c4 flexplate issue

[diggs00]

76 bronco
Motor: blueprint 306
Trans: stock c4
Flexplate: Hughes HP4397 - 164 Tooth Externally Balanced 50-oz.
5.0L Windsor, C-4 or AOD transmission, 4 x 11.50-inch bolt pattern
Torque Converter: Hughes F42XTM


Issue: Flexplate has rubbed the c4 BELLHOUSING PLATE/SHIELD/COVER PLATE creating metal glitter inside the bell housing.

? What the hell do i do?

 

[hunter1]

Flex plate in backwards?

 

[diggs00]

Flex plate in backwards?

not sure if on backwards. The Flexplate has a center depression only. If I flip it the rub would not happen, but not sure which way is correct.

Current install has the depression facing the Torque converter.
so looks like this:


https://drive.google.com/file/d/1t0NJMRThPg_s3vjrQSJa7twgKArCyQ_M/view?usp=sharing

 

[rguest3]

The Flexplate should be installed with the offset forward making the ring gear pushed back away from the Tin Block Plate. Installed this way?

Also, is the Blue Print motor a 28oz. or 50oz.? Flex plate and Balancer on front of motor have to match the Balance on the Engine.

 

[diggs00]

The Flexplate should be installed with the offset forward making the ring gear pushed back away from the Tin Block Plate. Installed this way?

Also, is the Blue Print motor a 28oz. or 50oz.? Flex plate and Balancer on front of motor have to match the Balance on the Engine.

Here is the diagram of current install

https://drive.google.com/file/d/1t0NJMRThPg_s3vjrQSJa7twgKArCyQ_M/view?usp=sharing


I have 50oz plate and balancer.

 

[JWMcCrary]

Is the balancing weight on the side towards the engine? If not mistaken that's how a stock flexplate is installed. You should be able to check that easily by turning the engine with the inspection cover off. If its not my bet is you have it on backwards. Check the depth for the starter engaging as well.

 

[diggs00]

Is the balancing weight on the side towards the engine? If not mistaken that's how a stock flexplate is installed. You should be able to check that easily by turning the engine with the inspection cover off. If its not my bet is you have it on backwards. Check the depth for the starter engaging as well.

Balance weight is on the engine side.

 

[JWMcCrary]

Here is the diagram of current install

https://drive.google.com/file/d/1t0NJMRThPg_s3vjrQSJa7twgKArCyQ_M/view?usp=sharing


I have 50oz plate and balancer.

Your diagram looks right to me

 

[diggs00]

If the bell housing cover plate did not have the dimples I would not be in this situation.

 

[72_EB]

Unfortunately, you'll probably have to take the trans down and see where those shavings are coming from upon rotation. Your flexplate is installed correctly and it appears you installed the converter correctly (or you'd have a larger problem - 3 steps down when completed installed into transmission - folks can not fully seat the converter, but I don't think that is your problem).
I had a rebuilt converter give me some issues a while back when it was contacting the bell housing to transmission mounting bolts. Drove me nuts finding the issue. I later switched the converter and the problem went away. The theory later being that some used/professional rebuilt converters may have stretched original torque converter housings overtime for overwork and excessive heat causing an ever so slight difference overall TC size. Not much - but enough to cause clearance issues like you are experiencing. It happened to me. It could be an out of balance converter too.

 

[diggs00]

Here are some pictures of the issue:

https://drive.google.com/file/d/1lU8AUZjVRwaL7nUWtkrbeDytGqdkAnic/view?usp=sharing

https://drive.google.com/file/d/18F-FKIjSoXEDCa3toRroBxkWfWRx2Lds/view?usp=sharing

 

[Rustytruck]

check the length of your starter bolts. check the end play on the crank shaft.

 

[diggs00]

check the length of your starter bolts. check the end play on the crank shaft.

Explain the starter bolt theory to me please.

 

[hthomas]

flexplate

Make sure the flex plate is for a newer engine. The blueprint 306 takes the newer 50 oz flexplate. I will check the part number when I get to the house. I had the same issue on mine when I installed it. The flexplate on the old style engines is thicker. The new style is thinner. I caught mine while bolting it up. It will lock the torque converter up because of that millimeter difference

 

[75MIKE]

https://classicbroncos.com/forums/showthread.php?t=304441


Maybe get with him and see what he found out.

 

[diggs00]

Make sure the flex plate is for a newer engine. The blueprint 306 takes the newer 50 oz flexplate. I will check the part number when I get to the house. I had the same issue on mine when I installed it. The flexplate on the old style engines is thicker. The new style is thinner. I caught mine while bolting it up. It will lock the torque converter up because of that millimeter difference

@hthomas
Did you mean to say the newstyle 50oz flexplate was thicker rather than thinner?

 

[Viperwolf1]

Flex plate in backwards?

Can't be done.

 

[diggs00]

Can't be done.

@Viperwolf1

Do you think my c4 bell housing plate(with dimples) is for a stock 302? I found an aftermarket plate at Wild Horses that is flat without dimples.

I wonder if I can remove this current plate and hammer the dimples flat.

I really don't want to drop the trans but it looks like I am gonna have to.

 

[Viperwolf1]

@Viperwolf1

Do you think my c4 bell housing plate(with dimples) is for a stock 302? I found an aftermarket plate at Wild Horses that is flat without dimples.

I wonder if I can remove this current plate and hammer the dimples flat.

I really don't want to drop the trans but it looks like I am gonna have to.

I have seen the dimpled plates before. They only seem to have issues with the 50 oz. balance weights. You will need to remove it to fix but you could just cut out the dimples and re-install it. Hammering is likely to distort the plate.

 

[diggs00]

I have seen the dimpled plates before. They only seem to have issues with the 50 oz. balance weights. You will need to remove it to fix but you could just cut out the dimples and re-install it. Hammering is likely to distort the plate.

@Viperwolf1

You think I can keep the d20 connected and just drop/pullback the d20 and c4 a smidge to get to the flexplate bolts? Or just drop the whole thing.