99 & up 7.3L Power Stroke Engine and DrivetrainDiscussion of the 99 & up 7.3L Power Stroke diesel engine and drivetrain in the 1999-Up Super Duty trucks and Excursions. No gas engine discussion allowed except on transmissions and drivetrain that pertain to all models. Please confine discussion of topics in this forum to those items that are specific to the 7.3L Power Stroke engine.
Hello there, new to the forum here. I have a 2001 F250 4X4 with 213,000 miles on it, engine is completely stock. It is running great, however I have noticed the tranny cannot decide between the top gear and overdrive (shifts back and forth), between 50-55mph or so, the first time I get on the highway and up to speed after the truck is cold. It will go back and forth 4-5 times, and then it is fine the rest of the time you drive it, goes into overdrive when accelerating properly and holds it while cruising no problem. Shifts all feel good and smooth except for this small problem. I have watched the "o/d off" button on the shifter during the hunting, and it is not doing anything funny so I do not think it is the steering column wiring.
So I am curious what direction I should go from here, thanks in advance for any help. I am hoping it will not require a complete transmission teardown!!
So as not to assume anything, did you check the tranny fluid level when it was warm and on level ground? Correct if necessary. Does the O/D light ever flash during start-up or any other time? (Indicates a possible electrical circuit/solenoid problem in the trans.) Does the trans shift properly if you turn off the O/D? And, if so, once you are up to speed (50-60mph) will the trans shift into O/D and stay there once you press the O/D button on?
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2003 F250 XLT 7.3L, Auto, FX4, Crew Cab, Long Bed, 6.5" Pro-Comp all spring lift & Firestone HD Rear Air Bags, BFG KM2 37x12.50x17 tires on Eagle 17x10 Rims, 4" Turbo Back Exhaust & muffler delete, Bully Dog Programmer @ 120 Hp setting ALWAYS, Machined & Bellowed International Up-Pipe Kit, Autometer Overhead Gauges (Boost, Pyrometer, Trans. Temp), Custom Pre-Filter Ram-Air with K&N filter, "John Wood" Custom Stage I Transmission, 6.0 Billet 3 Disk T/C, External T/C Lock-up switch, 6.0 Trans Cooler, Hughes Racing Deep Structural Pan, and a few more goodies. Now spinnin' AAM Rear & Dana Spicer Front 4.30:1 Gears with Warn Premium Locking Hubs.......I do a lot of towing.(13,000 lb 33' Toyhauler & 21' Ski Boat). 84,568 miles as of 11/09
Does the O/D light ever flash during start-up or any other time? (Indicates a possible electrical circuit/solenoid problem in the trans.)
Actually, the flashing OD light indicates an error code was stored in the PCM's memory. It could be electrical, hydraulic, or even mechanical.
This sounds like the torque converter is locking and unlocking. A possible cause is a burned out brake light bulb. It could be in either side or in the center brake light.
__________________ Mark Former Automatic Transmission Engineer 1988-2007
Actually, the flashing OD light indicates an error code was stored in the PCM's memory. It could be electrical, hydraulic, or even mechanical.
This sounds like the torque converter is locking and unlocking. A possible cause is a burned out brake light bulb. It could be in either side or in the center brake light.
Thank God you watch this site!!! I never would have thought a burnt out "Brake Light" would cause transmission issues. NOT in a million years. Thanks for the new tool. That info will be valuable to me and those I know.
You're a good man M.K.
