What does the LLY mean?
 

2005 Allison Transmission, 5-/speed, Automatic with an LLY Designation

LLY was the engine generation designation, I'm not up one which one was the "good" one.

Correct. LLY typically means I Lost my Little Yellow coolant as the 04.5-05 LLY's had cooling issues. The LB7 in the 02-04 proved to be a very good motor just light in the HP/TQ side but mileage was excellant. The LBZ in the 06-07 was a really good motor too and you got the good mirrors stock. I haven't owned or been around the new LMM though.

Well,I don't know from engine designators,but the craigs list ad I was looking at

2005 Allison Transmission, 5-/speed, Automatic with an LLY Designation

Duramaxx

Only 5,000 miles on this '05 Allison Transmission. Serial #: 8320583122, (6320S83122) Model #: 1000PK. Excellent Condition, OSE17. Located in Glen Ellen.
as I am still on a quest to replace my AT 542 with a 5-speed.

Well, that would be a good one, get the PATC block adapter and I am not sure which one, but one of our members did the computer.........

I think LBZ is the good one (and maybe LLY 2006 and later)

http://en.wikipedia.org/wiki/Duramax_V8_engine

~Rob

iroc,
The LLY designation is the engine designation. LB7 01-04, LLY 04.5-06, LBZ 06-07, note 06 LLY's have the same internal upgrades as the LBZ motors, just a LLY ECM, less stock power.
Looks like you're looking at just a Alli trans for sale. AFAIK the 5sp Alli's are the same, but the TCM's are different for different engine designations.

LLY has EGR where the LB7 did not. That coupled with a smaller intercooler made for cooling issues.

LBZ is the good one. More power, and I think the later versions of the LBZ had the Allison 6 speed. LLY powered trucks have a 2 as the 8th digit of the vin, LBZ powered trucks have a D as the 8th vin digit. Almost bought one a while back, did a bit of research. LLY is something like 50hp more than the LLY, no regen/urea garbage like the latest models. It's the one to have if you gotta have a Duramax.

LLY did have cooling issues but did not have the injector issues of the LB7.

Thanks for all the replies.Grit-Dog you are right as all I want IS the transmission itself and the tcm and the cable and the speed sensor and whatever else I need to r&r my at 542 with an Allison 1000.I really need/want /desire a 5spd with lock up converter.I also unnerstan that I MIGHT be able to have this programmed as a 6spd?
Since this came out of a Duramax...I do need to change the bell housing and torque converter,right?

I don't think you can change the Bell, but I'm no Allison expert.

If you can't. PATC makes a nice block adapter for $1,390 that includes the flexplate.

Dunno about the bellhousing. I don't think the TCM from the GM truck will work standalone, remember guys on dieselplace.com talking about standalone TCMs for Alli swaps.
You can convert it to a 6speed, kit is expensive and it's not just programming, again from what I read.
Go to dieselplace .com and ask your questions. There's a bunch of Alli geeks over there.

You need to talk to destroked.com. They have an adaptor for that. The PCS trans controler should work for that also.

Randy

LLY is the 310hp/605tq Dmax. I have an 05' Dmax with 201k miles on it and get steadily over 20mpg. Its been very reliable. The intercooler is NOT smaller than any other year. It is actualy better than the later LBZ intercooler because it has aluminum end tanks, no plastic crap. The #1 reason for the turbo lag and running hot issue is the VERY restricted turbo inlet. Right in front of the turbo the intake actualy chokes down to about 2.25". Can you imagine a turbo trying to suck air thru that? As it tries to pull more air and build more boost the exhaust closes down to spool harder. Both cause the EGT's to rise high. In stock form at WOT I could easily get over 1400*. While towing the EGT would stay over 1300* on any sort of grade.

Now with 5" turboback, intake, EGR delete, and Juice w/Attitude my EGT is nice and low. On level 2 (tow) pulling a 12k travel trailer thru Colorado in late June my max EGT was about 1150*, and held 75mph up 6% grades without downshifting. My trip total MPG towing 75+mph was 13.5mpg. Overall the truck has been amazing.........