LMM: converter lock up

gary25

gary25

New member
Mar 1, 2014
5
0
0
hello i am new to this forum and new to the duramax world,,well to start it all off i do a mixture of city and highway driving.. i do alot of driving at 70km/h and the truck is hard on fuel with up and down rpms.. the converter locks up in 5th gear at about 80-85mph and shifts to 6th with lock up at about 100km/h this is enoying..while driving at 70km/h it is in 5th gear but no lock up, to lower my rpms soon as i go over 80km/h lock up.. but i can not maintain that speed.. is lock up suppose to happen at a lower speed or is there something i can do to fix this... help would be great

thank you
gary
 
JoshH

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,636
678
113
Texas!!!
You swap from MPH to km/h in your post. Are you saying it locks at 80-85 mph or km/h? I'm assuming you're talking about part throttle here. Is that correct?
 
gary25

gary25

New member
Mar 1, 2014
5
0
0
ya sorry guys i mean km/h it locks at 80-85km/h..yes part throttle while cruising on the road at 70km/h it is 5th gear but no lock up and rpm are over 1500-1600 slight hill gos up to almost 2000.. go over 80/km lock up accures and rpms drop to 1200-1300 but i cant hold that speed as the road is rough,and winedy .....not sure if the 5 speeds are different then the 6 speeds..not going to run in tow haul already tested that ya lock up happens but you stay in a lower gear which causes higher rpm turn off tow haul tranny shifts to high gear.. not worth running it in tow haul,... already hard on fuel as it is.. would be nice if lock up turn on in 4th gear at a cruise or even 5th with a lower speed allowance...
 
mike diesel

mike diesel

I'm alright.
Sep 6, 2012
4,005
0
36
SLC, Utah
gary25 said:
ya sorry guys i mean km/h it locks at 80-85km/h..yes part throttle while cruising on the road at 70km/h it is 5th gear but no lock up and rpm are over 1500-1600 slight hill gos up to almost 2000.. go over 80/km lock up accures and rpms drop to 1200-1300 but i cant hold that speed as the road is rough,and winedy .....not sure if the 5 speeds are different then the 6 speeds..not going to run in tow haul already tested that ya lock up happens but you stay in a lower gear which causes higher rpm turn off tow haul tranny shifts to high gear.. not worth running it in tow haul,... already hard on fuel as it is.. would be nice if lock up turn on in 4th gear at a cruise or even 5th with a lower speed allowance...
Click to expand...

Sounds like your trans is doing exactly what it's supposed to do. If you change lockup to an earlier speed/gear on part throttle driving...i dont you will like it. Low speed and lockup will result in a very unresponsive truck especially on a rough windey road.
 
gary25

gary25

New member
Mar 1, 2014
5
0
0
thanks for the response... glad its doing what its suppose to do,, but is there a way i could change it to see how it responds to different driving
 
T

TWINDBLACKLMM

New member
Feb 13, 2013
33
0
0
lock up

Converter should lock up Just past 50mph. Not sure what that is in kmh. Tire size will have an effect on that if you speedometer hasnt been recalibrated.
 
gary25

gary25

New member
Mar 1, 2014
5
0
0
ok so never mind my speedometer was off due to my over sized tires i reprogrammed my truck so now its dead on but the torque lock does not activate until 93 km/h... at 80km/h my truck is over 1500rpm someone please help me
 
gary25

gary25

New member
Mar 1, 2014
5
0
0
it should be locking at 83km/h so frustration im running a mini max and has been reprogrammed to run 38s
 
plowboy_lbz

plowboy_lbz

Farmer
Aug 6, 2013
431
0
0
Ne-max said:
It shouldn't. :thumb:
Click to expand...

Used to lock in 5th around 45 mph (about 1500 rpm) with stock tires (and stock tire size program), now with bigger tires it locks up at about 50 mph with 33" tires still locks at same rpm just different mph. Both truck do this. Also had other tuners tune it and lock up is the same.
 
You must log in or register to reply here.
Top Bottom