CVD pins falling out.

[Nigel]

Yes I know there are many threads on this but I have tried almost all the suggestions and even some of my own methods with no success. I still have then fall out after around 2 heats or a main.

So far I have tried using, Blue lock loctite, Red loctite, CA glue and Heat-shrink + Red loctite.

The problem I find with the Heat-shrink is that if you dont put it on the axle joint far enough it will end up sliding off, and if you put it on too far it gets torn apart by the bearings/hub.


Any suggestions other than rebuilding all four CVD drive shafts after every heat?

Thanks!

[wingnut]

are you cleaning the sets and the threads in the barrel parts with motor spray?

[mattr]

Are you putting the grub screw onto the flat part of the pin? That's the only thing that has caused me to lose any drive pins in the last 18 months.

I've built them clean, dirty, with threadlock, without threadlock and doused in oil/grease. Only lost 2, both times as i wasn't careful about aligning the flats on the drive pins.......

[reg]

also make sure the grub screw is flat on the end,sometime they have a little pip on them

[Chris-S]

Clean all the parts with brake cleaner, then make sure they are dry. Use a new bottle of genuine red loctite, not some old bottle that you've had for years.
Use two grub screws, one on the flat side and one on the non flat side. You want to nip the flat side down, then the non flat side and then tighten them both up. Never had a pin come out with the above method.

[hloland]

You should make sure that the ball bearings are ok. Bad ball bearings and bad shimming could make a lot of vibration. This can make ting loosen.
You should also make sure that the drive train is free. That there is not a lot off friction. This will make the axel CVD warm, then the lock-tight will loosen.

[pugboy]

As well as what's been said, One other little thing, occasionally there may be small burrs on the thread inside the joint so when you think the grub screw is tight it actually isn't, it may be bottoming against a burr (ooh err). Ensure that the grubscrew screws freely sufficiently into the thread in the joint.

[Nigel]

Sorry was away on a short holiday.

I always clean it all with varsol and that totally cleans all the grease and thread lock away with a wire brush/varsol so cleaning it should not be the issue.

I always make sure to screw it tight and its not hanging up on grubs as when I don't have the pin in place, the grub screw is able to go all the way through.

My red thread lock is only around 1 month old and my blue thread lock was brand new. Plus you think CA glue would have held it

The bearings where all replaces about a week ago and I had newly shimmed it after replacing the bearings.

I'm kind of stumped on what the problem is.

[coleman758]

Sounds odd! My driveshafts have never missed a beat.
The only thing I can think:

What's is the wear on the driveshafts like, are the 2mm holes round? Or have they started to go oval? Do the pins sit in the holes correctly?

I there is any movement here, that could cause the screw to loosen. Everytime you hit the power the pin could get a sharp shock causing the grub screw to loosen.

A good tip is to put some tipex on the flat, that way you can ensure the flat is under the grub screw.

Also, get some new grub screws, then get a dremel/file on the ends, get as much surface are as possible.

[Nigel]

Allright will do, one of the front CVD's are staying in place as I have used 2 screws so im thinking of doing that all around front and rear as well as using brand new ones filed down.

[Pipi]

i wouldn't use varsol cause it leave a greasy residue, only brake clean or even GoofOff.

[Chris-S]

Originally Posted by 1slash

Allright will do, one of the front CVD's are staying in place as I have used 2 screws so im thinking of doing that all around front and rear as well as using brand new ones filed down.

Been running the two screws for a long time and never had any pins come out. With one screw you end up bending the pin when you tighten the screw.

[OneKiwi]

Originally Posted by Chris-S

With one screw you end up bending the pin when you tighten the screw.

Ahh smart one... Im going to try that now.