Flex plate bolts backed out again...............

Flex plate bolts backed out again...............

Post IDT-572 Today at 10:32 pm
I backed the car out of the trailer, (hadn't been out since the US-43 race) to give it a once over before heading to Eric's race. Found a slick with a hole in it and my flex plate bolts backed out again.

I put new ARP bolts in it last time and torqued it to ARP's specs and then put red lock tite on the bolts. The holes may have been slightly egg shaped and caused this to happen again.

I have a new JW Wheel in the shop of a buddy of mine. I am putting it on tomorrow night with a new set of ARP bolts and ordering something better later to put on it when I get back from the race this weekend.

Blake,
Take a look at the hole in the Wheel and make sure it is not contacting the radius under the head of the ARP Pro Series bolt. ( The Pro Series has a larger radius..) I noticed this a few years ago, talked to the JW folks about it, and as far as I know, they never corrected the issue. To fix the problem, just chamfer the bolt holes in the Wheel.
I never had any back out, but always checked for clearance on that bolt radius. When I used to run a JW Wheel, I used blue Loctite also.
At least something to look at....
Hope it helps,
Keith

Wheelie58 wrote:Blake,
Take a look at the hole in the Wheel and make sure it is not contacting the radius under the head of the ARP Pro Series bolt. ( The Pro Series has a larger radius..) I noticed this a few years ago, talked to the JW folks about it, and as far as I know, they never corrected the issue. To fix the problem, just chamfer the bolt holes in the Wheel.
I never had any back out, but always checked for clearance on that bolt radius. When I used to run a JW Wheel, I used blue Loctite also.
At least something to look at....
Hope it helps,
Keith

Thanks Keith, I will check it tomorrow night.

I've had them wallow out the holes as well. As Keith said...underhead radius on the bolt. I have since swapped to just a regular grade 8 bolt + blue loctite on the the threads. No radius to speak of but plenty strong.

No problems, none backed out, no holes messed up. I also use a dab of anti-seize under the bolt head to keep if from galling the flexplate when I torque it down.

David Cole wrote:I've had them wallow out the holes as well. As Keith said...underhead radius on the bolt. I have since swapped to just a regular grade 8 bolt + blue loctite on the the threads. No radius to speak of but plenty strong.

No problems, none backed out, no holes messed up. I also use a dab of anti-seize under the bolt head to keep if from galling the flexplate when I torque it down.

Yeah...
It seems like JW and some others just punch a square- edged hole without considering the type of fasterner that will be used.

Use a 7/16" head bolt washer with an I.D. chamfer under the bolt head....that's what i used on my dragboat engines. Requires a longer bolt in some applications.

Got them in hand now.

I used a set of the APB std trans "flywheel" bolts, they are longer than the flexplate bolts, iirc they had a shoulder on them..........I just had my machinist buddy cut them to length..................they std flexplate bolts didnt go all the way into the crank flange as they are too short. This was with my JW wheel.

Of the engines I supply with a flexplate on them, I use the FORD bolts which also have a 3/4" hex head.
There have been no problems however, I don't use the JW wheel. I have several times used a flexplate called the "Reactor" for Big Block Ford, powerglide cars, (from Coan in Indiana), which seems to work really well for my customers.

Blake,

Thanks for posting this. I'm running a JW Wheel and will be putting the engine back in the car for the last time soon. I'll have to check this while it's still out. I'm using a set of 9" ring gear bolts though. I may be OK...

Sorry a bit late to this thread but you could try nordlock washers under the bolts if your still concerned. Dont know whod supply them in the states but sure if you put nordlock into your search engine youd come up with them. There a 2 piece washer we use them on the gas turbines in work they are very very good.
Hope this helps

put stock bolts in it,blue loctight,75 lbs, have seen many a problem with aftermarket flywheel bolts

and we never use a washer