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Hey guys just got an Allison AT540 for the old beast. This transmission came from an 86 Top Kick with a 366 for power; I got all the mounts and bell housing adapters to install it behind my 496 stroker.
Here are some pictures of it in the bed of my pick-up
http://rides.webshots.com/photo/2108300510096773078YuMTMJ
http://rides.webshots.com/photo/2540158390096773078faemMC
http://rides.webshots.com/photo/2022879640096773078vnHFtb
http://rides.webshots.com/photo/2095640270096773078aMRSuP

Back in the seventies when we still ran gasoline route trucks, we had quite a few AT540's running around. Some were C60's with the 350V8 and some were C65's with the 366V8, but they all used the same AT540 transmission. We even had a couple Ford LN750 trucks with the 361V8 and the AT540. They were very tough transmissions and held up very well. The drivers liked them much better than the manual transmissions. We also liked them because there was no clutch to worry about and they were much less likely to destroy driveshafts and axleshafts at the hands of inexperienced drivers.

Our route trucks are all diesel now, but we still use Allison transmissions. The smaller diesels use the AT545, which is just a disel version of the AT540. The heavier trucks used the MT643, and now we have quite a few of the Allison World Series electronics. I've been working on and with fleet trucks for almost 30 years, and I would recommend the Allison to anyone.

Hope yours works out great.

TruckNut
From what I have found the AT545 differs from the AT540 only in the filter assembly and in the Allison parts catalog they list a conversion kit as the replacement filter for the 540.
The only thing I am worried about is top end speed without an overdrive and the slip in the torque converter.
It is also killing some payload it weighs about four time what the SM420 weighs.

I cleaned the Allison really well with Castrol’s Super Clean, then took some acid wash, “the same stuff that we use for aluminum wheels and dump boxes” to it, that made it look like new. Now I am going to paint it with Dupli-Color DE1636 high heat engine enamel clear for that natural aluminum look the cast iron mounts were painted with DE1651 engine enamel cast iron gray the rest of the little exterior steel parts along with the parking brake will be gloss black except for the pan it will be Chevy Orange.
So far just a bunch of detail work but that is what will make this truck stand out. I hope to get the motor pulled back out so I can get it mated to the transmission today and get some of the firewall modifications that need to be done finished. Then I will start in on detailing the engine bay so I can get the power train mounted up for good.
I do need to find one of the Big Block Chevy front engine mounts used in the 70’s and 80’s two and three ton Chevy and GMC trucks if anyone has one to spare let me know please. I thought that this would be easy to find apparently I was wrong.

Looking good HH. You can't kill the Allison trans,but they are heavy. We had a AT545 in one of our wreckers years ago and it would snap your neck under full power.

Well all the painting on the Allison has had time to cure now and I am between jobs so I think I will try and mate the engine and trans together and slip then in place today.

BTW I may have the 56 GMC sold so that will help with the 56 Chevy project witch I think I will start calling the BULL DOG what do ya think all trucks need a name and this one looks like a bull dog

Well it is a good thing that I haven't gotten the motor mounts fit yet because today I found that the Allison transmission mounts will push the motor forward 1 1/2". I am hoping that I can still use the long water pump because the March Pulley set I bought was a grand and I don't have the boxes any more.

Ok mated the motor with the Allison pulled the grill out of the truck and slid the motor and transmission back in and put a strait edge a cross where the radiator will sit so I could see how much room I will have for a fan. Yheehaw it looks as if my heavy duty clutch fan will sit ½” from the radiator and the factory fan shroud should fit perfect as long as I measured correctly it could not have worked better. I now have enough room at the rear of the motor not only for the HEI distributor but I can run tall valve covers now. Then while I was surfing the net and stopped buy Speedway Motors I found this motor mount that will work perfect. http://www.speedwaymotors.com/p/6726,971_1...gine-Mount.html
This truck should be on the road about mid summer now that will be without the new paint and A/C of course.

