Any fixes for the shift flare?

[panteramatt]

Well Im gonna be dropping the tranny pan and replacing it this weekend. While Im in there I would like to get rind of the darn 2-3 shift flare it has. Ive already dried tightening the drum and I remember checking other things cant remember what they were with air and they were fine. What Ive read said it my be the VB. So, should I buy a complete VB or a rebuild kit for mine? If so which one? Anything else I need to check while Im in there? Also, is there a way I can make 1st gear wind out more, it shifts so quick you can even tell I have second gear.

 

[pcf_mark]

Sorry if you tried the basic external stuff the flare is here to stay until you rebuild it. You may be able to buy some time with a shift kit.

You can change how long first gear winds out by changing the length of the rod under the vacuum modulator. When you take the modulator out there is a rod about 1 1/4" long. I cut a piece of metal coat hanger just a little shorter as a test. You can trim the coat hanger pretty easy and keep test driving. Then when you get the length right you can grind down the stock metal rod as needed for a permanent fix.

Jack up the back of the truck high to reduce the amount of fluid that runs out the modulator hole.

 

[panteramatt]

Think the shift kit would be worth my time? If so which one?

 

[Slowleak]

Mine had a slight 2-3 flare at slow speed. I installed a Transgo 40-2 kit and it fixed it up. You can call Transgo for some options on the install to prevent high speed manual downshifts etc. I wanted mine to behave like a stock C4.

Based on the instructions, I left out the 1-2 accumulator spring and the puck. Next time I am in there I am going to put the puck back in. The 1-2 shift is a little harsh if I get on the pedal. It definitely fixed the 2-3 flare.

 

[cs_88]

X2 on the Transgo 40-2.

 

[panteramatt]

Thanks that's what I'm looking for. How hard was the install?

 

[Slowleak]

Thanks that's what I'm looking for. How hard was the install?

Not bad at all. Hardest part is removing and installing the VB. Label your old springs in case you have to put one back, keep everything surgically clean, and just follow the instructions.

There are options for harder or softer shifts. I used the ones for softer shifts and I'm glad I went that way. I also did not drill the hole in the plate quite as large as specified. I figured I could always make it bigger if needed.

Good luck.

 

[pcf_mark]

I would do the shift kit for sure. If it buys you some time it was worth it. If you need a rebuild it will still make for nice crisp shifts. I agree my Trans-Go 1-2 was kind of harsh.

There is an article in the tech section on cleaning and checking the spool valves in the valve body. Has good pictures too.

http://classicbroncos.com/tech/c4-valve-body-service-and-modifications

 

[BwoncoHowie]

Well Im gonna be dropping the tranny pan and replacing it this weekend. While Im in there I would like to get rind of the darn 2-3 shift flare it has. Ive already dried tightening the drum and I remember checking other things cant remember what they were with air and they were fine. What Ive read said it my be the VB. So, should I buy a complete VB or a rebuild kit for mine? If so which one? Anything else I need to check while Im in there? Also, is there a way I can make 1st gear wind out more, it shifts so quick you can even tell I have second gear.

Did you try a modulator adjustment?
A spin-up condition at light to medium throttle could be caused by inadequate modulator pressure. Although I was able to cure this same problem on my 73 by something as simple as disconnecting and plugging the small hose on my red stripe dual-diaphragm modulator.

What year is the trans? And what is the color code on the modulator? How many In-Hg vacuum @ idle? Answering these questions could find you a solution without spending any money...

 

[panteramatt]

If I follow the writeup bwoncohowie wrote, do I still need to buy shift kit? Is there something in the kit that helps cure the 2-3 shift flare?

 

[Slowleak]

If I follow the writeup bwoncohowie wrote, do I still need to buy shift kit? Is there something in the kit that helps cure the 2-3 shift flare?

The shift kit comes with a mixture of springs and you pick the ones to use based on the shift firmness you want. It includes gaskets but no magical parts just to fix a flare. I don't know what in the kit fixed mine.

I say bolt it back up and head down the road...... hopefully you fixed it.

 

[panteramatt]

I haven't taken it apart yet. I wanna see if it's worth buying the shirt kit first.

 

[Slowleak]

I haven't taken it apart yet. I wanna see if it's worth buying the shirt kit first.

Ah, I misread your post. I know for sure the kit fixed mine but I don't know if BwoncoHowie's instructions would have. Then again we don't even know if you issue is the same as mine, just that we both had a flare.

Much of what BwoncoHowie does is also in the Transgo instructions. You do get gaskets, options with different springs, and pins for the modulator. The springs give more options for firming up the shift etc.
the kit is not a bad deal. I think I got mine from Amazon.