Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: CJHenderson on November 07, 2020, 12:46:40

Title: Flywheel bolts
Post by: CJHenderson on November 07, 2020, 12:46:40
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.
Title: Re: Flywheel bolts
Post by: cfm65@me.com on November 07, 2020, 20:10:47
Hi CJ,
The flywheel bolts are standard rh threads. It is possible that  someone used locktite or something similar.
Regards
Chris
Title: Re: Flywheel bolts
Post by: CJHenderson on November 07, 2020, 20:18:14
Thanks for the reply. Looks like I'm going to drill those bolts out and buy new ones.
Title: Re: Flywheel bolts
Post by: JohnnyC on November 08, 2020, 01:20:38
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
Title: Re: Flywheel bolts
Post by: CJHenderson on November 08, 2020, 09:30:34
Yes, but it isn't helping any. what's worse is that those are allen head bolts.
Title: Re: Flywheel bolts
Post by: ja17 on November 08, 2020, 15:39:43
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.
Title: Re: Flywheel bolts
Post by: CJHenderson on November 08, 2020, 16:50:25
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?
Title: Re: Flywheel bolts
Post by: ja17 on November 09, 2020, 02:02:24
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.
Title: Re: Flywheel bolts
Post by: Cees Klumper on November 09, 2020, 13:53:25
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.
Title: Re: Flywheel bolts
Post by: CJHenderson on November 09, 2020, 14:32:15
I'll try the heat but unable to weld.
Title: Re: Flywheel bolts
Post by: ja17 on November 09, 2020, 23:32:12
Yes Cees, welding a nut on is another good trick that I have used often on broken studs etc. Any heat will help also.
Title: Re: Flywheel bolts
Post by: CJHenderson on November 13, 2020, 18:09:06
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.
Title: Re: Flywheel bolts
Post by: ja17 on November 14, 2020, 07:17:41
Why were you trying to get the flywheel off in the first place?
Title: Re: Flywheel bolts
Post by: CJHenderson on November 14, 2020, 12:11:53
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.
Title: Re: Flywheel bolts
Post by: Benz Dr. on November 14, 2020, 21:09:39
Something doesn't add up here. Those screws can be tight at times but they can usually be undone. My bet is lock-tight. 
Title: Re: Flywheel bolts
Post by: CJHenderson on November 14, 2020, 22:41:30
Two of the hex heads are stripped out and that's where I'm stopping, very concerned to go any further.
Title: Re: Flywheel bolts
Post by: ja17 on November 15, 2020, 17:11:00
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