CV install, now noise

[SuperBuickGuy]

like the splines aren't fully engaged



they are the same (bottom is new one)...


is it possible to push the shaft into the carrier to make the noise? the noise only happens under load and while driving forward. I didn't do it much (drove maybe 100' total, then brought it back and pulled it apart).

I'm stumped... help!

(and yes, a SAS would cure it, but it wouldn't cure my broke checkbook nor my full schedule)...

 

[amrg]

An SAS would cure all our troubles!

 

[4speedfunk]

Looks to me like the inner CV body is not the correct size (smaller than the originals). Hard to tell from the pic...but the new one also looks shorter.

Years ago I exchanged my CV shafts for rebuilt ones, at a walk-in driveline shop. The ones they gave me were not near as beefy. I complained and said I wanted my original GM shafts back. Fortunately, they still had them in the core pile, and they pulled them out and rebuilt them on the spot for me. If possible...take your original shafts to a shop and tell them you those exact ones rebuilt, and not exchanged. That way you'll know they are the correct ones.

 

[SuperBuickGuy]

it's an optical illusion, the ends are the same size, and intermediate shaft is larger....

 

[SuperBuickGuy]

Is it possible to push #19 so that the splines don't engage because the clip on the CV joint is too big?

 

[4speedfunk]

No. The coupler (#19) is held captive inside a casting (#15)...so it can't go anywhere. However, shaft (#21) is a common problem. It can break in half, and the two ends will slip on each other creating a clicking sound. Breaking this shaft will usually require 4HI-Lock to move the truck but, sometimes you can get the two ends to line-up and hold together enough to accelerate. Eventually though...the two ends of the shaft will eat themselves.

Since the problem did not exist since you swapped the half-shaft...I'm guessing the issue is entirely related to it. I still say your inner CV looks substantially different...looks to me like the entire "bucket" that holds the inner-CV is at least a half-inch shorter...

While the shaft as a whole may be the same length...this bucket determines the amount of "plunge" the CV has built into it. If the joint does not have enough "plunge", it could possibly be un-plugging itself from the coupler when you turn. That's actually a good thing because the alternative is that the joint will pull itself apart inside the boot (which might be the clicking sound you heard).

I have heard two separate stories of H3's that have accidentally un-plugged a CV shaft from the differential like this. After all...they are not bolted-in. They rely entirely on that little snap ring to keep em in place. Both incidents happened on the street, by soccer-mom type drivers. I would check the shaft you bought to make sure it has the same "compressed" and "stretched" lengths as your stock ones.

 

[Best4x4]

Yeah it also has one less bump in the boot vs the OEM. What brand are the replacements?

 

[4speedfunk]

Sometimes the quality control is horrendous on aftermarket parts like this. That's why I would recommend getting your original GM shafts rebuilt if possible. Definitely post up what brand they are: Dorman, Epi, NAPA, etc.

The boot design is probably not an issue. Most likely this company uses the same CV boot on many different models of replacement shafts. I doubt if it has any effect on the life-span or flexing ability. A boot is a boot. Even if you get your stock shafts rebuilt...they will probably come with rubber boots like this, (and not the hard plastic boots that GM shafts come with).

 

[SuperBuickGuy]

great info guys... I will check it out and report back.

I did call about rebuilding them.... $1,150... I can buy AC Delco (originals) for 250/ea from Rock Auto and probably about the same from GM (I get discounts)....

I talked to a friend who owns a mechanic shop, he says the clicking is normal for the first driving that they manufacture them so tight they ratchet/click until they break in. As that's the cheapest option and the one that gets me on the street - I'll try it; my concern that it was creating pressure on the inside is unfounded...

 

[Best4x4]

I was talking about the boot being smaller/shorter than the OEM due to a different design/size/length of the CV. Yes a boot is s boot, but it could be totally different smaller CV hidden under it is what I meant.

 

[SuperBuickGuy]

the old one is 26 1/2" extended, the new 27" extended....

 

[SuperBuickGuy]

So I stopped by my friend's shop and let him listen - and he unequivocally said that the noise is not what he thought

New Theory

They didn't machine the slot in the CV joint long enough and those balls are bottoming out... I'm at 23 3/4 - so this should not be an issue.

 

[Best4x4]

Still don't know the brand??

 

[SuperBuickGuy]

still don't know the brand??

apwi