Anyone ever break a flexplate?? ITS RUNNING!

[turtle5353]

Well I fired up the mustang this weekend and pulled it out of the garage to finish up the welding on a guys firebird im working on. When I was done I fired up the mustang again and heard some AWFULL sounds coming from the motor. I immediately shut it down. My heart sank...sounded like some beating on my bellhousing with a sledge hammer. I started it back up and pulled in the garage. Got looking around and it is definitely coming from the front of the trans/bellhousing area. At idle it sounds horrible. Its a tinging clunking sound. If you touch the gas and rpms up to 1000-1100. Quiet as can be. So im pretty sure I broke my flexplate. I had an old F150 do the same thing, but when I took the trans out the flex plate was in 2 pieces. Im going to try to pull the trans tomorrow night and see what going on in there. Kinda sucks, that flexplate only has a few thousand miles on it. But if that's all that's wrong Will be happy with that!! Taking it down to my buddies garage to get it on the lift so I don't have to pull the trans laying on my back. Just hoping its nothing in the torque converter or pump.

Anyone else ever bust one up?? I will let you guys know what I find when I pull the trans.

 

[Jeff73Mach1]

No clue, but good luck.

 

[Don C]

I have never broken one, but did have the flexplate to torque converter bolts loosen on a company pickup once. It didn't sound very good and by the time I could get it back to the shop a couple of the bolts either came out or broke, doing a lot of damage, including cracking the flexplate. My best guess for the cause of a broken flexplate would be a misalignment of the bellhousing, causing the flexplate to flex too much.

 

[Carolina_Mountain_Mustangs]

On my Ford van I had this ding ding ding noise that would come and go. Sometimes is sounded like you were dragging a license plate under the car. I took to dealer, I didn't have time to work on it. They pulled the transmission and a snap ring had broken in the transmission. It let one of the hubs get into the planetary gears and made a big mess of things. They cut me a great deal with parts and labor it was only $800 and there was a box of parts they had to replace that got chewed up.

I hope it is the flex plate or converter easier to fix. Keep us informed and take pics.

 

[turtle5353]

I have never broken one, but did have the flexplate to torque converter bolts loosen on a company pickup once. It didn't sound very good and by the time I could get it back to the shop a couple of the bolts either came out or broke, doing a lot of damage, including cracking the flexplate. My best guess for the cause of a broken flexplate would be a misalignment of the bellhousing, causing the flexplate to flex too much.

Hoping its just flex plate. How can you get the bellhousing misaligned?? It can only go in 1 way and has dowels pins for alignment. I have had motors and tranny in and out of this thing at least 10 times in the past 8-10 years!!LOL

 

[rvrtrash]

I had some of the welds for the starter ring break once, but don't remember any unusual noises, except while starting.

Steve

 

[jbojo]

I have never broken one, but did have the flexplate to torque converter bolts loosen on a company pickup once. It didn't sound very good and by the time I could get it back to the shop a couple of the bolts either came out or broke, doing a lot of damage, including cracking the flexplate. My best guess for the cause of a broken flexplate would be a misalignment of the bellhousing, causing the flexplate to flex too much.

Hoping its just flex plate. How can you get the bellhousing misaligned?? It can only go in 1 way and has dowels pins for alignment. I have had motors and tranny in and out of this thing at least 10 times in the past 8-10 years!!LOL

Was the transmission replaced? Those dowels can have offsets to dial in the offset of a bellhousing. I know that for Manual transmissions you need to dial indicate the bellhousing to get the center of the crankshaft aligned to the the center of the input shaft on the tranny. The tolerance is no more than .005" and you use those offset dowels to get it within specs. These dowels come in 0, .007 and .014 offsets. Think about what would happen if there was a misalignment between the crank and the input shaft of the tranny, there would be pressure on the tranny bearings causing premature failure and possibly a flexplate failure too.

Again not sure if this applies only to manual tranny's but if the motor you replaced was from a manual transmission that had offset dowels the alignment could be off between the two parts. If the motor and tranny are the original ones then this not likely the issue. Just some thoughts on a possible issue you may be experiencing.

