LB7 LML Allison Swap Results

Have had the LML Allison in the 02 Duramax for a few months now with zero issues truck has been performing great and making trips from North Ga to Florida and back 5 times now as well as a lot of normal around town driving. Have done a decent amount of hauls with the 4 horse as well as the 30' goose neck and enclosed motor cycle trailer all have shown great results with the way the transmission shifts and keeps cool most of the time it wont go over 165 degrees.

Here is a log from around Christmas when I was playing with the lockup on the stage 2 converter don't mind the oil pressure I have to replace the connector.

This Project has been fun and im always improving on what I've learned and how the driver wants the truck to react. Milage is around 18-22 city and 24-26 hwy around 70 to 80 mph Engine calibration is spot on and has not limped the LML trans yet. Even on hard pulls the truck is all there vs the stock calibration it originally had pushing the lb7 to around 3800 to 4000 RPMS and it pulls hard when asked to.
Normal driving feels as good as my uncles 2015 LML which is surprising considering that truck is 13 years newer. But it just goes to show when you have the parameters set the way they need to be old vehicles can run as good if not better than new vehicles and not need all the stuff the newer visions require to stay legal.


Next time Im out in the truck Ill record another new log with all the current updates to the trans calibration and engine.

I am really considering doing the 6 speed swap to my LLY. I posted in the other thread and had some questions for you. Thanks for sharing.

For sure ill add some more info and logs as soon as i play with my little brothers truck again. I also have to finishing wiring up that LML transfer case have all the stuff and a gen 1 and gen2 transfer case module to see if I can use the newer version with the 02-07 4wd switches should be fun love wiring lol.

I bought today a 02 allison to put in my 05 LLY. Need to know what valve body to find and what wiring needs to be done along with config files when you get time please.

You need to get either a 11-19 VB or a 06-09 either can work I have an extra LML VB and harness if you are interested. I could set you up with the complete drop in package and tcm to go with it or send you a flash file once the correct parts are installed. PM me for more details I’d be happy to help you out.

Our truck is doing great just added some more power to it and everything is working out great.

Come to find out a couple people are claiming you might be able to use a 17-19 VB which can save some money msrp from gm is $700 for the 11-15 VB and only $375 for the 17-19 VB not sure why the price difference is, but it should work. The 2 valve bodies seem the same to me & look identical. There isn?t much info on the newer valve bodies other than they now use a main modulation solenoid like the gas autos have. My personal opinion is right off the bat buy the blocker for that solenoid and it will make a huge difference as well as the calibration needs to be set to the specific truck. The one cal fits all is never gonna be perfect it will work but there are always be improvements that can be made on it as with all things.

You will still have to make modifications to the internal harness for the VB to function properly but this is the main starting point to making the 5 speed transmission a 6 speed

Also if you have a 01-03 Allison you will not need the shorter front right bolts. But the 04 and 05 guys will due to the g solenoid plate it will damage the case using the longer bolts in that VB in the front right.

If anyone needs help just let me know have done a few of these now and can try to assist. But I will say the calibration is everything or you?re gonna burn up your C3 clutch.

I also suggest the C3 oiler modification and PTO covers that direct the extra oil to the C3.

Here is the blocker for the 2010 and newer VB and the C3 oiler modification as well as the proper jig to do the oil redirection mod.

I?m still not 100% sure the 17-19 VB will work so I don?t wanna say I?m sure it will but I do know the 10-15 and the 06-09 Will work with no modifications to your 01-05 LCT1000 cases.

People might think it?s a 17-19 VB but unless they can confirm the part number on the valve body I can?t guarantee that will work.

One other upgrade while you are playing with your Allison might be to upgrade the torque converter I will say I have had 2 florida torque converters 1 their stage 1 and the other the stage 2 they have held up great and hold the torque without any issues. We regularly are shifting the trans at around 3800 to 4000 rpm’s and pulling decent size gooseneck trailers up good size grades in north ga and have never had the trans get hot usually on the highway it stays around 150 to 160 degrees and the highest I have seen in that truck is 185 to 190 in heavy stop and go traffic.

As for a stock update to the converter you can do the 11-16 oem muti clutch converter it will help with economy and hold the torque better than the weaker 01-05 units that came in the hds at the time.

Have you had to change anything pressure wise anything in the file to run the newer valve body?

Absolutely if the adjustments are not properly made the clutches will start to slip and you will eventually have a bad day a a ruined Allison 1000. Its a delicate balance with this transmission and its programming especially on these older TCM's. The power level of the engine you need to take into account as well as ay modifications you have made to the transmission. Stock this transmission is one of the best light duty diesel tuck setups & one of the most durable, its once you start to add power to the engine that it can start showing premature ware if the calibration is not spot on. Also wat to add every truck is different truck A might need something that truck B might not and vise versa.

Our D-max is actually going on another Florida haul tomorrow Ill ask my little brother how it does with the current calibration im running in the truck. I took a ride last week with him for some logging ad I have to say the truck is feeling great. The shifts were firm yet smooth depending on the pedal position. Hwy driving was near perfect as well as the stop and go city driving I really like the Duramax and all it has to offer especially for a older truck.

Now if we could just get HP Tuners to give us a selectable shift on the fly set of calibrations it would be one of the best platforms in the diesel world just such a reliable truck.