Keeping the Flexplate on the Crank [Archive] - DSM Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum: DSMtalk.com

: Keeping the Flexplate on the Crank


2XtheGreen
02-22-2010, 10:22 AM
Are you guys/girls doing anything special? 55ft/lbs & Red Loktite is what I'm using on my kiggley plate and I cant seem to keep the bolts from backing off the flexplate/crank connection. I had to re-torque them last season, and last weekend I went to the dyno and on the last pull (thank God) they loosened up again. It's not like the auto's have a dowel pin like the 5 speed flywheels have. Vibrations maybe? I do have a fluidampr on the other end of the crank, 2 poly mounts, and the rear one is welded solid. I ordered another plate this morning from Kevin, just in case this one's bolt holes are trashed. I'm trying to make it to e-town this weekend if they're going to open. I'm open to any ideas, thanks guys!

Kevin Kiggley's plate: (if you've never seen one)
http://www.kigglyracing.com/parts/images/Flexplate_Small.jpg

-Mike

blue_gsx
02-22-2010, 10:36 AM
Over on the dsmlink forums a few guys have had this problem. They seem to be using loctite on the bolts and some of them even use arp bolts.

97gstbabe
02-22-2010, 11:55 AM
Are you talking about the bolt between the convertor and the plate or the boltes that hold the plate to the crank it self? I have never had the bolts loosen on the plate to crank. But they seem to loosen on the plate to convertor on a regular basis.

I run a standard single plate with bolts locktited in convertor then welded in place.

Migsubishi
02-22-2010, 12:06 PM
Are you talking about the bolt between the convertor and the plate or the boltes that hold the plate to the crank it self? I have never had the bolts loosen on the plate to crank. But they seem to loosen on the plate to convertor on a regular basis.

I run a standard single plate with bolts locktited in convertor then welded in place.Whoe wtf... you welded the bolts in place that bolt into your converter? Any pics of this... lol

2XtheGreen
02-22-2010, 01:07 PM
I don't have issues with the converter to plate bolts. They stay tight. Its the crank bolts. Welding them is definite possiblilty for now. Does anyone run studs and nuts? I will be pulling the trans asap to see exactly what's going on and if there's any damage. I caught it early so I have my fingers crossed.

BTW In no shape or form am I blaming the plate for this. In my mind there is no other option but to run this flexplate. Kevin and his wife are top notch people.

-Mike

GDNF2ET
02-22-2010, 04:36 PM
The torque specs from the Haynes Repair manual:
Engine section page 2A-3
Flywheel or driveplate bolts (to-crank)..........94 to 101 FT-LBS

Automatic transaxle page 7B-1
Torque converter-to-driveplate bolts........33 to 38 FT-LBS

The driveplate is the flexplate..You weren't torquing the crank bolts down enough...

2XtheGreen
02-22-2010, 05:00 PM
Wow, I gotta double check my install notes tomorrow when I get to my shop. I think I torqued them to 101, and the converter to plate was 55. I think I just switched them when I was typing earlier. Good looking out. Thumbs up!

-Mike

2XtheGreen
02-23-2010, 06:38 AM
So going over my notes I have the bolts that go into the converter are supposed to be 37 ft/lb and I torqued them to 55ft/lb. The crank bolts I have 100ft/lb. I guess I should have increased that number also, but I didn't.

I talked to Kevin last night, he said to increase the torque on the bolts with red locktite, and green locktite on the face of the crank and backside of the plate. I'll probably stick to this method, marking bolts to see if they move, and just re-torquing every couple events.

97gstbabe
02-23-2010, 07:09 AM
Yeah just watch those convertor bolts. I have had them pull out on more then 1 occassion and snap flexplates. Kevin's is a little stronger then OE but with loose bolts anything is possible. Hence why mine are taced in place...

2XtheGreen
02-24-2010, 09:08 AM
Just got all new bolts from my dealer, and a new flexplate from Kiggley just in case. I'm gonna rip it apart tonight and see whats going on.

-Mike

97gstbabe
02-24-2010, 10:36 AM
Out of curiousity what did the car lay down on the dyno? What turbo are you running again???

Colin
02-24-2010, 01:30 PM
I have not had my car running yet with the Kiggly flexplate but I used Red Loctite and torqued mine to 101lb ft. I'll have to keep an eye on this.

Let us know what you find and or if they repeat loosen again in the future.

Migsubishi
02-24-2010, 04:41 PM
Yeah just watch those convertor bolts. I have had them pull out on more then 1 occassion and snap flexplates. Kevin's is a little stronger then OE but with loose bolts anything is possible. Hence why mine are taced in place...I think I might use that idea and tack weld the flex plate bolts. I will leave the converter ones alone till I decide wether I like my current stall speed or not. I do have a high output stroker and their known for flywheel bolt issues....

