I know that most 700R4's won't shift 4th gear at WOT. I went to the FAQ section on TGO.orgs home page and they said that there is an upshift value made by GM#8673948 ($20)and another made by B&M#70237($30) that will give you 4th gear at WOT(these parts wont give you 4th @WOT). I installed the GM 8673948 and my car still wouldn't upshift into 4th at WOT. I just wanted to let people know that fix in the FAQ section is wrong. I believe I found the correct part # after doing a search at Summitracing.com and B&M Racing. The Part is B&M #70249($115).I'll be ordering this soon for my car. Hope this help anyone looking to fix this annoying problem in there car.....Eric

 

When you installed the part did you use the red spring that came with the kit? Does your tranny have any other modifications to it like a shift kit?

 

yes and yes..... those parts will only give you 4th at 3/4 throttle. If you goto B&M site they will tell you the same thing

 

If you modify (blocking them) the 4-3 part throttle passages in the TV plunger sleeve. Then you can in 90% of the cases make the 3-4 WOT shift, and prevent the 4-3 downshift at high speeds (85-90 mph & higher). You will need to install 2 allen plugs in these passages (use a dremel to grind allen plugs to fit if necessary for reinstallation of the TV plunger & bushing). You do not have to remove the valve body to do this, just remove the 2 bolts holding TV plunger bell crank, pin, and pull out the plnger & sleeve assembly, "modify" TV plnger, & reinstall, tighten the bolts to 95 inch pounds, reset the TV cable, and you are done.

 

How can you raise the downshift speed threshold from 85-90 to 100 or higher?

 

^^^

 

What do you mean, "raise the downshift speed threshold"?

 

To make it be able to downshift at a speed higher than 90.