Billet flex plate and input shaft?

[CTcummins24V]

So a bolt backed out of the converter and got stuck in the transmission adapter case and broke part of it, I guess that explains the shards of metal that came out of the inspection port and not the flexplate. Should I worry structurally about this? I can't see this being a big issue or requiring a new adapter. 

 

 

[rancherman]

that is what I call  'bunged up a bit'...  but  still  very  usable.    

 

You got lucky....  most time  when  a foreign body is  floating around inside a  enclosed  space,   grenade  comes to mind!

[MnTom]

Looks to be perfectly fine to me! Bolt it up and you won't see it!! Out of sight=out of mind.....

[CTcummins24V]

Good, that's what I hoped...because I already red loc-tited and bolted up the new BD flexplate. It's at least twice as thick as the OE unit.

 

[MnTom]

What are you going to do about the input shaft? I jinxed myself and *think* I broke the input. I did a search and it seems as though the inputs will fail eventually with a bit more power and a built transmission. I hope that is all that is wrong with mine.

[CTcummins24V]

Currently, my truck is grounded as well and I'm saving up for a TCS 2 piece unit. TCS(the converter shop) out of Arizona. They are $650, made in USA, billet input 300m and the hub is a different metal or treated differently. They were recommended from a long time builder of torque converters/drag racer (Phil). The rationale behind the 2 piece is price(secondary at this point), and that the weak point will be the shaft to hub connection, so if there is too much power or abuse the splines will strip first and hopefully the shaft won't snap causing other destruction. From reading other forums, boosted launches, track time, and old age/high mileage and crazy power seem to be the factors that determine a billet input shaft's life span. So in our case, a quality billet input shaft should last forever...you're only as strong as the weakest link, so hopefully a triple disc, heavy duty flexplate and billet input should hold 800, 900, 1000 ft-lbs and more of torque for heavy towing and some fun.   

[hex0rz]

I think I'm going to have to be right up this alley real soon, too. Got an exhaust brake on the he351ve turbo and not to mention what kind of boots it could make...

[CTcummins24V]

Yup, unless you get lucky it's only a matter of time before the stock input breaks with your power level triple disc torque converter and exhaust brake. When I got my transmission rebuilt in January everyone tried to talk me into getting a billet input, but it was too much money at the time

[mulcher812]

Yeah it sucks that that green stuff doesn't grow on trees. Wish I could plant a few and get them to grow for me

[MnTom]

Yup, unless you get lucky it's only a matter of time before the stock input breaks with your power level triple disc torque converter and exhaust brake. When I got my transmission rebuilt in January everyone tried to talk me into getting a billet input, but it was too much money at the time

This^^^^^ This is EXACTLY what just happened to me. I had the shop put stock back in due to the financial aspect of the situation, but if you can afford billet you would be better off. I guess I jinxed myself when I said I had no problem with the stock shaft. Mine lasted approximately 140,000 miles.

[hex0rz]

I've got a few things to address before I even bolt the he351ve up to the truck.

 

I'm hoping to rip the tranny out myself and do the flexplate and input myself.

[CTcummins24V]

Sounds like fun! Especially on your back! I ordered the TCS billet input shaft on Wednesday from DAP, hope it gets here soon. I'm going to have a local tranny shop pop it in for me, one less thing to go wrong. Hopefully be all back together next weekend and I'll do a little write up on it with some tips. FYI, the rubber was dry rotted on my vacuum hose harness that hooks up to the the transfer case, it was $32 from the dealer, it would be a good time to replace it with the tranny out.

[CTcummins24V]

TCS input shaft came in today! I dropped everything at my local tranny shop...hopefully have her running by the end of the weekend!

A lot of money for this small piece...the inner shaft walls seem to be thicker

 

[cajflynn]

From Stefan of DTT (reprinted from tdr):

 

As we have a lot of high hp trucks i can tell you that these guys are not breaking flexplates,I know Doug Smith did break one but we discovered when he came to our shop that he was missing a dowel pin. Needless to say, that shop never touched another tranny of ours after that. Mis=alignment of tranny to engine and the weight of the billet covers are what we see breaking these flexplates. If you ever have to deal with a broken flex plate make sure you replace your oem factory dowel pins with a set of new dowel pins, chrysler part # 4429678, you will need 2 of these. They are about $5 each. 

I checked with Bill on this and he said most consumers are not aware of this small fact. The converter in the Dodge Cummins Diesel is centered by the flexplate not the crankshaft. The pilot of the converter whether you buy brand A,B or C doesnt matter is 1. 8 inches. The center of the flexplate is approx. 1. 8 but the actual center of the crankshaft is 1. 945, think of it like this, if you had a standard tranny and your input shaft bearing was not centered would you have problems shifting your truck. In other words everything has to be centered properly to make things work properly and last. Guys seem to understand that the pilot bearing is critical to the standards but dont seem to realize the centering of the TC in the automatic is just as critical. 

So do not let shops try and convince you that its hp and torque that is breaking these flex plates. 

Things to check for when you have a broken flexplate, 

Dowel Pins, either kinked damaged or missing dowel pins. 

You can check to see if you have a missing dowel pin without removing the transmission, remove the 3rd bell housing bolt from the bottom of the transmission( dont worry the tranny is held in by a lot more than 2 bolts, and insert a magnet, the magnet should grab on to the dowel pin. Since the tranny case and the adapter is made out of aluminum the magnet will not grab onto either one of those pieces. 

When the tranny is out , since you have to take it out any way to fix the broken flexplate , the pilot of the TC must be checked for any damages, ie) nics , burrs, or damage to the hub of the TC or the pilot of the TC. If there is any damage , you cannot sand away the burrs, you must replace the pilot of the TC. Trying to sand or file actually makes the odds increase of having a second broken flexplate. 

Check your flexplate ID, it shoud measure 1. 8 , since all manufacturers have a plus or minus in tolerances verify the measurement. 

More rotating mass is more likely to break an oem factory flexplate . HP and torque have very little to do with it. 

Bill has made this very clear when training , the torque converter is only turning the pump, whether you have a 200hp truck or 

700 hp truck, it is still only turning the pump. 

As for tighter fluid coupling causing broken flex plates

 

 

I am sure you were joking but some guys might actually believe you . 

Tranny guys know the shock of a tighter fluid coupling is felt from the turbine back not forwards. Since the turbine is free floating in oil inside the TC and not physically attached in any way shape or

form to the flexplate it would take one heck of a load to even come close to even nicking the flexplate. And i know the Dodge trucks we are discussing are not equipped with transbrakes.

[CTcummins24V]

Thanks Caj, very informative. I did not know the dowels and pilot were so important.

[CTcummins24V]

The billet shaft definitely has thicker walls. The fluid hole is smaller and the outer walls are thicker too. The first 3 pics are the oem shaft, the next 2 are the TCS shaft.

 

[MnTom]

Yea, the billet is stronger, but what about the front drum? A billet shaft would not have helped me......

[CTcummins24V]

I think they increase the number of splines for the input shaft to drum connection, so there is better load distribution and hence more strength!

[CTcummins24V]

Oops, after looking at your picture again it seems your hub failed. I believe they use a stronger metal for the hub.

[MnTom]

I have heard of the splines letting go, but in my case...... I really don't know what caused it to break like it did.