That may be so. It feels ALOT better, but it still feels like it slips too much.

I wish I had saved a "before" graph, the RPM went like this with a 3-4 shift (my Paint skills lol)






BTW, not a regular Jack and coke; a Gentleman Jack and coke


I wish

 

I get the idea on graphs but the Gentleman's Jack and Coke, you lost me. Just thought I would throw that senario out there for yaa, you know your truck before and after so good luck to yaa. I seen our resident trans expert Mark Kovalsky on earlier, he built these tranny's for Ford for 20 years give or take, maybe he'll see your thread and shed some light on it. You could look him up, do a search, his name is his screen name and send him a PM, might get him sooner than later, good luck.

 

Typically the 3-4 shift problem is the software not releasing and relocking the torque converter at the proper time. The converter clutch is supposed to slip during the shift, but the software either slips it too soon or too late. I can't tell which one you have from your data. With that resolution it looks like it's relocking when it should.

The only way to fix that is new software. The '99s were especially bad at that, I think the problem still existed in the 2000 model year. It's been a long time, but I think there might have been a valve body change, too. There was a TSB that is probably still accessible, though I don't have a copy of it.

 

Ok, the converter is not slipping. The input shaft speed matches engine RPM as soon as 100% lockup is commanded. Now another question, I was planning on installing the transgo lockup valve that converts it from PWM to on/off. Since the PCM drops TC duty cycle to about 50% during a shift, will the new on/off valve still allow the TC to slip a little during the shift?

 

Probably not. It is going to either stay 100% locked or it's going to go 100% unlocked. The on/off solenoid has nothing in between those two extremes.

 

That is what the CURE was designed to fix. .It speeds up the un lock ,re lock of the converter You can get it here ....Yahoo!

 

It is designed to slip , to smooth out the feel ...PCM Programming ...You can change every mechanical part & it will still slip as designed. The cure fixes the programing...

 

My 2000 has An MNM1 code PCM which is listed for '99 model year and I had the goofy 3-4 shift lock up
When I put the DP tuner in it went away,now in the last year it want to eithe lock with a bang in second or lockup as soon a it shifts into third

 

Do you think it is a bad idea? It is the 4R100-LU

 

I wouldn't install it in my 4R100.

 

The E4 and early 4R's were a on/off switched tc lock/unlock.
The latter 4R was PWM, tc lock/unlock.
The PWM mask's the issue of the 3 to 4 shiftpoint.
As you firm/shorten your shiftpoints (3 to 4) you unmask the issue more.
Even a change in line pressure will unmask it.
Alot is going on at the 3 to 4 shiftpoint. Its not just a relase
of 3 and engage 4. The TC and coast clutch have a role in it.
Removal of the PWM will help the 3 to 4 but not fix it 100%

My trans (E4) shifts like a 5 speed.
Every gear hits (feels) the same as the 2nd gear shift.

Bill

 

Thanks Mark. I'll send it back then.

 

The non PWM is a better system.
It helps with heat a wear on the tc clutch.
PWM = Slip.

Bill

 

The 3-4 shift is accomplished by applying the overdrive clutch. That's it. The coast clutch is not on in 3rd gear, nor is it on in 4th gear, so it is not involved. The exception to this is if the truck is at a high enough speed to be in 4th gear with the OD turned off. When the OD is turned back on the coast clutch will drop off and the OD clutch will apply. If the OD is enabled with the shifter in OD the coast clutch is ALWAYS off.

The torque converter clutch does have a role. The PCM slips the converter clutch via the pulsewidth modulated solenoid (on the 4R100) during the 3-4 shift. On the E4OD with an on/off solenoid the clutch is briefly released and then reapplied during the 3-4 shift.

 

Do not agree. And alot more than apply 1 clutch.
Other fluid ckts change.
The flux in pressure and flow are part of the issue.
What is the CC doing at this time?(shiftpoint)
What is the TC doing this time? (shiftpoint)

Do not agree.
As of the 4R the CC is on full time and is only off while in OD.
The OD cancel has nothing to do with the CC. If you cancel
the OD your CC stays locked.
Your getting confused between a early E4 and 4R, on how they control the CC.


Agree.
The TC is just to slow to transfer from a lock/unlock/lock state!
As you firm your shifpoints the issue elevates and you can see
how bad ford slips the clutch. It only has to last to the warrenty.
Why the clutch has dampers on it with PWM is just dumb.

My .02

Bill