overdrive quit working?

[Dunc]

So I have a 89 b2 w/ 2.9 6cyl. and every thing works great at the moment...except the overdrive. I have had zero transmission problems and nothing is making funny noises when shifting. It just doesn't go into overdrive anymore. So if I want to go 70 mph on the free way I have to hit about 4300 rpms. Which makes me uncomfortable. This is my daily driver and though I dont take that many long trips on the free way I would like to know perhaps what would be causing this. Around town and out in the sticks at lower speeds I notice nothing goofy.

Thanks a bunch.

 

[94 splash]

possible trans Solenoid

 

[baddis]

but you should be able to pull codes and the comp will tell you

 

[Dunc]

Thanks guys for the info, Ill look into it. Sorry about the wrong forum I thought this was engine & transmission section.

 

[Southern3.0]

If you put the selector in OD dose it drive around and just not go into OD or do you have to put in D for to drive it around. Cus when I had my 91 w/ the A4LD if I put the selector in OD and gave it gas it would just rev like it was in neutral, turned out the Overdrive sprag was bad

 

[arrabil]

In the meantime don't be too worried about 4300 rpm. The 2.9 can handle it.

 

[southernlifttruck41]

It may be your 3 - 4 shift selinoid . Put it on a computer.

 

[F150hybred]

BUMP! I have the same issue. Want to know what's the issue is too.

 

[Dunc]

as for some of the questions:

if I put it in Overdrive it runs fine, it is just like it is in normal Drive. So I am going to take it to a puter on monday to check it out.

My questions: I dont know much about transmissions, havent had problems with them so havent taken one apart yet. Can you get to a solenoid without much trouble or is it more invovled?

Also what RPM level will cause excessive wear on the 2.9 if 4300 is ok?

And there are no check engine lights or anything if that matters.

 

[pimtool]

Make sure you speed sensor in the t case is ok. You speedo can work and the sensor can be bad. If its givving bad info to the computer it wont know its supposed to be in OD

 

[grumpyguy]

Mine keeps jumping in and out of OD...maybe I've got a similar problem.

 

[baddis]

Mine keeps jumping in and out of OD...maybe I've got a similar problem.

this is how mine started but now more often than not the o/ doesn't work

 

[F150hybred]

Speed sensor you say??? hmmmm... Gonna have to look into that.

 

[baddis]

Make sure you speed sensor in the t case is ok. You speedo can work and the sensor can be bad. If its givving bad info to the computer it wont know its supposed to be in OD

i got to thinking about this and in a way it makes sense but in a way it doesn't . if you were having a 3/4 shift problem AND your cruise control didn't work i could see it as a problem. but if the cruise works i would say that that is not your problem. it would be a 3/4 shift solonoid .

 

[F150hybred]

UPDATE: After looking over wiring drawings and testing... and probing, I finally broke down and had a code scan done. This may not be your problem, but my problem was in the ECU. Turns out that my computer was not working correctly and not shifting from 3 to 4. If you have a spare one hanging around, maybe try plugging it in and see if that cures your issue. If not, it's rather easy to figure out. First step, confirm you have power (12V) coming from the center connection (red wire) of the three pin plug on the left side of the transmission with the key in the run position and engine off. If you have power there, then check the other two leads for continuity. The coloring on the connection is the same as the colors on the computer plug in. These two leads are located next to each other. Mine were a brown wire with a light blue tracer and a white wire. If you have continuity in these wires (no breaks) odds are, you have either a faulty shift solenoid or a faulty ECU. Remember, this is just MY EXPERIENCE. Your problem may be different.