What's the trick to keep flex plate bolts tight?

What's the trick to keep flex plate bolts tight? - 09/27/09 02:28 PM

The first time I put the motor (470) in I made 70+ passes and the flex plate came loose. I bought a new flex plate (didn't want to take a chance of it coming loose again due to using the old one) and new ARP bolts, cleaned the treads so the lock tight will grip. I used a torque wrench to install and torqued to the arp specs. I went to the track twice and now there loose again.

One guy at the track said he uses chevy bolts, they have some locking head on them I quess like a star locking washer.

What bolts do I need or is there a trick most mopar people use I haven't heard about yet? Thanks.

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Posted By: Anonymous

Post deleted by Defbob - 09/27/09 02:34 PM

Posted By: bonefish

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 02:37 PM

i have found that if i ignor the torque specs and just tighten the holy crap out of them they stay tight,and i use the red loctite.

Posted By: Anonymous

Post deleted by Defbob - 09/27/09 03:15 PM

Posted By: mopar dave

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 03:19 PM

i use blue loc-tite and never have a problem.

Posted By: VernMotor

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 03:20 PM

red loc-tite stock bolts beat them tight..if they come loose. something else is wrong..

Posted By: bigtimeauto

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 03:42 PM

I have a jw adapter and 6 bolts. red loctite here also no issues at all.

Posted By: moparniac

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 05:21 PM

How much do you guys torque them to.... ARP stuff.....

Posted By: Torred

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 05:29 PM

Quote:

i have found that if i ignor the torque specs and just tighten the holy crap out of them they stay tight,and i use the red loctite.

Posted By: dusturbd340W5

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 05:37 PM

Quote:

Quote:

i have found that if i ignor the torque specs and just tighten the holy crap out of them they stay tight,and i use the red loctite.

Red Lock Tite and a air impact= no problems

Posted By: VernMotor

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 05:38 PM

Quote:

Quote:

i have found that if i ignor the torque specs and just tighten the holy crap out of them they stay tight,and i use the red loctite.

Same here.. beat them tight with a hammer and a wrench..been doing that for 25 years.. I know we will have all them guys coming on here O-no thats not right! boo hoo..It works.. beside geting a torque wrench up there is a real pain too.

Posted By: Diablo

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 05:57 PM

Dont want to be a downer but you might have a cracked crank shaft. I couldn't keep mine tight on the new engine. Ended up having a cracked crank. I didn't want to believe what some were telling me but i took the crank out and had it tested. Didn't want to loose my entire 636ci engine due to someone lying about the crank being checked. Better safe than sorry. I acted safe and probably saved my engine from turning into a BOMB!

Posted By: B1KILLER

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 07:16 PM

Quote:

Try red Loctite.
X2

Posted By: W5DART66

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 07:27 PM

What balancer is on engine?

Posted By: Bob_Coomer

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 07:35 PM

Quote:

How much do you guys torque them to.... ARP stuff.....

What ever a 1/2 drive Impact will hit too several seconds after the socket stops moving, plus some red loctite as mentioned.

Posted By: mac56

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 07:47 PM

Quote:

Dont want to be a downer but you might have a cracked crank shaft. I couldn't keep mine tight on the new engine. Ended up having a cracked crank. I didn't want to believe what some were telling me but i took the crank out and had it tested. Didn't want to loose my entire 636ci engine due to someone lying about the crank being checked. Better safe than sorry. I acted safe and probably saved my engine from turning into a BOMB!

Doug I never read that was what ended up being your problem. Sorry to hear that. I hope with all the issues you have had this season getting that monster running your are laying a smack down on those chevies.

Posted By: 77DragracerR/T

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 09:15 PM

I just had the same problem with my converter bolts becoming loose and i used red loctite and they have a lock washer on them as well.I was told to retorque them after a couple passes

which really doesn't make much sense to me especially with the loctite in there.

Posted By: challenger73400

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 09:44 PM

Quote:

What balancer is on engine?

440 source SFI balancer. No unusual vibrations.

Thanks guys, I'll put red lock tight and some bowinkle on the bolts!

BTW. how does a cracked crank cause the flex plate bolts to come loose? Added vibration?

Posted By: Diablo

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 10:13 PM

Quote:

Quote:

What balancer is on engine?

440 source SFI balancer. No unusual vibrations.

Thanks guys, I'll put red lock tight and some bowinkle on the bolts!

BTW. how does a cracked crank cause the flex plate bolts to come loose? Added vibration?

At a certain RPM there will be a harmonic vibration and just spin bolts and nuts out. On the Dyno i could actually watch the valve cover nuts come off when going up the RPM range. We didn't have an idea of the crank being cracked at that time.

Mark (Mac56): We ended up running the 496 again for most of the summer. For the two runs with the 636 we were pretty happy. We know we will be in the top 3-4 trucks for hp next year. There were three other GM boys that came in with 600ci 1000-1100hp engines and the 496 had a hard time trying to run with them on the clay tracks. But it did well for what it is. Next year they will have a mopar to watch for

Posted By: 602heavy

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 11:02 PM

Great idea using a torque wrench , how do you get it in there with the sump on? , or am i missing something

........ ring spanner doubled up is all that fit in there.

Posted By: W5DART66

Re: What's the trick to keep flex plate bolts tight? - 09/27/09 11:50 PM

Quote:

Quote:

What balancer is on engine?

440 source SFI balancer. No unusual vibrations.

Thanks guys, I'll put red lock tight and some bowinkle on the bolts!

BTW. how does a cracked crank cause the flex plate bolts to come loose? Added vibration?

you will not feel the vibration that will loosen the blots. I had this same deal on SM block mopar street car even went as far as to weld the bolts it just broke welds. I put good balancer on it never had bolts back out again.(BHJ at the time) If you have any other balancer to try I would start with that.

Posted By: bonefish

Re: What's the trick to keep flex plate bolts tight? - 09/28/09 12:11 AM

do you have the bell notched out so you can get a good pull on the wrench?

Posted By: challenger73400

Re: What's the trick to keep flex plate bolts tight? - 09/28/09 12:20 AM

Quote:

Great idea using a torque wrench , how do you get it in there with the sump on? , or am i missing something ........ ring spanner doubled up is all that fit in there.

I slide the tranny back about three inches. remember we are talking about the flex plate bolts holding the flex plate to the crank. I don't think you can get to them without sliding the tranny back some.

Posted By: bonefish

Re: What's the trick to keep flex plate bolts tight? - 09/28/09 01:24 AM

Quote:

do you have the bell notched out so you can get a good pull on the wrench?

oops ,yeh i knew that but was thinkin tq,