Seems I have run in to a few more set backs. The Allison transmission has 4 tabs on it that hit the trans tunnel and will have to be removed no big deal there but I still may need to cut the floor board and fabricate a new tunnel or build a custom body lift (don’t know yet), as I didn’t realize how big this transmission is. Originally I thought this Allison was slightly bigger than a turbo 400, well looks are deceiving it’s a lot bigger and heavier for sure. With the transmission mated to the big block and hanging from the engine crane it becomes apparent how much heavier when I found that the balance point is right above the distributor, this transmission weighs as much as the motor, wow.
The starter that came with the Allison will not work with the headers I have either, however it appears as if a standard starter will work fine the only difference that I can see is the mounting on the one for the Allison turns the solenoid out away from the motor and in to the headers every thing else looks the same.
On a good note the new motor mount got here from Speedway Motors on Thursday, wow a day early that never happens to me. It looks like it is just what I the doctor ordered only a few little modifications needed here the power steering pump plumbing hits so I will need to clearance it there and there is a mount for the A/C pump from the March Pulley set -up that will need to be trimmed the thickness of the mount because the mount has to sandwich between it and the block as they bolt to the same place. At the ends of the new mount I will need to fabricate some small pedestals for the cushions to rest . These will fill the space between the bottom of the cushion and the cross member not a whole lot different than the factory Taskforce V8 mounts just a whole lot more stout.

Ok the Allison and motor are back in the truck looks like I Will have to make a 2 inch body lift so everything will clear it is hard to tell for sure at this point the mounts are not between the transmission and the cross member yet and their about an inch thick.
If I lift the body, it will take some body work at the front valance to fill in between it and the bumper. I will also have to make a longer brake actuating arm because the master cylinder is mounted to the frame and the pedal comes through the floor.
The front drive shaft will need to be shortened 10 inches making it only about 15 inches long. I would like to find some sort of overdrive unit for it that could be made to shift in an automatic mode with the transmission that would make it an eight speed and give me a decent top end without turning blinding RPM. This truck will have plenty of power so it would be nice to get a 65 MPH cruse speed out of it.
I should have pictures for you all tomorrow I had to come in to get cleaned up and eat so I can make it to Bible study and I have got a big mess in the shop I want to get cleaned up before I go snapping pictures out there I find it embarrassing that it looks the way it dose.

I have a 3" body lift on my 48, made spacers for radiator, and 3 cab mounts, and also move the running board brackets up 2" and a 1" spacer.
And the pedal assembly I was able to make a bracket to lift it up 3" as well, so pedal geometry stays the same.
If you lift the cab, and not the pedals, then you either put new holes in the floor for them. Or lengthen the arms so they fit the original holes, and also re curve the part that does come through the floor so it is the radius of the new arm length (so it stays centered in the hole through the entire travel).

Does a 15" front driveshaft give you satisfactory angles within the range of suspension travel? Would be a real bummer to find out that at full droop or stuff that you exceed the max driveshaft operating angle and it tears itself apart.

I can't think of an overdrive like you want, closest would be a US Gear or Gear Vendors unit, but they are not ideal for a big truck, even though they say it will work...
Now, the real answer is an OD transmission, which for an Allison you have to step up to a modern computer controlled one, probably a 3000 would be good and they can be had to work with a non computerized engine. Price would be a big factor though.

Awaiting pictures,
Grigg

Yah I know Grigg I think I will lengthen the brake arm and reark the rod that goes through the floor like you said.
As far as the front drive shaft goes it is fixed from the rear of the transmission to the carrier bearing

You said front drive shaft, and I was thinking 4X4...
That makes more sense now.

