Need help trans wont shift
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Need help trans wont shift
My buddy has a 1990 ranger with a 4.0 auto 2wd. When i got it the trans wouldnt hift out of first. Then, I replaced the vac line going to the mdulator on the trans and the modulator itself. Now, it will only shift if i let off the gas. it downshifts perfectly, just wont upshift. The other thing ive seemed to notice is that in second gear i ca go almost 80 without being at rediculous revs or without shifting higher. Is this normal? I need help with this!
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Joined: Jan 2002
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From: suburban atlanta
Are you sure that the pin that sticks out of the modulator was in place when you installed the modulator? Is the hose up by the intake manifold snug or is it oily and loose? Follow the tube from the trans up to the intake to make sure that it is not broken somewhere.
Check the kick down cable to make sure that it is not too tight.
tom
Check the kick down cable to make sure that it is not too tight.
tom
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When i installed the pin in the modulator i made sure it was in properly. I measured the vacuum at the modulator just to eliminate any possible vac leak and it registered at 20hg. All the conections are clean and tight and the engine produces sufficient vac. Where is the kickdown lever? I dont think it is a torque issue as it can smoke the tires right off if you wanted to.
Logistics Pro
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From: suburban atlanta
It has a cable that is attached to the throttle linkage.. if it is like other models of the same vintage. I can't quote the procedure to adjust it, but remember it involved flooring the gas pedal. With the engine off.
You may have a stuck valve in the trans that 'thinks' you have no vacuum, as if the modulator pin was not being retracted by the vacuum. OR, you may have an adjustable modulator. Where the vacuum line connects, if you look in and see a flatblade screw head, you may be able to adjust the modulator and thus the shift characteristics.
Weak spring -> shift sooner Stiff spring > shift later/higher rpm
tom
You may have a stuck valve in the trans that 'thinks' you have no vacuum, as if the modulator pin was not being retracted by the vacuum. OR, you may have an adjustable modulator. Where the vacuum line connects, if you look in and see a flatblade screw head, you may be able to adjust the modulator and thus the shift characteristics.
Weak spring -> shift sooner Stiff spring > shift later/higher rpm
tom
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The replacement modulator is adjustable, but it said it was set to factory specs already, plus i turned it one full turn in the direction recommended on the package for soft shifts. I guess ill try and adjust it some more. Does anyone have the procedure for adjusting the kickdown??????? Thanks!
Logistics Pro
Joined: Jan 2002
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From: suburban atlanta
There are 3 things that affect shifts, IIRC. 1) governor, 2) throttle pressure (kickdown) and 3)modulator. If the governor sticks, it won't shift. If the modulator is broken, it won't shift. If the throttle pressure is stuck, it won't shift.
I'd try flooring the gas pedal with the engine off, which may adjust the throttle pressure.
I'd try poking a straight rod (coathanger? awl? punch?) thru the modulator hole to see if you can feel the lever move that the modulator pushes against.
If this is an A4LD, it may be that the governor is not getting good pressure as they *can* wear grooves where the sealing rings ride, and lead to 'off' pressurees.
So, if all that doesn't work, you could remove the tail housing and take apart the governor, or drop the pan and look at the valve body where the modulator pokes around and where the kickdown lever moves stuff.
If you can get the trans to kickdown while cruising then the throttle pressure is probably set OK. If the trans puts itself back in the 1st when you come to a stop, the governor is doing *something*.
Me, I'd pull the pan and check that the gizzards are lined up right where the modulator does its thing...
tom
I'd try flooring the gas pedal with the engine off, which may adjust the throttle pressure.
I'd try poking a straight rod (coathanger? awl? punch?) thru the modulator hole to see if you can feel the lever move that the modulator pushes against.
If this is an A4LD, it may be that the governor is not getting good pressure as they *can* wear grooves where the sealing rings ride, and lead to 'off' pressurees.
So, if all that doesn't work, you could remove the tail housing and take apart the governor, or drop the pan and look at the valve body where the modulator pokes around and where the kickdown lever moves stuff.
If you can get the trans to kickdown while cruising then the throttle pressure is probably set OK. If the trans puts itself back in the 1st when you come to a stop, the governor is doing *something*.
Me, I'd pull the pan and check that the gizzards are lined up right where the modulator does its thing...
tom
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Ill definetly try that. Ive pulled the pan twice already (once to replace filter and fluid, second time to put on o-rings that i forgot to put on filter DURR) and nothing looked abnormal, but if thats what it comes to, then ill pull it again. Also, do you guys recommend any places to get a rebuilt trans from?
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Joined: Jan 2002
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From: suburban atlanta
Almost 80 in second gear seems a little high. Have you counted the shifts? You should get a torque converter lockup above 35 mph, which you can check by cruising along and tapping the brake pedal enough to turn on the brake lights (same switch), and you should hear or feel the rpms increase for about 10 seconds holding the gas pedal steady and then fall back down as the lockup occurs. You can get lockup in 3rd and 4th so you have 1,2,3,3L,4,4L - L being the tc is locked...
It seems as if the modulator or the lever it moves, is not being moved. Pan drop here you come...
tom
It seems as if the modulator or the lever it moves, is not being moved. Pan drop here you come...
tom
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