I was at first told my C4500 has a LLY. However, the paperwork says I
have an LRX. What's the difference? Also, I know that they are not
putting exhaust brakes on LLYs. However, they are offered as an option
for the C4500 and Pac Brake offers one for the medium duties. My
dealer, however, says that GMC told them that the use of an exhaust
brake would compromise my warranty.



I am so confused...http://www.dieselplace.com/forum/smileys/smiley5.gif

IIRC the LLY is only used in the 3500 and down. LRX is used in the 4500's...as a matter of fact I just pulled this of my on-line ordering guide:

LRX: 300 hp (223 kw) @ 3000 rpm, 520 lb-ft (702 N-m) torque @ 1600 rpm - Maximum engine speed 3250 rpm.

Basically the same engine, just not rated for 310hp and 605 lb/ft like the LLY is. You do, however, get a wider range of rear differential choices.

Hope this helps http://www.dieselplace.com/forum/smileys/smiley1.gif

Thanks,



Does your ordering guide say anything about an exhaust brake on this
model. I heard rumor that there may be a different turbo on the medium
duty but can't get this confirmed.

Yes,a factory exhaust brake is available.

If I understood another post correctly, the MD trucks ie. 4500's the power/torque numbers are at the rear wheels. On the 3500 and below they are at the crankshaft.

The build sheet for my C4500 codes it as an LLY.LRX may be the 210/520 lbs torque before build date of 1/04..JB. Edited by: 4500/LLY

LRY 210 hp (156 kw) @ 2750 rpm, 520 lb-ft (702 N-m) torque @ 1600 rpm - Maximum engine speed 2900 rpm.

LRX 300 hp (223 kw) @ 3000 rpm, 520 lb-ft (702 N-m) torque @ 1600 rpm - Maximum engine speed 3250 rpm.

These are the two engines that are available on the 4500's for 2004 and 2005. The ratings are at the crank just like the 3500's and 2500's. The LLY is NOT available on the 4500. If you think you have any LLY in your 4500...you dont. http://www.dieselplace.com/forum/smileys/smiley19.gif

These are copy and pasted from my online order guide from GM.

LLY was available in the 4500. Same engine with different tunes also available



Current offerings: http://www.chevrolet.com/medium_duty/kodiak/c4500/engine.htm

I have an LLY in mine.....option code says it is....LRM is....JB.

Thanks Bartman.



My build sheet also said LLY, but no price next to it. The next lines
says LRX, 300/520 with the option price. Perhaps the LRX and LRY are
"versions" of the LLY for medium duties.



Now, if I can convince my dealership as well as Medium duty customer
service that I can put an exhaust break on this...............