A727 Transgo TF-2 install

I'm sure this has been discussed somewhere, but couldn't locate the answer.

I just install the TF-2 shift kit in a rebuilt 1971 torqueflite for a 440 I suspect will be around 450hp for street/strip. I've added the shift command feature, and all mods went well. Just hoping to get some additional clarity on a few of the adjustments.

Pressure Regulator Adjustment;
Shims, spring seat, inner spring, and outer spring and valve were replaced per instructions. Transgo suggests 3/16" allen adjustment be backed off until spring seat is just flush to edge of retainer. Factory was 1 5/16". Some forums discuss 3 turns from flush, and up to 6 turns from flush. I'm suspecting this is more for race application. Should I just stick with instructions, and check with a pressure gauge once running? Hate to have to drop the pan again.

Throttle Valve Adjustment;
Transgo kit makes no mention of any adjustment here. Stem end was ground per instructions to 9/32". With the throttle lever touching the stop, I set the clearance to 3/16 using a drill bit. I've read on some forums many adjusting to 1/8.

Orifice Plug;
Not sure if I should install this into the case, but it appears it's used in 80% of the mods.

Any suggestions greatly appreciated.

I have installed many TF 2's over the years and have always followed their instructions and have had ZERO issues.

The confusion arises from the fact that Transgo changes their instructions like I change my shorts (once a year or so).

The older instructions gave a PR spring setting of so many inches, then so many turns and finally flush.

Ditto the throttle valve, it was originally a 1/8" air gap and then no mention.

The cup orifice is a crap shoot, I would install it and remove it only is you experience RPM flareup on the 2-3 shift.

I personally experiment with the size of the orifice plug. The 2-3 overlap is one of my pet peeves. You can use tiny core plugs to drill progressively smaller openings till you get a flair up, then back up a little. Others may have a better way to get to the sweet spot, but that is what has worked for me. Usually .075-.100 gets the overlap out.

Of course, that means repeated valve body pulls. It is not "one size fits all", so the only way to get it right on any given tranny is to experiment.

"Usually .075-.100 gets the overlap out."

Is this the typical range for a band adjustment of 2.5 turns from 72 inch lbs on a kevlar band, 4.2 ratio lever, 4 alto red clutches/kolene steels (not sure of clearance) 12 return springs, and PR adjusted flush to the retainer?

I have never kept track of the combination of factors that results in any given orifice size curing the overlap. I just keep putting in smaller sizes until it just starts to flair, then I usually go back .005"-.010" larger.

It helps to have access to the numbered drill bits because the fractional ones are usually too large of a step between. Although a 3/32" (.094) might be a good place to start.

The .075"-.100" orifice was just a suggested starting range so as to help minimize the number of times you might have to pull the pan.

Dorman 3/8" cup expansion plugs part #555-115 is what I use.

Trial and error is the only way I know to get it right on any particular combo.

It's hard to predict with any certainty the shift quality of a trans even when the components/clearances are known, that's the purpose of the restrictor orifice....it can be changed without the necessity of removing/disassembling the trans to change the internal setup.

The restrictor supplied with the TF-2 has a .140" orifice and the orifice in the later factory separator plates is .125"

Tapping the case for a 1/8" NPT socket-head plug makes changes easier....drill the plug to the desired size.

Where is the later year .125 orifice located in the separator plate? I'm wondering if this is one of the holes that Transgo instructs to open up, then you install a .140 orific in the housing. This doesn't make any sense. Even if not modified, why install a plug with a larger hole than the plate.

,140 restrictor doesn't do much for curing the overlap with the tf2 kit; been there, done that. i think most people ignore the heavy throttle pressure spring that's in the kit. that spring, in my opinion, is too heavy and creates issues.

Quote:

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Where is the later year .125 orifice located in the separator plate? I'm wondering if this is one of the holes that Transgo instructs to open up, then you install a .140 orific in the housing. This doesn't make any sense. Even if not modified, why install a plug with a larger hole than the plate.

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Yes, Transgo instructs you to enlarge this hole...the thought being it's easier to manipulate the orifice in the case.

In the pic below D is the front clutch feed (3rd gear) and B is the kickdown servo feed (second gear).