Transmission Conversion?

Big Red-TC

New Member
Joined
Jan 12, 2014
Messages
6
Location
Lewis
Hi, I am a New Member and I hate to start off with this question, because it might make me look and sound like a lazy old man, but I was wondering if anyone has an answer to my question of if I can convert my Peterbuilt Race hauler from the current Fuller/Eaton to an Allison or other type of automatic tranny. Another question is could I convert the existing trans ti something like a electric shif assisted trans? I hope the "hard core" guys don't scoff at me. I can drive and shift my rig "clutchless", but I am getting where I would like my Wife or someone else drive besides me. I have owned this Set-up for over five years and use it to haul my 33 Willys Gasser to Nostalgia Drag Events. It is a Peterbuilt one-piece unit with a lounge, that is powered by a 400 Big Cam Cummins Mechanical injected Turbocharged. I love the Rig, but if I can not switch it over to an automatic, I might be forced to switch over to a ShowHauler type of coach and tow my car in a trailer. I hope I haven't shown my ignorance by asking these questions,but I am open to all answers and inputs. I am a motorhead, so if someone thinks I can do this conversion or not I would understand the reasoning. Thanks Tony
 
It is possible. A few questions... what is your rear end ratio? What transmission are you using now and what gears do you usually use? What is the weight of the rig? Also, what are you wanting to spend on the conversion?

I have several rigs with NTC400's (big cam 3) and 5 speed Allisions. They are direct drive with lockup in 2nd through 5th. I'm using a 3.08 ratio to make mileage decent. You can get 6 or 7 speed Allisons but the price goes up and you loose efficiency with the OD's
 
It can be done but I don't think you would be happy with the results. You would have to go with a non electronic allison being as your engine has no electronics to control an a Fuller Autoshift or newer Allison. If you can find a low mileage used Allison (or fresh rebuild) and do it yourself the costs msy be reasonable but if you have to buy new and pay for it to be done it may not be reasonable.

I know it is pricey but if it were me making the decision I would trade up to a newer unit with a factory installed Autoshift.
 
Good points about a electronic trans and a mechanical engine. The 5sp Allison is an excellent choice and I think that Dad had a 6sp Allison in his last bus that was mechanical (could have been computerized though). Some of the transmission makers probably make a transmission computer which will work with a mechanical engine but they are usually very expensive. If you are interested in a computerized transmission you may consider swapping the engine and trans at the same time. Dad's current Prevost project came without engine & trans. He bought a 12.7L 60 Series paired to a 10spd autoshift from a 2000 Freightliner to install in his bus.
 
the guy i bought my truck from was in a wheel chair. he changed from a manual to a allison. he had it as a tractor & trailer. dont know what it cost. only drove twice and it seems to shift kind of hard. still building motorhome.
how about some inside pictures.
 
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Thanks everybody. Why am I having trouble posting a response?? I typed two long information responses and lost them both. Help! My index fingers are getin TIRED !!! Ha ha ! Tony
 
It is a 1988 377 Pete Day Cab with conversion done around 2004. Rear ratio is probably 3:08 Or 3:73, it cruises at 60/65 just above an idle,but will go to 75/80 if you don't pay attention. It weighs 26,000 unloaded. My 33 Willys only weighs 2,200. The car is only 14 feet long and the garage area is 21 feet with a 10 foot by 8 foot lounge in front of that. The motor is a reman with low miles around 230,000. I can do my own work. Can I do it for 10Gand or under? I do my own service and I do love the Set-up. I am getting where I would like to have some help with driving chores. I crank the Willys in with a powerwinch and cross tie the rear tires and have "basket belts" for front tires. How do I send pictures on Quick Reply??
 
Thanks ASITOOL, PORKY69,ANDYG and VOLVOMAN....when I learn how to send pictures I will. I have a good computer and did manage to send a video Thanks again everyone.
 
I do have a complete very low mileage tractor (less 5th wheel) that I was going to turn into a water truck. The big cam III doesn't meet the new California emissions standards though, (motorhomes are exempt)

It has the Big Cam III and the 5 speed direct drive Allisoin with lockup in 2nd through 5th. You would definitely want to keep your tall gears. I'd part with it for 6200. I figure you could take the trans, cooler, shifter and all the small parts, then sell the bogies, (hendrickson walking beam, 4:33 with detroit lockers) and scrap the rest and probably get 3k back. You'd have an engine, trans, and all parts for about 3200.

I'm in Southern California.
 
That deal that ASITOOL has may work pretty good for you. Don't forget that you can get a few buck$ for the existing transmission after you take it out. You will likely loose a little bit of fuel milage but the increased drivability on a hobby truck more than makes up for it. I have a FLD120 Freightliner with a 350 Cummins and 9sp RoadRanger. It works great for towing my steam engines but takes a 100 acre field to turn it around.
 

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Andyg, Thanks for the heads up. I actually just dropped him a line to let him know that I appreciate his offer. I am in Florida now for some R&R and won't be back to my Hauler up North until April. I have a friend of mine in Redding,Ca. So I could use his shop and leave the leftovers with him as a paypack. The motor in my hauler now is a low miles Reman. So that is a good Idea you had about motors, I could keep or swap accordingly or keep my reman for a spare. Right now I have a couple of months to come up with a plan. I love Big Red and know it inside and out (for an amateur) so I am leaning toward a "swap", but If the right set-up comes along to upgrade , I might go that route. Either way as they say " I am just happy to be alive" and my wife is still cooking for me!! Thanks for your input. I will try to message you through your regular email so I can see your pictures. I could not open your attachments. Take care Tony
 
I was going to quickly add that you would be best off by swapping a motor and trani combo. Allisons (pre-electronic units) are able to be fine tuned to a motor (especially with a souped-up pump) if they are dyno'd together.

I bought a motor and bought a trans, then modified the pump, then modified the trans, and bolted everything together... and luckly got VERY close to perfect. But after the fact, I wish i did it the correct way.
 

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