Bad trans limit RPM?

[TR87386]

Got another post in the engine section but thought that maybe someone might know in here. The question is the tranny wont' shift at over 20# from 2nd to 3rd but seems ok at lower boost. Also the motor won't go over 4400 rpm. If the trans was going south is there something that would limit max rpm Is rpm shift point controled by the TV cable? I currently have the cable set by the factory reset procedure and have not messed with it. Trans was built by Eric from Dynotech (RIP) but only has about 2500 miles on it and otherwise has been perfect. I guess what I want to know is how does the trans know what RPM to shift at?

 

[mikestertwo]

The T.V. cable does control the shift points but if the engine won't go over 4400 rpm at WOT then the trans is not the problem, it's the motor. Ignition problems, valve springs, fueling?

 

[TR87386]

I have a post with a power logger file over in the engine forum. Fueling is good to go both injector duty cycle and pressure. Coil ohmed out fine 11.5- 11.7 ohms across all terminals. The valve springs are older (kirban's from 12 years ago ) That is what I thought as well. The module is possible also as it is original.

 

[TR87386]

Not looking like the trans. Went back out and tried a run from 0-70 @ 18psi. Could barely detect it before the 1-2 shift but on the 2-3 shift it still did it just not as exaggerated as on high boost.

 

[dank GN]

Change the govener i think you would have to lightin it up a little bit call one of the great trans builders on this site they will point you in the right direction

 

[Justin85]

Did anything come of this did you find out if a trans can limit RPM because I cant pull over 4700 rpm and I don't think its my valve springs.

 

[TR87386]

I ended up changing out the ignition mod, coil pac, and plugs. With no change.... I was spraying too much alchy lol. I just ended up seeing A/F in the low 10's high 9's when the issue would happen and realized I was drowning the motor with too much. Backed the knob on the controler down to about 5 from 7 and good to go. It pulls to about 5,000 now but that's it. I need to swap out the valve springs still, probly a little more RPM there as they have been in for a while. I thought it was odd that the car shuttered and seemed to hesitate when shifting but that was definently my problem.

 

[ikle]

It pulls to about 5,000 now but that's it. I need to swap out the valve springs still, probly a little more RPM there as they have been in for a while.

My car does the exact same thing, let's us know the out come when you replace the valve springs. My Kirban valve springs are about 8 years old and was wondering if changing them would correct my issue. Thanks, Kyle.

 

[dank GN]

First off the TV cable does NOT control shift points. The governor in the trans does . if you remove the trans pan it is near the back. it has a cover on it with 4 bolts . if you lighten the weight it will shift higher . more weight it will shift sooner google it

 

[SSedan64]

At WOT the Gov & Vbody shift valves control shift points. At part throttle the Gov, TV & Vbody shift valves control shift points.
From BTO's site:
"The TV cable used with the 4L60/700R4, 2004R & 200/200C transmissions should not be thought of as an automatic downshift cable. The TV cable used on the these Trans controls line pressure, shift points, shift feel, part throttle downshifts and the detent downshifts. The function of the TV cable is similar to the combined functions of a vacuum modulator and a detent cable."

Sticking/binding TV can cause all sorts of up/down shift problems.

 

[ricturbo]

do you have to remove trans pan to install tv cable or does it bolt on trans??

 

[TexasT]

You should be able to "fish" the bent hook out of the trans hole where the tv cable bolts up. The hook will slip through the eye on the cable then you insert the cable into the trans hole and secure it with the bolt. Then attach the engine end.

I'll see what I can dig up for pix.

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