Flywheel bolts

[CJHenderson]

Is the flywheel bolts right or left handed threads? Having trouble removing them and since they should have only 28 FT LB of torque then it shouldn't need that much effort to remove them. Unless they are rusted in place.

[cfm65@me.com]

Hi CJ,
The flywheel bolts are standard rh threads. It is possible that  someone used locktite or something similar.
Regards
Chris

[CJHenderson]

Thanks for the reply. Looks like I'm going to drill those bolts out and buy new ones.

[JohnnyC]

Hi, I think those are hardened bolts. Drilling out my cause damage to crank threads if you are off-center. And, if using an Easy-out, it may break.  Have you tried using a good impact driver (if accessible), possibly with a little heat from a torch prior to using the impact (set to CCW rotation).

I wish you the best.
Cheers and Good Bless,
JohnnyC

[CJHenderson]

Yes, but it isn't helping any. what's worse is that those are allen head bolts.

[ja17]

First of all if yours is a 280SL with a automatic transmission then the flywheel bolts are a special hex socket with a center hole. They are stretch bolts and torque is more than 28 ft. lbs. I believe torque might be 36 ft./lbs then 90 degrees of rotation. Mercedes uses a special hex bit with a round insert at the end which makes a more positive connection. Once you damage the head by using a standard bit removal is very difficult. Since the bolt heads are most likely damaged already you can still remove them. Use a large steel mallet and directly strike the head of the bolt hard enough to "mushroom" the allen head inward. Next drive your allen tool into the "mushroomed" head. You will notice it is tight again as some force is required to drive the tool in place. The combination of the impacting and the renewed tight connection always works. Sometimes it may take several attempts. Obviously you will need to replace the bolts. The process sounds a little brutal, but it always works.

[CJHenderson]

Yes, that is brutal to be sure since I have two bolts in bad shape. How about using a small pipe wrench on the head of the bolt with a pry bar?

[ja17]

Looks like the bolts are scrap at this point anyway. You can try your pipe wrench idea, if you can get a grip on them.

[Cees Klumper]

Could you weld something (like a nut) onto the bolt heads and use that to undo them? Also puts some extra heat into the equation.

[CJHenderson]

I'll try the heat but unable to weld.

[ja17]

Yes Cees, welding a nut on is another good trick that I have used often on broken studs etc. Any heat will help also.

[CJHenderson]

Change of plans, the hex bolts are not going to come out without ending up destroying the flywheel and most likely the crank. I'm going to reassemble the motor then exchange it for a refurbished one just to get the car on the road. It also will allow me to restock my savings account.

[ja17]

Why were you trying to get the flywheel off in the first place?

[CJHenderson]

To clean out the shroud around it. This motor was so caked in oil, grease, and dirt that it was impossible to find any oil leaks. I have no way to see if the rear seal is leaking and if it is then that means I will have to lift the crank out. This motor was totally abused.

[Benz Dr.]

Something doesn't add up here. Those screws can be tight at times but they can usually be undone. My bet is lock-tight. 

[CJHenderson]

Two of the hex heads are stripped out and that's where I'm stopping, very concerned to go any further.

[ja17]

You can take the engine to a welder who can easily weld a nut on the end of a damaged bolt head at which point it can easily be removed with a standard socket. Only the damaged bolt will need replaced and no harm will be done to the flywheel or crankshaft.
https://www.bing.com/videos/search?q=removing+stuck+bolt+by+welding+on+nut&qpvt=removing+stuck+bolt+by+welding+on+nut&view=detail&mid=C3DD90CFEEAC1DA7902BC3DD90CFEEAC1DA7902B&&FORM=VRDGAR&ru=%2Fvideos%2Fsearch%3Fq%3Dremoving%2Bstuck%2Bbolt%2Bby%2Bwelding%2Bon%2Bnut%26qpvt%3Dremoving%2Bstuck%2Bbolt%2Bby%2Bwelding%2Bon%2Bnut%26FORM%3DVDVVXX