I bet most of you have forgotten about this build huh? Well...life, customer builds, shop space, etc... sometimes get in the way of personal projects. In this case, all of the above plus some.
Once the van was together last summer, we started getting really busy with customer builds and Transit development. I got to drive the van a bit and sort out some little things (like power steering leak, fuel leak, engine tuning, trans tuning...) but there was a concerning sound coming from inside the Allison trans that had me worried...that and there was a ton of friction material and metal shavings inside the pan and filter. With no extra time to play and no shop space, I decided to put the Cummins project on hold and took the van to a "storage facility" (thanks mom and dad's farm) to sit until I could find a break in the chaos around here.
We're not any less busy and I don't have any more shop space but you can't let a build like this sit unfinished. Brought the big beast back to the shop, I got it on the lift, pulled the trans and took it to some local Allison pros.
I was fearing that I had a bearing go bad and the planetary gears were shredding parts that get really expensive really quickly. The trans tech called me up and said that the insides looked great. In fact, he commented that it looked like a pro-built trans and he was impressed with my work. No smoking gun though... All the parts checked out under a thorough inspection. He asked about the torque converter and I thought, since I bought it new as a high performance, billet, triple disk, specifically designed for Cummins/Allison conversions unit...how could that be the problem?
There had to be something making all the extra material and metal so I gave authorization to cut open the torque converter and check it out.
I got the call.... "We have a smoking gun!".
It isn't often that discovering that a $1500 part is junk is a relief but I can tell you that I was pretty stoked to know that it wasn't something I did and that my transmission was going to be ok.
The failure looks to be splatter from the welding process that got into the disks and just shredded them. There were also some broken fins on the stator which explains seeing both tons of aluminum and steel in the pan. Thankfully the TC manufacturer agreed to refund my money but I'm still out a HEFTY sum to get the trans inspected and reassembled.
Trans is back in the van now and I'm just about roadworthy again. While it was out, I took the opportunity to reroute some of the wiring harness to get it out of a pinch zone and I made some new trans cooler lines to get up out of the way more. I also had to change out a couple sensors on the engine for the new gauges to work right and the last thing is to reroute the dipstick tube so I don't have a pull the doghouse to check/add oil.
I'll update again soon with a video.