View Full Version : VW CV bolts

01-30-2002, 03:09 PM
I was wondering if I can use a standard allen head bolt to replace the triple square bolts that hold the cv's to the output flanges on the transaxle. The triple square bolts seem to round out so easy. Are there any hardness concerns, etc?

Thanks alot,

01-30-2002, 03:15 PM
I don't think the bolts round out too easy, but I do notice that if you don't get the triple square bit to go all the way into the bolt, it can round out easier.

At least in the case of my old Bug, there was alot of dirt and oil/grease in the bolt hole, I stripped the outside of the bolt and thought I was screwed, but was able to scrape out the dirt and hammer the bit in far enough to get a good bite.


83 Rabbit GTI - future ITB

Ryan Williams
01-30-2002, 04:51 PM
Scott, don't know of any reason why Allen bolts would not work as long as they are the correct metric thread. Always had good luck with the 8mm 12-point socket head bolts, torqued to 32 ft-lbs. Regards, Ryan Williams

Bill Miller
01-31-2002, 12:15 AM
I was going to switch to allen head botls and a professional mechanic friend of mine suggest that I not. He felt that the allen head bolts would strip easier than the triple-square ones. My idea was to take a ball-end 6mm allen key and fit it to a socket. I figured this would make a great tool for getting the bolts out. I'm still looking into hardend allen bolts to use. Biggest problem I've had so far is finding ones that are the right length.

MARRS #25 ITB Rabbit GTI

01-31-2002, 01:02 AM
I would worry that some of the "graded" commercial hardware out there is actually TOO hard - to the point of being brittle enough to break before it bends, from shock loads. I also THINK that the 12 pt socket/driver combination is actually rated for more torque than an equally sized 6 pt but I couldn't tell you where I got that. Torque shouldn't be an issue at the setting specified but might become one, if you are trying to get out a bolt that has seized in there.


03-14-2002, 11:39 PM
Spend the $25 and buy the snapon tripple square socket. Use it with a very long (42") extension and lightly tap it in with a hammer before you start to unscrew it.

I'v changed hundreds of CV's and never stripped a bolt with this method. Even when it was done in an Enduro with a electric impact wrench.

If you do strip one, just use small vise grips to grip the outside of the bolt head.


Bill Miller
03-15-2002, 12:32 AM
I would caution against using an impact on these, even a 3/8 butterfly. I snapped three bolts w/ one! http://Forums.ImprovedTouring.com/it/eek.gif

MARRS #25 ITB Rabbit GTI

03-15-2002, 11:35 AM
Hey there,
I run a rabbit at our local dirt track, and I switched out the bolts for allens.
Just makes it easier at the track, and less stipping for sure. That dirt can get packed in there pretty good.
I have no regrets switching them.

03-18-2002, 12:57 AM
The allens work and so do the 81-83 style torx head ones are the best, . Yes you should hand torque em.

03-19-2002, 03:28 AM
What's the difference between the '81-'83 bolts and the later Golf ones that I have? I'm just curious.

Thanks alot...

03-21-2002, 12:23 AM
Some of the US cars had TORX style bolts, not 12 point,. MM

03-21-2002, 11:16 AM
Should be no problem, just as long as you make sure you get M8.8 rated bolts or better. I agree that, with either triple-square or allen-head bolts you should tap the bit in with a hammer to make sure it's fully seated (after cleaning out dirt if necessary).

I'd also recommend (if you don't already) that you cross-drill and safety wire all CV bolts; don't know about you guys, but having the bolts back out is a common problem on our rear-driver cars (we use VW Type4 CV's all around). I wire them in sets of 3 bolts - 2 wires each side. Fortunately drilling the bolt heads is not hard, since you're only drilling through the walls of the allen head socket.

Vaughan Scott
'79 924 #77 ITA
Plymouth, MI

03-21-2002, 12:20 PM
Really good advice. Safety wire doesn't get enough attention...


03-21-2002, 06:49 PM
Using safety wire is a great idea. In 6 years of racing an ITC Scirocco I haven't had one of these bolts come loose, without resorting to safety wire. BUT I religiously check the torque on these bolts (33 ft-lb) before each and every race weekend.

Now I've probably jinxed myself. I just wanted to point out that a properly torqued fastener will stay put (I hope!).


03-22-2002, 12:23 AM
Since we're in this general area of the car, I've got a really nice differential worked out. Seems to work quite well. Costs about $55. I welded the differential spider gears and put the tranny back together. Then I cut the axle shaft on the passengers side of the car in half and installed an over-running clutch from an agricultural use tractor PTO. It's basically a rachet device that's installed in the axle instead of in the diff. In reverse, I'm unlocked. When I get off the gas, I'm unlocked. When I stand on it, I'm welded solid and locked. When the engine RPM's go down lower than the speed of the axle, the rachet "free-wheels". I can drive into a corner as low and sharp as I please without the negative side-effects of being welded, but then I lock when I stand on it.

Seems to work where I race, Not sure about your rules though.


03-22-2002, 01:06 AM
I've had thoughts and discussions about something similar to this but that was the extent of it because it would be illegal. Great idea though.


87 ITB Scirocco
www.geocities.com/highspeedconnectionracing (http://www.geocities.com/highspeedconnectionracing)

03-24-2002, 06:12 AM

Do you have any pics of your axle with the over-running clutch.