PeteK you still perusing the forums for transmission questions? LOL.

I put a TH2004R in my 1977 Corvette behind my roller 405 SBC. I installed a B&M lockup controller and the Grand National lockup converter that came with the transmission.

I'm not happy with the shifting points...like it never knows what gear to be in.

I need suggestions for what I assume I need, a shift help kit and possibly a higher stall converter. It seems like it's shifting too early, and I want to elongate the RPM band per shift without keeping the accelerator floored.

Thanks.

You've probably already checked it, but is it possible the TV cable is just a tad on the loose side? I believe that would cause quicker, softer shifts.

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Yeah I built a TV cable bracket that allows me very specific and exact adjustment and it's just as tight on the carbs as the throttle cable. It starts at a 1 - 1 adjustment. I need to change the position of the bracket to account for more throttle movement of the carbs but for the time being it should be fine. I don't even use but a small portion of the throttle travel.

Thanks for the suggestion.

Shift points are controlled by the governor, similar to how the 700r4 works. Here are a couple links to get started:

http://www.oldspower.com/vb/showthread.php?p=408813#post408813

http://www.turbobuick.com/forums/tran ... -higher-shift-points.html

Matthew

DB, give Troy a call. He's a GN guy.

DB, any progress?

No my work schedule and the weather has kept me out of the garage. I'm going to have some time Saturday I think to tinker.

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I still check in from time to time.
Shift kit and converter will not change shift timing, but both will affect shift firmness.

Higher stall converters will soften a shift, due to internal slippage. How much it softens it will depend on the efficiency of the converter, and stall. Better quality converters result in a happier end user.
Shift kits are nice, and can be used to tailor shift firmness depending on the kit, and the converter conbination.

Triple check your tv system is working properly, and play around with the weights and springs in the governor.

I don't know if it will help, but this was our process in setting the TV system:

We started with a freshly rebuilt 700R4 and the Bowtie Overdrives kit.

First, we noticed that the TV plunger was not fully returning to its outermost position with the spring that was in it. So, per BTO's recommendation, we installed the TransGo SK700-Jr kit, which provided full plunger travel. Supposedly it also added some other desirable shift qualities, but I didn't have a "before" comparison, so I can't really speak to that.

Then, after installation, we set the TV cable per BTO’s instructions using a pressure gauge as a guide, but we obviously didn’t get it quite right. Over the course of a few hundred miles, I ended up attempting to reset it several times, due to occasional erratic shifting (mainly late shifts or no 3-4 shift). I did notice that if I went too far in my adjustments, I could get what I would consider "quick" shifts.

Finally, we decided to start over, but this time I dropped the pan so I could see exactly what was happening at the tranny end. One person made the bracket adjustments at the carb while I monitored the effect at the plunger.
We set it such that:
- at idle, the cable provides a very slight bit of pressure to the plunger, and
- WOT corresponds exactly to full plunger travel, no more and no less.

That adjustment has been good for several thousand miles, and I’m happy with the shift characteristics.

And I should mention I'm using one of the stainless universal cables and the BTO Holley carb brackets. Obviously your setup is different, but maybe something I mentioned will help.

Now, I’m just hoping Pete doesn’t tell me I've done it completely wrong.