4r100 went bang

mustube · May 4, 2014

I really don't see this as a power/weight/tuning issue. This transmission still shifts funny. I haven't beat on this truck at all since it was put back together in February and my truck is probably putting down very low 3xxhp to the ground. My limited slip is even so worn out that it acts like an open rear end, and I just get a one wheel peel when if I get on it too much from a stop.

What causes a 4r100 to not shift into third until you push the overdrive button?

mustube · May 7, 2014

Shop called and said it's another broken intermediate shaft. It will be back together friday, but they said they don't know why this is happening. They told me when they rebuilt it the first time, the clutches in the direct drum or whatever the intermediate shaft goes into were more worn than the rest. Not sure where to go from here. I think it has something to do either with the pcm or the valve body because they are the only old things left from before the rebuild. I think I will put a bts valve body in it and hope that's the problem.

Matt, who's your tranny guy in B/CS? Might take it for him to look at before I leave town with it.

Gearhead · May 7, 2014

His name is Charles and he used to work for John's transmission. but if they haven't done it yet they may be able to send your valve body to John's to see if he can put it on his valve body test machine.

mustube · May 8, 2014

What are the odds a BTS valve body would be the ticket here? I would be telling him my tire size, gears and power.

Dmstrucks02 · May 8, 2014

Im not sure if its your problem or not
But I put the Transgo Tugger kit in mine, simple install and the same as BTS' valve body mods if Im not mistaken
Trans is firm and fast now, no flare or 1 to 2nd hang like before

OBS-Addiction97 · May 8, 2014

I broke my intermideat shaft as well in a bts. They seem to be hit or miss.

mustube · May 8, 2014

This is 2 in under 3 months. I dont drive my truck hard or make any real power either.

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mustube · May 8, 2014

I'm reading that a PCM issue might be to blame. Any way to do diagnostics on mine to see if that's it? Can a dealership look at it?

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Gearhead · May 9, 2014

Does anything not feel right about the shifts? if it was binding you would feel it.

mustube · May 9, 2014

Normally it feels fine, but sometimes it seems like its lazy on shifts and both times it has broken, has been on days where I had to push the overdrive button to get it to shift. Also both times it went was a casual 2-3 shift on an access road just getting up to speed. I have a pmt3 PCM which I have read doesn't have the best shifting strategies.

Mark said in another thread that needing to push the button to get third means it might be a direct seal problem but with it being a fresh rebuild and having a clutch issue originally when it had worn out injectors I don't see that.

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Gearhead · May 9, 2014

Sounds like a hydraulic leak.

mustube · May 9, 2014

Could this be checked by looking at line pressure?

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Gearhead · May 9, 2014

they should look at the pressures in all the gears on each clutch..

Mark Kovalsky · May 9, 2014

Gearhead said:
they should look at the pressures in all the gears on each clutch..

And how would they do this?

Gearhead · May 10, 2014

See what's being commanded and make sure the tv pressure is following. If there's a major leak the pressure should drop off and the commanded wont change. Sorry i didn't mean that there's a port for each clutch on the side of the trans.

mustube · May 10, 2014

Is there a PID I can look at for commanded line pressure in my torque app or how do I figure out what it's commanding? Matt would it be based on your tunes alone or a combination of things?

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Gearhead · May 11, 2014

I don't know what's in the torque ap but there's a way to see what the EPC is doing.

mustube · May 11, 2014

It can see any parameter that the PCM sees, you just have to figure out what the PID is and enter the custom info for it into torque and it will convert it into a gauge.

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mustube · May 15, 2014

Got it back today. ****'s still ****ed. It shifts worse now than it did before. Picked it up after 5 so I couldn't really talk to anyone about it. The 2-3 (the shift that broke it both times) shift is much harder, and the 4-3 downshift is ridiculous. I'm going to call Truck Source Diesel and see who their go to guy for 4r100s is in San Antonio and go talk to them. Also, I didn't break an intermediate shaft this time, I stripped out the forward drum. They replaced some seals, the forward drum and they also put in a new solenoid pack though I'm not sure why they thought it needed a new one.