LLY: Couple of issues?????

jbullet1

New member
Jul 4, 2010
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EASTERN WA
I bought a 04 3500 ,cc ,lb, lly ,allison tranny ,and edge juice and attitude moniter with 250,000 miles about two months ago. I tow a trailer every day to work that wieghs about 7000 lbs. When in tow-haul going down hill at about 45 to 50 mph it shifts down and rpms go up to 4000. Is that normal for this truck? Because it scares the crap out of me when it happens. Then when going up real steep hills egt gets up to 1350 and motor heats up to around 230. Is this something i should worry about? Never had this problem in other diesel trucks i have owned.:confused::eek: THANKS ABUNCH!!! GREAT WEBSITE!!!
 

darkness

Well-known member
Jul 15, 2009
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The downshifting in t/h is the grade braking doing its job. 4000 might be a little high but I wouldn't worry about it. And getting hot up hills was a common problem with the lly motors. There has been lots of info about cooling them off and you can do some searching for that. As far as egt's you can set your attitude to keep those down if you want but I always ran high egt's with my edge pulling hills on level 2. I think I had my limit set to 1450* but I never hit it.
 

darkness

Well-known member
Jul 15, 2009
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P.s. What else is done to the truck? Exhaust and intake will help lower your egt's
 

jbullet1

New member
Jul 4, 2010
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EASTERN WA
It has 4" exhaust and every thing else is stock as far as i know. This is the first truck i have had with any mods on it and also first chevy. I like it so far just need to get all the bugs worked out.:thumb::thumb:
 

Burn Down

Hotrodder
Sep 14, 2008
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Boise Idaho
I remember the first time the grade braking kicked in on my truck, scared the crap out me to, thought I just blew it up. Lots of talk on the overheat issues & the LLY. Some say that putting a LBZ turbo inlet on helps, if you ever compare a LLY & a LBZ there is a huge difference in size between the two, cheap mod and can't hurt. I can tell you twin turbo's will cure your egts & high water temp, but the transmission will hate you!
 

jbullet1

New member
Jul 4, 2010
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EASTERN WA
I had a 07 and 08 ford with the t/h tranny but the rpms never went into the red. Just don't want to blow up motor i need it to last awhile.;);)