Broken Flexplate. What is a good replacement?
So I have to drop the trans... Been reading all the writeups on dropping it and whatnot. But I havn't found a great one with pics so if anyone could steer me in a good direction that would be great. I pretty much know what to do but I just want a clear and correct guide.
Can anyone recommend a good flexplate? Im not trying to spend a ton but I figured I would upgrade since I'm in there. Should be making right around 500 crank hp.
I figured I'll be able to just side the tranny back off the motor enough to access the flexplate and get the new one in there. Have welded exhaust I'm trying to avoid cutting even if it is a little more difficult. Can anyone confirm this for me?
I'm also going to replace my rear main and pinion seals while I've got everything apart
Any other things I should know or keep consious of?
Thanks,
EJ
I'm also going to replace my rear main and pinion seals while I've got everything apart
A few suggestions...
1) Get a trans jack, or at least a spare floor jack rigged up with a board you can set the trans on and lower it down. A trans jack is preferable, though.
2) Grab a buddy when you finally get ready to take the trans out of the car. You will want another set of eyes and hands to help. Manuals aren't too bad by yourself, but a 250 lb auto is no joke if it lands on top of you.
3) Read up on it a good bit before you do it, which it sounds like you have done already, and take your time. Allow a full weekend, plus some extra evenings to finish, just in case. When I did mine, it took me almost a week total, but I did a trans cooler too, plus I'm slower than the average guy because I like to make sure I'm doing it right. And, because you're working on a car, you will inevitably run into another problem to fix while you're in there...at least that was my experience

4) Now might be a good time to put a trans pan on with a drain plug, as well as drill and tap the pan for a trans temp gauge and install one. I wish I would have done this when I had mine out.
5) Flexplate--Get an SFI one for sure if you're making that much power. I used the Hughes FP, which I liked and haven't had any issues with, but any SFI one will do (except for TCI's--I've heard the runout on them isn't so hot).
Hope this helps! Let us know how things go. Sorry to hear about your luck, but you will do well to replace the rear main and pinion seals while you are in there--plus you shouldn't have to worry about the FP again.
Scott
Thanks!
A few suggestions...
1) Get a trans jack, or at least a spare floor jack rigged up with a board you can set the trans on and lower it down. A trans jack is preferable, though.
2) Grab a buddy when you finally get ready to take the trans out of the car. You will want another set of eyes and hands to help. Manuals aren't too bad by yourself, but a 250 lb auto is no joke if it lands on top of you.
3) Read up on it a good bit before you do it, which it sounds like you have done already, and take your time. Allow a full weekend, plus some extra evenings to finish, just in case. When I did mine, it took me almost a week total, but I did a trans cooler too, plus I'm slower than the average guy because I like to make sure I'm doing it right. And, because you're working on a car, you will inevitably run into another problem to fix while you're in there...at least that was my experience

4) Now might be a good time to put a trans pan on with a drain plug, as well as drill and tap the pan for a trans temp gauge and install one. I wish I would have done this when I had mine out.
5) Flexplate--Get an SFI one for sure if you're making that much power. I used the Hughes FP, which I liked and haven't had any issues with, but any SFI one will do (except for TCI's--I've heard the runout on them isn't so hot).
Hope this helps! Let us know how things go. Sorry to hear about your luck, but you will do well to replace the rear main and pinion seals while you are in there--plus you shouldn't have to worry about the FP again.
Scott
2. Definitely. I already told my little brother he was going to have to give me a hand with the actual dropping of the trans. And 250 lbs. Damn. I read 130 somewhere else, but thats exactly the type of thing I wanna find out through cross referencing all of the info I've found.
3. I have, and will continue to until I do the job. I'm like you as far as taking my time and going slow goes. Whenever I do a bigger project its usually over a day or 2, partially due to a crazy work schedule. I would rather go slow and make sure everything is done right the first time. Lol @ the "because your working on a car.." so true, something always breaks or find something that needs replaced.
4. Already have a deep TCI pan with a drainplug and a cooler. But good call on the gauge. I was going to do one months ago but never ended up doing so.
5. Noted. I'll stay away from tci then. And what do you mean the runout?
6. Yeah that is what I was thinking as far as sliding the tranny back. Slide the rear end of the tranny as far back over my exhaust and subframe connector as possible and hold it with the jack while I change out the flexplate, given there is enough room.
Thanks for all the input, it helps for sure. I'll keep y'all posted on what I do.
All others feel free to add your two cents
Runout is the term used for the flexplate's "straightness." It's similar to spinning a bike tire to make sure the rim isn't bent. Runout is much more precise however, and is determined by bolting the flexplate to a lathe or motor to spin it like it would be on the engine. While the flexplate is spinning, a dial indicator rides across the surface and measures how much it goes out of true during its rotations. There is always a certain amount of runout, but there is a general accepted range and I can't remember what it is. I was talking to my trans builder and he said they tested a TCI one time and it was way out of the accepted range--not something you want to bolt to your crankshaft and have spinning constantly. Some people have had no problems with theirs, but then again why take the risk IMO.
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And thanks for explaining the runout. Definitely want to do it right the first time and get one with good ratings. But I dont see runout ratings on these flexplates I've been looking at
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Scott












In the end it wasn't near as hard as I thought, and was actually pretty easy and straightforward, only time consuming labeling bolts/cleaning stuff/etc. I actually ended up doing 100% of it solo, but it wasnt bad. I appreciate all the help and advice from you guys here on tech
Last edited by Ls2SilverBullet; Dec 8, 2011 at 08:24 AM.
@LS2SilverBullet, how do you like your Yanks flexplate?
I've been considering my options a little and my car isn't really modded, so I could probably go with a stock replacement like the ATP one from RockAuto, but I wonder if I should just go ahead and get the Yanks for an extra $50.
If Yank is here somewhere, are these lighter than stock? Just wondering if I could see any difference in throttle response from getting the Yanks one.
Thanks!
Personally I have the TCI Aluminum flexplate, but I think that is heavier than stock too because it is about 3 times as thick.
The stock one seemed so lightweight and flimsy that it scared me.
The Yank one certainly looks like an excellent value.
I didn't see any difference in throttle response with mine, which wasn't much different in thickness than Yanks. I doubt you'll see any difference unless you're running a CSR Billet Aluminum flexplate or something.