2XtheGreen
02-25-2010, 09:21 AM
So after an extra long night at my shop, everything is back to normal. The crank bolts did loosen up a little, causing abrasions to the plate and the face of the crank. I cleaned up the crank pretty good and it actually came out better than I thought. I added a "5 speed" dowel to my crank, and made a hole in the new plate Kevin sent me. I used a generous amount of locktite on everything and I have my fingers crossed.

Nick- as far as my dyno numbers, I'm kind of embarrassed to say. I never re-tuned the car since the 5 speed swap, so the session was to just clean up the tune-up, which she needed. We fought the car trying to pull itself off the dyno, then fought tire spin on the rollers, and never ended up with a realistic "number". Now that's she's ready to roll down the track, I'll let the time/mph speak for themselves. This weather really sucks because I was planning on going to opening day @ e-town on sunday, but its not looking so good. Maybe next week.

To be continued.......

-Mike

blue_gsx
02-25-2010, 10:02 AM
Heck there's 500hp auto dsm's that run 9's.

Migsubishi
02-25-2010, 11:59 AM
Heck there's 500hp auto dsm's that run 9's.Any vids or info on said cars.

blue_gsx
02-25-2010, 12:34 PM
Think his name is John from Wier's racing in NC. Dynoed like 520 and the car ran 9.89@138 at full weight 1g. This was a while ago though. don't have vids but i believe it was a 2.3 with a t67.

16g-95GSX
02-25-2010, 01:01 PM
Mike,

What bolts are you using, I dont see it mentioned anywhere and IMO it is something that is important. There are slight variances between the various crank bolts. You need to not use automatic bolts but 5spd bolts that are shaved down to the proper length.

97gstbabe
02-25-2010, 01:31 PM
Think his name is John from Wier's racing in NC. Dynoed like 520 and the car ran 9.89@138 at full weight 1g. This was a while ago though. don't have vids but i believe it was a 2.3 with a t67.

I believe it's Jason's car and it ended up running 9.77@139. It's a 6765 with 2.3 and a 65 shot for spool up. Very quick car. They have a couple of them running around down there.

2XtheGreen
02-25-2010, 02:02 PM
Mike,

What bolts are you using, I dont see it mentioned anywhere and IMO it is something that is important. There are slight variances between the various crank bolts. You need to not use automatic bolts but 5spd bolts that are shaved down to the proper length.


I've been using part # MD952233 bolts. I measured the bolts, and the threads inside the crank. They don't bottom out and they have good engagement depth. They are automatic bolts, because when I did my swap to auto, the 5 speed bolts were too long for the thin flexplate. These bolts are going into an Eagle crank btw. I dug up an old OEM crank I had around the shop and everything seems to be the exact same dimensions/depths.

As far as the HP conversation goes, Dyno #'s mean nothing till you make it down the 1320:cool:

-Mike

16g-95GSX
02-25-2010, 02:20 PM
That is just it, when you use 5spd bolts you need to grind them to the proper length. I have a nice picture that I used to have hosted online of various crank bolts that I had laying around, the auto, 6bolt, 7bolt, and I believe the grinded to length 6bolt. If I remember correctly the 6 bolt is longer than a 7bolt, and both the 6bolt and 7bolt crank bolts will need to be ground to length. However, the difference is that the 6bolt crank bolt is threaded throughout its entire length, unlike the 7bolt crank bolt which has a 3-5mm portion of unthreaded shank. The auto trans bolt is just simply too short and for any higher hp build I would run the longer bolts ground to length.

As for the torque converter to flex plate bolts, I would not use OEM bolts there either as they are just way too short. Instead I would head to mcmaster and pick yourself up some properly sized high grade hardware and grind them to length. I ran 10.9 grade hex head bolts ground to length, and kiggly runs 12.9 grade allen head bolts ground to length. With 8 bolts on the flex plate Id imagine either bolt would work, I just worried about rounding out the allen head hole with 50+ftlbs of torque after I shaved the head down, even though kiggly seems to do it just fine.

Of course you want to bottom tap the crank, clean it out very nicely, and use the high temp red locktite, but the hardware selection is a very good way to solve the issue that you're having.

Migsubishi
02-25-2010, 03:53 PM
Very informative guys, Thanks and keep it up!!!!

Colin
02-25-2010, 06:13 PM
For the flexplate I used some off the shelf GM torque converter bolts that are grade 10.9 and came with HD loctite on them already. I had brand new ones sitting in my tool box at work so they were free for me. They had the correct thread pitch and thread length to get the right depth all the way to the bottom of the converter bolt holes. However they did need to have the tip cut off as it's a style of bolt that has about 1/4 inch of unthreaded rounded tip to it.

