Shifting problems
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Shifting problems
I have a 91 F250 4x4 which does not want to shift into high gear. It seems to shift fine through all other gears but when it should shift into high (around 50-55 MPH) the truck sounds like a 747 getting ready for take off. I have had no issues with slipping and trans fluid is red and there is no burnt smell. I'm not sure which trans I have but if I'm reading the plate on the door correctly it says "E" under trans. I understand that there is a vacuum modulator that helps control the shifting could this be the problem ? Can anyone help shed some light on this ? 
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Shifting problems
I have the identical problem on my 1993 F-250 460 4x4. I just finished having the engine replaced and as soon as I get the problem diagnosed I'll let you know. It has been doing this before and after replacing the engine and it's periodic with mine.
Last edited by danieljray; Nov 2, 2003 at 11:27 AM.
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Joined: Feb 2003
Posts: 315
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From: Alabama Gulf Coast
My 1992 Ford tech. CD shows the E code as being the E4OD. Do you have an Overdrive button? If so, you've got an E4OD.
Going on the assumption you do have an E4OD, is your overdrive light flashing? If so, you might want to draw the codes from the computer to find out what it sees wrong with it's ability to shift. A bad or maladjusted TPS (throttle position sensor) can cause "harsh engagements or shifts and/or upshifts late and harsh and/or no LU and/or no 3 to 4 shift."
I'm going to email both of you through FTE. Then send me an email. Then I will send you information which will help you test this sensor and all the rest of the sensors the computer needs to shift the E4OD. This is assuming you determine you do in fact have an E4OD.
R.A.
Going on the assumption you do have an E4OD, is your overdrive light flashing? If so, you might want to draw the codes from the computer to find out what it sees wrong with it's ability to shift. A bad or maladjusted TPS (throttle position sensor) can cause "harsh engagements or shifts and/or upshifts late and harsh and/or no LU and/or no 3 to 4 shift."
I'm going to email both of you through FTE. Then send me an email. Then I will send you information which will help you test this sensor and all the rest of the sensors the computer needs to shift the E4OD. This is assuming you determine you do in fact have an E4OD.
R.A.
Post Fiend
Joined: Jun 2001
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From: Running Springs CA
You can also identify an E4OD by the fact that it has 20 pan bolts. There is no vacuum modulator as it is all-electronic. The pre-'95 versions of this transmissions were full of problems.
Jim
Jim
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Joined: Feb 2003
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From: Lakewood USA
The truck is a 1995 F350 7.5L crew cab 4x4 manufactured Aug 8, 1995. It has the E4OD with the overdrive button. The case casting show 1995 and valve body casting show 1996. It has five green check ***** in the lower valve body and 8 plastic and 1 steel check ball in the upper valve body. I've been told this is okay because of Ford's transition to 1996.
Problem: All gears work in manual 1,2,3. In normal OD gear selection it starts in first gear and stays and will not shift to second until letting off throttle slightly then shifts to second and almost immediately to third. Shifts to overdrive normally and can be switched out of overdrive with button on gear selector.
Checked codes and replaced TPS. Cleared codes. Helped only slightly. Checked TMLS and is within specifications and is adjusted correctly. Also checked VSS and it is within specs.
No other codes present.
Any ideas or comments?
Problem: All gears work in manual 1,2,3. In normal OD gear selection it starts in first gear and stays and will not shift to second until letting off throttle slightly then shifts to second and almost immediately to third. Shifts to overdrive normally and can be switched out of overdrive with button on gear selector.
Checked codes and replaced TPS. Cleared codes. Helped only slightly. Checked TMLS and is within specifications and is adjusted correctly. Also checked VSS and it is within specs.
No other codes present.
Any ideas or comments?
Senior User
Joined: Feb 2003
Posts: 315
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From: Alabama Gulf Coast
mitchell,
I don't know if I shared this with you when I sent you the zip file but I bought my van with a known problem of not shifting out of 1rst. I would have to get the speed up to 35 (in 1rst), let off the pedal briefly, then re-apply and it would shift to third. The shift from 3 to 4 occured normally at about 45mph. I found my u-joints to be bad. Once I replaced them the problem cleared up. RA.
