Shimming "The Wheel" flexplate to the converter

[ranger]

Hi folks,

getting ready to fire up my new engine combo. I am using "The Wheel" SFI flexplate and it does indeed have the teeth on the correct side. I remember a few years back some peeps got them and the teeth were facing the wrong direction.

Anyway, everyone agrees that we have to use washers to push the converter back toward the pump. As the spacing comes on the wheel, it pulls the converter too far forward. People say they uste 3/8" washers and longer/hardened 3/8" bolts. I believe the converter should come forward no more than 1/3" from when it is bottomed against the pump.

My tranny guy, who also races, said "DO NOT DO THIS UNDER ANY CIRCUMSTANCES!" He says he has tried it on different engins and has always had issues--bolts coming loose or breaking, I guess.

He said that if "it absolutely just has to be done" than it would be best to use solid spacers instead of individual washers, though he doesn't know where to get those.

He said it would be best just to use a stock flexplate.

Any input/thoughts/experience would be appreciated.

Best,

Ranger
Aiken, SC

[Rob Ross]

I have used the flywheel you speak of. My trans guy says no less than a nickel and no more than two nickels for shimming. I've used grade 8 washers or thick shims with great success. Make sure the converter pads aren't interferring with anything. If the joint is good, you should not have any loosening. I do use loctite and torque the bolt per a torque chart. I also always use fine pitch. HTH

[Houndogforever]

I would not use stacked washers for something that takes that much torque. You need a machine shop to make you solid spacers.

I would still be a little concerned about using solid spacers too because won't you lose the center hub centering location? I don't know specifically what the assy looks like offhand, but if memory serves, isn't there a raised ridge on the crank that fits into the center of the flywheel?

If so, I would think you need a solid 5/16" thick spacer plate that goes under the flywheel and onto the crank to ensure balance and centering. Any combination of individual parts may, and probably will cause balance problems and then there goes your rear main.

Seems like a terrible design flaw on the flywheel if you have to shim it out to make it function as it should.

[BillA]

Steel shims would be preferable to washers because they are machined to a precise thickness and you want all three shims to be the same thickness. That being said, I'm using grade 8 washers as spacers but I measured them with a micrometer so all 3 are the same thickness. Since I'm only using one spacer each (.079 thick) I was able to use the original flexplate bolts. This is on a street car with a stock flexplate.

[LARRY70GS]

I would not use stacked washers for something that takes that much torque. You need a machine shop to make you solid spacers.

I would still be a little concerned about using solid spacers too because won't you lose the center hub centering location? I don't know specifically what the assy looks like offhand, but if memory serves, isn't there a raised ridge on the crank that fits into the center of the flywheel?

If so, I would think you need a solid 5/16" thick spacer plate that goes under the flywheel and onto the crank to ensure balance and centering. Any combination of individual parts may, and probably will cause balance problems and then there goes your rear main.

Seems like a terrible design flaw on the flywheel if you have to shim it out to make it function as it should.

Jon,
We are talking about the torque converter to flex plate, not the flex plate to the crank. If the torque converter is pulled too far forward, it will not engage the front pump drive adequately, and damage it. I have never had any issues with using grade 8 washers. Using locktite is a good idea.

[Houndogforever]

Jon,
We are talking about the torque converter to flex plate, not the flex plate to the crank. If the torque converter is pulled too far forward, it will not engage the front pump drive adequately, and damage it. I have never had any issues with using grade 8 washers. Using locktite is a good idea.

Doing my best Emily Lattella....... Nevermind

[MN GS455]

I use the nice hardened black oxide coated washers all the time. They come in several thickness ranges. You can get them at Fastenall. They are similar to the ones that come in ARP stud kits. Never had a problem, I use a little red loctite too.

I like from 3/16" to 1/4" end play in the converter to allow for expansion.

[Jim Weise]

George Sweesy's car had 2 machined Grade 8 washers under each converter pad, to obtain the desired spacing. That particular converter used 7/16 bolts, and appropriate hardened fasteners were used.

No issues at all with 765 ft lbs of torque, coming off the trans brake at 5500 rpm, in a 3200 lbs race weight car.

Don't worry about it durability wise.. as MNGS455 said, about 3/16 out of the converter is the sweet spot, and make sure you use hardened and machined (not cut) washers.. and then mic their thickness to insure your using even stacks. As I recall, hardened machined washers are about .100 thick.

They do vary a little bit, so take your mic or veiner caliper to the hardware or fastener store when you buy. The spacers Ron speaks of, if they are in the size range you need,will be generally more accurate in thickness.

JW

[ranger]

Hi folks,

Thanks for all the replies. Are "hardened and machined, not cut" washers the ones sold at Fastenall?

"To my eye," when I bottom the converter all the way in it looks like I have about 1/2" space between converter pads and "The Wheel." Assuming I pull the converter forward by 1/4" I would still have another 1/4" to shim, and that sounds like too much.

From what you guys have said it appears that a guy wouldn't wanna add more than .100" of shim, am I understanding this correctly.

As well, I'm sure I have 3/8" bolts in my old K-B switch/pitch converter. Is it worth it to drill them out to 7/16??

Thanks again to all!

Best,

Ranger
Aiken, SC

[MN GS455]

The Fastenall washers are cut parallel. Stack as many as you need, you won't have a problem. You will have problems if you leave too much clearance, usually the pump gears will break.

I have seen converters built with these washers tack welded right to the mounting flanges.

[ranger]

@ Ron,

Thanks! But if I do end up using enough Fastenall washers to take up .250" or so, might it be prudent to enlarge the converter holes/threads to 7/16" or do you think I would still be o.k. w/ the stock 3/8"?

Best,

Ranger
Aiken, SC

[Schurkey]

What moron designs and builds a flexplate that needs to be specially shimmed? How tough can it be to get the distances correct on the part itself, rather than "custom-fitting" the thing?

"I" would send the flexplate back with a note telling them to build it RIGHT instead of CHEAP.

[paul c]

What moron designs and builds a flexplate that needs to be specially shimmed? How tough can it be to get the distances correct on the part itself, rather than "custom-fitting" the thing?

"I" would send the flexplate back with a note telling them to build it RIGHT instead of CHEAP.

if i remember the stock flex plate has a slight dish to it which brings the mounting pads out where they should be. we are probably lucky that the aftermarket supplies us with a sfi unit and thats how they are going to do it i suppose. if they would sell a million of them they would probably have it identicle to a stock one. i have used stainless washers and miced them up for spacers. no issues yet.

[MN GS455]

@ Ron,

Thanks! But if I do end up using enough Fastenall washers to take up .250" or so, might it be prudent to enlarge the converter holes/threads to 7/16" or do you think I would still be o.k. w/ the stock 3/8"?

Best,

Ranger
Aiken, SC

Sorry, just saw this...

I would enlarge them to 7/16". I use fine thread, grade 8 on my race stuff and sometimes have to shim them .250" because of the mid plate. The converter company makes them with an interchangeable crank pilot that is threaded on. They use all the same core, but with spacers and a longer pilot for different mid-plate thicknesses.

---------- Post added at 01:03 AM ---------- Previous post was at 01:01 AM ----------

What moron designs and builds a flexplate that needs to be specially shimmed? How tough can it be to get the distances correct on the part itself, rather than "custom-fitting" the thing?

"I" would send the flexplate back with a note telling them to build it RIGHT instead of CHEAP.

A flat flex-plate is stronger than one that is stamped for offset like OEM.

Race parts require fitting. You'd hate to see what it takes to get a set of aluminum rods to fit in a stroker engine