03sierraslt

iTrader: (22)

It shouldnt but it most certainly can, I would swap the wheels and find out for sure. Another good point mentioned above, what is your RPM drop when this happens around 60mph? Are you sure it is not the converter locking and unlocking? Transmission settings can be very picky depending on how close certain tables are to each other.

2doorfury

iTrader: (12)

About a 300-500 rpm drop. I'm guessing converter is unlocking..what reason would make it lock and unlock when it gets to a certain speed?

03sierraslt

iTrader: (22)

Speed and throttle position is what make it unlock, if your tire size is off in tune and the threasholds were already close then that can happen. Swap the tires and try it.

2doorfury

iTrader: (12)

Thanks guys! I'll go give it a try

AKlowriderZ71

iTrader: (22)

It's a tune adjustment. Unless your trans is slipping.

2doorfury

iTrader: (12)

Just got back from a drive. I left the 275/60/15 nitto 555's on. Did totally fine until the trans temp went up between 120-140. It feels like it gets stuck in 3rd. I can go from D to 3 and no difference. Then go from 3 to 2 and it'll go in second. but go back to D and it just whines out until I get to about 30, or when the gear catches up with the speed of the truck. If I shut the truck off and let it cool down, it'll go back to normal.

2doorfury

iTrader: (12)

Any ideas why it only does this when tranny warms up?? Its not even getting near operating temp really 140 is the most its got. I doubt it'll be drivable when a 80* days comes.

2doorfury

iTrader: (12)

Trans and converter are brand new with 1000 miles on them. Rpm stage 4 trans and a yank 3600 SST stall

PaulyC

If you are heating your trans up past 160* on the regular theres something wrong. So by you saying it only got to 140 isnt good, that should be full operating temp. What speed and rpm are you going to when shifting from d to 3? if you really didnt have 4th the mil would be lit.

03sierraslt

iTrader: (22)

140 is not full operating temp...