48re trans rebuild having issues

[JasonW]

Just recently got my truck back (early 04) from a semi local rebuild. Bought the truck to find it was detuned by previous owner and opened a can of worms.

Seems to have been a tow trans from firepunk as all it had was the triple disc converter
I installed the ATS gov pressure solenoid and adjusted bands to try to remedy my issue prior but no luck, I had the transmission rebuilt by a local shop.

Now the trans has a fresh rebuild, billet goerend input shaft and the converter was rebuilt

Problem I'm having now is, truck feels as thought it has 5 gears.. 1st to 2nd shift is fine, but around 24mph feels as though it slip shifts, then around 30-34 it shifts to 3rd and lock up around 45-47.

Builder claims it might be a TV cable adjustment as prior it kept giving me shuttle shifts..noticed at WOT it seemed like it wasn't putting much power down (120HP street tune) and my slipping in 2nd..

So I've adjusted the cable several times, shifting got a bit smoother and slip in 2nd wasn't as noticeable but still there, but from what I've been seeing at WOT the TV lever should also be wide open..but with the way the cable was previously (had marked it before moving) I had almost 1-1 1/2" of play before the TV lever was fully open.

So I've set the cable to the point where the TV lever is wide open with the throttle.. 1-2 shifts aggressive at times and downshift at times but I can deal with it helped seem to put the power down to the ground. The heavier slipping after being in 2nd gear is my concern, if I WOT from stand still seems at times it's not putting down the power when I'm in higher hp tunes.

I've checked band adjustment and set it 2 turns out, no difference. Wondering if my line pressure could be too low? Or if there's already problems with this trans.. asked the builder to make it safe for 800HP as I have a compound turbo set up to put on it and yet they gave me an Economy billet shaft technically rated for 500hp..shop owner claims he'll put in a Sonnax billet input shaft for free since I was unhappy with their choice

Shop seems to be ignoring my texts now so taking it back to them currently is not happening potentially could be bringing lawyers in..just trying to see if there's something I can personally do to fix this or if it's about to get ugly. Any help would be greatly appreciated as they had my truck for 6 months and it's been a nightmare.

 

[AEdelheit]

I am a bit confused by your post as it sounds like you are blaming Firepunk in the title but then not sure if it is a Firepunk much less that they actually worked on the truck???? Have you tried calling Firepunk directly? Seems like that would be a logical first step if it is there transmission....

 

[JasonW]

Wasn't meant to be directed towards firepunk just stating it was a transmission that was purchased originally by previous owner through firepunk, this was a local builder that had rebuilt the transmission for me that I'm having issues with that I can't get direct answers on fixing.

 

[CoastyAV8R]

Wasn't meant to be directed towards firepunk just stating it was a transmission that was purchased originally by previous owner through firepunk, this was a local builder that had rebuilt the transmission for me that I'm having issues with that I can't get direct answers on fixing.

My transmission was rebuilt just prior to me buying it but it had a "high performance" torque converter installed as part of the rebuild that when it engaged it would rattle your teeth. The truck is stock and I hated that so I replaced it with a billet torque converter that engages much more humanely. They also adjusted the bands when they were in there but I notice a significant amount of slippage in mine prior to the torque converter locking up as well so I'm curious if you ever got an answer/fix?

 

[Ozymandias]

Why didn't you stay with Firepunk?
I'd never ever mess with a built transmission by mixing parts from other brands, that calls for trouble.
Now the Trans is all messed up, no one will ever know which part doesn't work together with the rest and every mechanic will blame the other ones parts/labour.
Call FP and tell them what's going on, if someone can help you to sort it out then FP.

 

[SSage]

Sounds like your feeling the 3rd gear shift then TC lock up and then it unlocks and shifts to 4th and locks again. But all shifts should be firm and quick.

I'm not familiar with Firepunk parts, but my Stage One Gorends shifts as hard as my fully built billet DTT trans at WOT. The Goerends is smoother with light throttle though. My old DTT trans shifts hard all the time, you really know what gear your in, its hard to miss.

I know I've had to take both of mine back after spending thousands on fancy name brand parts and well known builders. I feel cursed somedays! The TV cable position is very important, I had to replace a worn out TV cable that wouldn't hold adjustment. It was really messing up my shifting, pressure was low.

 

[JasonW]

Sounds like your feeling the 3rd gear shift then TC lock up and then it unlocks and shifts to 4th and locks again. But all shifts should be firm and quick.

I'm not familiar with Firepunk parts, but my Stage One Gorends shifts as hard as my fully built billet DTT trans at WOT. The Goerends is smoother with light throttle though. My old DTT trans shifts hard all the time, you really know what gear your in, its hard to miss.

I know I've had to take both of mine back after spending thousands on fancy name brand parts and well known builders. I feel cursed somedays! The TV cable position is very important, I had to replace a worn out TV cable that wouldn't hold adjustment. It was really messing up my shifting, pressure was low.

Yep its the 2-3 shift that feels sloppy/slow, wasn't fully aware of how the gearing was set up in these. Now I'm curious as to why, adjusted the band out 2 turns but didn't help, curious if I turned it in 1/4, turn to Mopar spec if it would help, or possibly bumping up line pressure...or if there's something wrong with the rebuild.

 

[SSage]

My current builder tells me the bands will be good for 80K without adjustment, no need to mess with them right after the new install. But I don't know if thats a common opinion. I know I've only needed band adjustments around that point on my OEM trans. I am having issues with my fresh 48RE rebuild right now while towing, so hopefully he can figure out whats wrong quickly. Gotta get it in after the holiday and see whats up. I sure hope its minor, I want to get 5th wheel hooked back up soon. I only have about 700 miles of towing on the new build, it was running great for about 1,200 miles solo and then it started abruptly down shifting while towing and won't stay locked up in 3rd sometimes. Crap happens, hopefully my builder will figure it out.

 

[SSage]

Ever get fixed up?

 

[Timd32]

I ran across this place on YouTube, they don't do alot of build videos, but they do disassembly videos and show the short falls of lots of transmissions.

They seem pretty legit and it's entertaining to watch.

https://youtube.com/c/PrecisionTransmission

 

[SSage]

I've watched those Precision Trans videos, the mud truck ones were interesting. Around here the only diesel transmission specialist I've found is Ashley Black. He built my 48RE a few months ago.

My shift selector cable got out of whack again and he thinks that was causing my issues. I'm approaching 3,000 miles now, hopefully it will hold up like my old DTT 47RH in my old truck.

The stage one Goerend triple disc set up shifts smoother than my DTT single disc billet trans, so far the stage one build suits my near stock tow rig. You can drive it softly, the 4th gear OD lock up is smooth if you back off a little at 45 mph. Not as aggressive as my DTT build, but it was built for higher HP.