Hello there!
I have been through a few posts including the 727 transgo tf-2 orifice plug https://board.moparts.org/ubbthreads/ubbthreads.php/topics/774603/727-transgo-tf-2-orifice-plug.html
quite a few times and decided to try post a new one once I would very much appreciate some input from the trans techs concerning a possible 2-3 upshift overlap on my 46RE dodge dakota.
I bought the truck a few years ago in very good condition but the trans had never been touched, I did change the governor pressure solenoid and transducer to resolve a 1-2 shift hunt issue which was noticeable only at low rpm (solved), adjusted bands to factory specs, changed fluid to ATF+4 and filter and also put in a Superior shift kit to preserve the transmission.
The truck always had a very hard 2-3 upshift only at WOT or near WOT, before and after the shift kit, feels like an abnormal bang or bump in the powertrain but only near WOT so I decided to make a restrictor orifice for the direct clutch port. I made it 0.140 inch diameter.
The trans and the truck are in great working condition besides that detail, 66,000 miles now.
My question is, when I previously spoke with the Superior tech representative he told me to loose the front band half turn to get rid of the bump, it helped a bit but the bump is still there, and when I told him I would put in an orifice plug in the direct clutch he said I`d FRY my clutches... I undertand the orifice only slows down the flow of fluid during the shift but after that the amount of fluid that has to pass the orifice will be much smaller and the orifice will not cause restriction in that condition (front clutches applied). Am I correct? Is there any concern or problem the orifice plug could cause? I am going to test the 0.140 inch orifice tomorrow (homemade aluminum plug 0.140 inch shown on picture) http://s1295.photobucket.com/user/estate...k5h5mu.jpg.html , not sure if it will work, maybe I need to go smaller... hope not.
Well thank you for any info concerning this subject,
Cheers,
DLJ [img]http://s1295.photobucket.com/user/estate...k5h5mu.jpg.html[/img]

I don't use orifice plugs. I like to use a 4.8 band lever and then adjust the band to get rid of the overlap. You can get rid of the WOT overlap this way but it may still have a little at low speed. It's never perfect, there's always a comprimise.

Nonsense !!!! The "tech" probably believes that the delayed clutch engagement will cause the clutches to wear...we're only talking fractions of a second delay. In fact, the factory reduced the size of the front clutch feed orifice in the VB separator plate in '71 to eliminate overlap, the orifice plug does the same thing but further downstream.

His VB should already have the separator plate with two holes and a check ball in it for that port.

I am not a transmission guy but I read a lot before I started to play with my 46Re and in my case the 2-3 upshift overlap is noticeable only at WOT or near WOT so I am not worried about low rpm overlap and I understand the 2-3 overlap would be more pronounced whith a 4.8 lever than with my 2.5 stock, thanks for your input!

Thanks John_Kunkel, I have just tried today the 0.140" direct clutch orifice I made out of aluminum and must tell I also changed the Pressure Regulator spring for the heavy duty spring that came in the Superior shift kit so I noticed all the 2-3 upshifts became more aggressive than before, feeling more like a little bang, even at lower rpm, at WOT it still feels like a bump in the powertrain but somehow not so much as before.
Maybe the increased line pressure (15 to 20% stronger PR spring) is causing the 2-3 upshifts more perceptible and the orifice plug I installed should be smaller... I saw a few trans techs posting they end up in the 0.110" diameter range but my 46RE is for street use, not into offroad or track at all so I want to preserve the clutches and bands not having harsh shifts.
I will drive the truck a few more days and by the weekend probably will remove the VB again, come back to the stock PR spring and try a smaller orifice plug, should I go 0.130"? or 0.120"? If I get a flare up I know I have to use a larger orifice... don't want to remove the VB that many times but I can't sleep with my current harsh wot 2-3 upshift, just have to try.

Again, my question would be, an orifice plug installed in the direct clutch port would not really fry my clutches because after they have been applied, they require a small amount of fluid flow to maintain pressure on the clutches, am I corretct?