Grigg

After all that I have done with the Allison I may still take yet another turn. I found a Brown-Lip three speed auxiliary transmission with an under, direct, and an overdrive. This transmission originally came out of a little dump truck like mine. I am not sure yet I may put it behind the Allison but have a GM NP435 4 speed that I may use with the Brownie. Either way I will have the overdrive that I need, with the 435 it would make a true 12 speed or if I started with the 2 speed rear in low and shifted it to high after going thue the two transmissions it would be a 13 speed. Not sure about split shifting the Allison I think I would just use direct to get going and after the Allison hit 4th I would shift to overdrive making it a 5 speed the under drive would just be use for a low crawl speed. If I use the NP435 I will put the Allison in my 71 1 ton that I want to put a service body on and use for lube fuel and repair.

Well after scouring Spicer flange catalogs I think I have figured out how to adapt this Brown & Lipe 3 speed to the truck.
First let me explain that after I got this Brownie I was a bit disappointed do to its large size and the fact that the yokes and u-joints that it came with were even bigger with the biggest part being the enormous driveline brake that it had. After I removed that huge brake I decided that it wasn’t all that big after all, but I still needed a driveline brake and the yokes were still out of the question. Not being one to give up easily I set out on a research journey from hell first identifying what I had and then deciding what it was that I needed to make it all work. First off the yoke on the Allison uses a 1480 u-joint and the input to the Brownie is a 7 7/8” 8 bolt companion flange oh and the shaft is 1 ¾” 10 spline my first thought was to ditch the companion flange and find a 1480 series end yoke that would fit the shaft but during the search for that end yoke witch I did find I found that they also make 1480 companion flange yoke to mate to the existing piece on the Brownie. Ok that wasn’t too bad now I have the ability to build a reasonable drive shaft between the two transmissions with 1480 u-joints at both ends with off the shelf parts. Now I have to figure out what to do about a driveline brake and couple the Brownie to the rear end. The output on the Brownie has a very odd hub that mounts that very big and very ugly clubbed foot of a driveline brake and very big antique butterfly style u-joints. Well I didn’t want to buy a new driveline brake and I have many different transmissions with different brakes on them so after staring at them for what seemed like hours on end I discovered that the bake backing plate off the Allison will bolt right on the back of the Brownie **WOW**now if I can just find a 4 bolt companion flange that will except the brake’s drum and a matching flange yoke that will except either 1480 like the ones between the two transmissions or a 1410 u-joint like the one at the rear end I will have it made. A few hours with my nose in the Spicer catalogs and YIPPEE I found just what I need a 1 ¾ 10 spline 4 bolt companion flange hub that will except the brake drum and will center it perfectly on the shoes along with a matching yoke that will except 1410 series u-joints. So now as soon as finances will allow I will take my list of part numbers too my local Spicer dealer for the parts then off too the driveline shop to hook it all together.
I figure that if I start in under drive in the brownie and low in the rear end I can let the Allison run though its 4 gears hit direct and over in the Brownie and finally high in the rear end for an easy 7 speed with outrageous creepy crawly gears to get any load moving and an overdrive that will let me runn 60 mph.

Sounds like you have a plan. Glad those catalogs worked out for you.

You may need to save your money for a while longer than you expect.... The two 1610 series shafts I had made for my truck ran about $500 each, all new Spicer brand parts, professionally assembled and balanced. The companion flange for the transmission was pushing $300.

Grigg

Yeah the drive lines I had made for the 64 ran about the same I expect too have a good $25,000 to $30,000 in this truck when done. The project is sitting at about $15,000 now but I got a ways to go paint and body will be costly but a comparable new to two year old truck goes for $40,000 to $60,000 around these parts and they don't have near the cool factor.
BTW thanks for your help Grigg.

Well haven’t done much here for a while been busy with other stuff.
I have been thinking about doing some modifications to drop the motor and trans down into the frame rails a couple of inches as the Allison transmission causes some serious interference with the firewall and floor boards. I had thought about lifting the body but that opens a few cans of worms that I don't want to deal with. I also thought about modifying the firewall and floor but have decided against that as well.
In order to lower the drive train I will have to notch the front cross member to clear the crank pulley and build a dropped cross member for the bell housing.
Well time to get busy and stop talking about it wish me happy fabricating

Happy Fabricating!
Don't forget the pictures,
Grigg