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727 shifts late

Started by culp71, July 18, 2018, 06:19:41 AM

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culp71

freshly "stock" rebuild on 340 727 combo, test drove fine, I thought.
I drove out to a friend, that had many ebodies growing up and he commented that it shifted too late.
I had noticed that I revs a little high before shifting but did not clunk or "jump"
when it did and I was uncertain as to when they should normally should shift.

so under soft or hard acceleration 1 st to 2nd seems a little high but 2 to 3 doesn't happen until beyond 4 thousand rpms... around 50 mph...but all down shifts seem to be fine.
after I got home I let it cool down, and adjusted kickdown linkage all the way forward in the slot where the carb side stud passes through. also tried various adjustments on the rod to the trans too,
took it for a drive... still shifts too late I think....
I have looked over "adjustment procedures" and gather that when the lever on trans is all the way back, the carb should be at wot; and also that at idle the lever on trans should be all the way forward, and the carb stud should be all the way back in the slot on slot ....this sound correct?
I have tried many adjustments but doesn't seem to bring the shift points down.

any ideas, thanks?
possibly the wrong linkage type? etc?
pic shows the style I have?

RUNCHARGER

I think your understanding of the adjustment is correct. All the way back on the carb linkage will match all the way back on the trans throttle linkage. Is the kickdown linkage quite free? Sometimes they will bind up and this will hold them further rear than they should be at part throttle. This can easily occur at the trans if you don't have enough clearance between the two transmission levers. Another thing to look for is a kinked transmission line which will slow down fluid flow and lead to late shifts.
Sheldon

Shane Kelley

I think you have the adjustments correct. I'm leaning toward something with the governor in the transmission. I would put some more miles on it before I jumped into anything yet. Maybe throw in a few hard romps through the gears.  :alan2cents:


1 Wild R/T

There are a number of things that effect shift points....  Throttle pressure/governor pressure & line pressure all effect it...  if line pressure is high it will shift late & firm... Governor pressure high it shifts early..... Throttle pressure high it shifts late.... The easiest adjustment is throttle pressure & most trans guys use it to tailor the shift points... Obviously it has it's limits, lucky for you your doesn't sound far off.... Try shortening your kick down linkage 3-5 turns....

culp71

#4
 "Try shortening your kick down linkage 3-5 turns"

what part are you referring to as I find nothing that can be turned on the kick down linkage but a set screw at the trans arm?
I will look over system, and shorten what ever I can, thanks.

1 Wild R/T

Quote from: culp71 on July 18, 2018, 10:51:07 AM
"Try shortening your kick down linkage 3-5 turns"

what part are you referring to as I find nothing that can be turned on the kick down linkage but a set screw at the trans arm?
I will look over system, and shorten what ever I can, thanks.

Red circle

HP_Cuda


Usually the kick down linkage has a threaded end (near the throttle) so you can adjust it but yours seems to be one piece.

1970 Cuda Yellow 440 4 speed (Sold)
1970 Cuda clone 440 4 speed FJ5
1975 Dodge Power Wagon W200


chargerdon

I think you are both correct...   the big blocks have a linkage that the rods have threads in them and can be screwed in or out at both the tranny up rod, and the rod from fulcrum to the carb.

The small blocks do not...they are adjusted down at the transmission by losing the set screw and sliding it forward or back.   Since you have a 340 im fairly sure the adjustment is down at the transmission itself.   

After it finally shifts into high...  cruising say at 40-50 do you have to floor it to get it to downshift?   Or is downshift at say 1/2 to 3/4 pedal...it should be about 90% floored...if earlier then the rod is reaching to deep too early.   

1 Wild R/T

You both are not paying attention... In the photo above I circled the adjustment.... It's on the down rod....  318's & 360's have the normal adjustment of the top rod, for some reason 340's don't... Also 318 & 360's in Aspen/Volares have it on the down rod... Plus they can be adjusted down by the trans....   If this 340 has an adjustment down by the trans it probably has Aspen/Volare kick down linkage.... I've done that swap myself... Back in the 80's & 90's when 340 linkage was scarce Aspen/Volare stuff was in wrecking yards everywhere & it's close enough to work...

Shane Kelley

Quote from: 1 Wild R/T on July 18, 2018, 12:47:17 PM
You both are not paying attention... In the photo above I circled the adjustment.... It's on the down rod....  318's & 360's have the normal adjustment of the top rod, for some reason 340's don't... Also 318 & 360's in Aspen/Volares have it on the down rod... Plus they can be adjusted down by the trans....   If this 340 has an adjustment down by the trans it probably has Aspen/Volare kick down linkage.... I've done that swap myself... Back in the 80's & 90's when 340 linkage was scarce Aspen/Volare stuff was in wrecking yards everywhere & it's close enough to work...
:iagree: 

HP_Cuda

1970 Cuda Yellow 440 4 speed (Sold)
1970 Cuda clone 440 4 speed FJ5
1975 Dodge Power Wagon W200


culp71

so mine is all one piece, with no adjustments at any point, accept at the trans arm connection...so this style is correct for a 340 right?
if so, ill keep trying various adjustments....

Shane Kelley

Quote from: culp71 on July 19, 2018, 05:49:18 AM
so mine is all one piece, with no adjustments at any point, accept at the trans arm connection...so this style is correct for a 340 right?
if so, ill keep trying various adjustments....
Look where 1 Wild R/T circled. That is a adjustment point. Pop the linkage off the ball socket and turn it to shorten the linkage. That should make your trans shift sooner.

culp71

#13
I removed that rod at that point and there nothing but a "fixed" hole and clip to retain it, no adjustment...

so is this the wrong style setup?

checked throw of carb and trans, they seem to have the correct amount of throw on both ends...
contemplating cutting out a section of the rod and installing a threaded rod for adjustment. just want to make sure its not the wrong style before I do a bunch of mods....

HP_Cuda


So I was right all along, Thanks Wild I'll take my apology now.

:haha:
1970 Cuda Yellow 440 4 speed (Sold)
1970 Cuda clone 440 4 speed FJ5
1975 Dodge Power Wagon W200