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Drive shaft bolts
72TWINCAB - July 28th, 2003 at 10:41 AM

Has anyone had problems with the bolts working loose that connect the drive shaft to the gearbox mounting on a Kombi?

Mine have worked loose for the second time in about 6 months. I have bought some loctite and will apply when I put the new bolts in.

Just wondering if I'm the only one having this problem:o


RISKY^VW - July 28th, 2003 at 12:06 PM

had the same prob with my buggy would go into 1st but not 2nd and thats all it was


Baja Wes - July 28th, 2003 at 01:15 PM

no I don't have that problem. Do you use the correct bolts, with the serraded washes, and then the plates that connect every second bolt? The washers are important.


Brad - July 28th, 2003 at 01:34 PM

I have answered this on another thread so if you want more details do a search on it.

This is caused the first time by lack of tightness. After that it will continue to happen in most cases. What happens is that when the bolts run loose they pull the threads up. This creates a small rise around the thread, this means the CV will not make full contact with the drive flange. The cv bolts are only there to maintain surface pressure / contact between the cv and drive flange. They do not provide the majority of drive force as you may think. Kind of like wheel studs.

Anyway as long as you have these small rises it will continue to happen, loctite may prolong but will not STOP it.

Solution: take off drive flange and machine it flat again. There is no other soloution, I guess you could drill oud the CV to accomodate the rises but now we are being silly. Anyway I will bet on this being the problem.

You can easily check just remove it and have a fell, any rise is bad, it only need a mm or so. It is all about surface contact areas .

:cry Bummer huh..... I learnt the hard way ..


72TWINCAB - July 28th, 2003 at 03:49 PM

Quote:
Do you use the correct bolts, with the serraded washes, and then the plates that connect every second bolt? The washers are important.

Yes, I do have the backing plates and correct bolts. Seems like baggy Brad has the right idea

I got some new high tensile bolts and spring washers today. Have fitted them to the CV. Guess I will just keep an eye on them every few months and check they are tight.

thanks everyone for your input:thumb


11CAB - July 28th, 2003 at 05:12 PM

Brads right, and it is important to do the bolts up with some decent leverage.....no Supercheap allen keys here..........we use the correct drive ie 6mm Allen or 8mm multispline, with a 1/2 inch drive & about a foot long bar.....seen it too many times when someone does them up with an allen key and then wonders why they came loose.


Baja Wes - July 28th, 2003 at 05:30 PM

Quote:
Originally posted by 72TWINCAB
Quote:
I got some new high tensile bolts and spring washers today.


Don't use spring washers, use the proper serrated washers. If you don't know what I mean then you probably haven't seen the proper washers :D


Brad - July 29th, 2003 at 06:12 AM

If "Baggy Brad" was right then why aren't you pulling them off and machining them flat ?

If you think you can check them every few months then you had better carry a spare drive shaft and bolts. I am talking about they coming loose as often as every few days. Fix it once and fix it properly.
YOu can drill the bolt heads and run wire through then all with a half turn on each head if you want. This will reduce the problems and may get you more time. They will still come loose though. The bolts are not designd to handle the torsional drive force they are designed to maintain the surface bearing pressure and in turn create a friction surface.


72TWINCAB - July 29th, 2003 at 08:11 AM

This is not what I want to hear a couple of days before the trip to Valla:( I don't think I will have time to get them machined flat before Thursday as I have too many other things on my plate at the moment.

I will however make sure that the bolts are tightened correctly as outlined by 11Cab.

First job I will get done when I get back is have them machined. Doe's anyone know of someone in Brisbane that I can get to do the job.