Throttle valve adjustment

[ddarnell]

The transmission on Bud (76W200) will not go into first when in drive. As I'm fiddling with the trottle valve lever I notice that it has approx. 90 dgrees of movement. The first 30 or so degrees is free play with no spring pressure applied internally. Is this normal? Should the lever be full forward at idle as the books suggest?
Thanks,
David

[712edf]

Are you refering to the kickdown linkage? Sounds out of adjustment. This lever does more than just downshifting. Its actually a pressure valve control. Must be hooked up & set-up properly for transmission to work correctly.

[ddarnell]

Yes it's the kickdown linkage. It is currently adjusted with the slot full forward on the carb shaft at idle. The lever on the trans is also full forward at idle. I'm wondering about the free play at the beginning of the throttle (kickdown) lever acutation.

[712edf]

Without going into how to adjust it, basically you want the lever on the transmission to "almost" be all the way backwards at wide open throttle., without any binding. Most all manuals have the procedure, but trial & error road tests are the best way to get it where it needs to be.

Bucky

[ddarnell]

Bucky, do you suppose that the throttle valve adjustment is the reason that the trans does not shift into first? Currently with the throttle wide open there is approx. 15-20 degress of acutation left on the throttle valve lever.
David

[712edf]

Its possible, but not definate....There are 2 kickdown bands to adjust. The 3-2 can be adjusted from outside, the low-rev band is accessible by removing the pan.

I'd get a manual, or at least play around with the kickdown linkage adjustment & see if you can improve it. If you go too far one way, it won't upshift correctly & may bind preventing the carb from reaching WOT.

Whatever you do, DON"T remove the kickdown. Tranny's burn up quickly that way. Only a specially modified 727 such as those with manual valve bodies work w/o kickdown.

Bucky

[ddarnell]

Spent the last couple hours researching. It does NOT appear that a mal-adjusted TV will prevent the automatic return to first while in drive. Sounds as though it may be governer problem. More research!
David

[Deathdeelr]

Bucky, do you suppose that the throttle valve adjustment is the reason that the trans does not shift into first? Currently with the throttle wide open there is approx. 15-20 degrees of actuation left on the throttle valve lever.
David

I just covered this in another thread but the answer is YES. I just double checked the book and according to the manual there must not be any actuation left on the lever at wot. The throttle valve needs to know where that carb is at all times and yes, it could prevent a first gear return at idle. The trans thinks that the carb is still open even though it's at idle and the truck is stopped.

This is definitely a popular subject this week!

[ddarnell]

You are correct!. I moved the slot up forward on the carb pin and 1st returned. It would appear that the books procedure is not entirely correct. Adjusting the TV to it's forward most position at idle is not neccesarily the the proper position. In my case it left the TV with 20 degrees more travel at WOT and made for quick soft shifts
David

[Deathdeelr]

I just took another look at my truck and there's an adjustment on the vertical rod to take up any further travel you might need.

[ddarnell]

I'll take a look at mine to see if has vertical adjustment as well. I'm no longer getting the entire range of motion on the TV.
David