Howdy All,
I have a 2001 379, I have owned this truck for 6 years in that time I have driven it around 70,000 miles towing my huge RV trailer. In that time I have had NO problems with the transmission. The day we had planned to go south this winter the truck would not start, would not crank at all, the gear indicator showed a dash - rather then a gear number or N for neutral.
I spent hours on line researching this, had a guy who has the computer program needed come out and check the truck, everything pointed to the X-Y shifter needing to be replaced. Bought a new X-Y shifter, installed it, followed the instructions on how to "calibrate" it. Truck now starts, transmission will go into Neutral, Reverse and Drive. It will move in Reverse, it will move in Drive, but it will NOT upshift or downshift.
The transmission is programed to start in 3rd gear when it's placed in Drive. When the transmission is working properly, "I" can select any gear from 1st, to 5th as a starting gear. Now when I start the truck and put it into Drive, 3rd gear is selected and engages, but when you drive the truck it will NOT shift, it tires to shift but won't complete the shift when it's in Drive. If I put the shifter in "HOLD" position I should be able to pick a gear to start in AND when moving up shift or down shift at will within the TCM's parameters, this is NOT happening.
So now I am perplexed as to what could be wrong. Like I said, until the first no start situation this transmission has worked flawlessly, it has always depending on load skip shifted up and down, allowed manual gear selection within parameters, held the gear when in the HOLD position, worked with the Jake and cruise control. Now I don't have a clue what's going on and would appreciate any help or suggestions you folks can offer. Thanks.
Dave
Gen 1, Auto-Shift, replaced X-Y shifter, now won't shift out of 3rd gear
Discussion in 'Peterbilt Forum' started by Mr. Cob, Feb 12, 2024.
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I forgot to put this in the first post, I also replaced the two shifter sensors on top of the transmission and the speed sensor on the out put shaft of the transmission.
Dave -
I have 3 trucks that originally came with auto shifts and ended up converting all to manual. Nobody knows how to work on these trannys anymore and it's a big pain to diagnose.
The most common problem I had was transmission wiring -
I have read many times that these transmissions can be full converted to manual, but to date NO ONE has posted details on what parts are needed or the actual address of a shop that will do it. Others have said they had it done in chigago, seattle, Dallas and some place in Tennessee, but again no names of shops or part numbers. If you can shed any light on this subject I sure would be interested. Thanks.
Dave -
The Autoshift have the same guts as the manual trans. Just that the autoshift is controlled by computers.Mr. Cob Thanks this. -
You basically need a new transmission top plate ($500) and a meritor electrical 10 speed stick ($200 at a junk yard). The rest is labor, dropping the transmission, making a new harness, reprogramming the ecm (depending on the engine). Might as well throw in a new clutch.
I did my last one like 3-4 years ago and all together it was under $3k. Might be a bit more expensive now, since price of labor went up.
There is also a possibility that your tranny itself needs a repair. I suggest to not waste time and just get a rebuilt exchange for like $3500 instead of tearing old one apart. I bought mine from Valley Truck Parts in MIMr. Cob Thanks this. -
parts needed.
New transmission case, couple sliders and maybe 1 gear. used top plate and shift tower, simple parameter change in ecm and probably disable a neutral safety switch( I didn't know that and just ran a new wire to starter)
inland truck parts did my conversion. he just looked at the parts list for the auto vs manual and changed anything that was different.
I can give you more details if you have the same transmission and are interestedMr. Cob Thanks this. -
I have the 18 speed A-S transmission and C-15 engine. I have heard that the case is different and that a regular shifter plate will NOT bolt to the Auto-Shift case but some have mentioned an adapter plate but again no details. If you have the time please provide me with as much detail as you can. THANKS.
Dave -
most autoshits came with a solo, self adjusting clutch, they are garbage. if it still has one, get rid of it!
I did this probably 10 years ago. cost me 2-3k then. for me it was Well worth the cost. I removed and replaced transmission and had a shop do the actual transmission work.
Inland truck parts. sioux city, IA. ask for Doug. he knows his stuff.
but like I said before a simple comparison of part numbers is really all anyone needs.
reused most all my original gears and bearings.Mr. Cob Thanks this.
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