Flex Plate vs TC Mismatch

[Fitz24]

Ok, on to next problem encountered with my 4r70w install. The TC that Monster Transmission sent with the tranny doesn't work with my flex plate. The new TC bolts have a wider spread than the one from the C4.

Now, do I get them to ship another and return the other, or do I purhase a new flex plate? Not sure about what model year 302 I have or what flex plate. It is 164 tooth but not sure of balance. Any way to determine which?

 

[ricky]

i'm pretty sure the c4 bolt pattern is 10.5, sounds like your 4R needs the flexplate with 11" bolt pattern, is your 302 the original from 1975 or newer? early 302's used 28oz flexplate,newer 302,i think from 1985-early 2000's all used 50oz flexplate

 

[LSUpete]

That torque converter is probably correct. The bolt pattern diameter should be 11 7/16", so measure that on your flexplate.

 

[Fitz24]

That torque converter is probably correct. The bolt pattern diameter should be 11 7/16", so measure that on your flex plate.

The 11.5" is what the TC they sent for the 4r70w measures. Problem is my flex plate mounting holes are 10.5". So I need a new flex but not sure what year 302 I have. It was in the bronco when I purchased it so don't know if it is original or some other year.

Looks to be more like a 70's model with original style intake and accessories mounting for alternator, PS, exhaust manifolds, etc. Had no emissions equipment when I purchased it but PO may have removed it if it originally had any.

 

[Viperwolf1]

There were no small pattern 164 tooth flexplates with the newer 50 oz-in imbalance. Yours will be 28 oz-in unless something custom was done.

 

[oldiron]

Verify engine year and imbalance before going any further. Accessories and intake/exhaust are not good indicators. I've owned several with newer engines wrapped in original accessory drives,intakes,oil pans,etc.
Greg

 

[Broncobowsher]

You're engine should be the old 28 balance. That is the only way that flexplate was made. There would be a clear non stock welded on weight if it was rebalanced, different than the stock welded on weight.

 

[Fitz24]

There were no small pattern 164 tooth flexplates with the newer 50 oz-in imbalance. Yours will be 28 oz-in unless something custom was done.

That's good to know. Wish they would have stamped them so it was easy to verify what you had.

 

[Fitz24]

Verify engine year and imbalance before going any further. Accessories and intake/exhaust are not good indicators. I've owned several with newer engines wrapped in original accessory drives,intakes,oil pans,etc.
Greg

Yeah, figured that since a lot of people but new dressings on old motors. Is there a block casting number or easier way to verify year and imbalance?

 

[DirtDonk]

Seems the easiest would be to continue using what you know has worked with the engine, and get them to send you a new converter.
However, since they had no way of knowing your engine might have had the smaller pattern (but they should at least have been aware of two possibilities with a '75 vintage vehicle and asked I would think) you may have to pay the costs of replacement.

Usually what we've found over the years is that two different patterns are still available in torque converters, but only the large pattern survived in the flexplate world. Whether 50oz or 28oz, only the large one exists.
So normally the best route would be for you to get a new flexplate. But not knowing what imbalance you need is the fly in the ointment.

Any reason to think it's not the original '75 engine? Or just no way of knowing for sure?

Paul

 

[Fitz24]

Believe it's an original or close to engine with 28 oz. Just not sure. Ordered a new 28oz so hoping it's correct.

 

[Viperwolf1]

There's a number cast into the block above the starter. That could verify the imbalance.

 

[rafitz24]

There's a number cast into the block above the starter. That could verify the imbalance.

Good time to look for it since I had to pull the header on that side and the starter to get C4 out.

Sent from my SM-N960U1 using Tapatalk

 

[ricky]

the block casting number is really only good enough to tell you what year the block was cast/made..no telling what assembly is in it..BUT, since all late model 302 assemblies use a one piece rear main seal, I highly doubt its been changed..can you snap a pic of the flexplate weight and post?

 

[Rustytruck]

Is the pully on the harmonic balencer a 3 bolt pulley or a 4 bolt pulley. 3 bolt should be 28 oz. 4 bolt could be either way.

 

[Fitz24]

the block casting number is really only good enough to tell you what year the block was cast/made..no telling what assembly is in it..BUT, since all late model 302 assemblies use a one piece rear main seal, I highly doubt its been changed..can you snap a pic of the flexplate weight and post?

Here's a pic of the original flex plate. Also pic of the block casting number and rear of crank. If anyone can determine if its a 28oz that would be great.

 

[Fitz24]

I don't think I got the correct number off the block but it is the only one I can see above the starter. May be buried in old oil and dirt. Would help if I knew exactly where the number is lol.

 

[garberz]

Here's a pic of the original flex plate. Also pic of the block casting number and rear of crank. If anyone can determine if its a 28oz that would be great.

If there’s a Ford part# on the flex plate, then it’s a 28oz. Like Viper said, they never offered a 50oz. plate in the 10.5” bolt pattern.

Mark

 

[Viperwolf1]

Here's a pic of the original flex plate. Also pic of the block casting number and rear of crank. If anyone can determine if its a 28oz that would be great.

That looks like a factory 28 oz-in 10.5" 164 tooth flexplate to me.

 

[Fitz24]

If there’s a Ford part# on the flex plate, then it’s a 28oz. Like Viper said, they never offered a 50oz. plate in the 10.5” bolt pattern.

Mark

No part number stamped or visible.