CDN SS

iTrader: (1)

I have a 04 Silverado 5.3 RCSB factory tow package trans cooler etc truck has only 12 k on it and I will be starting to tow a 22' enclosed car trailer .7000lbs just installed a Transgo Hd-2 shift kit and vette servo in it ...... just completed 1st tow .......800 miles hills and wind and flats ........lots of power but trans would rarely tow in OD unless at 55mph or lower .........what is correct way to use tow/haul ?? with shifter in D or 3?? I would like to tow at65mph which would be about 2400 in 3rd with converter locked up I think 265 tires 3.42 rear .......I tried leaving in Tow /haul and 3rd .worked fine but i did notice when I needed tp pass or go uphil downshifted real easy but would rev to 4k I would excpect it to shift but just stayed there had to back off throttle to make it shift .......ended up driving in 3rd with tow haul off was alittle better mileage was not good ......... assume I should be towing in Tow/ haul all the time .does tow / haul lock out OD and does t/h lock up the converter sooner ?? as you can see I need a better understanding of how T?H functions and converter lock up when towing ........can you make changes to the pcm that will adjust converter lock and or OD engaement that would be beneficial ?? I have a trans temp guage and on this trip temp never went above 170 and a low of 145 .......

xsports33

iTrader: (1)

One of the first things i would do if you're going to be towing often is get a bigger aux transmission cooler on there. Also, 3.42's suck for towing. Might want to consider a re-gear.

If you can tow in OD without your transmission dropping down into 3rd or even 2nd and keeping the TCC locked, such as flat straight land, then do it. If you're dropping in and out of OD and unlocking the TCC a lot i would hit that tow/haul button. If you're still doing it drop it down into 3rd and use the tow/haul function. Your TCC will still lock up in 3rd. t/h changes your shift point and possibly line pressure (not sure though).