that part but I'm thinking a fresh dose of grease might quiet it for a short time confirming it alone is my bad part. What do you think?

[oragex]

If it doesn't "click" in tight turns in a parking lot, I would rather look for a wheel bearing. As for the pedal vibration, this may be related to engine vibration: misfiring, faulty valve, stuck piston rings

I did regrease my boots with molybdenum graphite grease I think, I had to undo the clamp with some wire cutting pliers, but tightening back the old or a new clamp is less obvious, it takes something like this (nut sure is the right size)

http://www.ebay.com/itm/Trident-Oetiker ... SwgQ9V6Pic

[abscate]

You really have to remove and disassemble a CV joint to lube it. The working surfaces are ball bearings on hardened races and squirting grease into it just doesn't get where it needs to be.

[98v70dad]

You really have to remove and disassemble a CV joint to lube it. The working surfaces are ball bearings on hardened races and squirting grease into it just doesn't get where it needs to be.

My idea was more of a temporary thing and not really meant to fix it. More a diagnostic technique to perhaps damp the noise if that's where its coming from. My thinking is that a big glob of grease would damp any vibration that might be a result of wear, at least for a short time. I fully understand that its not the correct way to lube a cv joint.

[98v70dad]

If it doesn't "click" in tight turns in a parking lot, I would rather look for a wheel bearing. As for the pedal vibration, this may be related to engine vibration: misfiring, faulty valve, stuck piston rings

I did regrease my boots with molybdenum graphite grease I think, I had to undo the clamp with some wire cutting pliers, but tightening back the old or a new clamp is less obvious, it takes something like this (nut sure is the right size)

http://www.ebay.com/itm/Trident-Oetiker ... SwgQ9V6Pic

I put in new plugs and checked wires and distributor etc just a week ago. There are no real signs of misfiring...a slight white-ish arc trace on the number 4 plug and boot, but I've addressed that. Apparently the boot was slightly loose on that plug at one time. It seems to be a very minor problem from the past.

I'll have to research how to diagnose a faulty valve or stuck piston rings - no idea how to do that. I have reason to believe it could be a wheel bearing but I've done everything mentioned on this site for diagnosing a bad bearing and it has passed my checks.

[abscate]

Both of my FWB went out on my 99 betweeen 120-170k miles, FWIW

[JDS60R]

Vibration under acceleration or load that goes away when you lift off gas pedal is usually an indicator of worn inner cv joints. The outers click.

The inners usually wear a pattern in the metal cup and adding new bearings will be a very short lived solution if at all. The Oreillys import direct axles are so cheap and durable I can't remember the last time I did a single joint or even a boot on a customers car.

[98v70dad]

Vibration under acceleration or load that goes away when you lift off gas pedal is usually an indicator of worn inner cv joints. The outers click.

The inners usually wear a pattern in the metal cup and adding new bearings will be a very short lived solution if at all. The Oreillys import direct axles are so cheap and durable I can't remember the last time I did a single joint or even a boot on a customers car.

Well thanks, but I never indicated that I would be adding new bearings.

My question was if injecting some grease into the boots would quiet the noise and vibration enough (for a short time) to be relatively sure that its the CV joint that is causing the issue. I'm trying to isolate the problem rather than replacing everything that it might be. I have OEM axles from a wrecked car that so no sign of any play at all. They have good boots on them. However, if I can isolate the problem and be relatively sure its the cv axle I'll go ahead and clean out the grease in the extras I have, put in new grease and install new boots. I don't want to invest a couple of days doing that and then find that the vibration and noise was coming from my wheel bearing if I can avoid it.

[abscate]

In my experience if a wheel bearing (FWB) goes bad enough to vibrate you can feel it if you get the wheel up. Ive never had one go bad that does this though - the start growlng and get louder over 10-20k miles

[JDS60R]

Vibration under acceleration or load that goes away when you lift off gas pedal is usually an indicator of worn inner cv joints. The outers click.

The inners usually wear a pattern in the metal cup and adding new bearings will be a very short lived solution if at all. The Oreillys import direct axles are so cheap and durable I can't remember the last time I did a single joint or even a boot on a customers car.

Well thanks, but I never indicated that I would be adding new bearings.

My question was if injecting some grease into the boots would quiet the noise and vibration enough (for a short time) to be relatively sure that its the CV joint that is causing the issue. I'm trying to isolate the problem rather than replacing everything that it might be. I have OEM axles from a wrecked car that so no sign of any play at all. They have good boots on them. However, if I can isolate the problem and be relatively sure its the cv axle I'll go ahead and clean out the grease in the extras I have, put in new grease and install new boots. I don't want to invest a couple of days doing that and then find that the vibration and noise was coming from my wheel bearing if I can avoid it.

You mentioned your were going to rebuild your used axle and you can't properly rebuild a cv joint without changing bearings (if worn), replacing grease and honing housing to tolerance and heat/stress treating the newly ground surface. I was saving time for all those who did not know that putting new bearings in or just adding grease doesn't normally cure the issue. The issue is wear and the tolerances must be restored before adding grease and bearings. Extra grease will not fill the void created by wear under load. It can't hurt but it wont help much either

As far as grease , make sure you use cv axle grease . There is a blend for outers and one for inners now ,as they each have a different style of bearing (Big debates in the cv axle rebuild community about this - I stay out of lubricant issues as folks go nuts ) . Most companies use a cv grease for both and I have never had a problem using it in outers or inners. With the clamping and unclamping of the boots it seems like to much hassle for the reward but its cheap and may help in diagnostics. I prefer to spend $125-$140 and throw in 2 new axles. I was forced to go to the Oreillys axles as GKN has made it impossible to get a deal on their cv's. Its been over 2 years now and no complaints or comebacks.

If the wheel bearing isn't howling its probably fine. I've changed hundreds and have seen them go as early as 60K (rare) but normally around 125-150K. Bearings will make noise consistently while the inners or outer cv joints need the load to make them act up. Inners give a vibration that many people say they feel in the floorboard or gas pedal or steering wheel. From what you have explained so far it sounds like inner cvs are worn which is normal for your 150K.

Best Wishes on your repairs,
John