I had Brayden fleece reprogram the stock allison computer almost 3 years ago. I believe it was the first one he did, and I`v been satisfied ever since. the stock `puter up shifted at 2200 rpm at full throttle. he set it up to shift at 3200 rpm, and the tow haul works really well. he said he could put any shift rpm in the program, what ever I wanted. hope this helps:beer: :beer:

 

What did you use for a wiring harness?

 

I got a wire harness from the wrecking yard. it was from a chevy with the 8.1 gas engine and allison 1000.One from a duramax would work too, but this was the only one I could find. took a while to seperate the allison plugs and wires from the engine harness. I got a wire schematic from the allison dealer to see what wires I really needed and how to hook up the in puts and diagnostic plug. gotta get that from allison. I also had to get 2 plugs and plug-in resistors for either end of the "can bus" wire assembly that the diagnostic plug is wired to. also allison has the best T.P.S. it`s cable operated, weather proof, and is cheaper than the ones by tcs or jet. it is not a rheostat type but a sliding wiper setup that is dead smooth through all of its travel. get the install directions from the allison dealer.the TPS is the only connection that is on the engine, the rest of the chassis inputs are 12v+, 12v -, Tow haul switch and light, 12v switched. I added a 7 fuse water proof fuse block from pain less wire to have the trans electrical seperated from the truck fuses. hope this gets you on the road to recovery.:beer: :beer:

 

I am still waiting on the 6spd computer from brayden but he says he is working on it so we will see. I got tired of hearing about the connectors for the wiring harness they are waiting on from destroked.

You do know your going to have to build the allison up to reliably handle 600hp right? You will burn the clutches up on the 5 spd with around 300-325 rwhp and 400rwhp on the 6 spds (these are general estimates but are very typical from most duramax owners). You will need new clutches and steeles along with a good converter at minimum.

 

What does braydon's trans need done in order to make it a 6 speed? Does the valve body need droped?

I am building a stage 4 suncoast kit. Any more info would be great.

 

Ok, I talked to Braydon today. I am now leaning towards the 6 speed. Now here is the next problem. What gear ratio? I have 3.42 3.73 & 4.10 ring and pinions already, so I can choose which ever one I want to put in. According to Randy,s a
3.73 .61 DOD at 70 = 1691
3.73 .71 OD at 70 = 1968
4.10 .61 DOD at 70 = 1859
4.10 .71 OD at 70 = 2163
If I stuck with the 5 speed, than I would go with a 3.42
3.42 .71 OD at 70 = 1804
What is the best crusing RPM? The truck will be a daily driver and towing up to 20k from time to time.
Thanks for all your help.

 

I would go with the 3.73, being that its a 6 cylinder you will have plenty of tq to pull that weight with them and they will cruise better than 4.10 but thats just my opinion.

 

More Allison questions

Hey guys, I am 99.9% certain about going the Allison 6speed route as well. Where (or who) did ya'll get your torque converter from and what stall speeds are you running. I assume you had to have one custom made for the stall speed for the cummins. The problem is that I don't need a high dollar billet torque converter costing an arm and a leg and all the aftermarket ones I can find are beefed up for gobs of output that my little 4bt won't be seeing. Also, Is the output from the allison a 29-spline, if so, I need to try to find a coupler for my NP 205 Tcase I plan on running (32-spline female input). I know I may have to clearance the oil pan for the front drive shaft.

 

i have been friends with brayden and a guinea pig on the allison. I have been running one for 4 years now with now problems. I had a twin turboed 800hp motor pushing it. A stock allison with a transgo kit will handle 500hp. His stuff is good quality. You will want at least 4:10 gears if you opt for the 6 speed. The rpm's would be too low if you had less of a gear.

 

my 06 duramax cruises at 1700rpm with 33" tires 6spd allison and 3.73 gears.

 

Cruises at what speed? 70 I'm guessing??

Gear calculator

 

I talked to the Allison folks at the big trucking show in Louisville last weekend.. and learned a lot.
I inquired about installing the newer computer controlled Allison's on mechanical engines (as they did for some Cummins in Freightliners).

The short answer is YES, you can do it, and it's not that difficult, or so the dealer (from Decatur, IL) says.
They told me the only sensors needed are for engine RPM, like from a hall effect sensor on the ring gear used for a normal tachometer, and a throttle position sensor, and Allison sells a nice one of those.
The rest of the computer and wiring you need comes with the transmission you find, or for big bucks you can buy new stuff.
The dealer I talked to assured me that they could wipe clean the existing computer and reprogram it to work just right for my application. (or could buy a new "blank" computer for them to start with)

He cautioned me that the right torque converter would be very important in a working truck. One form an engine with similar operating characteristics is what to look for, or again they could help spec a new one to work as it should. He did say if you didn't haul much then just about any converter that fit would be OK.

In my case for a Detroit he said the new Allisons will physically bolt where an older style was. For example I could use the flex plate/torque converter drive from a 53 series Detroit with a MT653 or similar Allison to adapt a new 3000 Allison to a 53 series Detroit.

Again, I haven't tried any of this, but the Allison dealer did confirm what I have already been told, this is not impossible like so many folks think. Actually sounds easier that I had thought.. I don't know what he would charge for the reprogramming and tuning, but he did seem eager to help with such a unique and interesting project.

On another note, if the 1000 series Allison isn't strong enough then they do make bigger ones. But the next physical size up, a 3000 weighs 535 LB; which is 200 lb more than a 1000/2000. Has anyone stepped up a size, or is it better for some reason to throw money at the small ones?

Grigg