Tranny shifts from 1st to 3rd

[Coley]

This one's got me worried...
When under light acceleration, my transmission (727) will shift to 2nd, then almost immediately I'll hear a slightly higher-pitched sound coming from the tranny along with a slight "slip" feeling, and then it's in 3rd. When driving in D2 it works ok-no noise as it's moving through the gears, and when in D under heavier acceleration, it seems to actually go through 2nd gear (not perfect though, still seems to shift a little early to 3rd). I've adjusted the throttle linkage and the shift linkage, and that didn't help. Neither did verbal abuse. Also, the kickdown works about half the time-but from what I've seen that's a separate problem.

Any help is greatly appreciated..

Thanks



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84 GW
360 NP229

[ClarkGriswald]

You may want to search around these forums for info on that "kickdown lever" that is not actually a kickdown in the traditional sense. I belive if i have read right myself (if my bat sense's dont fail me) that that is actually a throttle pressure sensor or something that sense's (throttle pressure duh? haha) but that has to do with that shifting of the trans.. Mabye one of the more knowledgable people can give ya the real skinny on this one.. hope this helps anyway.. Good luck.

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88 Grand Wagoneer
D44's front\rear
AMC 360
TF 727
NP 229 (Funky)
Bone Stock (for now)
NO RUNNING BOARDS!

[Drew M]

The chrylser auto kickdown controls the fluid pressure to the clutches (how hard they grab) and, in part, upshift points. You have a Chrylser automatic transmission in your truck.

Your downshift linkage is not adjusted right. Get it fixed pronto or you'll be replacing the trani. I did you manual shifting routine for a few months after rebuilding my engine, then I lost third, then second, then first . . . burned out my clutches. $800 later, I knew how to adjust the kickdown linkage!!!
-Drew M.

[Coley]

2nd attempt on this post, don't know what happened to the 1st..

Drew,
You're talking about adjusting the two kickdown adjustment screws right? I just found it in Haynes (sect. 1-40). Having already adjusted the throttle linkage and the shift linkage, I can't think of anything else it would be.

Thanks for the assist guys!

Coley


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84 GW
360 NP229

[scotty]

the "downshift linkage" does control the shift points,and the firmness of the shifts, and it is very important for it to be adjusted properly. not enough trhottle pressure causes the tranny to shift too soon.ths can cause lugging,and excess heat,which is very bad for the tranny. too much throttle pressure causes the tranny tothink youre accelerating faster than you are,and delay the upshift. ths causes higher rpm shift points when accelerating lightly,high rpms create tranny heat,and are also bad for the engine. http://www.cs.colostate.edu/~zeimet/ubb/frown.gif

if youve allready adjusted the throttle linkage according to the manual,then the problem could well be elsewhere.you should first change the fluid and filter,and check it well for metal,clean out the pan and adjust the bands.

if the problem still exists,youve got worn clutches,or some other internal problem.does it slip in any other gear? reverse? first in D or 1? second in D or 2?

in 3rd gear,both the front and rear clutches are applied,and no bands.if youre only slippage/noise is in 3rd gear,the rear clutches are slipping. if it also slips in reverse,the front clutch is slipping. it may be time for an overhaul.

you can use air pressure to check the clutches and servos with the tranny in the car,but youll have to remove the valve body. or you could have a reputable tranny shop check it out. you could still save money by pulling it yourself if it needs rebuilt and youre not comfortable doing the rebuild yourself.

hope this helps.

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scott
85 grand wagoneer
258/904/twin stick dana 300/dana 44/amc 20
38x15.5 gumbo mudders
snorkel/dual batteries/onboard air/"custom" convertable
3 inch body lift/mostly stock suspension/"modified" fender openings
custom front/rear bumpers and brushgaurd