TRANSGO TF1 QUESTION

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CFD244

CFD244

"I LOST MY ID IN A FLOOD"
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Hi folks

I have just finished installing a shift kit in my 1971 727. I did all of the mods as directed in the kit with the exception of the command shift option (downshift at any time at any speed). Transgo wants me to install an orifice plug in the transmission case in the passage that feeds the direct clutch assembly where it mates to the valve body. It seems counter productive to make that passageway significantly smaller.......What does this do? Is it necessary? Help me understand. Thanks
 
It's a crutch to eliminate the 1/2 shift lock up.
 
I don't know why you would think it is 'counter productive' while at the same same asking what does it do because you don't know.....
 
Bewy said:
I don't know why you would think it is 'counter productive' while at the same same asking what does it do because you don't know.....
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You missed the word "seems" in that sentence (in other words, in my mind). Since I don't know why reducing oil flow in a hydraulic circuit is beneficial, that's why I am asking. If you have nothing constructive to contribute, please move on. Thanks.
 
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Bewy said:
I don't know why you would think it is 'counter productive' while at the same same asking what does it do because you don't know.....
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This post is a good example of "counter productive".
 
I've called there tec line and got great service.. Try calling asking and please report back... I've installed many tf2's and one tf3 and about to do another 3...
Actually I did install a 1 in a Chevy 350 turbo and I couldn't tell it did anything...
The tf2's always have a firm but not banging shift...
 
Being the weekend, I wanted to get the VB installed and the Tech Dept is closed and was hoping to find my answer here on FABO. I found a really good posting courtesy of the International Harvester truck enthusiasts forum "Binder Planet". Although referring to a TF2, a very good explanation of the orifice plug. Here's an excerpt from the posting.........

........"So everything's buttoned back up and I take it for a spin. I immediately notice a 2/3 flare up. If you don't know (like I didn't) what a flare up is, it is an RPM increase between gears. It's exactly the opposite of the issue associated with a Torqueflite transmission. They're know for a 2/3 overlap in which the kickdown band is still holding when the front clutch is applied to shift to third. Overlap is the time that both of these are holding at the same time. Eliminating/improving this overlap is the reason that Transgo kits will extend the life of the transmission. Well, in my case it eliminated it too much, I was getting a 100-200rpm rev between the 2-3 shift.

After many conversation with Transgo telling me it was lost motion between the throttle and the TV, and another site telling me I had "tired" transmission, It wasn't looking so good. Tightening the kickdown band and over adjusting the Throttle rod a little helped but didn't eliminate it and obviously I could go extreme with these adjustments. To keep the truck shifting properly I had to let off the accelerator before it shifted to third allowing the hydraulic fluid to go through the small hole in the TV instead of the large one. It would shift good this way but it wasn't right.

Well, I fixed it this morning. There is an orifice plug provided in the kit that you are supposed to drive in the Front Clutch apply hole. It slows down the fluid to the front clutch allowing time for the kickdown band to disengage simultaniously (idealy). The problem is these plugs are not a one size fits all (specifically outlined in the Carl Monroe book).

There are many factors that effect the way the 727 shifts from 2/3 but the kickdown apply lever ratio is one that can dictate the use of, or size of the orrifice plug. If you have an aftermarket 4.+ ratio, then the plug is useful as it is or it's possible that you could use even a tighter restriction, if you're running a stock or numerically low kickdown apply lever, you may need to either enlarge the orifice hole or remove it completely if you're getting flare ups.

I ended up removing mine completly and it's FINALLY shifting exactly the way it supposed to.....no bandades and nice, firm shifts.

If you are planning on installing a shift kit and want more details on a custom orifice plug tailored to your specific setup, it's outlined on page 178 in the Monroe book."
 
Following along here Troy as I want to do the 904 for the cuda. Immediately when I think/hear transmissions I think of @VOETOM , Tom Hand. Dont get much better than someone that's published to help.
 
4spdragtop said:
Following along here Troy as I want to do the 904 for the cuda. Immediately when I think/hear transmissions I think of @VOETOM , Tom Hand. Dont get much better than someone that's published to help.
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Yup, agreed. I bought his book before I even took the pan off! Fabulous resource. Our members @transman @SMCARNUT and @Duster346 have been great help with my build.
 
on another mopar site, john kunkle says to open up the orifice a little at a time to cure this. but having to drop the vb several times may be more than some people want to do.
 
rbkt65 said:
on another mopar site, john kunkle says to open up the orifice a little at a time to cure this. but having to drop the vb several times may be more than some people want to do.
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On and off with those aluminum threads would scare me. Everything into aluminum I normally stud.
 
I always thread that hole and put a set screw with a orifice in it. Set screws are cheap so if you need to change something it’s a lot easier this way..
 
mcodecuda said:
I always thread that hole and put a set screw with a orifice in it. Set screws are cheap so if you need to change something it’s a lot easier this way..
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Yes, that would be the best way I would think. Unfortunately, the transmission is back together and I would not want to risk any filings going AWOL. :)
 
CFD244 said:
Yes, that would be the best way I would think. Unfortunately, the transmission is back together and I would not want to risk any filings going AWOL. :)
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Just pack the tap with grease and tap it slowly. There is no drilling required. The set screw and tap size is 3/8-16 and I start off with an 1/8” orifice. The other thing that you can do is use a shop vac while tapping the hole.
 
i agree with mcodecuda. on both accounts. set screw with diff sizes and tap wit grease, now that trans is in the car.
 
mcodecuda said:
Just pack the tap with grease and tap it slowly. There is no drilling required. The set screw and tap size is 3/8-16 and I start off with an 1/8” orifice. The other thing that you can do is use a shop vac while tapping the hole.
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My trans is still on the stand.....Upon closer look, I will do what you suggest. It looks like I can pack something deep into the passage as a safety measure. I have a spiral fluted tap, which tends to pull the chips outward as it advances, and a bit of grease as well.
 
CFD244 said:
My trans is still on the stand.....Upon closer look, I will do what you suggest. It looks like I can pack something deep into the passage as a safety measure. I have a spiral fluted tap, which tends to pull the chips outward as it advances, and a bit of grease as well.
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Just tap it just deep enough so that the set screw is below the pan rail. I would also find the set screws before you tap it.
 
mcodecuda said:
Just tap it just deep enough so that the set screw is below the pan rail. I would also find the set screws before you tap it.
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Thanks, I've got tons of this stuff in my shop. This will make it a lot cleaner, and if it doesn't work out, easy to remove. I will go with a 7/64 to start as that is the size that came with the kit. I assume that the parts in this kit are supposed to work together.......But you know what happens when you assume! Thanks for the input.

BTW....I like your forum name. Here's the plate for my Demon.

IMG_3478.JPG
 
I tapped and installed the .140 orifice. Nice clean install. Thanks for the tip :thumbsup: . I made a few more ranging from .125 to .170 while I had everything set up.
 
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