I can see if I can't dig up the part number I used.

16g-95GSX
02-25-2010, 06:55 PM
http://www.ncdsm.com/16g-95gsx/OEM%20Converter_Ground6bolt_7bolt_6bolt.JPG

This should help put it into perspective.

On the far left is a stock auto trans crank bolt, next to that is a ground to proper length 6bolt crank bolt, then comes a 7bolt crank bolt, and then finally a stock 6bolt crank bolt. As you can see from the ground to proper length 6bolt crank bolt, the stock auto trans crank bolt leaves a lot on the table as far as thread engagement. The 7bolt crank bolt will need to be ground down just as a 6bolt crank bolt will, but the 6bolt crank bolt has a longer threaded region.

If you're using the stock auto trans crank bolts then you are selling yourself short, proper hardware will solve your issue.

2XtheGreen
02-25-2010, 07:05 PM
Thanks for the input Chris. Next time I'm inside there I'll be sure to change them out. How exactly are you guys cutting/grinding/shaving down the hardware?

3_eyed_talon
02-25-2010, 07:26 PM
Thanks for the input Chris. Next time I'm inside there I'll be sure to change them out. How exactly are you guys cutting/grinding/shaving down the hardware?

I have always just put the bolt head in a vise and cut the desired amount off with a hacksaw or portable bandsaw. But make sure to cut strait, take your time. Then take a file and file down the cut edge at a 45* angle all the way around.

Im pretty good at it considering im a electrician and I cut bolts and allthread all day and never have a problem getting them in or a nut started. So it DOES work just fine.

16g-95GSX
02-25-2010, 08:29 PM
I use an electric grinding wheel and a cup of water to dip it in and keep it cool.

Migsubishi
02-25-2010, 10:07 PM
For the flexplate I used some off the shelf GM torque converter bolts that are grade 10.9 and came with HD loctite on them already. I had brand new ones sitting in my tool box at work so they were free for me. They had the correct thread pitch and thread length to get the right depth all the way to the bottom of the converter bolt holes. However they did need to have the tip cut off as it's a style of bolt that has about 1/4 inch of unthreaded rounded tip to it.

I can see if I can't dig up the part number I used.Nice please get us that part number! Thanks for the info...

Also "16g-95GSX" You too have been a great help, Thanks for the info and pic!

GDNF2ET
02-26-2010, 06:55 AM
Make sure you run a nut up on the bolt before you cut it.That way when your done cutting, it will clean the threads as you take the nut off..

drewkeen
03-04-2010, 10:46 PM
Isn't there a stronger loctite than the red as well? I forget the color but it is supposed to be "permanent." Also, some have recommended torquing the bolts down to 120+ ft/lb as well to hold them on better.

Colin
05-30-2010, 04:21 PM
http://www.ncdsm.com/16g-95gsx/OEM%20Converter_Ground6bolt_7bolt_6bolt.JPG

This should help put it into perspective.

On the far left is a stock auto trans crank bolt, next to that is a ground to proper length 6bolt crank bolt, then comes a 7bolt crank bolt, and then finally a stock 6bolt crank bolt. As you can see from the ground to proper length 6bolt crank bolt, the stock auto trans crank bolt leaves a lot on the table as far as thread engagement. The 7bolt crank bolt will need to be ground down just as a 6bolt crank bolt will, but the 6bolt crank bolt has a longer threaded region.

If you're using the stock auto trans crank bolts then you are selling yourself short, proper hardware will solve your issue.


What year were those auto bolts from? I had the trans out yesterday today and I upgraded to the modified 5spd bolts today. However My auto bolts are heaps longer than the ones you have pictured there.

My stock auto bolts on the left, Modified 5spd bolt. Stock 5spd bolt(6bolt) and again to show between the two another of my auto flexplate bolts.
http://i483.photobucket.com/albums/rr200/ColinWB/IMG_7769.jpg

Colin
05-30-2010, 05:01 PM
Oh and forgot to mention do you guys have to modify the auto pilot bushing in the crank to use the 5spd bolts??

I found I had to grind down a bit of the smaller lip on the pilot bushing as with the 5spd bolts they are a 19mm headed bolt with a larger shoulder compared to the 17mm socket size auto bolts.

Without grinding down the pilot bushing the shoulders on the 5spd bolts were hitting the bushing before being able to contact the spacer plate/flexplate.

http://i483.photobucket.com/albums/rr200/ColinWB/IMG_7767.jpg