48RE shutter and downshift jolt!

[RichardTaylor]

The Truck is a 2003 CTB Quad-Cab Laramie 4X4 short box.

I recently had the transmission serviced at the dealer. They told me that everything looked good, however, the bands were loose more so than might be the usual. They tightened them and finished the service. The transmission now feels like it drops in to low gear when I come to a stop just before I stop there is a bang or boom and a hard down shift felt throughout the truck. Not cool! I spoke with the dealer and of course they stated that band tighting would not cause that problem, they want me to bring it in for a look see but I have not done so yet. Now for the SHUTTER! Not everytime but most of the time since I bought the truck new when I am excelerating not hard but steady just as the torq-converter locks up the truck shutters and it sounds like the door locks engauge at the same time. I don't think the door locks are activating it just sounds like it. Any ideas? Thanks for any input!

 

[JDiepstra]

I had an aftermarket (HTS) valve body put in my truck a few weeks ago. When I got my truck back I also noticed the boom when the truck shifted into a lower gear coming to a stop. I called my mechanic (local diesel shop) and he said it was normal. For me it happens every time at about 12 mph when slowing down. The next time I stopped at the shop I pressed the owner about it cause I must admit it did rattle me a little. He said that he had talked to the guys at HTS and they said that it was normal also. Their explanation was that the 48RE just does that when you turn up the pressure like an aftermarket valve body will do, and that no harm was being done. I guess I will cross that bridge if I get to it. They said it was the 3-2 downshift. Good luck.