I don't know if I shared this with you when I sent you the zip file but I bought my van with a known problem of not shifting out of 1rst. I would have to get the speed up to 35 (in 1rst), let off the pedal briefly, then re-apply and it would shift to third. The shift from 3 to 4 occured normally at about 45mph. I found my u-joints to be bad. Once I replaced them the problem cleared up. RA.
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New User
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From: Lakewood USA
I'll have to check the u-joints. Your description sounds exactly like the situation that I have.
Thanks.
Thanks.
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Senior User
Joined: Feb 2003
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From: Alabama Gulf Coast
Have you got grease nipples on those u-joints? If so, shoot 'em full of grease and take it out for a test. That's how I found mine were bad. Shot 'em full of grease and the problem cleared up for several shifts then went back to the same ol, same ol. Shot 'em with grease again and the shifts became good again for a few times. I immediately replaced the u-joints thereafter. R.A.
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Joined: May 2003
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From: Philadelphia
dieselzen,
I have the exact same issue as you did. Won't shift from 1st to 2nd until i get rpms up to about 2500 then let off the gas. Seems to shift fine through rest of gears. How in the world are the ujoints responsible for this? I assumed it was transmission or sensor related. I have replaced the mlps and no fix. Had tranny fluid replaced in sept....no change. I had the tps replaced about a year ago but that didn't help. I am still leaning towards a misadjusted tps b/c the mechanic who replaced mine was a pos. I don't have a multimeter yet to test current and such on that. Only codes I have a are for 'insufficient egr flow'. Would appreciate any feedback on this. Thanks.
I have the exact same issue as you did. Won't shift from 1st to 2nd until i get rpms up to about 2500 then let off the gas. Seems to shift fine through rest of gears. How in the world are the ujoints responsible for this? I assumed it was transmission or sensor related. I have replaced the mlps and no fix. Had tranny fluid replaced in sept....no change. I had the tps replaced about a year ago but that didn't help. I am still leaning towards a misadjusted tps b/c the mechanic who replaced mine was a pos. I don't have a multimeter yet to test current and such on that. Only codes I have a are for 'insufficient egr flow'. Would appreciate any feedback on this. Thanks.
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Joined: Feb 2003
Posts: 315
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From: Alabama Gulf Coast
Crazyromi,
I can't really give you the specifics as to why the u-joints caused the problem in my experience as I didn't inspect them or have them inspected by someone.
The long answer:
The only theory I can come up with is the PO did not keep them maintained (i.e. shoot 'em full of grease every year). Because there wasn't enough lubrication on the bearings, and therefore a film of lube between the needle bearings and all pressure surfaces, there was excessive wear. Because of the wear to the bearings and pressure surfaces, the tolerances became greater (the bearing cups became looser) and there was greater play at the transmission and at the differential. The torque created from the vehicle attempting to increase speed from a dead stop was enough to exploit the greater tolerances so that it bound the transmission as it tried to shift.
The short answer:
Some annoying replacement work and $25.00 later and the transmission no longer had the above shifting problem.
R.A.
I can't really give you the specifics as to why the u-joints caused the problem in my experience as I didn't inspect them or have them inspected by someone.
The long answer:
The only theory I can come up with is the PO did not keep them maintained (i.e. shoot 'em full of grease every year). Because there wasn't enough lubrication on the bearings, and therefore a film of lube between the needle bearings and all pressure surfaces, there was excessive wear. Because of the wear to the bearings and pressure surfaces, the tolerances became greater (the bearing cups became looser) and there was greater play at the transmission and at the differential. The torque created from the vehicle attempting to increase speed from a dead stop was enough to exploit the greater tolerances so that it bound the transmission as it tried to shift.
The short answer:
Some annoying replacement work and $25.00 later and the transmission no longer had the above shifting problem.
R.A.
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