904 and B&M 10235 flexplate

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ir3333

ir3333

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anybody have interference problems with the B&M 10235 weighted flexplate when used on a cast crank 340 and 904 transmission?
 
Yeah, on a similar forged 340 no weights, using 999LA automatic. I found that an old type starter has a front Bendix bearing that was going to hit the solid flexplate, that is Mopar sfi. universal,on a 904-9 trans. I had to use the mini starter, and buy a modern drivers side header, to clear the mini. A fiasco waiting for you without any warnings before you buy.
 
that flexplate looked to have about a 32nd of clearance during assembly.It's all up on jackstands now to re- check things out.
...Thinking that if the converter balloons at all, the flexplate could interfere with the mini starter too or dust cover
 
when i google b&m 10235 the discription comes back, 340 cast crank with a 727. so maybe wrong for a 904?
 
checked everything and filed a little more clearance on the mini starter where the flexplate could interfere.
put everything back together and still have a sqeak chirp.squeak chirp but only in reverse.
Rebuilt 904 and everything works fine but the annoying noise in reverse.
Will have to check with the trans shop....any body have some input on this?
 
your trying to put a 727 flexplate in a 904. the plate is TOO BIG DIAMETER. you need a plate for a 904.
 
i checked with B&M and they said it would work fine and that is why they no longer make the cast crank 340 flexplate for the 904.
It bolts up o.k.but is a little wider than the 904 unit
 
you can file or modify all you want. its still the wrong plate. look at your plate. there are three bolt patterns drilled into it. the large bolt circle is for large bowl 727, then theres a small bolt circle for 727 high stall, and the other bolt circle is for using 7/16 bolts. high stall and later 727 lock-up use the small bolt circle which is the same as 904. this way mopar only had to make two flex plates for all their engines. its the large bolt pattern that screwing up your starter fitment. i dont know if you need the sfi rating, but if b&m dosent make the 904 plate anymore, your going to have to put the small oem plate back on and put the proper weights on the convertor to fix it.
 
heres a thought if you wanted to stay sfi. how about using a small bolt circle flexplate from a steel crank 440. then put the weights on the convertor. you wont have to worry about the flimsy oem plate then.
 
all good points and i'm convinced there is enough clearance and car drives fine in all gears including reverse.
...so why the squeak clink..squeak clink..squeak clink in reverse?
 
because of crankshaft end play. the flexplate is still hitting the starter or something in the bellhousing. you said yourself that you had to modify the starter to get it to fit. you shouldnt have had to do that. the extra inch or so differance between the small bolt circle and the o/d of the plate is whats interfearing with your starter.the plate must be overlapping the ring gear by at least half.
 
zijmer said:
because of crankshaft end play.
keep torquing it up! it will make its own clearance.
Click to expand...

so the noise has nothing to do with the transmission or flexplate?
not quite following you...can you explain this?
 
Might you have a ujoint that is getting dry?
The reason I ask is because everything in the trans works exactly the same for forward and reverse, and drive direction gets reversed at the rear planetary gear set.

For this reason it's hard to believe that the trans or flexplate is causing the noise only in reverse.

Just a thought.
 
Tx TrailBeast.
My Trans builder has given the noise a check from under the car while i ran it in the different gears (on jack stands).He assured me it's a harmless squeak,the trans is bullit proof and i should get some miles on it.
now it's time to change the leaky front seal in my rear gears ...just another surprise like the heater core that started leaking ,glad i hadn't installed the interior yet.....these projects age you.
 
TrailBeast said:
Might you have a ujoint that is getting dry?
The reason I ask is because everything in the trans works exactly the same for forward and reverse, and drive direction gets reversed at the rear planetary gear set.

For this reason it's hard to believe that the trans or flexplate is causing the noise only in reverse.

Just a thought.
Click to expand...
i dont think its a u-joint cause the car doesnt have to move to get the noise. its just like a bent dust cover kind of rattle. he says that the plate overhangs the ring gear to just about a 1/16 before the v in the tooth. rite were the starter housing sits. i think the plate is rubbing against the starter housing. we'll know later tonite. he painted the housing before reinstalling the starter and we'll look for fresh marks or he will.
 
ir3333 said:
Tx TrailBeast.
My Trans builder has given the noise a check from under the car while i ran it in the different gears (on jack stands).He assured me it's a harmless squeak,the trans is bullit proof and i should get some miles on it.
now it's time to change the leaky front seal in my rear gears ...just another surprise like the heater core that started leaking ,glad i hadn't installed the interior yet.....these projects age you.
Click to expand...

I actually feel like they keep me young, because I love any excuse to do things to it.



zijmer said:
i dont think its a u-joint cause the car doesnt have to move to get the noise. its just like a bent dust cover kind of rattle. he says that the plate overhangs the ring gear to just about a 1/16 before the v in the tooth. rite were the starter housing sits. i think the plate is rubbing against the starter housing. we'll know later tonite. he painted the housing before reinstalling the starter and we'll look for fresh marks or he will.
Click to expand...

Hm, I guess it isn't that big of a deal then as it'll probably just clearance it'self.
Sure wouldn't want metal dust in the pump seal though.
Could always loosen the starter just a hair after it's running and see if it changes. :iconbigg:
I wouldn't suggest it to someone unless I knew they were up to it, but I would do it if it were my car.
 
I put the same combo together, no problems with mine, used a starter off a 95 ram.
 
Update..Finally driving the Dart..there were 2 problems the flexplate bolts were ticking the dust cover and the squeak disappeared after a couple of short trips just like my trans builder said
 

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