Improving Transmission Shifting

[sl33p3]

Very interesting.

As I was reading, I kept thinking "What is the difference between the Power button and this mod?"

Once done, do you still have the two settings, Power and not, just both firmer?

Signed,
Generally Mystified About Auto Trannys
;p

from what i can gather, the "power" button in 343's as well as the "ECT" button in the 442's DO actually change the shift points slightly (signal to tcm). it will wait to lock the TC longer, kick out of it easier, and hold rpm higher before upshifting. teh FSM gives the shift point deltas for ECT and normal modes for my '93. i have had little use for my ect button (i'm sure it's not as good as the later "power" button ) but i have also adjusted my kick cable and could be on the tight side, but it is where i like it. i used to have it tighter but lowrange 1-2 was murder and now its firm but but wont' spin wheels in soft stuff and you dont' see your passengers neck snap back in your peripheral on every shift out of 1. i wish i had second start on my 93. oh well.

 

[Tools R Us]

Other than personal preference is a firmer shift (to a point) better or worse for the transmissions longevity? IDK.

My guess; if anything makes the trans slightly more durable. Stock they have a bunch of slip, at least the ones that I work with, US spec A343. For ultimate durability, a stock rig is likely the best, but for me that ship has sailed, it has a lift, 37" tires, etc. As always it greatly depends on intended use, for my use a stock rig would be worthless. From the factory it is tuned for stock use, comfort, etc. On the trail, with bigger tires, etc, the stock tune is very soft, firming it up better matches the need for how it is now used.

 

[Tools R Us]

from what i can gather, the "power" button in 343's as well as the "ECT" button in the 442's DO actually change the shift points slightly (signal to tcm). it will wait to lock the TC longer, kick out of it easier, and hold rpm higher before upshifting. teh FSM gives the shift point deltas for ECT and normal modes for my '93. i have had little use for my ect button (i'm sure it's not as good as the later "power" button ) but i have also adjusted my kick cable and could be on the tight side, but it is where i like it. i used to have it tighter but lowrange 1-2 was murder and now its firm but but wont' spin wheels in soft stuff and you dont' see your passengers neck snap back in your peripheral on every shift out of 1. i wish i had second start on my 93. oh well.

Toyota is pretty tight with their programming info, but from what I have heard: The "power" button uses the same map as full throttle. So I see the button as mostly useless, see no advantage to revving the motor that high when part throttle cruising and when I want power, I'm in the throttle, so using the same shift map.

 

[yoopercharged]

In stock form (tires, gearing, etc) , I would imagine that it is tough to beat the reliability of the OEM setup. However, once you go up in tire sizes there is more load on the driveline. The more load, the more slip. Turning up the pressure to reduce slip might be the ticket for bringing the tranny back to stock function. I have no data to support this, so take it for what it's worth.

 

[sl33p3]

Toyota is pretty tight with their programming info, but from what I have heard: The "power" button uses the same map as full throttle. So I see the button as mostly useless, see no advantage to revving the motor that high when part throttle cruising and when I want power, I'm in the throttle, so using the same shift map.

i'm with you TRU, good info on the full throttle=power map, makes some sense. and i can say that loaded trans temps are significantly higher due to less TC lock in "power". unlocked TC pumps heat into fluid like crazy, but whaddya know it works on fluid shear you may be unlocked and railed in non power/ect mode anyway but why abuse your trans when unnecessary and you aren't.

 

[murf]

In my interest in performing this Mod, Tools - the OP of this thread - contacted me and suggested some additional tips after 4.5 years and tens of thousands of miles of testing:
The adjustment dial comes with 3 settings. From factory it is set in the #2 position with the 3rd position for highest pressure. After some discussion I decided to use a like size diameter washer with the thickness equivalent to the amount of the dial indent to further push the valve in to simulate a fourth position.
The appropriate washer was sourced a the local ACE hardware. This was placed between the primary regulator valve and the spring along with the thin OE spring. (see picture in first post).
Next was to adjust the throttle cable - suggestion was to be slightly conservative with the adjustment. A balance needs achieved on a later shift so when youre in 4 low, the shift to second isnt too late/harsh to spin the tires in case you are off camber in hard pack gravel for instance.
several adjustments later, I have found a good balance for both on and off road driving.