 

[will e]

I don't mean to be a downer but a broken flex plate seems unlikely.

 

[turtle5353]

Well i'm gonna tear into it tonight and see whats going on. Its same tranny I have had for years. This motor has been in it for around 3 years. I will keep you guys posted.....hoping for the best!!

 

[Mister 4x4]

It'll be interesting to hear about what you find. I would think a broken flex plate wouldn't allow the car to start (unless the starter ring gear is just that tough. But hey, stranger things have happened, eh?

Good luck! You know your car, and you know your stuff. Can't wait to hear about it. ::thumb::

 

[turtle5353]

Well I got the trans out tonight and took a look at everything. Wasn't too bad. I found the flex plate bolts had come loose and caused the flexplate to make a bunch of noise. Well with it moving around, it oblonged a couple of the holes out. So I decided to order a new flexplate instead of trying to use my stock one I had in the garage. Also got new bolts for the flexplate. While I was unbolting the torque converter one of the studs snapped off really easily. Got to checking them and the studs were all galled from the flexplate moving around. That sucks pretty bad. I really don't want to buy a new torque converter so im going to try and replace the studs. Gonna be tough but I think I can do it. They are 7/16 studs that are splined like wheel studs. If I can find similar studs I can install them and tack weld the heads just like the originals from B&M. If this works out ok, I will only be out $70 for new flexplate and couple quarts of Type F. So I think it could of been a lot worse!!! But im pretty happy that's all it is!!

 

[will e]

WOW that's great. A pain that you had to pull it all apart. Hopefully you can get away with a cheap repair but even if you have to replace the coverter it's cheaper than some kind of internal engine or transmission damage.

 

[jbojo]

Glad to hear that its a fairly simple fix, lots of work though.

 

[timachone]

Good to hear - good luck to fix it ::thumb::

 

[turtle5353]

Thanks guys. Im pretty sure I can fix the studs on the torque converter. I hope so anyhow Don't really want to buy another one. This one was around $500. I ordered my flexplate from summit last night, checked tracking info and it will be here today! Man they ship fast! The tranny is a little tough to pull out because my headers are so tight. you have to roll it on its side a bit for the starter bump to clear then go back up over the x pipe, then tilt the front way down to come out. It was a little sketchy doing it myself but I got it. Took a little less than an hour and a half total. So that's not bad. I did get a couple pics so you guys can see what im working with. I gotta cut the tack weld holding the studs, then tap them out. Going to try and find the same type of studs but it may be hard. They are 7/16-20 x 3/4" and they are splined/knurled like a wheel stud. If I cant find those I should have enough clearance to put a regular head bolt in there and weld it into place. I already got one out and they are pretty easily removed. Going to contact B&M and see if they sell them.

 

[Carolina_Mountain_Mustangs]

I am sure you probably already use it but put Loctite on the crank bolts and converter nuts to help prevent coming loose in future.

Glad it was pretty simple.

 

[turtle5353]

I am sure you probably already use it but put Loctite on the crank bolts and converter nuts to help prevent coming loose in future.

Glad it was pretty simple.

Yeah, I always do, but it somehow worked loose?? You can still see some on the threads of the stud in the pic. I guess I will use the higher strength sh!t next time.

 

[Jeff73Mach1]

For the torque converter studs, you might want to call a local transmission rebuilder- They should have that kind of sh!t in stock

 

[turtle5353]

Well, I checked around and couldn't find the exact studs so I ended up using regular bolts and welded them in place. They turned out pretty good. I installed the bolts then bolted the torque converter to the new flexplate to make sure everything lined up like it should. Snugged it down and welded the bolts. I am going down to my buddies place in the morning to put the tranny back in. So hopefully I will be back up and running tomorrow. I will keep you guys posted, wish me luck lol!! ::thumb:: Heres a couple pics of the torque converter with new studs and fresh coat of Ford Blue.

Broken:

FIXED!!