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airplanejoe's avatar
airplanejoe
Explorer
Jan 10, 2016

Allison 3000MH WTEC 3 electronic control system data

Dear friends...
I have a 2003 Tiffin Allegro Bus with the Allison 3000MH transmission and a Cummins ISC 8.3 diesel. This baby runs great and the transmission is smooth as silk however I have absolutely nothing, maintenance manual wise, to help me if the transmission decides to stop working. This has the push button controls on the console.
I've been a mechanic forever and am anal about having knowledge about being prepared for unforeseen mechanical breakdowns...
There is a clear cover box with relays and a motherboard, blinking lights in the battery compartment door area just aft of the batteries. I believe this is the electronic control system.
Does anyone know where I can obtain maintenance manuals and data about this?
I've searched the Tiffin website, called their parts department and searched the Allison website. Any suggestions out there?
  • Call or email Allison, most of there stuff is online. There is very little to service on these other than filters and fluids. The service recommendations are very long but they do say 1 year or x miles. Otr trucks run 750,000 miles before service.
    I'm one of those who's a big believer in oil analysis. For $25 you can get real insight into the transmissions condition.
    I use Blackstone
    Good luck
  • OTR trucks do not use Allison Tramsmissions. lately Allison is trying to get into that market and has produced a Tranny for OTR but I doubt you will see any on the road. They are used in busses and HD trucks like cement mixers. OTR trucks use either a manual tranny or an auto shift transmission. Theis is a real manual transmission that is shifted automatically and controlled by a computer. Some of the new trucks have that tranny and the engine and tranny computers have a GPS. The transmission will downshift before you get to the hill. Amazing.

    Moisheh
  • I replaced the relays in the control box several years ago as a precaution or preventive maintenance issue due to the age of my coach. It uses the same relays as those that are use everywhere else in my coach, but I can't recall the identifying number. I had bought a box of 24 on e-bay a few years earlier, so the cost was minimum to me. The box is black, about 5 inches square, and has Allison written on the cover. Mine was in the ceiling of my electrical bay, and right under the touch pad.

    A second potential problem is one of the main relays could be sticking. The relays look just like those used for starters in cars in the 50's and early 60's, and look like a miniature beer can. They have copper posts in each side and two smaller electrical connections in front. They don't last forever but will generally fail intermittently, so there is some warning. If the relay doesn't work, your transmission won't be activated.

    Good luck.
  • I have the manuals in PDF but I cannot attach them to the message. If you send me a private message with your email address, I will send them to you.
  • Moisheh, where do you get your information? I have been delivering brand new class 8 and 7 trucks from the manufacturers to dealers (mostly fleets) since 1998 and many hundreds of them have had the Allison transmission in them!