1st to 2nd shifting issues

[62Creepergear]

...in my buddies 2001 F250 super duty. It supposedly had a tranny rebuild, but in 2wd shifts late and sometimes goes right into 3rd. Strange thing is, if she is in 4 low, tranny shifts like a champ, nice crisp positive shifts through all gears. I told him it's got to be electronic. Any ideas?

thanks!

-62Creeper

 

[d-kuzmen]

Some 2001 vehicles equipped with 4R100 transmission, having a transmission build date between 7/27/2000 and 3/23/2001, may exhibit an intermittent, delayed or no second gear condition. Diagnostic Trouble Codes (DTC's) that may be set with this concern are P0781 (1-2 shift error), P0755 (shift solenoid B malfunction) and P0756 (shift solenoid B performance). This may be caused by the Intermediate One Way Clutch (mechanical diode style) not operating properly.

ACTION:
Verify condition, follow normal diagnostics per the appropriate Workshop Manual. If diagnostics leads to the described condition, replace the Intermediate One Way Clutch (OWC) (mechanical diode style 7A089), Intermediate Brake Drum (7D044) and Intermediate Clutch internally splined friction plates (7B164). Refer to the following Service Procedure for details.

SERVICE PROCEDURE

Verify above "ISSUE". Refer to Figure 1 for replacement components. Refer to the appropriate Workshop Manual for Transmission Disassembly and Assembly procedures. If contamination is present, a full disassembly and cleaning will be required. Follow all the normal service procedures as indicated in the appropriate Workshop Manual.

NOTE: MAKE SURE ALL MATING COMPONENTS LISTED ARE CHANGED. THE MATING COMPONENTS OF THE TWO DESIGN ONE WAY CLUTCHES (7A089) ARE NOT INTERCHANGEABLE. IF ALL THE COMPONENTS ARE NOT CHANGED, INTERNAL TRANSMISSION DAMAGE MAY RESULT.



NOTE: THE MECHANICAL DIODE DESIGN ONE WAY CLUTCH, DID NOT USE A #7 THRUST WASHER. THERE ARE NO MACHINED SLOTS IN THE INTERMEDIATE BRAKE DRUM FOR THE THRUST WASHER TABS. THE SPRAG DESIGN ONE WAY CLUTCH MUST BE USED WITH A #7 THRUST WASHER. THE INTERMEDIATE BRAKE DRUM USED WITH THE SPRAG OWC DESIGN HAS SLOTS MACHINED IN THE DRUM FOR THE #7 THRUST WASHER TABS.

 

[62Creepergear]

Thanks for the information, any idea why it works fine in 4 low?

 

[d-kuzmen]

Thanks for the information, any idea why it works fine in 4 low?

I looked but couldn't find a answer on that, my thought is that in 4 low the shift pcm controls the shifing differently, also in 4low you will feel every shift because of the reduction inside the t-case. I find that most of the 4r100's I see are sloppy shifters, usually late and soft shifts.

 

[62Creepergear]

I'm a Ford guy from way back, but these type of "quality" issues really torque me off. My T-bird had issues with the 4r70w tranny, that was resolved by upgrading some components and changing one or two orifice sizes. Another reason I prefer gears and a clutch!

 

[d-kuzmen]

I'm a Ford guy from way back, but these type of "quality" issues really torque me off. My T-bird had issues with the 4r70w tranny, that was resolved by upgrading some components and changing one or two orifice sizes. Another reason I prefer gears and a clutch!

Yes I agree the 4r70 has it's problems also.! I much prefer a manual anyday.