In other words, the 0.010" orifice would still be large enough to allow fluid flow to maintain the front clutches applied at the correct pressure, is that correct?

Interesting info about the reduced size in the front clutch feed orifice for 1971.
I understood from what the Superior tech said that the orifice plug I am installing in the front clutch passage on the aluminum case could somehow restrict flow of fluid and cause the direct clutches to slip due to a reduced apply pressure but I hope that would not be the case...???

I think you may be confused, hard shifts do not wear clutches, slippage does. Slippage creates heat so the faster the clutches are applied with more holding pressure the less chance of slippage.

Shift overlap feels more like a binding as the trans shifts as two different elements are applied at the same time.

If you're referring to the port restrictor where the VB mates to the case (second pic below), that's for the rear clutch to protect the Belleville spring and came later than '71. The reduced front clutch orifice I referred to is internal and was reduced to .125" or less in '71. (the "D" orifice in the first pic)

It's common practice in shift kits (or bench overhauls) to open the "D" orifice and then use the removable port restrictor to control the flow. The logic here is to place the restrictor in a location where it can be changed without disassembling the VB.

the smaller orifice in the restrictor reduces the speed the clutch can fill with fluid, not the final applied pressure in the clutch, the pressure will eventually be the same with or without the restrictor, it just takes longer to apply the clutch giving the 2nd gear band more time to release.

You are correct, I was thinking of something else.

I was just in a 440/ 727 car that had a strong shift overlap feel on the 1-2 upshift, never felt that before!
What causes that?

The 1-2 upshift is only applying the front band unless the valve body is applying the rear band in first. So if it's a rear band apply valve body or you were manually shifting a stock valve body then the problem is timing the rear band release and the front band apply. This is one of the reasons why all the original manual valve bodies were reverse pattern.

Overlap on the manual 1-2 upshift is why rear servo mods are so important when other performance mods are made, quicker release of the rear servo eases the overlap but it can never be totally eliminated.

In earlier units the overlap was less noticeable because there was a delay between moving the shift lever/button and the actual shift; in '70 the factory changed the profile of the 1-2 shift valve to force an upshift but this exacerbated the overlap.

It was manually shifting 1-2 on a forward shifting automatic valve body. The trans was rebuilt, shifts pretty good UNTIL it is shifted manually at higher rpm. Then it has a binding feeling as it shifts, as if in two gears for a split second.... I've never felt anything like it.
Is there a fix? Different valve body or?

What can be done to the rear servo to minimize this?
Would like to fix it, weirdest shift I have ever felt!

I would think eliminating the cushion spring on the shaft and making it solid would help. Maybe increasing the return spring pressure would help too.

mrrandyj sells these billet servos here in the trans and differential for sale section. I've bought both the rear and front servos from him. Real quality pieces.

Thanks!!! I'll take a look. Gotta try something!

Good info!!

Just to give you folks an update, it took me long but I finally got rid of the brutal harsh 2-3 upsift (thump) at Wide Open Throttle on my 46RE.
I had to go down to a 0.115" orifice plug put into the aluminum transmission case at the direct clutch port.
I had tried larger sizes orifices before with little or no difference, such as, 0.140" then 0.125"and finally 0.115" when I got the harsh hit reduced to what I would call a real firm shift (clutch apply) but I am only talking about 2-3 upshifts at WOT, other than that the shifts were fine without the orifice plug.
It really made the difference, I can't believe that later year 2000 46RE's still could benefit of a direct clutch restricting orifice plug, because other than that, the transmission was fine.
Anyway, I am happy I do not get a flare in any situation. Still would like to go one size smaller (0.105") but really do not want to mess with the Valve Body, seals and screws any more.
Hope that helps someone with real harsh wot 2-3 upshift, best hint is start with a 0.110" orifice, you will probably have to replace it but then you know it is small (if you get a flare) or still large if you still get the thump harsh shift.