Broken Flex Plate

[chuckndonna67]

I have been told by a repair garage that I have a broken flex plate on my 88' YJ, a/t, L6. And he says he has to pull back the transmission, etc. to get to it. The part apparently is not expensive, but the labor is a killer. First, what the hell is a flex plate? Second, is this a major job? I feel like I have poured a lot of $$$ in this black hole called a Jeep and ready to ELIMINATE it! CAB

 

[graewulf]

the flex plate is what goes between the torque converter and the engine, basically its an adaptor, and yes you have to unbolt the transmission to replace it, i'd say its a good 2 hour job if you have a lift. It's not hard to do, just takes time.

 

[redrooster]

the flex plate is what goes between the torque converter and the engine, basically its an adaptor, and yes you have to unbolt the transmission to replace it, i'd say its a good 2 hour job if you have a lift. It's not hard to do, just takes time.

It's a plate that bolts to the crank and then the torque converter is bolted to the flexplate. The main thing is that it is the gear that turns the engine when you hit the starter. It's unusual for one to break. It's more likely that the teeth are worn off. I take it you are having starter troubles.
It's true that you have to drop the shafts and separate the transmission from the engine, change the plate, torque the bolts and put the transmission and shafts back on.
If you want to inspect it yourself to see what the mechanic is telling you then there is a dust cover that you can take off to look at the flexplate.

 

[Snitty]

its a flywheel

 

[redrooster]

My Modified Jeep

It's not a flywheel, that's a common misnomer. A flywheel is part of the clutch sytem on a manual in addition to having the starter gear. They are definitley not even close to being interchangeable. Don't go ordering a flywheel when you need a flexplate or you will pay too much and have the wrong part.

 

[Snitty]

i realize that a flywheel is part of a clutch system... but saying explaining a flexplate as being a "flywheel" in an automatic is a perfect way to explain it... but... a flywheel of an engine is NOT always part of a clutch... a small engine such as a lawnmower engine has a flywheel, it is not part of a clutch... the flywheel of an engine is usually a part which carries momentum and balance and is usually the engine side gear of an electric starting system. so a flexplate IS a flywheel.. but is not what is known traditionally as the flywheel we know to be of a manual transmission clutch system

 

[exjay33]

Re: i finally did it

What makes the shop think there is a broken flexplate?

 

[redrooster]

Ok Snitty, I'll give you that since you referenced the small engines.
Just make sure you get it right when you order the parts or talk to the mechanic.

 

[Snitty]

oh i know... if i'm talking to someone who's vehicle i'm working on... i use the term "flywheel" to explain what a flexplate is... but when i'm talking to people who know whats going on.. i use the right terms... if you use mechanical terms with mechanically challenged people, you're speaking greek

 

[ROGLSTUBB]

I dont usally venture over to this forum very often but the topic caught my eye. There is usually a reason why a flexplate breaks. I have an XJ that broke flexplates regulary at one time. You may want to check for cracks in the bellhousing worn out motor or transmission mounts. Also know that even when a flexplate breaks it still may be drivable. Every time my flexplate had broken it was still drivable. It honesly sounded like a engine knock. Thats how I got the jeep, the guy thought it was a rod knock and gave it to me. My problem was a broken bellhousing that somebody welded back together. You may not have anything so drastic but a good inspection of your other parts could not hurt.

 

[chuckndonna67]

Thanks to all who replied to this question. The mechanic who told me this confirmed it thru the inspection plate. He said he had never seen one break where this one broke. Indeed he said he would have to drop the drive shafts, transmission, transfer case and the shape of the lines (brake, fuel) were so badly rusted it might open up another can of worms. Yes, I can drive it but it sound like hell sputtering all the way. I am not mechanically inclined so I appreciated the description of what a flex plate (fly wheel) is. I have decided to rid myself of this machine as it has cost me a fortune in the 15 months Ive owned it. I once owned a CJ7 and it was 100% better than this YJ.

 

[kevin4x4]

sorry to hear that I just bought my first jeep tj and love it the fun is working on it but not mechanical incline will hurt......