My setup 455, 391 gears, installed trans go shift kit.
Wot is working good, roast tires easily. Part throttle is good; shifts good and can feel the shifts. Line pressure is good also
My problem comes when I take more of an aggressive throttle, not wot, but when I dig into a little more than part throttle it seems to want to 'slip' past the gear and then grab and go... And I hate to use the word 'slip' cause I believe the trans is still good.
Does having the right governor affect any of these symptoms? I did shaved off some weight and removed a spring. Don't know what else to check before I tear back into it. Needing some opinions please, thanks.

 

TV cable adjusted ?

 

it is. I even took the pan off to make sure the plunger is going in. Cable is absolutely correct.

 

Try adding an additional quart of fluid. The Grand National guys do this to band-aid the less than desirable filter design. The filter pulls fluid from the top of the filter, under hard acceleration the trans can suck some air in addition to the fluid. The real fix is a deeper pan and lower filter. I doubt this will fix your issue, since you say it only does it at heavy throttle, and not WOT.

Back off the TV cable a click or 2, see if that helps. If so, you can add a spring to the TV cable between the lead cable end and the plastic cable clip. The idea behind the spring is to allow less aggressive cable adjustment, at WOT spring coil binds and has the tv cable at max adjustment. I have seen kits in the back of the Transtar catalog. Next time I’m in the garage I’ll see if I can find a part number.

 

I'll give it a shot when it stops raining, thanks.

 

Which weight and spring did you modify? The big weight and spring affects part throttle shifts from my experience. Did you set the servo clearance? I think one washer was about right for my trans, did what Dr Dan said to check clearance.

 

I'm a little fuzzy on the details but I did remove a spring from the governor and shaved the other weight. Can't recall if it was the big or small weight. The trans go kit actually sent a picture of the modified governor and I tried to duplicate it the best I could. They stated that some governor's are better than others. I don't have the worse governor but not the best. Hopefully that's what it is cause I'll get another one if that's the case. Servo clearance is ok. I only used 1 washer too. I believe that's good.

 

To raise shift points you shave the small weight. Removing the spring on the big weight might cause your issue. If anything I stake the spring on the small side and shave that weight thin to hit 5000 rpm.

 

Ok I'll go thru the kit again and install my spring back and see how it does. Other than that it seems to drive really good. Thanks

 

Looks like you were absolutely correct. I installed the spring on the big weight and It's not 'slipping' at hard throttle anymore. I appreciate your help and everyone who chimed in, thanks.
*side note* on the video for the shift kit it said to remove the spring on the big weight? Odd deal for me but I guess it works for everyone else. Oh well.. It's good now and I'll adjust shift points later in the future

 

Glad to hear it fixed the issue.