Recently i had my p993 left inboard cv boot replaced, after that repair the car vibra

[indra gunawan]

Recently i had my p993 left inboard cv boot replaced, after that repair the car vibrate (not actually vibrate, just like the axle was bent but it wasn't , i think it because that the 6 bolts are going to loose that make the car run like with a bent axle, and i'm still don't know what problem that make the 6 bolts llosening) at that side of the axle.
On the way home, the axle was loose totally from the stub axle and the mechanic tightened the 6 bolts again.
After the second tightening, the car vibrate again and the axle loose from the stub axle again even though the 6 bolts had been tightened by another mechanic from another workshop, and after the third tightening the car still vibrated and on the way home, the axle was loose again for the third times then tightened again for the fourth times with 6 longer bolts in order to get home.
I got home at last without knowing the car still vibrate or not because i run the car home very very slowly.
And i haven't checked the car now, and i am going to disassemble the axle again trying to see what parts need to be replaced and try to figure out what problem that make the 6 bolts always loosening and what problem that make the car vibrate.

What could be the problem ? Wrong method of tightening ? Wrong bearing assembling [the bearing was disassemble in order to replace the cv boot] ?
And could the stub axle be bent after three times loose from the inboard stub axle ?
Before i replaced the cv boot, the axle is in very good condition as from the factory, never been repaired/disassembled.

Thank you very much for any help or suggestion.

[indra gunawan]

Recently i had my p993 left inboard cv boot replaced, after that repair the car vibrate (not actually vibrate, just like the axle was bent but it wasn't , i think it because that the 6 bolts are going to loose that make the car run like with a bent axle, and i'm still don't know what problem that make the 6 bolts llosening) at that side of the axle.
On the way home, the axle was loose totally from the stub axle and the mechanic tightened the 6 bolts again.
After the second tightening, the car vibrate again and the axle loose from the stub axle again even though the 6 bolts had been tightened by another mechanic from another workshop, and after the third tightening the car still vibrated and on the way home, the axle was loose again for the third times then tightened again for the fourth times with 6 longer bolts in order to get home.
I got home at last without knowing the car still vibrate or not because i run the car home very very slowly.
And i haven't checked the car now, and i am going to disassemble the axle again trying to see what parts need to be replaced and try to figure out what problem that make the 6 bolts always loosening and what problem that make the car vibrate.

What could be the problem ? Wrong method of tightening ? Wrong bearing assembling [the bearing was disassemble in order to replace the cv boot] ?
And could the stub axle be bent after three times loose from the inboard stub axle ?
Before i replaced the cv boot, the axle is in very good condition as from the factory, never been repaired/disassembled.

Thank you very much for any help or suggestion.

[Flieger]

Are the metal retaining clips for the CV boots properly installed? If the heavy parts of the metal bands, where the screw tightener is, are lined up, it will result in a heavy spot and vibration. The inner and outer clips should be 180 degrees out of synchronization to cancel out vibrations.

Hope it is this simple...

[indra gunawan]

First of all, thanks a lot for your kind help Flieger.

Secondly, i'm just afraid get the wrong understanding of what "metal retaining clip" is, is it the one with the red arrow mark in the picture that i attached ?
If so, yes, as long as i know, it had been tightened, but we used the different ones, the oem retaining clip don't have screw, we use retaining clip that have screw to tighten (not oem).
I understand if you said that cause vibration, but what i don't understand is what problem that the cause that make 6 bolts of the axle joint to the stub axle always loosen.
Is it because of the small vibration from the possibility retaining clip as you said ?

Is there any possibilities that we assemble the ball bearing wrongly, in reverse order for example ?

[Flieger]

That's the clip. The problem is not in tightening them. It is making sure that the heavy parts of the ring are properly indexed to the axle's rotational axis. I think the vibration could be enough to cause the bolts to loosen if there is no Lock-tite on them. If the instructions did not say to put sealant on the bolts, you might try some medium-strength Lock-tite thread sealer. It is graded by color. DO NOT use the red stuff unless it says to. This will make it really hard to remove later.

[indra gunawan]

I used a blue Locktite at the workshop on the 6 bolts after second tightening on the road to make sure everything is ok (this is not the third tightening,and just consider as a 2.5 tightening and this 2.5 tightening was done by myself at the workshop with the car on the lift and i'm sure that i tightened the 6 bolts well), but it was still vibrate and loose again.
But i didn't disassemble the whole axle at that 2.5 tightening, only did tightening.
I hope, what you think was right, i'll make more attention of what you said in assemble the axle later.
I hope this is simple thing to fix, but it is a headache to find the cause of the problem that make 3 times loosening from the transmission stub axle.

I'll report any progress here, but it is still takes time, i am going to disassemble the axle first and inspect all the parts, after that, have to wait sometime for the parts to arrive here in my country.

And i'm sure that this vibrate didn't come from the axle bar itself (eg bent), since the axle itself was in perfect condition before disassembling except for the tear inboard cv boot.

[Don Plumley]

I think it would be nearly impossible to bend the axle shaft. But if the CV was not assembled correctly, the cage/internals could be bent, causing slop/vibration/loose bolts. So a disassembly/inspection makes sense.

[indra gunawan]

Hi Don, was "The Cage/Internals" you meant is the Stub Axle/Joint Flange from the axle housing ?
I'll disassemble that Left Stub Axle/Joint Flange too to inspect (just in case), but not disassemble the whole rear axle housing .

When the axle was loosening the first time, i asked the mechanic, and he said that he tightened the 6 bolts already, but the car vibrated on the way home , that the cause i should find out and still don't know what cause that vibration at the first time.
I don't think if the Stub Axle/Joint Flange bent at the first time (just in case the stub axle/joint flange now bent).
And when i did the tightening, i'm very sure that i tightened the bolts well and used a Blue Loctite, still vibrated and was loose again.

What do you think about "not assembled the CV correctly" ? Placing the bearing in reverse order so it make the axle didn't move freely ?
Other than that, what possibilities that could be wrong ?
Thank you Don

[Don Plumley]

Indra - I'm really guessing on this one. I've done a cv rebuild on my 87, it seemed pretty hard to get it wrong, but I recall reversing the cage on one trial and it did not move freely.

Do you have the three plates (993.332.191.00) that span adjacent mounting holes in place?

[indra gunawan]

Yes Don, the three plates (993.332.191.00) were in place for sure.
What do you mean by "the cage" Don ? Is it the one (911.332.030.01 called JOINT in Porsche parts cataloque) that hold the ball bearing ?
If yes, that's what i guess too, if it won't move freely if we assemble reversingly.

[indra gunawan]

here i attached the picture of the JOINT 911.332.030.01 , it is the one that i marked with a red arrow.
http://img529.imageshack.us/my.php?image=993axlejw5.jpg