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2003 F250 XLT 7.3L, Auto, FX4, Crew Cab, Long Bed, 6.5" Pro-Comp all spring lift & Firestone HD Rear Air Bags, BFG KM2 37x12.50x17 tires on Eagle 17x10 Rims, 4" Turbo Back Exhaust & muffler delete, Bully Dog Programmer @ 120 Hp setting ALWAYS, Machined & Bellowed International Up-Pipe Kit, Autometer Overhead Gauges (Boost, Pyrometer, Trans. Temp), Custom Pre-Filter Ram-Air with K&N filter, "John Wood" Custom Stage I Transmission, 6.0 Billet 3 Disk T/C, External T/C Lock-up switch, 6.0 Trans Cooler, Hughes Racing Deep Structural Pan, and a few more goodies. Now spinnin' AAM Rear & Dana Spicer Front 4.30:1 Gears with Warn Premium Locking Hubs.......I do a lot of towing.(13,000 lb 33' Toyhauler & 21' Ski Boat). 84,568 miles as of 11/09
My truck has this problem also, and I will add that my trans is making more heat than it did before. I had temps in the 230 degree range while towing a small camper in the mountains. I have never seen it get that hot even in hotter weather and more load.
The center bulb was burned out. I replaced the bulb but the problem still remains. I have no codes and according to a snap on scan tool the converter is locking 100 percent after it does this lock / unlock cycle 4 or five times. Also I can add, it will do it all over again after a key cycle. I have had this problem for over a year. Normally I would not let something go this long but I have the mechanical diode thing, and I am not sure I should dump any money into it. I may be wrong, but my gut tells me, based on the heat it is producing, the converter is bad.
We are planning on doing more towing soon so I am going to have to do something. Any ideas and or opinions? Thanks
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2001 F250SD PSD 4X4 AUTO TRANS 373LS XLT EXT CAB Born 9-2000. Heated Excursion Mirrors.Auto meter carbon fiber series pryo and trans temp guages and TTM. Hauls sled dog racing team in winter and 23 foot camper in summer.
Well, remember the old transmission commercial 'You can pay me now, or you can pay me later'? If you're already having problems with the heat buildup, etc., and you haven't had the mechanical diode problem before now, I would start planning on putting in a good transmission and torque converter (if you plan on keeping the truck). The problem with the mechanical diode (as I understand it) is that it can leave you stranded, with no warning at all. It would be better to swap the parts out now, while you're in control, instead of being halfway to your camping destination, pulling your travel trailer. just my .02 cents worth
short_stuff
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Y2K F250 CC PSD Auto, Short-bed Lariat, Woodland Green/Gold, ordered 07/10/99, born 09/12/99, delivered 10/08/99, Access bed cover, Bed Rug, Zoodad mod, Viper Remote Start Alarm, Fumoto valve, 103K somewhat error-free miles (so far) [never back to dealer for anything]
Repairs: CPS, Water Separator Valve assembly, rear axle bearings, VSS, batteries, brakes, alternator, serpentine belt (x2), driver door pwrlock actuator, water pump
2009 VW Tiguan 2.0 l turbo 200 hp gas engine (TDI engine not available for it yet)
My truck has this problem also, and I will add that my trans is making more heat than it did before. I had temps in the 230 degree range while towing a small camper in the mountains. I have never seen it get that hot even in hotter weather and more load.
The center bulb was burned out. I replaced the bulb but the problem still remains. I have no codes and according to a snap on scan tool the converter is locking 100 percent after it does this lock / unlock cycle 4 or five times. Also I can add, it will do it all over again after a key cycle. I have had this problem for over a year. Normally I would not let something go this long but I have the mechanical diode thing, and I am not sure I should dump any money into it. I may be wrong, but my gut tells me, based on the heat it is producing, the converter is bad.
We are planning on doing more towing soon so I am going to have to do something. Any ideas and or opinions? Thanks
as well as your check book..........lol,great tranny tho....worth every penny,all 400 thousand of em.
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2002 f250 lariat 7.3 200k(motor has 170k)
original 4r100 tranny....200k and counting
knock on wood......
tony wildman chip......
stock,economy,daily,towing,extreme,smoke.
red elc good for 150k
4r100 1-2 2-3 3-4sonnax accumulator valves,.427 sonnax line pressure mod valve
4.125"yes thats 4 1/8" diy tymar intake(size matters...lol)
AIH delete,ccv delete,zoodad mod,
4" exhaust no muff
built my own leafs for 4.0 of lift!!!!!!
18" xd bronze revolvers with 325 nittos to wrap them
isspro pyro and boost guages on pillar mount....
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