Stripped lifter tray bolt Question
#1
Stripped lifter tray bolt Question
OK, I have a stripped lifter tray bolt. Darndest thing. I torqued down all the lifter trays to 106 in lbs without a problem, got to the last one and herd and felt the strip.
DOUGH!!! Why me?!?!
So when I pulled the bolt out, about half the threads came with it. I tapped the hole out with the standard 6mmx100 thread but I just wasn’t comfortable with the way it felt.
I JB welded it and let is sit for 2 days to fully cure and tapped out a new hole. I put a ton of Red thread lock on it and torqued it to 60 in lbs. It felt tight, the lifter tray was totally secure, but I was afraid to tighten it to 106 in lbs and push my luck.
I re assembled the engine, and it runs, but my sphincter is a little tight about the repair job on the lifter tray. The bolt doesn’t really bare any pressure short of keeping the tray and lifters in place, but if it were to fail and the lifters moved off the cam it could get messy.I do plan on using the car for HPDE Road race style of driving. In retrospect, I would have gone to a 7mm bolt and re threaded the aluminum and come up with a way to keep the tray in correct alignment with a little brass washer/spacer or something.
Should I take the head back off and do the 7mm bolt fix or since the tray doesnt see load will the jb weld and red thread lock suffice?
DOUGH!!! Why me?!?!
So when I pulled the bolt out, about half the threads came with it. I tapped the hole out with the standard 6mmx100 thread but I just wasn’t comfortable with the way it felt.
I JB welded it and let is sit for 2 days to fully cure and tapped out a new hole. I put a ton of Red thread lock on it and torqued it to 60 in lbs. It felt tight, the lifter tray was totally secure, but I was afraid to tighten it to 106 in lbs and push my luck.
I re assembled the engine, and it runs, but my sphincter is a little tight about the repair job on the lifter tray. The bolt doesn’t really bare any pressure short of keeping the tray and lifters in place, but if it were to fail and the lifters moved off the cam it could get messy.I do plan on using the car for HPDE Road race style of driving. In retrospect, I would have gone to a 7mm bolt and re threaded the aluminum and come up with a way to keep the tray in correct alignment with a little brass washer/spacer or something.
Should I take the head back off and do the 7mm bolt fix or since the tray doesnt see load will the jb weld and red thread lock suffice?
#2
TECH Addict
iTrader: (1)
Where do you think the lifter trays going to end up? The only job of the trays is to keep the lifters from rotating as the lifter bores hold them in the correct position. The trays can't drop down and they can't really rotate since the lifters are held fast in their individual lifter bores so in a way the lifters actually help to keep the trays in position. The trays can't move upward since the cylinder heads are holding them down. If GM wanted the trays to be more secure they would have used two screw instead of just one to hold them in place. If you already took all the steps you say you did I wouldn't worry about it. Do you really need a torque wrench for that small bolt? Using a 1/4" rachet or a 10mm Gear Wrench and the torque wrench you have in your wrist you shouldn't find any more stripped threads if you have sufficient experience turning wrenches.
#3
TECH Senior Member
I would be weary of the bolt breaking loose from the JB weld and it causing problems than, as Eelanbogs mentionned, anything going wrong with retainer position. If it were me I would have used a helicoil instead.