I just got back from a short trip hauling a 5000lb travel trailer, the truck is a deleted 08 6 speed auto with a smarty jr, had the truck set on sw2 torque 3 and timing 3. Got a shudder from the tranny or maybe the rear end on an uphill pull rpms around 1300 in 6th gear. The shudder stopped as soon as the tranny shifted down. Pulled over and set torque and timing to default (stock I guess) and kept on going. Again the shudder occured under similar conditions only a the shudder was less than before. Pulled over again and set the program to sw0 or standard I think it said, timing and torque at default as well, no problem. After parking the trailer at camp I returned the truck to sw2 torque 3 timing 3 and went for a rip, everything seems fine. For the return trip home I kept the program on sw0 timing and torque at default, no problems afterwards. I guess the added horsepower was too much for the stock transmission while towing and the shudder was probably not good things happening inside the tranny. Are there any mods or affordable upgrades that can be done to the stock transmission?

 

I manually downshift mine before the computer does, stopped the shudder for me

 

I also tried downshifting first which did stop the shudder from happening, but figured it was probably better to run stock settings while towing.

 

You can run the SW3 but the higher torque setting will make the Torque converter shudder at low RPM at it removes torque management for those low rpms. If you run it down to 1300 loaded you are running low transmission pressure and will cause more damage than just the torque converter. Keep it at least over 1500 and use the shift selector in T/H mode all the time to keep the RPMS in that range. I usually downshift before it decides too as I don't want to lug it.

 

Thats good advice, I allways run in t/h mode to try and keep rpms between 1500 and 2000 but the truck does go to under 1500 if I don't step on it. I'll use the shifter a little more often while towing.

 

Most times now when I come to a stop there is a short vibration from the tranny maybe when its shifting from second to first. This also happens from park to drive. What causes this and can something be repaired in the tranny before I need to replace it? The truck is an 08 3500 6spd auto with 174,000 km.

 

1300 rpm under a load seems to be where the torque converter is least happy under normal driving conditions.

For unloaded driving H&S' transmission tune did wonders on my truck. When towing I still have to keep an eye on the rpm's when I get to a hill. Most of the time unless I'm on the interstate I leave it in 5th.

I was running mine on sw7 for a while. Right now it is on sw7 pod 75%.

 

Just looking at a pressure lock. Anyone else have one these?

 

BD diesel sells a pressure lock, it's just a cable to swap out on the tranny and it's supposed to increase the pressure in the tranny to prevent slippage.

 

How does the pressure lock Work? Anybody use one?

Booty

 

this is all I know

 

Anybody know what it costs to replace TQ converter?