CV Joint bolts

[sandomenico]

Hi all,
I'm going to replace the outer cv joints on my 2007 Mk5 Gti soon. The general rule seems to be to replace the inner cv bolts with new ones when refitting the shaft, but some people don't seem to bother. Is it really necessary to renew these bolts? Or could I reuse the originals with a bit of medium strength loctite? Anyone got the VW part number of these bolts if I do replace them? Or are they available elsewhere?
Many thanks for any input.

[LC5F]

I would say it is entirely dependant what state they are in - if they look good and not messed about I would be happy to re-use - get a fine wire brush and brake cleaner to properly clean out the bolt heads, this reduces the chance of stripping the splines out.

Not yet had the pleasure of doing one on a Mk5, but at re-installation keep an eye out for grease escaping the inner joint and getting onto the bolts & threads -this allows the bolts to torque too high and shear...don't ask how I know, lets just say it is a bad day when that happens

[pudding]

I would replace them. If they come loose, the load spreading plates under the bolts flap about and punch a hole in the gearbox casing. It’s happened several times, just not widely publicised. VW have also changed their policy(ies) on bolts due to reused engine mount bolts causing engines to hit the deck.

And that is why stretch bolts should be replaced. They can only achieve a ‘plastic’ state once. It’s actually the constant tension from the plastic state that holds two parts together in high vibration/stress areas, such as engines and suspension.....not the threads.

A lot of people reuse bolts with no problems, so it’s up to you. I always replace them for the cost of them and being diligent.

[sandomenico]

I would replace them. If they come loose, the load spreading plates under the bolts flap about and punch a hole in the gearbox casing. It’s happened several times, just not widely publicised. VW have also changed their policy(ies) on bolts due to reused engine mount bolts causing engines to hit the deck.

And that is why stretch bolts should be replaced. They can only achieve a ‘plastic’ state once. It’s actually the constant tension from the plastic state that holds two parts together in high vibration/stress areas, such as engines and suspension.....not the threads.

A lot of people reuse bolts with no problems, so it’s up to you. I always replace them for the cost of them and being diligent.

Thanks for your advice, and in my heart I know you're right of course!
So that said, would you replace the outboard cv joints using the method whereby you needn't disturb the inner joints at all? I.e dismantling the ball joint etc to get to be able to pull the hub off the end of the drive shaft?

[LC5F]

To be fair, if the bolts were to loosen you would have to be really unlucky to not notice rattling and drive line shunt.

CV joints are a horrible enough job without making them more awkward - rather than fighting the knuckle and shock, I would take the whole drive shaft off - if you can't source new bolts in time, temporarily run the old and replace when you get the new.

[sandomenico]

Mm.. Good idea. I've got the use of a lift to do the job so I'm hoping it's going to be reasonably painless!
Thanks for your input.

[pudding]

The 24mm driveshaft bolts are the stretch variety as well don't forget, although you usually get a new one in CV boot kits.  That bolt is 200nm + 180 degrees iirc, so make sure you have the right tools to hand     I bought a bloody great 3/4" breaker bar from Machine Mart. Pretty cheap. It will also come in handy for the rear bearing bolts, so not a total waste.

@LC5F Lol, you say that about the inner CV bolts coming loose, but I've seen them finger tight sooooo many times in the past.  Either from forgetting to torque them up, or coming loose.  People don't notice it because there's already a fair bit of play/backlash in the drivetrain to begin with.