16v cam/head stud question(s)
 

Hi all,

Thanks to the guidance of fellow members my 16v is now up and running sweet once again. I have finally completed the chain/tensioner swap.

During the works I managed to screw one thing up though....

On the cam on the left of the engine as viewd from the front. The cam shells that you remove twhen you want to remove the actual cam, one of the studs that these are bolted down with has lost its thread:

http://www.markthomastrimming.com/storage/stud.jpg

My question is: can this stud be unscrewed and replaced? I have removed the cam again, and the thread is pretty screwed up, I assume I can just grip this stud tightly and uncrew it from the head.....its not cast in or anything? Also, would anyone have a part number for a length of that studding???

Once thats done that car can finally go back together...

TIA.

Thanks for any advice.

any suggestions anyone.....

Hey Steve,

can you just leave it in place then start re-tap the stud?? If it has no more meat left on there then in the US I would go to an auto part store, they usually have them in their store.

Alex

It is a steel stud threaded into an aluminum head. If you can't salvage the thread with a die like 16VAlex has suggested, I would soak the base of the stud with a penetration fluid or WD-40. I would then grip the stud below the threads (if possible) with a small vise-grip. The vise grip has to be really clamped tight and have some room to swing. There are also tools to remove studs. I would then go to the dealer or parts store and get a replacement. The replacement can be tightened down using two nuts tightened against each other seperated by a lock washer.

Steve,

Yes it can be done - and you really should do it!
There is a special tool to screw out these studs that I highly recommend to you. I don't know the english word for that, it's Bolzenausdreher in German what altavista translates into "pin out turner". Seem to me that that is not a technical term... :rolleyes:

I wouldn't use a vise grip to unscrew the stud because that could produce small steel parts falling into the head. Not a good idea!
Furthermore that special tool will grip the stud from above and on the complete length of the bolt so the risk of shearing the bold will be smaller.

It may happen - hopefully not to you - that the bolt ruins the threads in the alloy head while screwing it out. That can be repaired with helicoil or similar repair sets.

Try to lend that tool from a mechanical workshop to get the bolt out.

New bolts are available at the dealer, part number is A 102 051 02 70.

as allways: good luck!
bis denn,
Christian

1989 300TE
1984 2.3-16

Dumb question -- wouldn't the double-nut trick work for removing the stud as well? Tighten the two nuts together at the root of the threads (top nut CW, lower nut CCW), then wrench the lower nut CCW to remove the entire nut/stud assembly. Just a thought.

Brian