guitarcrazy02

How in the world are you supposed to get the u joints off the half shafts on a 1981? I'm not sure what the designers were thinking, but the bolts that hold them in are allen bolts! On my dad's 69 and any other car i've ever seen, it's just a regular bolt.

I busted my allen wrench, failed repeatedly with vice grips, and hit it with a torch for a while, and no luck. I'm afraid of busting the head off and being SOL.

What do i do?!?

cargo247

worried about mine as well??

...Roger...

Hmmm I dont remember the factory putting in allens.I've seen everything else like torx and reverse torx and 12 points.
On to your problem.One of the guys in here tells of using a candle to help with stuck bolts.You can try it. Heat the bolt up with your torch and the rub the candle around the bolt allowing the candle to melt as the bolt and metal cools it will suck the candle wax into the threads and when it cools it will be in the threads.If this works,when it cools the bolt should come out.
It wont take but a minute to try and if it works let me know I,ve been wanting to try but keep forgetting.

guitarcrazy02

Sounds kinda weird, but I guess it could work. I'll try it today and let you know.

CA-Legal-Vette

They are not Allen bolts though they certainly look like them. You need a 12 point socket. If I can find a spare bolt in my rediculously large spare part storage, I'll verify and post the socket size.

...Roger...

Great ! I will try to locate his post about this.I do remember he was talking specifically about removing a broken thermostat housing bolt that had enough head on to get vice grips on.Should be the same concept I believe sorta like when sweat soldering a copper pipe...the solder is sucked in there(for some reason).

...Roger...

OK maybe it wasnt about therm. bolts.And it was pmullaly,should have remembered that ...he's older than me.EDIT..oops my mistake guess he's younger.
http://forums.corvetteforum.com/show...&highlight=wax

guitarcrazy02

I'm certain it's an allen bolt. There's no way that you could do anything with a socket on it. They're completely round on the outside, and I don't mean rounded off. It is a round head with an allen key hole in the center, and I'm almost positive that these are the original U joints, as pretty much all the rear suspension parts are original.

...Roger...

You could be correct but I also remember the very fine very small 12 point because I have a special socket for those tiny bolts that rounded very easy.....I would wonder if someone replaced them with the allen.It would be the easiest to find.I think I have a couple of the original 12 points left.

SIXFOOTER

My 81 has 12 pt bolts. I used a 12 pt 1/4" box end to get them off, no problem.

KevinK

Any luck with the candle technique?




I'd love to know if this works......because sometimes.....WD40 just doesn't cut the mustard.

bt57

when you get them off change them to the six point like zip sells
they are easy to remove and you will not need a 12 point socket-which is not easy to find

guitarcrazy02

Just made 3 trips to Home Depot because Advance didn't have any 12 point sockets. I bought a whole bunch of sockets hoping that they were indeed 12 points, but after buying first a standard set and returning it, a metric set, and returning it, I came to rest on a Hex socket set. The size is 3/16. I might not have to do the candle trick since I have the right tools now.

Now I'm just curious as to why mine are different than everybody else's. They're definitely original.

ShinodaVette

The originals are 12-point on an '81; no question. I've got my originals sitting out in the garage. I replaced mine with allen heads. I'm not saying it was the right choice, I'm just saying that's what is on mine now. FWIW....

As for motive; that's easy. Allen head 1/4-20 bolts are easy to find at the local hardware store and 12 points like the originals are not.

gingerbreadman1977

mine had allen key bolts on all uni joints as well. 2 were very hard to unscrew without ruining the head but i got them off eventually. dont use a alen key that is slightly loose , make sure it is really tight even if you have to hit it in there. i found if you get one allen bolt out you can hit the saddle back and forward and this will release the other side easier. once i got mine off i replaced them all with normal 12 points, i didnt do them up mega tight but used loc-tight on the threads. why is everyone using sockets, isnt a normal 1/4 ring spanner the go as it has 12 points? thats what i use.

c3corvettes

On my '80, I had the original 12 point bolts. I also switched to 6 point. By the way, the 6 point bolts appear to be a bit more stronger.

stinger12

Make sure whatever bolts you do install have a shoulder on them - they are much stronger and they help center the u-joint flange on the spindle flange.

guitarcrazy02

Ok I'm glad to hear that someone else has allen key bolts.

I'm just very very afraid of breaking the head off of the bolt. I'm SOL if that happens, and I don't really feel like drilling out any broken bolts. I think I'm going to go at it with an oxy-acetylene torch and get it really hot before I start cranking on it.

bruced267

My 81 had 12 point metric I think? I changed them to 6 point! I used a 1/4 socket and you have to keep rotating the shaft to get on straight.

I have tried the candle trick never worked!!! The heat needed to loosen anything up is to hot for wax it just drips away fast and just makes a mess!! PB blaster works for me!

gingerbreadman1977

if using any oxy torch is your only option then try to heat only the yolk part and not the saddle or allen key bolts. firstly because heat will weaken those allen keys and secondly because you want the heat to expand where the allen key bolt is threaded into making it come out easier.mine would not come out with a normal size allen key. i cant remember if it was metric or imperial sizing but i found one that fitted really snug and it had the longer handle on it which was usefull or you can just use some small pipe on it for extra leverage.