[SS70ElCaminoOwner]

I had my engine build for me. The builder installed the flex plate. I have installed it in the car and have been having starter alignment problems. The engine starts and runs but the started makes noises like it is not shimmed correctly. On close inspection I think the flex plate has been installed backwards. Can you look at the attached pictures and tell me what you think? (It is a TCI Flex Plate) Thanks.

[Oldani Motorsports]

Time to find a new engine builder, lol! Unless my eyes deceive me, the pads for the converter bolts are facing the front (and it appears you had to shim the converter to hold the 1/8" to 3/16" clearance range) .... not cool. Is your engine builder's name Ray? As in Ray Charles? Yikes... this is something that should not have been missed IMO!

[BillK]

Glen,
Yup its in backwards. Cant believe they got it on that way without noticing. The center on most flexplates has a "lip" that sticks out about 1/16" and makes it impossible to get it to sit flat on the crank if installed backwards like this one is

[SS70ElCaminoOwner]

Is this something you are sure on? It makes sense to me but I hate to take this apart to turn it around if I'm not sure.

[BillK]

Glenn,
One more thing ... if this is the 454 you show on your web site pics, the balance weight is probably in the wrong position if the flywheel is on upside down. I am surprised it does not shake badly Now the real question is ... if the engine was balanced, which way did he have the flywheel bolted to the crank when he was balancing it ??? ... This could turn into a real can of worms !

[BillK]

Glen,
Definitely backwards ... the converter bolt pads should be facing the converter.

[SS70ElCaminoOwner]

This is a TCI flex plate. It was posted that there is a lip that should face away from the engine. Because it is backwards has this been ruined? Should the flex plate be replaced?

[BillK]

Glen,
The other clue is that the weight appears to be towards the transmission, I am almost certain it goes towards the engine. If you want, call me in the morning after 9 AM at the shop and I will look at a flexplate to make 100% certain for you. 301-843-5700

[SS70ElCaminoOwner]

Yes, it is a 454. I know the 454 is externaly balanced. That is why I had the builder put the plate on before shipping the engine. Yes I have vibration problems. I started it for the first time this past weekend and drove it for the first time Sunday night (around the block) I get bad vibration at 45 MPH. I have no tack so I do not know the RPM.

[SS70ElCaminoOwner]

Ok, it is now 3:00 AM in the morning, EST, and there are four bolts holding the transmission in, the two lower bell housing bolts and the two transmission mount bolts. In the morning I will hold the back of the engine up with the engine host and a floor jack under the transmission, remove the four bolts. Pull the transmission and then the flex plate. I need to know if I should replace the flex plate and how it should go back in so the balance is right (454 external balance). Any help is welcome.

[bracketchev1221]

It can only go one way. The crank will have a dowel pin to index the flexplate. If by some chance the dowel is missing, then just line up the hole in the flexplate with the hole in the crank where the dowel was.

[SS70ElCaminoOwner]

I never looked when I put the car together. This has always been a hole in my knowledge. I am reasonable around engines but drive train I know little about. If it is this simple, what a mistake. 4 + hours to get it apart and who knows how much to get it back together! I am thinking that I will buy a new flex plate, but will wait until this one is out to make that call. I would hate to put it all back together to find it has to come apart again.

[BillK]

Glenn,

I pulled out a brand new Pioneer 454 flexplate this AM just to confirm everything. The balance weight is definitely towards the engine, so yours is definitely on backwards. If you are certain the flexplate is for a 454, you should be able to flip it over and be ok.

IF the engine was balanced, I would have to call your builder and make sure he had the flywhell on correctly when the crank was on the balancing machine. I think it would probably have been so far off, he wouyld have noticed something wrong but .... you never know.

Make sure that after you flip it over, that you have some clearance between
the converter and the flexplate pads before you bolt it together. You should be able to pull the converter away from the flexplate 1/8" or so. If it is tight up against the flyexplate, the converter is not into the trans correctly and will cause damage to the trans.

Hope it all goes together ok,

[Rich-L79]

You should also get on the horn with the engine builder so he is aware of this mistake. At the very least he will be aware of the issue ahead of time in the event this error leads to further problems. You might ask HIM to send you a new flexplate. You also need to talk to them as Bill suggested concerning any balancing that may have been done. Assuming for the moment that it was balanced with the flexplate on it now (also assuming it was installed correctly when balanced) if you change the flexplate you will also possibly change the balancing somewhat. If you do replace the flexplate, try to replace it with the same brand and model of flexplate so as to maintain the balance as best as possible.

If the flexplate has a lip at crankshaft hole you should probably replace it since this lip would have caused it to be deformed when the crank bolts were torqued. If the flexplate is flat on both sides you are probably okay to reuse it.

Good luck and report back with the rest of the story.

[charbilly2001]

It doesn't appear that either the starter nor the flexplate suffered any damage in the pics. You can probably flip the plate and just reassemble everything. With the flex plate on backwards that would place the weight in a WAY wrong place. I am betting that the balance was done correctly and your vibration is due to the improper installation. Probably will clear up when you get it right

Good luck.