Throttle linkage question

-
J

John'sDuster340

Active Member
Joined
Feb 6, 2006
Messages
27
Reaction score
0
I recently had my transmission rebuilt (727, 3550 stall, 3.55 rear) and the shifts are crisp. Problem is that the shift points are too high and it makes the engine pass redline before shifting. I have to lift off the throttle slightly for it to shift to save the engine from grenading. Passing gear also instantly also causes the engine to scream past redline... as if it is downshifting to 1st from 3rd.

I am told that the cause is an improperly adjusted throttle kickdown. I have read that the kick down lever has to be completely forward and at this point the linkage should just touch the back side of the throttle lever. This is easy enough (just rotate the linkage by turning in or out), but when the throttle is fully opened there is way too much slack going the other way. I know that there has to be some play...about 1/8 of an inch but It's more like an inch away from fully engaging.

There is a verticle adjustment rod that I have yet to touch. Is there an adjustment at the transmission that would lesson the travel?

I appreciate any insight you may have. More info...I have the original intake but use a Holley 750 and 1" spacer.

Thank you,
John
 
John the adjustment you refer too (throttle pressure is the correct name but alot of people call it kickdown) will alter your shift rpm. The only problem is the manuals description for adjusting is a little confusing. The best way I can describe to adjust it is if you want to lower the rpm shift point shorten the rod and if you want to raise the rpm lengthen the rod. In other words more slack in the linkage lowers the rpm shift point.
 
Thanks Fishy68. The problem is that if I make shorten the rod, I get better shift points but then I do not have a kickdown. I cannot find a good compromise.

John
 
Perhaps a shift kit is better for your needs. A basic street/strip kit can have the tranny shifting when you shift the lever at the desired RPM and drive normal when you put the shifter in drive, just to drive.
I can't recomend one since I normally drive manuals.
 
the vertical adjustment is back at the bellcrank. it snaps onto the ballstud of the bellcrank. to set it, unsnap it from the ballstud, line up the little holes on the bellcrank, put a drill bit thru the little holes, and then thread or unthread the part on the vertical rod so you just barely have to pull up to snap it back on. then set the one at the carb.
 
I've ran into the same problem before John especially with the older transmissions made before 71. They didn't have part throttle kickdown and were very touchy on the adjustment. Sometimes a shift kit helps and sometimes it don't. The best kit is the Trans-go kits. TF-2 for street/strip. TF-3 for full manual. A little more work putting them in but worth it.

John another option would be to go with different governor weights but that would require removing the tailshaft to access the governor.
 
Your right about the kickdown...you have to slam the pedal to the floor.

Do you know if the transmission can shift from 3rd to 1st? It seems that when I do hit passing gear the revs go crazy instantly. Can a stall converter effect the shifting of the trans?

Lastly, can the shift kit be installled without dropping the trans?

Thanks,
John
 
Yes if your going slow enough it can shift all the way down from 3rd to 1st. Generally the converter dosen't affect the shifting of the trans. The only thing it can do is possibly soften the shift somewhat if your running a high stall converter. And yes you can install a shift improver kit without dropping the trans. Just need to drop the pan and valve body.
 
You must log in or register to reply here.
-

Back
Top