727 Shift Issues

[krw74]

I just rebuilt a 727 for my 74 Scamp. The trans is a 78, and from my understanding the misfit of 727's. I used a standard rebuild kit, 6,000 rpm governor, turbo action cheetah shift kit, and i have a 38-4200 acc performance boss hog torque convertor. Front and rear bands are adjusted to factory spec (I don't recall the number off the top of my head) and the kick down linkange is adjusted properly. At WOT the 1-2 shift is at 5,200 rpm firm and crisp, and the 2-3 shift is at 6,800 rpm. It seems like it wants to shift into 3rd, but it just keeps winding up. Seems like an overlap issue to me. I'm thinking a whole new valve body, but i wanted to get other opinions from people with more experience and knowledge than me. I'm not claiming to be a trans expert by any means.

Thank you,
Kevin

 

[KickDown]

Kevin. You can match the shift points of the 1-2 to 2-3 shift by trial & error by changing the shift valve springs. It just depends on what you want. Do you want to bring the 1-2 shift up to the 2-3 shift point? Or do you want to bring the 2-3 shift down to the 1-2 shift point?
Give A&A a call & they've got you covered. They have a myriad of shift valve springs. That said, first off, check the shift valves are not hanging up in the VB
Cheers. Gaz.

 

[krw74]

Thanks Gaz. I would like the 1-2 and the 2-3 shift to be at 6,000 rpm.

 

[1965_belvedere]

if you don't mind my asking, why do you assume your kick down linkage is set correctly? I had a 1974 Road Runner shift like this once, and with a couple turns of the linkage, I had 3rd gear WOT 85-90 MPH. you may not be giving us enough info by just stating RPM's. what are your oil pressure readings? 1st, you need to get your line pressure adjusted correctly. then adjust your throttle pressure. maybe somebody was playing with the throttle lever stop screw on the valve body? the valve body is the heart of any tranny. stuck valves or poor adjustments will keep that tranny from ever shifting correctly.

 

[RustyRatRod]

Did you put the restrictor plug on the high gear orifice?

 

[krw74]

1965 belvedere
I said the linkage is adjusted properly because I looked at several posts before I posted mine and in almost every post the question was asked "is your kickdown linkage adjusted properly?" and I have verified it's correct already. Just trying to save some time for everyone and possible look else where. Now the stop screw on the valve body I have not idea where that's at. I've never touched it. My thought process was that I wouldn't be a kickdown issue because the 1-2 shift compared to the 2-3 shift is drastically different, and the kickdown would be in the same position for both shifts. I have absolutely no idea what the line pressure is. I don't have a gauge. The friend who helped me build the trans also recommended looking into line pressure. The reason why I was explaining in terms of rpm is because that's the only statistical data I have to relay besides mph and I don't recall that at the moment. I want both shift points to be at 6,000 rpm. That's why I installed the 6,000 rpm governor.

Rusty rat rod
Could you be more specific. I removed the shuttle valve throttle plug in the valve body and replaced it with the plug that came with the shift kit. I also removed a spring and plug in the valve body that I have no idea what its for or is called but I was instructed to do so with the shift kit. I also removed the accumulator spring and a spring in the valve body and installed a plug where the spring was removed. I left the valve in as noted by the instructions. I don't know if that's what you're talking about but I put a plug in the valve body somewhere the instructions told me to. Sorry I'm an idiot about this stuff. I've only had a few trannys apart and I learn more every time. I'll get there someday. Thank you both for all your help. Bear with me please. Here is a link to the install instructions for the shift kit. Look at figure 8 to see if that's the plug you're talking about. http://www.turboaction.com/frame.html

Thanks guys!

 

[krw74]

I guess that link was useless. All of the valves moved freely when it was assembled.

 

[krw74]

This Plug?

 

[KickDown]

Kevin.
The restrictor that Rusty Rat Rod is referring to is circled in red below



It is fitted to the oil channel for the reverse/direct clutch to delay the application of the clutch on the 2-3 shift, thus eliminating 2-3 overlap.

It is supplied with the TransGo TF-2 reprogramming kit. This is the only kit I will fit & I do not have any idea if other manufacturers supply a similar orifice.

You also may like to read this.-

http://www.hotrod.com/how-to/transm...creasing-shift-speeds-on-the-727-torqueflite/

Cheers. Gaz

 

[krw74]

Thanks Gaz. I've heard of people drilling and plugging those to alter different shifting issues. I may just get one of those TransGo kits. The Turbo action was one my father had floating around the garage so I figured I could make good use of it.

 

[krw74]

After reading that article, it looks like I need to get a gauge to verify my line pressure is satisfactory, see if TransGo can send me a plug, or figure out what size the hole is in their plug and buy a freeze plug and drill a hole in it to place in the orifice to eliminate overlap, and get ahold of A&A after the line pressure is correct to get some springs that will accommodate my desired shift point. Does that sound correct?
Thanks again everyone.

 

[KickDown]

Alternatively Kevin, the casing channel can be tapped with a 1/8-27 NPT thread & a drilled plug can be screwed into the channel. Drill an 0.140" or 3.5mm hole in the plug. You can also try different plugs with various size holes.
If you are going to tap the case, coat the tap with vaseline to prevent any cuttings entering the channel. Obviously it is best to cut the thread with the trans in the car. Make sure you screw the plug in flush with the case, or the valve body will not sit properly & you run the risk of damaging it. Also put a tiny drop of HT Loctite on the thread to prevent the plug from coming loose.
I would only recommend this with a TF-2 reprogramming kit as, like I said, I don't know what other manufacturers supply with their shift kits.
Line pressure check is very wise & easy to do with a 300psi guage & about 8 feet of hose.
The line pressure take off plug is also 1/8-27 NPT. Check the FSM on how to carry out a line pressure test.
Cheers. Gaz

 

[krw74]

Thanks again Gaz!!! I really do appericite it!!