CV grease selection.

[RichardZ]

I replaced the front CV inner boot on my Audi Q3 today. The boot didn’t appear damaged but it was leaking grease somehow. The grease from the boot kit had oil separating from it and looked nasty. So I just used some Valvoline Moly-Fortifided Multi-Purpose Grease I have on hand. My first time doing this.

Did I make a mistake using this grease?
Is it better to use a little less or more when repacking a CV cup?

 

[Overfill]

@RDMgr CV grease is unique, and unlike the OP put in, right?

 

[CDX825]

Would have been better off using an actual CV grease. I tried once to regrease a leaking cv axle on a atv with regular molly grease. It made the situation worse and the axle had to be replaced.

 

[Dave9]

Would have been better off using an actual CV grease. I tried once to regrease a leaking cv axle on a atv with regular molly grease. It made the situation worse and the axle had to be replaced.

What situation did it make worse? Once a CV wears out, fresh grease won't heal it....

CV joints benefit from a high moly grease, and all of the original grease should be cleaned out if there is any question of compatibility, or really, any time the boot is replaced and it's off the vehicle to do so, giving the opportunity to do so. Some people just get a spit boot kit and install on the vehicle, then I'd carefully examine the existing grease to see if any grime got in and contaminated it, and pull the axle to clean and repack if so.

 

[CDX825]

What situation did it make worse? Once a CV wears out, fresh grease won't heal it....

CV joints benefit from a high moly grease, and all of the original grease should be cleaned out if there is any question of compatibility, or really, any time the boot is replaced and it's off the vehicle to do so, giving the opportunity to do so. Some people just get a spit boot kit and install on the vehicle, then I'd carefully examine the existing grease to see if any grime got in and contaminated it, and pull the axle to clean and repack if so.

It was starting to make noise. After adding grease it became louder. Safe to assume the grease that was in it was a polyurea and it didn't play well with the grease I added to it.

 

[Dave9]

It was starting to make noise. After adding grease it became louder. Safe to assume the grease that was in it was a polyurea and it didn't play well with the grease I added to it.

So? ... it made noise because excessive wear, and sure, you can't add incompatible grease, have to clean all the old out, especially after wear causes metal particles to be floating around in it.

I'm just suggesting that your post could be misconstrued, that the issue wasn't "just" using a regular moly grease.

Waiting till it's worn out and then adding a compatible polyurea grease TO the contaminated grease without cleaning that out, was too little, too late. It needed cleaned out, and then, there isn't the compatibility issue.

 

[RDMgr]

@RDMgr CV grease is unique, and unlike the OP put in, right?

I don't think that cv joint greases are so much unique as they need to be selected carefully. Rzeppa joints are usually lubricated with moly and/or graphite grease with EP, AW, rust and corrosion inhibitors and antioxidants. Consistency is important, probably an NLGI 1 to ensure adequate mobility. Tripod joints use a similar grease without moly and graphite due to their use of needle bearings. I think the Q3 inner cv joint is a tripod type and the outer is a Rzeppa type.

 

[CDX825]

So? ... it made noise because excessive wear, and sure, you can't add incompatible grease, have to clean all the old out, especially after wear causes metal particles to be floating around in it.

I'm just suggesting that your post could be misconstrued, that the issue wasn't "just" using a regular moly grease.

Waiting till it's worn out and then adding a compatible polyurea grease TO the contaminated grease without cleaning that out, was too little, too late. It needed cleaned out, and then, there isn't the compatibility issue.

This was a long time ago before I knew better. Only reason I posted in the first place is because the OP made it sound like he might have done the same thing.

 

[wingxzero]

I replaced the front CV inner boot on my Audi Q3 today. The boot didn’t appear damaged but it was leaking grease somehow. The grease from the boot kit had oil separating from it and looked nasty. So I just used some Valvoline Moly-Fortifided Multi-Purpose Grease I have on hand. My first time doing this.

Did I make a mistake using this grease?
Is it better to use a little less or more when repacking a CV cup?

Do not use any other grease than cv grease. I made the mistake of using marine grease for drive shaft cv and it lasted about 2000 miles before it heated up and blew up.