Little Auto Tranmission Help Please

[Heelin]

Hi All,
OK so here is what I have. 1996 XLT 4dr 4X4 Auto trans 4.0L OHV with3.73 LS axle, the rig has 128 K on her.

Here is what it's doing. At 55 MPH With O/D on I'm turning 2900 rpm when I turn O/D off it goes up to 3600 RPM. Doing a search here it sounds like I have no 4th gear? So where should I look. There are no codes and the O/D light does not flash. I do have a rattle sound underneath could this also be caused by a Torque converter? The thing is @ 110,713 this truck had a transmission rebuild, I have the records. it says that " Road test Diag code po732 EEC system OK interm band broken, replace forward and direct clutches flush cooler replace Torq conv and O/H valve Body, road test all OK". on the bill there is pricing for a new Torq converter, band asy and valve asy. So it sounds like a pretty through rebuild? this work was all done at a ford garage that has a good reputation. The only catch is that this was done in 2004 and it has been driven very little since.

Now only 18k later it sounds like maybe 4th gear is out? Could that be? Wouldn't the band asy and valve body repaired the 4th gear then? Any ideas where to check? I'm not into trying to rebuild the transmission myself but I am capable of doing some checks and minor repairs. Any ideas or help would be greatly appreciated! Thank you!

 

[BrooklynBay]

The engine works easier in overdrive so it doesn't have to rev as much. You could do a band adjustment, and a valve body rebuild with a shift kit if you want to get less slippage. When was the last time you replaced the filter, and the fluid?

 

[Heelin]

Just did the transmission service and filter 2500 miles ago. Thats just it I don't think the truck ever even shifts into 4th gear or even try to. If I start out in 1 manually shift to second it shifts then I shift to D and it only shifts one more time that would be third and no other shifts or anything. The RPM's are way high for 4th gear. a friend has a 98 with the same axle and trans con fig and at 55 he is turning 1900 rpm about 1000 below me and you can hear it as well as the tach showing it.

Could the bands just be out of adjustment and that stopping the final shift? Thanks !

 

[BrooklynBay]

It could be a combination of several things. Start with the band adjustment since it is simple, and doesn't cost anything (no parts involved).

 

[Heelin]

OK I'll give it a try, My transmission code on the door is a T so How do I know if I have a 4R44E or a 4R55E ? They used the same code for both transmissions. I have never done this before but looked up the sticky on how to. Looks like tighten to 10 ft lbs and back of 2 turns on the O/D band and 2.5 turns on the intermediate band. The overdrive band is closest to the engine on the drivers side correct? Thanks for your help BrooklynBay!

 

[Pensa]

BrooklynBay, a question. Isn't overdrive fourth gear? If his RPM's change from OD on to OD off doesn't that meant fourth gear is there? Could it be the torque converter isn't going into lockup?

I don't know what my RPM is at 55 mph, but my tach only reads 2100 at 70 mph.

 

[BrooklynBay]

The 3.0L uses the 4R44E, and the 4.0L uses the 4R55E. You are correct that the overdrive band is the closest one to the front. The intermediate band is in the middle.

 

[BrooklynBay]

BrooklynBay, a question. Isn't overdrive fourth gear? If his RPM's change from OD on to OD off doesn't that meant fourth gear is there? Could it be the torque converter isn't going into lockup?

I don't know what my RPM is at 55 mph, but my tach only reads 2100 at 70 mph.

Overdrive on this transmission is 4th gear, and a change of RPMs does indicate that something is happening when it reaches the 4th gear. The torque converter should lock up much earlier.

 

[Heelin]

So its a 4R55E OK good. so what you are saying to Pensa is that because the O/D button has an effect that it's more like a Torque converter problem not going into lockup? Humm that wold be better than a rebuilt transmission. I need to get an in. pound torque wrench and I will be adjusting the bands to see what happens. thanks again, I'll let you know how it goes.

 

[Pensa]

BrooklynBay knows a lot more about automatic transmissions than I do, I was just making a somewhat educated guess. This is the first auto transmission I have owned in over thirty years and they aren't like the old ones in some ways.

 

[BrooklynBay]

The high RPMs could be related to a few other things, and not always the lock up of the torque converter or basic shift points. The clutch packs get worn down after a while, then you have metal against metal which creates slippage, friction, excess heat, and burned up fluid. The torque converer also has clutch plates. Servos dry out, and don't always apply full pressure against bands when they are suppose to apply. Bands wear out just like clutch plates. Rubber seals leak, and cause hydraulic pressure loss. Spools in the valve body wear down along with the bores which cause hydraulic pressure loss as well. So this shows that you can't always blame one part for a specific problem.