i have a 91 2wd 4.3 and my tranny has trouble kickin down at highway speed. i recently replaced the torgue convertor. and after a week my driveshaft blew out so i replaced the rear u joint and straps. since then i have had a crazy vibration around 70mph and i have to stand up on the pedal fpr it to kick down.
can the detent cabe stretch causing this problem? also where do you uys think i should start on the vibration?
thanks

 

It sounds like you have two problems going on right now.

The vibration may have been caused by the driveshaft being installed 180* out of phase with the yoke on the rear axle. Try flipping it 180* and see if that cures the vibration.

You can check/adjust the TV (throttle valve) cable quite easily. I would try that first.

 

i know i am gonna get roasted for this next question. but how do i flip it? are you talking about the u joint that connects to the yolk??
as far as the tv cable goes i have adjusted it to where at lower speed i have more respone so that might be why it is harder to kick down at higher speed. also thanks.

 

Remove the straps that hold it in place then rotate the driveshaft or differential yoke 180* and reattach.

 

thanks man, that was the picture that i had in my head but wasnt sure.

 

http://www.tvmadeez.com/article/index.php

This article explains the TV cable operation and it's CRITICAL importance to transmission operation. Unless you want to install a gauge to the test ports I wouldn't suggest adjusting the TV cable by feel. Even the slightest drop in line pressure leaves you with a rebuild. Ask how I know.

 

swartlkk, thanks for the advice on the drive shaft. easy fix. AND FREE! but i am still having issues with highway speed. getting up to speed is not difficult at all. but @65-70 mph it feels kinda sluggish. almost feels like there should be another gear there that it wants to go in to. could too much tranny fluid be a problem? and thanks again

 

nice link on the tv cable too.

 

Sluggish at 70mph in a heavy vehicle with aerodynamics of a barn door? Haha! You're not in a camaro! What gears & tires do you have?

Did you get your downshift issue resolved? (by tightening the TV cable a bit [pushing cable housing into TV bracket], it'll raise part-throttle shift pionts and make downshifts more responsive with lighter pedal movement)


Your fuel pressure may be dropping near WOT, preventing the injectors from delivering as much fuel as the engine can use. If there's no difference between 25% throttle and 100% throttle on the highway, fuel delivery is probably your issue. It can be confirmed with a pressure gauge.

 

lol! i did adjust the tv cable and it feels much better. but i have never had this problem until after i changed the torque convertor. so i thought the problem to be with the tranny. at 70 mph the throttle is still very responsive and i know it has much more but it force it and i am afraid of f'in somethin up