Ranger Jerking Between Shift

[truckzilla]

Hey everyone, I have been having one hell of a time lately with my 2001 2WD V6 3.0L Ford Ranger and im looking for some advice on what to do because I am just lost now.
The problem: The truck drives perfectly normal under any condition for about half an hour of driving or so, but after that when you stomp on the gas and do a full throttle acceleration it climbs normal but when it gets to the point its going to switch gears and shift up instead it starts to jerk back and forth until you let off the throttle to a more relaxed level of acceleration. It will not jerk at normal accelerating speeds but when you want to slam the pedal it almost always does.
Recent history: This whole problem started when my engine blew, about 107K miles on it (110k currently), I had to have the oil pan gasket and the crank case cover gasket replaced and apparently they had done something wrong and I lost alot of oil in a short time. Well I went to the junk yard and bought a new motor with 67k miles on it. I had never changed a motor but i built a motor stand pulled the old one and placed the new one (I also had to swap the fuel rails because they had diffrent plugs on them).
When I removed the motor (seeing as I had never worked on pulling an engine or trans) I just unbolted the motor disconnected everything and pulled it away from the trans, with the torque converter attached to the flywheel. When I put the new motor in I attached the torque converter and flywheel to it and set it into the trans all at once.
What I have done so far: I took out the trans and brought it to a trans shop to have them look at it, they said supposedly my pumps fine and replaced the torque converter, im pretty sure its just my old one rebuilt. But this time I properly installed the trans and torque converter and still the problem persists.
I know thats alot to read so thanks to anyone for help/suggestions because im fried, I dont know what im doing honestly, I can turn a wrench pretty good though.

 

[Ranger Kip]

maybe letting off the clutch to soon? happens.

 

[Big Jim M]

Sorry Kip!

maybe letting off the clutch to soon? happens.

I'd be looking at the tune.. Sounds like the plugs aren't firing well at WOT. There is a chance the detent cable is misadjusted, but I'm leaning toward the tune. What sparks are in there...motorcraft is what we advise.
Big JIm

 

[pcollins]

maybe letting off the clutch to soon? happens.

its an auto.

 

[Earl43P]

Sounds like you are hitting the 3000rpm rev limiter as though it were in Neutral or Park.

Take it out of D and shift it yourself. If it runs up in rpms fine in every other gear selection except D, you need to adjust the DTRS so it isn't in "electrical neutral".

Might you have pulled on the shift cable when pulling/installing the motor?

Do the shifter selections read correctly in the indicator or is it slightly off?

Check the operation of the reverse lights. If they are "off" too, meaning you have to wiggle the shifter around to get them to come on, that confirms the DTRS is maladjusted.

That part used to be called the Neutral Safety Switch. Just loosen its 10mm mount bolts to adjust it. No need to mess with the big spline nut unless you are removing it.
Left side of the transmission, where the shifter cable connects, you'll see it.


Welcome to The Ranger Station!

 

[Ranger Kip]

auto's have a clutch =P it still has to disengage and reengage the tranny to change gears. my truck jumps when shifting and I KNOW thats the issue.

 

[pcollins]

auto's have a clutch =P it still has to disengage and reengage the tranny to change gears. my truck jumps when shifting and I KNOW thats the issue.

autos have a torque converter. and Multiple wet disc clutches and friction plates on the inside of the transmission, inside of drums. which have clutch bands around them to control the different ratios that the planetary gear set can produce. the auto does not actually have to be disconnected from the engine to change ratios. look here perhaps?

http://auto.howstuffworks.com/automatic-transmission.htm

to the OP: it almost sounds like its trying to change gears back and forth, does the RPM change?

 

[Ranger Kip]

about 1000 or so rpm difference going down, it reaches about 5k, jumps next gear and hits 4k, reaches 5,500 and jumps to third, and shoots down to 3k ish

 

[truckzilla]

Thanks for the quick responses guys,
to Big Jim: With the new motor I installed Autolite Double Platinum plugs APP104.
The plug wires came from the yard with the engine, they looked really good but I suppose they could be junk. It may have a slight misfire, no check engine light, just a small shake noticeable at stopped idle.

to Earl43P: It seems RPMs are always good its just when shifting comes into play, but I will try driving it in one of the other options. While I am checking this what should I be looking for?
I had the shift cable on and off a dozen times on the trans, it seems to select fine, the edge of the selector arrow is parallel to the edge of the D so very close to perfect.
I will take a closer look at shifting to reverse and my backup lights engaging and let you know, although I dont think I've had to ever wiggle it to get the lights on.

to Pcollins: while the whole truck starts bucking the motor does change rpms, its hard to tell if because it cant shift the motor stutters or if the motor stuttering wont let it shift, but there is a change in rpm. While its happening the arrow looks like its bobbling a little.

to Ranger Kip: I will compare this to my truck at full speed acceleration and get some details on what rpms it shifts.

Again I appreciate all the help, I will check into everything that was said on my way home from work.

 

[littleblueranger]

My 2002 3.0l 2wd Ranger has been having the same problem. The truck misfires right before a hard shift, and only when the truck is warm. If I take it easy then nothing happens. I have replaced everything I can think of; plugs, wires, fuel filter, coil pack....... Its on my last nerve so I figured I'd bump this thread and ask for help.

 

[TomB1269]

Check the syncronizer out. The shaft will start to wobble. Under normal load (also when engine is cold) is runs fine. You get in the gas a push the runs up over 3, 4 or 5K depending on the severity of your wear and it bucks and kicks like its as standard in the wrong gear or you just lost spark on 2 or 3 cylinders.
THIS IS A TELL TALE SIGN OF SYNCRONIZER FAILURE. There is a TSB that, something about monitoring ERG signal if it pulses more then 150 times upto over 1000 it signals a synchronizer shaft problem. PS: 2001 / 2002 engines 65000 to 75000 seem to be fairly consistant mileage when the problem shows up............

 

[littleblueranger]

Just to be clear on things, when you say syncronizer do you mean the "throttle position sensor"? Also my ranger decided today that everytime I go to start the truck I have to crank it three times to start, could that also be from a failing syncroizer?

 

[TomB1269]

Just to be clear on things, when you say syncronizer do you mean the "throttle position sensor"? Also my ranger decided today that everytime I go to start the truck I have to crank it three times to start, could that also be from a failing syncroizer?

No the syncronizer in the reminents of the distributor on threar passenger side that the CPS (cam position sensor) mounts too.
The Syncro as a usual will not cause the starting problem. Sounds more like a weak fuel pump not maintaing pressure on the line.

 

[littleblueranger]

So I got a little bit out of control. I pulled the syncronizer assembly out of the motor today to look at it. Got a new one from autozone and read my manual on how to install it. Now I realize I should have put the engine at TDC and marked the sensors position. What in the world do I do now???

 

[scott5640]

your truck jerks cuz its soooo fast