Trans guys- How to tune for noticeable down shifts on 47re?

biggy238

biggy238

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Aug 3, 2008
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I put in my Borg warner solenoid last week. It completely amazes me that I made it this far without it.

What do I need to do to get it to downshift again? I toyed with the throttle valve cable a bit. The truck shifts now with a trailer behind it like it did when it was new and unloaded.
I think the answer is to pressure test again but I was hoping there would be a good direction to go. I can't remember the name for the screw next to the line pressure adjustment and having trouble finding it with my phone. I'm guessing this is the one I need to go after?


From my Not-So-Smart phone
 
It will downshift but there is no feeling and no reaction in engine speed. Just a coast to stop. The trans grabs again when the brake is released.
Coming to a stop and pulling out again shifts up from first like it should.
From my Not-So-Smart phone
 
No. Dtt parts assembled in 2007. Single disc ,VB, billet input , 4.2 or 4.4 apply lever. Servos, overhaul kit, upgrade clutch count. I didn't build it. Pot mod and resistor in the signal return.
Reused my gov pressure transducer and solenoid in 2007, both of which had low miles. Truck started going into limp mode after the first hard run of my daily drive in 2009. I put a governor pressure solenoid in then and adjusted the bands. It never acted right after the limp mode issue. Slipping either the tcc or OD (guessing of since I don't remember slipping direct), stacked shifts, 3rd gear starts, and refusing to lock the tcc unless the throttle is lifted.

I made some changes to line pressure, throttle valve and base governor pressure last summer. I got it to stop stack shifting and hunting. I could still slip it (something else that started about 09) but things improved. Governor pressure wasn't linear.
Last week I put the new solenoid in. The truck has been mostly idle since 2010 so it hasn't seen many miles since the trans really started to act up.

The solenoid has cured every issue I had with the exception that it used to downshift like a truck with an exhaust brake and now it will not. The upshifts are clear and defined now. It was locking the tcc like it should this weekend until I tweaked the throttle linkage. I want that back those clear defined downshifts. I suspect setting base governor pressure higher will get me what I want since towing a trailer required more throttle, which in turn firmed my upshifts.



From my Not-So-Smart phone
 
Yea if you turn in the screw that the tv lever sits on at no throttle input you should get earlier(firmer) downshifts
 
The trade off is going to be heat while at a stop in traffic? That was another characteristic from before things got bad. It was tight enough I would have to kick into neutral at a long light.

What kind of baseline TV/governor pressure should I shoot for? I can go back and read the trans thread.

From my Not-So-Smart phone
 
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