Hi guys, been a long time since i posted. So I finally got the motor and transmission installed in the car and quickly realized I had installed the flexplate backwards. Luckily it was just placed in the engine bay.

so I removed the transmission and took off the flexplate. Now I am confused as to where the external weights on the flexplate are supposed to be in relation to the crank. Usually there is hole where the dowel is to line up. We'll I don't have a lineup hole on the flexplate.

How do I go about making sure the flexplate is installed in the correct alignment. Only thing I noticed is that the holes for the converter bolts on the flexplate is that 2 of the mounting areas as 2 holes drilled but one side has 3. Wondering If the side with 3 is to line up with the dowel hole on crank???

The flexplate is a FRA102

any help would be appreciated.

thank you

 

There should be a dowel pin installed in the crank. You also may want to remove the pilot bushing from the crank.

 

1. the crank doesn't have a dowel pin
2. the factory Flexplate will only mount one way as in the bolt holes will only align one way.
also the weights face towards the converter...

 

I see that the crank doesn't have the dowel pin. I had to puchase a new flexplate FRA102.....it doesnt have a provision for the dowel line up hole.

I'm thinking I may need to find myself a factory flexplate with the lineup hole.

Also is the flexplate a 166 , 168 or 153 for 455 Olds. Want to make sure i have the correct flexplate

i had the flexplate weight facing the converter and they were touching...super tight.

So confused........

 

I had to think back, don't worry about the dowel pin. You have the correct part number flexplate and 166 tooth is what it should be.

 

post a picture of the flexplate and converter. I just looked at the FRA102 flexplate and it looks like a factory plate. the weight should face towards the trans or convertor. if its tight the converter may not be seated all the way in....

 

^^^THIS! The hole pattern has one hole clocked 5 degrees off. The flexplate only goes on the crank one way. You cannot install it backwards - that one hole won't ever line up. And because of this, there was no need for Olds to use a dowel pin.

 

Could it also be the converter is not one with threaded lugs as typically used on Olds engines, and has the through-bolt flange design used on Chevy engines? I have read some folks needed to use washers to space that style converter away from the flex plate weights.

 

Thanks for the replies guys.

So the weights on an Olds 455 flexplate face the converter in the BOP Th400? There's some people out there that say the opposite mostly on chevy applications.

I had the weights facing the transmission originally before i took the tranny out......either way there is an issue.

The converter may not be fully seated....do they click 2 or 3 times?

i have posted the pics of the flexplate amd a picture of the converter showing the gap at the bottom inspection cover area....there is bit of a gap there...should that be pushed in more.

The converter is the same one ive had behind my previous olds 400 and 455...its a GM3H.

Thank you everyone who responded, appreciate you guys very much.

 

Those pictures are way too small to see any details.

 

let me see if I am able to make them bigger

 

let me see if I am able to make them bigger

 

https://i.postimg.cc/DZfkkpjH/20240924-154632.jpg

 

https://i.postimg.cc/8k089HhX/20240924-153817.jpg

 

https://i.postimg.cc/cC6p6gNc/20240924-153826.jpg

 

https://i.postimg.cc/7hsqWrqK/20240924-133114.avif

 

correct. If it’s a Chevrolet style converter with bolt and nut mounting flange you typically space it back with an arp or similar washer to clearance it from the weight. Usually there’s enough clearance to slide the converter back enough without binding the converter into the pump of the trans. It shouldn’t be tight or binding against the flexplate either. You have a piicture of the front of the converter?

 

Here are pics of the converter,

https://postimg.cc/gallery/W2Rp9hG

 

https://i.postimg.cc/d1x38jMk/20240924-204926.jpg

Sorry its blurry

It's about 1inch from the mounting pad on the converter with a straight edge to the outside edge of bellhousing

https://postimg.cc/HcmkV3KV

https://postimg.cc/phjKt0jr

​​​​​​

 

Here's a close up pic of the crank....don't see a pilot bushing....unless my 20/20 vision is no more...

https://i.postimg.cc/kM8T4BpC/20240925-122141.jpg

 

So I spent a few hours today on the flexplate and torque issue. After cursing a few times I got it set perfect. I spun the torque converter which felt like 30 times while pushing it in until it stopped at its maximum. Installed the flexplate with the weights facing the TC. Using 2 Jack's to get it lined up and mated to the motor everything seems perfect. I just need to bolt up the Flexplate to the TC. The gap looks to be around 1/8.....will do a proper measurement tmrw.

I think the issue could have been maybe the TC wasn't fully seated on the final click and the Flexplate weight and mounting pad were contacting and stopping the TC from moving freely.

Here are some pics:

https://postimg.cc/gallery/JrhGG99

Thank you everyone for helping me figure this out.... now that i'm slowly putting the drivetrain back in I will be reaching out......Dual Gate shifter cable to Tranny install is next.

 

Sorry, the original picture looked like there was one.

 

The gap between the converter and the flexplate looks good according to the pictures. That’s the bop converter with the threaded lugs. Your on your way…

 

No worries......I'm just glad I didn't need to pull one out!

 

Phew!
Just a bit of blue loctite on the flexplate bolts and put the inspection cover on!!