GM Longroof Forum
Would you like to react to this message? Create an account in a few clicks or log in to continue.



 
HomeHome  PortalPortal  GalleryGallery  Latest imagesLatest images  SearchSearch  RegisterRegister  Log in  

 

 Torque Confusion on Balancer Hub Assembly: Uh-Oh

Go down 
4 posters
AuthorMessage
Bull

Bull


Posts : 164
Join date : 2013-02-09
Location : MA

Torque Confusion on Balancer Hub Assembly: Uh-Oh Empty
PostSubject: Torque Confusion on Balancer Hub Assembly: Uh-Oh   Torque Confusion on Balancer Hub Assembly: Uh-Oh Icon_minitimeWed Sep 04, 2013 5:30 pm

I'm looking for you guys to confirm that, thanks to being a bonehead, I stripped a bolt and possibly also a bolt hole in the balancer hub assembly.

My RMW has the mechanical fan.  Therefore, it has the extra pulley up front.  Please excuse my large zip ties; that's what I was using to keep the pulleys from turning as I torqued the bolts.
[You must be registered and logged in to see this link.]


I was using this diagram in the FSM to guide me as far as the names of the three types of bolts I had; the correct name would allow me to find the correct torque values.
[You must be registered and logged in to see this link.]

I have three sizes of bolts; one for the crank snout; three larger for the balancer assembly to crank hub, and three smaller diameter for what I now believe mate the extra pulley for the mechanical fan to the balancer assembly.
[You must be registered and logged in to see this link.]


I was using the torque value of 63 ft. lbs for the smaller bolts, being confused I think by what they were in the diagram and torque chart.  The first bolt kept turning with no click from the torque wrench, and I was thinking "hey, this feels like I should have enough by now."  Then, I felt something give and said a few choice words.  I took the bolt out and it has clearly been damaged in the part of the threads just under the head.  Sorry for the blurriness in the one pic.
[You must be registered and logged in to see this link.]

It's weird looking.  The bolt still has threads along its entire length, but you can clearly see the threads under the head look coarse and the diameter seems smaller than on the undamaged bolt.  I'm not really sure exactly what happened.


So, am I correct in assuming that there is some other portion of the FSM that covers these extra bolts and different torque numbers for cars that have the mechanical fan option?  

And, am I now looking at pulling the balancer to fix the damaged hole?  I assume it's damaged, since the bolt is stripped.
Back to top Go down
200OZ
Moderator
200OZ


Posts : 1745
Join date : 2009-08-06
Age : 50
Location : Farmington NY.

Torque Confusion on Balancer Hub Assembly: Uh-Oh Empty
PostSubject: Re: Torque Confusion on Balancer Hub Assembly: Uh-Oh   Torque Confusion on Balancer Hub Assembly: Uh-Oh Icon_minitimeWed Sep 04, 2013 6:23 pm

Never seen a variable pitch bolt, interesting.Wink To answer your question though, GM calls it a crankshaft pulley bolt and the torque spec is 18 lb. ft. The info is in book 1 of the 3 books, in the engine, on-vehicle service section, page 6A4A-12 (1994). Love the panduit straps, good luck.

Mike
Back to top Go down
Bull

Bull


Posts : 164
Join date : 2013-02-09
Location : MA

Torque Confusion on Balancer Hub Assembly: Uh-Oh Empty
PostSubject: Re: Torque Confusion on Balancer Hub Assembly: Uh-Oh   Torque Confusion on Balancer Hub Assembly: Uh-Oh Icon_minitimeWed Sep 04, 2013 6:33 pm

Dear Golly; 18 ft lbs and I was shooting for over 60. No 

What an idiot!
Back to top Go down
Fred Kiehl

Fred Kiehl


Posts : 7291
Join date : 2009-11-13
Age : 76
Location : Largo, FL 33774

Torque Confusion on Balancer Hub Assembly: Uh-Oh Empty
PostSubject: Re: Torque Confusion on Balancer Hub Assembly: Uh-Oh   Torque Confusion on Balancer Hub Assembly: Uh-Oh Icon_minitimeWed Sep 04, 2013 7:09 pm

It is lbs. ft. not ft. lbs. You got lucky, and stretched the bolt instead of breaking it off.
Back to top Go down
Bull

Bull


Posts : 164
Join date : 2013-02-09
Location : MA

Torque Confusion on Balancer Hub Assembly: Uh-Oh Empty
PostSubject: Re: Torque Confusion on Balancer Hub Assembly: Uh-Oh   Torque Confusion on Balancer Hub Assembly: Uh-Oh Icon_minitimeWed Sep 04, 2013 7:23 pm

Fred Kiehl wrote:
It is lbs. ft. not ft. lbs. You got lucky, and stretched the bolt instead of breaking it off.
Old habits (ft lbs vs lbs ft) die hard, Fred. I wasn't taught correctly and it stuck, unfortunately. I'll work on it.



Back to top Go down
buickwagon

buickwagon


Posts : 958
Join date : 2011-06-10
Location : Muskoka, Ontario

Torque Confusion on Balancer Hub Assembly: Uh-Oh Empty
PostSubject: Re: Torque Confusion on Balancer Hub Assembly: Uh-Oh   Torque Confusion on Balancer Hub Assembly: Uh-Oh Icon_minitimeWed Sep 04, 2013 7:59 pm

The bolt has been tightened past it's yield strenth, so, as Fred correctly pointed out, it stretched. Permanently. If you had not stopped, you would have twisted the head right off and would now be trying to figure out how to extract the broken bit from the crank.

It is possible that the female thread is stripped or damaged, but I would expect to see bits of it in the male thread if that was the case. Try torquing a good bolt in there (to the correct value this time ;-)) to verify. If the thread is stripped, you will have to heli-coil it. I would not trust that spinning bolt with any less of a repair. (but that's just my 2¢)
Back to top Go down
Sponsored content





Torque Confusion on Balancer Hub Assembly: Uh-Oh Empty
PostSubject: Re: Torque Confusion on Balancer Hub Assembly: Uh-Oh   Torque Confusion on Balancer Hub Assembly: Uh-Oh Icon_minitime

Back to top Go down
 
Torque Confusion on Balancer Hub Assembly: Uh-Oh
Back to top 
Page 1 of 1
 Similar topics
-
» what about michigan assembly?
» Looking for an oil filler assembly...lt1
» 17 inch torque thrust?
» Parking brake assembly-94 RMW
» ballstud castle nut torque value

Permissions in this forum:You cannot reply to topics in this forum
GM Longroof Forum :: Longroof Tech :: Engine-
Jump to: