3-4 Shuttle A Part Throttle

[alocker]

I got my WOT shifts perfect with the help of some board members here (thanks David H and Texas T). I am really impressed with the heavy throttle and WOT shifting of the 2004R.

The last issue is when I lightly accelerate it will shuttle back and forth between 3-4 rapidly. I do run a lockup but have no delay device installed. This trans has always done this no matter what converter or governor has been installed. I am 95% sure it is not just the lockup. I will confirm this later by pulling the power to the lockup. It has a CRF valve body with a CK shift kit.

Any suggestions?

 

[mikestertwo]

What mods have been done to the transmission? Are you sure it's a 3-4 shuttle and not 2-3?

 

[alocker]

Guys, I apologize but I'm a idiot. It turns out its the lockup that is cycling. The new converter just makes it seems like its the gears because it fluctuates almost 1000 RPM. When I first installed the trans I played with delay circuits but for some reason they would work for a few cycles then stop working. I made a home made delay out of a transistor and some capacitors. I also purchased a delay relay setup from ebay and that burned out too.

Not sure what to go with here. If the 4th upshift was later it would help but delaying the converter lockup it probably the real answer.

 

[TexasT]

Stay at it, very few problems just go away on their own.

As for the 3-4 shift you could get a stiffer spring for the 3-4 shift spool in the vb. #325 in the diagram

http://www.gnttype.org/techarea/images/valvebody.gif

 

[McHaggis]

Have you considered 2 RPM switches in conjunction with a vacuum switch? You'll need two because as soon as the TC locks it'll drag the revs below the set rpm limit causing the TC to unlock and therefore start to cycle. (I think the same may be true for the vacuum switch but I run 2 of these as well so I don't have that problem). This way you can delay TC lockup until you're at a high speed. This could take a bit of playing with to get right though as I got carried away and run a system with two RPM switches, two vacuum switches a timer and 5 relays. It works great now but it wasn't so good with only rpm switch. This setup allows me to set upper and lower vacuum limits, same for the RPM's and the timer delays activation until is been driven steady for a short time. Stops it locking too quickly once it changes into 4th.