Thread: Flexplate orientation Engine side ??? Help..

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I am building a BBC see the other post about a BBC in a Jet Boat. I got a SFI flexplate (163 tooth) and a mini hi torque starter from summit. I have it all set up on my engine stand. When I put the flexplate on, the orientation was hard to fiqure out. We put the starter on and manually pulled the starter "bendix gear" out to see ring gear and sarter engagement. It lined up with full gear to gear engagement. We checked the spacing with the old paper clip trick and had about .060. So we did not put a shim in it. Fast forward: we got the motor on the run in stand and all wired. I bumped the starter button and noticed a lot of tiny chips of paint flying off of the flywheel starter area and also the starter gear did not retract. I did not have the dist. in so it did not start. I had to manually push the starter gear back into its home. I am now wondering if I have it on backwards but I doubt it. I think I might need a shim only on one side of the starter that would be closer to the oil pan side. Help I want to fire this thing but do not want the starter gear to grind the new flexplate. I will have other things to worry about when breaking in the camshaft. The flexplate has a little indentation on it is installed so that the indentation part is on the crank side. Picture a cereal bowl, well the outside bottom of the bowl would be on the transmission side and the inside of the bowl would be on the crank side. Is this correct.
Thanks.
T.J.
www.tjsperformance.com

The Crank shaft side of the flex pate should be indented where the bolts go to the touque converter.

Originally Posted by cffisher

The Crank shaft side of the flex pate should be indented where the bolts go to the touque converter.

Like this. Sorry for the drawing.

Flexplate

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T.J.

There are atleast 3 bolt holes on the flex plate these attach the flex plate to the converter. The indent is toward the crank. There also should be a flange on the crank opening which faces the converter see pics.

If I read your drawing right you have it wrong. The flange in the crank opening should face away from the crank. If it was backwards you would bow the plate by tighting it down to the crank.

thanks. This is a TCI unit and not a GM one with the flange/lip. That is why I can put it on either way. Thanks. for the info. When I get home I will look about the converter mounting indents.
T.J.

Also, the pads that the converter mounts to should face away from the engine block.

Thanks for all the help. I did have it on correctly. Now I just have to see why the starter gear will not retract back, it just stays on the flexplate and I have to push it back manually. Again I have not fired the engine yet. I have a Summit mini hi torque starter. I put a .015 shim and it still does it. I checked the clearance between the starter and ring gear and is about .050 now. The TCI unit is powder coated everywhere and I think this may be causing the sticking. I even took the starter off of the mouting pad and it retracts fine.Thanks. T.J.

Sorry to dig up an old thread, but I think the flexplate on my TH400 is mounted backwards. I put on a mini-starter at least 6 years ago and all was working fine until yesterday when I got back home and my '40 Chevy wouldn't start.... just grinds.

When I crawled underneath the car I saw chewed up teeth on the flywheel, but also noticed that the starter pinion only engages about 25% of the teeth on the plate. I bought an identical starter last month just to have as a spare on road trips, and it has the same amount of throw as the starter that is on the car.

Looking at the following picture:


The raised areas on the flexplate are facing the crank, which I believe is incorrect, and could have moved the plate farther from the engine and is keeping my starter pinion from engaging all of the flexplate teeth. Does it sound feasible that if mounted backwards it would still (sort of) work without warping the flexplate?

Also another question concerning this flexplate:


Is this a universal style that would work as a replacement for my plate that only has three raised areas and holes to mount to the converter?

Thanks!

They will sometimes work for a while in backwards, but the pump drive is not engaged fully because the converter is too far out. It's hard on the pump.

Here is a thread that was on here recently. I'm posting it because a senior tech from Powermaster Starters came on and posted some info that might be helpful to you. It relates to a turbo 350, but the principles should apply to the 400 as well.

http://www.clubhotrod.com/forums/sho...rter+clearance

Don

Originally Posted by Itoldyouso

Here is a thread that was on here recently. I'm posting it because a senior tech from Powermaster Starters came on and posted some info that might be helpful to you. It relates to a turbo 350, but the principles should apply to the 400 as well.

http://www.clubhotrod.com/forums/sho...rter+clearance

Don

Don, thanks for the link. I had done a search and read that thread earlier. I have the opposite problem that Jag454 has (or had) in that my mini-starters don't engage far enough, and I don't know what his final solution was.

I guess I'm going to have to look at a stock starter and take some measurements, but it would sure be nice to know for sure if my flexplate is in correctly or not.

Originally Posted by DennyW

Maybe this photo will help also. And, don't forget !! One of the holes is just the size of the bolt. This is the start hole, so the rest will align ok.

Heres what I mean. I borrowed this picture from Jack.

OK, so in the picture you have of the gold flexplate, does that side go towards the engine or the converter?

Thanks!

Originally Posted by DennyW

converter. Also, the crankshafts bolt holes are offset. That flywheel should only fit one way.

Thanks! Since this side of my flex plate is facing the engine:



It looks like it is in backwards, which explains why my starter only engages about 25% of the flexplate teeth.

Might as well start hunting down a new flexplate and a better quality starter (Powermaster).

Thanks again!

Since I verified that my flexplate is in backwards (thanks to your info) I did some more searching and found a thread from 2 years ago where you guys gave some very good info (and pictures from the OP) on changing one out:

http://www.clubhotrod.com/forums/sho...ight=flexplate

Lots of good info on this forum...... now I just have to get my parts together and decide if I'm going to try it in my garage, or try to get up to Columbus where a couple of friends have lifts.

Thanks!