Rocker shaft bolts breaking?

[rb68rr]

In the last few months I've had two rocker shaft bolts snap off while cruising down the highway with the cruise control on! Both times it was the same one. Front drivers side. What could be causing this??? Thanks, R.B.

 

[BlackBandit]

Do have a roller cam? If so the stiffer valve springs are probably causing it.

 

[rb68rr]

Yes I do have a roller cam but I don't see anyone else having this problem!!! Anybody???

 

[rb68rr]

I really believe that this bolt is backing out a little at a time and when it becomes loose enough it snaps from the vibration. Going to put some lock tight on it and see what happens!

 

[BlackBandit]

I snapped the end off of the front passenger side of my stock passenger side rocker shaft. At a minimum get a good set of heavy duty shafts and maybe some of those load spreaders that RJC sells. I have the HD shafts now and no problems.

Edit: My bolt wasn't loose when mine boke.

 

[jhanson1750]

I broke the rear pass side rocker bolt. I've got the FT 210/215 roller kit. Went back with "slightly" longer grade 8 bolts throughout. Just use caution and don't get a bolt that will bottom out or the next time you post it will be "Will heli-coil hold on rocker shafts?" I would think the locktight would help. You may want to use blue so you can get the bolts out at a later date. Good luck with it. Jon Hanson

 

[BlackBandit]

http://www.turbobuick.com/forums/ge...198668-broken-rocker-shaft-bent-push-rod.html

http://www.turbobuick.com/forums/general-turbo-buick-tech/243433-pics-broken-ta-rocker-shaft.html

A quick search came up with these. You are not going down a new road with your problem!

 

[rb68rr]

I have broken both HD shafts and solid shafts on this car!!! The heavy duty ones on the end and the solid one right in the middle where the bolt hole is!!! In fact this time the heavy duty one has a crack all the way around the bolt hole in the center!!!

 

[turbofabricator]

If you have broken a solid one, then you must have a VERY odd issue. Chek the align ment of the rocker pedistal. What do you torque the bolts to? THe HD Sealed Power shafts are JUNK. They are very brittle and will crack if you torque them too tight. They REALLY need the RJC braces. A broken bolt is indictive of an over-torque. What is your retainer to guide clearance? What heads? Stock rocker arms? How about a picture.

 

[rb68rr]

Stock heads and rocker arms. Don't know how to post pics. When the solid shaft broke I could take out the front and middle bolts with my fingers! It snapped right on the center bolt hole. That's why I think they may have backed out and the vibration caused it to crack!

 

[liv4gnz]

warped heads or uneven rocker pedestal surfaces?

 

[rb68rr]

How bout just bad bolts or threads???

 

[dr_frankenstein]

I lost a HD shaft this morning. broke off at bolt.

Who or Where has the Solid shafts? I cant seem to find them?

A.j.

 

[BlackBandit]

Who or Where has the Solid shafts? I cant seem to find them?

BOP Engineering Buick V6

 

[rb68rr]

BOP doesn't carry them anymore! Weber racing has one set left at $200!!! Too much for me. There number is 440-327-7702. Give them a call.

 

[dr_frankenstein]

200? rediculous.

I'll keep my stockers then.... took forever for one to break, lets hope for the same luck.

A.j.

 

[ryan319]

do you have the shafts on the right way? they might not look it, but there is a front and back and they're not reversible.

i figured this out when i tried putting my HD shaft backwards. i could have forced them on if i tried.

 

[rb68rr]

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[Rodney87GN]

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There's an extra hole on a stock shaft...or on an HD shaft a "dimple". That hole/dimple faces forward on the passenger head between the #2 and #4 cylinders...and on the drivers side it would go to the rear between the #3 and #5.

They can go in the wrong way, I've done it.:redface: The bolts were hard to put in so I knew something was wrong. Not to mention I had to deal with those stupid nylon buttons again so I could put the rocker arms the other way.

 

[ryan319]

There's an extra hole on a stock shaft...or on an HD shaft a "dimple". That hole/dimple faces forward on the passenger head between the #2 and #4 cylinders...and on the drivers side it would go to the rear between the #3 and #5.

They can go in the wrong way, I've done it.:redface: The bolts were hard to put in so I knew something was wrong. Not to mention I had to deal with those stupid nylon buttons again so I could put the rocker arms the other way.

i did the same thing. i could definately see the bolts breaking if they are forced to go on the wrong way, or messing up the mount threads.