Busted input shaft

[JD3020]

Made a 500 mile trip Saturday in some pretty sketchy ice/rain conditions, with a ton of stop and go in the hills. Trans did awesome, never slipped and never got over 140* like normal. Got home, loaded a new tune onto my Hydra and went out for the night. Made it 10 miles, locked in the new tune at a stop and got on it some. Got into 2nd gear, started climbing north of 3k rpm's and ICP was dropping like a rock down below 1200psi. Around 4k rpm's it locked the converter/hit 3rd gear. BAM! Immediately lost the trans. And of course at that point it was 9 at night, starting to rain pretty good, and i was by myself. LOL


So last night i got the trans out and took a look. Fluid looks fine, no metal shavings at all and the magnet was relatively clean. Popped the converter off and sure enough it twisted the end off the input. To me it looks like a stock shaft. I'm 99% sure i requested a billet input for the build as it was only another $2-300, i mean hell i spent $1200 on a freaking converter. But i haven't been able to dig up my receipt and after how the build went i don't even feel like going down that road anymore.

So my question is, should i worry about anything else inside the trans, or just throw a new input in and go on my way? Plan at the moment is a Suncoast input, custom VB(either JW or Punisher), add a 4r pan, and replace the flexplate. It also has a PI converter, so i've been thinking about sending it back to them just to get checked out, but with Thanksgiving this week that makes it a bit challenging for me to get done. This trans has 40kish miles, and is 3 years old. The truck doesn't make much power, but i don't baby it.

 

[JD3020]

Anybody?

 

[trackspeeder]

I would replace the shaft and drive it.

 

[co04cobra]

That sucks! I know a guy with a zf-6 swap available LOL.

How did you get the broken piece out? I have a suncoast converter at the shop that broke a shaft and the end is still in the converter.

 

[JD3020]

Haha, i'm just glad it lasted that entire trip and then decided to break a couple miles from our farm. Judging by all the wrecks on the highway i woulda been waiting a while for a tow truck. LOL

And i just turned the converter over and it came out. Splines on the shaft and what i can see in the converter look perfect. It simply twisted the end off.

 

[David N]

That sucks! I know a guy with a zf-6 swap available LOL.

How did you get the broken piece out? I have a suncoast converter at the shop that broke a shaft and the end is still in the converter.

Yeah I learned the hard way on that. I broke a piece of my input shaft off in my converter and ended up trashing the converter because we couldn't get it out. Oh well.

I would have whatever shaft you go with cryo'd just for a little extra insurance.

 

[mandkole]

I guess I'm not familiar w E4 tuning-- that TC lock at the top of 2nd wasn't expected. That hit the input pretty hard.

 

[JD3020]

With an E4, or at least how i have my truck tuned and how my stock TDE1 PCM is, it pretty much hits 3rd gear and locks at the same exact time. And with an OBS there is no modulating the converter, its either locked or unlocked. I haven't gone back to look at this tune yet to see if i did something funky in the trans tuning.

To be honest this converter is pretty harsh, when it locks it jolts the whole truck. Cruising around pretty easy its not bad, but its harsh when i'm towing heavy, grossing in the 22k range on a hill. When the converter locks there is such a sharp and instant RPM drop that it will chirp the serpentine belt. Or theres times, espeically if i'm accelerating pretty hard right before it locks then let off, it'll bang in. Its been like this since i had the trans built, so i figured thats how the PI converters are. I've talked to some SD/4r guys and they said their converter isn't like that, but again they have PWM and i don't.

Either way this trans shocks itsself pretty good, i'm very very very surprised a stock input lasted this long with how much abuse this truck gets.

 

[elrodalexander73]

The shifting sequence needs to be adjusted, you can lock your converter after the 3rd gear is achieved, thats a clean break on the shaft, clearly a shock load break, the problem with PWM converter strategies is that the trans constantly hunts for gears, I've spent a good deal of time working with Allison on this, we've seen alot of shafts broken even on Allison 4000s due to shock loads... The converter is activated in the front pump via a circuit that delivers fluid to the lock up piston, the E4OD solenoid block delivers a more related on/off signal where as the 4R100 uses a pwm signal which can regulate the amount pressure via ICP, wheel speed and input throttle percentage to regulate how to lock in the converter.. The transgo kit has detailed instructions on how to adjust lock up pressure. Talking closely to someone like Bill or Matt at gearhead should help you regulate your lockup in your tuning.. Allison strategies lock the converter in 2nd gear and hold in gear all the way into 5th/6th, they developed this to reduce shock load and heat reduction due the constant in and out of the lock up, this is why 4R100 stock converters last very short compared to the E40D because the pwm wasn't sophisticated enough to understand input torque, and well the converters were trash from the factory.. My opinion would be build a shifting strategies that allows the converter to lock in after a delay after third gear is achieved. Not only are you tearing up the input shaft, but the planetaries are taking quite a shock, which stretches the pressed fit area where the planet gears are held on the carrier, this leads to catastrophic failure (seen this on many plow trucks in Mi) THis is just an opinion though..

 

[JD3020]

So you think the lock-up in 2nd gear is what snapped it?

I have a BTS valvebody and a Suncoast billet input on the way for it.

 

[elrodalexander73]

Talk to Bill Cohcran or Matt at Gear head or even call Jonathon at swamps about tuning the trans, they know alot more than I do, I remember years back driving a truck with the "crappy Banks Trans command" and the lock up was delayed in 3rd gear under hard throttle to help assist in converter life with the lovely 40hp chip.. It did its job though. Tuning a trans for even what you and I only have is a huge part of the longevity. Unless you're running all billet drums, input, intermedaite and output, tuning will play a huge part on what breaks with all that torque those 250/200s are putting on it.. I know delaying the convereter lock up helps alot too because thats how bill set mine, under super hard accel it doesn't lock in until it see's certian ICP levels and doesn't snub the charger hard when the converter hits. Really helps the whole truck imop.

 

[JD3020]

This truck doesn't make all that much power. With the 15* HPOP ICP ramps up slow, and with the ****ty stock turbo/major up-pipe leaks it'll barely hit 38psi and spools slow. But i've been thinking about throwing this S467 on it with an Adrenaline, and keep it tuned very mildly to keep the drivetrain alive. I plan on talking to Bill at some point to see if he as any pointers. I definitely don't want this to happen again.

 

[elrodalexander73]

A billet shaft will keep this from happening again, swamps has em for around 250 bucks, MAKE sure to flush your cooler while its out!!! I'm running is the Adrenaline and so far ok luck, still throws ICP code,but 250/200s are border line Gen 3/dual hpops ya know. I'm running a D66 turbo (wasted money imop) and it's alot of fun to drive, can't wait to get the rest of T4 stuff around, gonna run and H2E for reliabilty (Holsets are just tough I don't care who says what) and see what I lay down next fall.. But there's lots of guys alot farther along the yellow brick road here and may have some more helpful advice.

 

[JD3020]

Figured i might as well update this as i got the truck going a month ago. Put in a billet Suncoast shaft, BTS valvebody, new transmission mount, and had the entire rear driveline re-built. Carrier bearing was toast and the joints were showing their age. Absolute night and day difference now. My truck used to slam lock-up which is what i think broke it, and felt sloppy. Now it just feels like a firm shift. Even when towing 12k and hard in the throttle its nice and crisp, but not harsh. Although now with a billet input i hope i don't start breaking **** thats expensive/hard to replace. LOL