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I've had great success fine tuning the shift points to my liking but am experiencing one frustrating issue.
I can’t seem to get the 2-1 downshift as slow as I want it in light throttle situations. For clarification, I'm trying to delay the downshift.
Is there a “floor” to the speed you can program a downshift?
in my experience, i havn't found any "floor" to the down shift limit on the 2-1 shift points, but.. i have found when too low the transmission has a hard time making the shift with little vehicle speed or RPM. it ends up preforming the shift when you are almost stopped and it kind of bumps into 1st gear with a little jerk to the truck. have you tried putting "0" in the appropriate cells in pattern A of {D5005}?
Thanks for the reply.Quote:
Originally Posted by LB72004
WRT D5005, yes.
I've experienced the less-than-smooth 2-1 downshift (very rarely) exactly as you describe, before and after my transmission build, and before modifying shift points so I think it must be related to the shift valve.
My objective is to carry 2nd gear around slow speed turns and over speed humps exactly like you would in a standard shift transmission.
I'm very close to the objective but still get an awkward 2-1 downshift (once in a while) just as I touch the throttle to carry the same speed or accelerate very slowly. This is with zero MPH programmed all the way past 25% TPS.
Of note, I found H0136 "Tire Revolutions Per Kilometer" to be in error due to tire size change so I'll have to try a correction to that next.
I used to have for a while the shift patern E for when the shift selector is in 2nd set to 0 mph for the 2-1 down shift. I used it as you described, slow speed driving, speed bumps, dirt roads, etc. Anywhere you dont want it constantly shifting on you while moving slowly
Worked good but i changed it because I started using the "tap shift" fuction for towing more and it still bumps into gear when coming to a stop, so i put it back
PS: i did notice that before i got my 5 speed on my 04 built i could program it for 1st gear delete and it worked great with no problems bump shifting. Afterwards it would bump shift. Wonder if it is because of the more aggressive clutchs
Interesting, I haven't even looked at pattern E.Quote:
Originally Posted by LB72004
No change after the correction.Quote:
Of note, I found H0136 "Tire Revolutions Per Kilometer" to be in error due to tire size change so I'll have to try a correction to that next.
I would not make any changes to the tire size settings or gear ratio in the transmission. Make the changes in the ECM if you need to correct anything tire related