johnsmack Posted August 20, 2015 Share Posted August 20, 2015 ok here we go. a month ago I bought a 2005 cxn613 with the 460 and 18 speed. after 3 weeks in the shop getting wet kit, replacing broken springs, bad wheel seals etc. I got to move some heavy equipment. The hoes and dozers I am moving put me at a gvwr of 90 to 95 thousand. Living and hauling in west central Illinois we have hills but nothing huge. I have a mack tandem with 350 mack and a super 10. Grossing 75 to 80 we down shift once on "the hill" when moving smaller machines. With the new setup [460 mack grossing 90 to 95] we had to down shift twice. What should I expect? Turbo boost maxed at 25 psi when pulling the hills. Someone tell me what is normal. .Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/ Share on other sites More sharing options...
carlotpilot Posted August 20, 2015 Share Posted August 20, 2015 not knowing the top end of the truck with an 18 i`d say droplng 2 gears on a grade with 95 grand would be close to normal 1 Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-300760 Share on other sites More sharing options...
Dieselwrenches Posted August 20, 2015 Share Posted August 20, 2015 25 psi is very low on pulls. Should be getting 35 minimum on big pulls. Check cac, cac boots. What's exhaust temp.? Smoke? Codes? Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-300781 Share on other sites More sharing options...
Dirtymilkman Posted August 20, 2015 Share Posted August 20, 2015 25 psi is way to low. Mine pulls 40+ Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-300792 Share on other sites More sharing options...
david wild Posted August 22, 2015 Share Posted August 22, 2015 Our 460 runs 35 to 40 lbs. of boost also. We pull 400,00lbs all the time with no problem, if your pup can't handle 95,000 you got a sick dog. all so depends on gearing but I'm sure know that. Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-301034 Share on other sites More sharing options...
johnsmack Posted August 22, 2015 Author Share Posted August 22, 2015 Next question, Dealer says 20 to 30 is normal boost. Have the trucks that are getting 35 or 40 factory original or have they had some enhancements? The truck does seem geared high, it runs 60mph at 1250 rpm in 18. I seem to be in 16 or 17th gear at 1800rpm at the bottom of the hill. then drop 1 or 2 gears to get to the top. 1/2 mile long hill medium grade. Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-301057 Share on other sites More sharing options...
Dieselwrenches Posted August 22, 2015 Share Posted August 22, 2015 20 to 30 can be normal for factory but not max boost pressure from factory. Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-301059 Share on other sites More sharing options...
Dirtymilkman Posted August 23, 2015 Share Posted August 23, 2015 They told me 38psi is the top spec. But mine would tap 41. With stage 2 injectors it'll just go over 44 Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-301074 Share on other sites More sharing options...
RedBullDog Posted August 25, 2015 Share Posted August 25, 2015 Boost is a little low for 460. Seems like it might be a little long legged for heavier loads. What rear ratios does it have? Also is it a Mack 18 or a Fuller 18. Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-301388 Share on other sites More sharing options...
460P Posted August 26, 2015 Share Posted August 26, 2015 What is your fuel pressure from the supply pump? If you're not maintaining 70 psi your pump is weak, or you have a bad check valve. Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-301582 Share on other sites More sharing options...
johnsmack Posted August 26, 2015 Author Share Posted August 26, 2015 (edited) its getting a reman tranny this week. not concerned with power at this time. we we recover from new tranny expense we will revisit the power issues. its a mack 18 thought synchronizers were bad but had a broken gear as well. don't like used trucks. Edited August 26, 2015 by johnsmack Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-301591 Share on other sites More sharing options...
johnsmack Posted February 15, 2017 Author Share Posted February 15, 2017 well its been a while but i am back. we got the tranny rebuilt, and then a new turbo as well as 2 eup pumps, I think that was what they were called. Power is still lousy although the turbo made a difference. The boost went from 20 to 35. Moving identical weight loads my 98 tandem with tag trailer at 350 hp will catch the 460 hp semi on a hill. I have noticed the pyro meter will only reach 600 degrees after a long pull on a hill with 90,000 pounds. Filters have been changed (is it ever that simple). Miles are at 620000. Where do we go from here? I am ready for the ":it's like a new truck experience". Any suggestions? Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-361788 Share on other sites More sharing options...
fjh Posted February 15, 2017 Share Posted February 15, 2017 (edited) Still needs fuel add as mentioned 70 psi under load min! after that injector up grade! Edited February 15, 2017 by fjh Quote Link to comment https://www.bigmacktrucks.com/topic/41430-05-mack-460-18-speed-power/#findComment-361804 Share on other sites More sharing options...
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