I have a 2007 Kenworth dump truck with Cat C13 stuck in my parking area that won't go into gear. No Codes, ran fine when parked. Idles at 650 rpms. This is a 6 speed Allison auto 4000. When you touch D or R, the the D Or R blink, why the N stays still on the screen. Normally it blinks for second, then engages. Foot is on the brake pedal, air brake is off. Almost like it's in limp mode. I'm not a transmission guy, so need to be able to get it into a gear to get it down to a shop. Anything I can look for like a loose corroded connection? If so, where do I look. This has happened before, but seems like I was able to clear the limp mode, like if you turned the engine off when the rpms were high. Thanks, if anyone has advice.
Did you find out what was wrong?
Thanks for asking. No haven't solved anything! I don't know a thing about transmissions. I hate to have to do it, but I may have to pay a lot just to get the Allison Transmission shop to come out with their service truck and trouble shoot it. I would think that would be a better idea than getting the truck towed to the shop. I also have a feeling it's just a bad connection something more simple, but I don't know where to start looking. Truck was shifting fine on the road.
Depending how the truck in programmed the park brake switch and the application brake switch may be able to inhibit the transmission from engaging. You will need to scan it to see if the switches are working. Does the fast idle with the cruise switches work?
Ok, so it's actually a RD4500 6 speed auto, S/N 6610202041 2007 year. Truck serial last 8 digits 7J185524 Going to cost $500 to tow to the Allison Repair shop!
Cheap, cost that to have a ding dong in service truck come and look, and make three trips on top.
Won't get towed down to Catalyst Powertrain until the end of the month, so I will follow up with what they found in a few weeks. They said likely a TCM or speed sensor issue.
With the key on push the up/down arrows at the same time until fault codes come up. Then scroll through them using the up or down arrow. You should be able to look up the faults on the internet or maybe the Allison shop will be able to tell you what if any they are.
Funny, we were just talking about Allisons in the service truck thread. Not much stops a 4500. First thing I would do is check the park brake switch. The TCM thinks the brakes are still set. That switch is common to fail with that year of rig. But, check the codes with the shift console, first. It’s just a two wire on/off, air powered switch. You can check it with a test light or jump the wires. Where is it at? You may ask? It’s located on the inside of the firewall behind the steering wheel. It’s horrible to access. It’s soul crushingly, horrendous. A total heartbreak, slam your penis in the door jam, type of pain. Good luck.
probably be easier to lay it on a anvil and smack it with a dead blow.
Just dont get it stuck in a bench vice!
Almost sounds like a personal experience Tyler??? ha ha ha
Check the grounds for the TCM while your at it, that hung up one of ours but I can remember what it was doing
Well the truck got towed to the service shop. The tow truck had a booboo backing my truck into the shop and damaged the radiator petcock and pipe which is taking Kenworth a long time to track one down. So I still don't have the truck back yet. I have not seen the paperwork yet, but the transmission problem I think was a bad speed sensor or something? They also say I may need to get the brake treadle looked at eventually.
Gene's has been around a long time--IIRC. The reach get too close to bottom side of radiator/crossmember?
Yeah, when the tow truck driver went to back it up into the shop it's a steep easement. So right when the tow truck gets halfway up he has to raise it up which didn't happen. Anyway, the shop and Gene's are working it out. Got the transmission bill - Needed a Speed sensor assembly, and Treddle valve. Had air leak on one of the air lines to the back axle air canister. Total cost of repair for labor, parts, tax is $2,298.55 (8 hours labor @ $205.00 per hour). Not too bad I think.