Ok let me explain whats going on.(2006 ram 1500 slt ext. cab 4.7L 4wd auto) My transmission has no problem with shifting and no weird noises or anything. But when i come up to a hill and the trans is in drive, sometimes it will feel like the clutches slip for a second. Then it will down shift and its fine. It only happens when it tries to pull a hill at rpm's lower than 1800ish. This gives me the assumption that at that rpm i just dont have enough pressure on the packs. I know i could just floor it at every hill to make it downshift before this happens but i shouldnt have to and ive resorted to riding around in tow/haul mode a lot. I just want to know if other people have experienced this and is the diy resistor like the sonnax is a good fix for me. Thanks for any input

 

Sonnax only works at WOT and up shifts. Not sure it does anything for downshifting.

 

Maybe a fluid and filter change

 

I'm thinking a Superchips with transmission tune option. Firms the line pressure quite a bit, can modify shift points and all the other benefits a tuner gives you...

 

I would love one and want one, it just aint in the budget right now. My biggest thing i want is just more pressure when in 5th gear. Id like to hook a gauge up to it and see what im getting then do the resistor and see if it ups the pressure while cruising or just when shifting like some people are stating. I want proof so unless anyone else has done i guess i'll have to. I just dont have a gauge so theres more money.

 

I had both superchips and the sonnax. Custom trans tuning and all. Honestly, like I said, the only time I ever felt the sonnax kick in was a completely wide open run through all gears. Superchips with torque management made more difference than the sonnax did in normal driving. If I floored it, sonnax made more of a difference. I did runs with and without the sonnax. With superchips and sonnax, it would snap my head back every gear change. With just superchips, it was a hard shift, but not like with the sonnax. I never felt anything different with either on downshifts.

 

Well i tried the resistor, didnt help the issue. I feel like its either the tcc or overdrive clutches slipping. Ive read that some will eratically shift in and out of od due to tps issues but this doesnt feel like a shift. Also i only experience the slip on hills which makes me believe its the clutches unable to hold the load. Are there any 545rfe gurus on here?

 

I would change the fluid and filters if you haven't already. I know that sometimes the torque converter unlocks before the trans will downshift which can feel slippage. I also hate the secondary 2nd gear used as a kickdown gear, especially when towing at low speeds.