68RFE 545RFE Sonnax Line Booster Kit With Pressure Regulator Spring

Boosted pressure under towing. Easy to install could feel a better shift. Quick and not sluggish but not harsh.

This is a great product. I put it on my 2018 Ram 3500 6.4 Hemi. It has the 66RFE . With a little work it has lots of power. I will be Procharging it next. The Trans liked to lag between gears or not fully engage. Not sure which. Checked on line. I seen the RFE trans all have this problem, it seemed. After installing your product. It does not seem to lag much if at all. Its so easy to install. Will see in time if it throws a code. As for now it works great. Thanks

A good cheap upgrade for your 45 or 545. It's been working great for a couple of thousand miles now. Doesn't firm your shift, just makes it faster. Which I love. Less annoying in between as it goes between gears.

Does as advertised, purchase this and save over BD Diesels same product.

Bought this pressure booster to try and help out some shifting issues and put it in when I did a filter kit on the Trans along with a new shift solenoid pack....short of, this booster caused codes to trigger and put the truck in limp mode....removed this booster, did the quick learn procedure again and no problems since.

I used this on my wife’s 2008 6.7 dodge Cummins with a 68 RFE transmissionIt really helps the shifts be firm and solid.It does take a bit at first for it to get used to it so at first your shifts might be a little harsh, but after some driving time, it’s pretty smooth and solid

Works as advertised. Trans shifts much better A no brainer product for the 68rfe can’t wait to tow my camper and see the results

I drive a 2015 Ram 2500 with the 6.4L engine with a stock, rebuilt, 66RFE transmission. I purchased this hoping it would fix my occasional transmission shuddering problem and it did for only the first drive cycle. I was disappointed the second I opened the package to find the part looks nothing like what Sonnax advertises on their website, one side was even missing one of the red locking tabs, but I held onto my judgement until I at least put it to the test. I know to reset and relearn the transmission, but figured I would try it first just by putting it in and seeing what happens. RAN GREAT! One time, the first time, drove around and felt much better than the transmission has ever felt. Then the second start up the check engine light came on and drove much worse than it ever has. Ok I figure time to relearn it. I did a quick and dirty battery cable disconnect and left them off for about 2 hours. Money light did turn off and ran ok till it warmed up, and then started shuttering like the first time. Unplugged it, went back to factory harness connection and no check engine light like usual but I still have my same issues. Figure it wasn't even worth going through a proper trans relearn procedure with a fancy scan tool.TLDR: Ran good once, not official looking part, gave me more problems than I had, returned to sender