Feedback: The difference is subtle but very noticable. The shifts are immediate between gears now with no flaring between gears. In no way does it "hit" like a shift kit - rather it is very smooth and immediate. With both of these adjustments, to me my truck is more enjoyable to drive - almost like this compensated for the weight, lift, and tires and make it more of a crisp and positive shifting feel. I also no longer find myself occasionally reaching to manually shift my 80.

I wish I wouldve done this years ago ~

Murf

 

[mikedamageinc]

In my interest in performing this Mod, Tools - the OP of this thread - contacted me and suggested some additional tips after 4.5 years and tens of thousands of miles of testing:
The adjustment dial comes with 3 settings. From factory it is set in the #2 position with the 3rd position for highest pressure. After some discussion I decided to use a like size diameter washer with the thickness equivalent to the amount of the dial indent to further push the valve in to simulate a fourth position.
The appropriate washer was sourced a the local ACE hardware. This was placed between the primary regulator valve and the spring along with the thin OE spring. (see picture in first post).
Next was to adjust the throttle cable - suggestion was to be slightly conservative with the adjustment. A balance needs achieved on a later shift so when youre in 4 low, the shift to second isnt too late/harsh to spin the tires in case you are off camber in hard pack gravel for instance.
several adjustments later, I have found a good balance for both on and off road driving.

Feedback: The difference is subtle but very noticable. The shifts are immediate between gears now with no flaring between gears. In no way does it "hit" like a shift kit - rather it is very smooth and immediate. With both of these adjustments, to me my truck is more enjoyable to drive - almost like this compensated for the weight, lift, and tires and make it more of a crisp and positive shifting feel. I also no longer find myself occasionally reaching to manually shift my 80.

I wish I wouldve done this years ago ~

Murf

Thanks for posting! Can you give more details about the washer installed? Do you have to remove the valve body or just pull the dial thingy and pop it all back in?

 

[Kernal]

So the washer was added plus the dial was set to the third position?

 

[Tools R Us]

Thanks for posting! Can you give more details about the washer installed? Do you have to remove the valve body or just pull the dial thingy and pop it all back in?

The "dial thingy" is called the sleeve in this diagram. If pushed in far enough the retainer falls out, then the sleeve and plunger will come out. Find a washer(s) the thickness that you desire, that will fit over the plunder snout and install it to additionally preload the spring.

 

[Tools R Us]

So the washer was added plus the dial was set to the third position?

Yes.

 

[NLXTACY]

What about doing this with the Transgo kit? Or is it already part of it?

 

[Tools R Us]

...
I wish I wouldve done this years ago ~

Murf

Success!

 

[Tools R Us]

What about doing this with the Transgo kit? Or is it already part of it?

Any of the kits will address system pressure, so part of it. I have never driven a modified valve body/accumulator rig that I liked. For the go fast, street use, great, but for relatively technical wheeling use, not so much. If I were a mud, momentum, type driver, would likely have differing thoughts, but for the more finesse type wheeling that I do, find them way too harsh in low range.

 

[Finnyfam60]

Any of the kits will address system pressure, so part of it. I have never driven a modified valve body/accumulator rig that I liked. For the go fast, street use, great, but for relatively technical wheeling use, not so much. If I were a mud, momentum, type driver, would likely have differing thoughts, but for the more finesse type wheeling that I do, find them way too harsh in low range.

Just for those of us on the short bus, this mod is INSTEAD of the transgo kit, NOT in addition, correct?

 

[Kernal]

What needs to be disassembled in order to add a washer and how is it done?

 

[Tools R Us]

Just for those of us on the short bus, this mod is INSTEAD of the transgo kit, NOT in addition, correct?

Correct, but it would differ on the A442 trans.

 

[Tools R Us]

What needs to be disassembled in order to add a washer and how is it done?

See post #48

 

[Kernal]

Missed that, just push the sleeve in far enough. Thanks

 

[mikedamageinc]

See post #48

Thanks Kevin, so is there any long term downside to adding a washer? Too much pressure? More wear and tear?

 

[murf]

Thanks again Tools.

to answer the previous question: the valve body stays in the truck. We positioned the washer on the far side of the spring in this set up next to the reg valve.

The "flaring" from lower pressure actually creates much more heat so it should run cooler. Again, Tools has run this for a long time now with no adverse effects.