trans problems on an auto

[95talon]

ok so i picked my new truck today ... 2002 f250 7.3 auto 4x4 31,000 miles. has full exhaust which to my knowledge is the only aftermarket mod besides gauges...

problem:
driving home down the high way and it wouldnt go into overdrive... was doing about 60mph and was at like 2200 rpms and wouldnt shift into overdrive. when i press the overdrive off button nothin happens... it also shifts hard and kinda fast..

is there a trans chip or something that would make something like this happen maybe for towing or plowing or something that i can take out?? thanks.

 

[CHPMustang]

My first thought was the filter was plugged due to high miles but it only has like 31k

When you first took it out for a test drive did it shift into OD?

 

[Big K]

Hmmm, Very odd

 

[95talon]

not sure didnt really get higher than 35, 40mph on the test ride... any other suggestions?? possibly sensor, relay, fuse, selinoid etc?

 

[95talon]

o yea an also forgot to mention... when im driving wheather its doing 50, 60mph or just driving around the city the overdrive "off" light on the column shifter blinks...and when you push it it doesnt do anything.....

 

[CHPMustang]

I know the VSS (vehicle speed sensor) on top of the rear axle diff housing can get dirty or the electrical connector can become loose and cause the OD light to flash/illuminate and/or the CEL (check engine light) to come on.

Now the VSS throwing an error causing the transmission to shift erratically or not go into OD I'm not sure of?

Possible to put a diagnostic scanner on the truck to show any error codes?

Did you purchase this truck before test driving it and handing over the fundage?

 

[95talon]

ok so i ran the code on a like 8500$ snap on scanner....

had 3 trouble codes

-waste gate malfunction
-turbine sensor malfunction
-speed sensor input malfunction

any ideas??

 

[dougger222]

The OD light blinking may mean your OD shifter is out. Recall my mechanic having to replace the end of the OD shifter on some older Ford pick ups which to my knowleadge hasn't changed much for several years. Pretty sure the part isn't really expensive.

It could also mean there's an electrical issue with your tranny.

Don't be fooled with big buck Snap on scanners. My cousin has about $150K worth or Snap On equipment and his big dollar scanner found no codes in the Excursion but the light is still on and my $150 scanner shows three codes.

 

[trackspeeder]

ok so i ran the code on a like 8500$ snap on scanner....

had 3 trouble codes

-waste gate malfunction
-turbine sensor malfunction
-speed sensor input malfunction

any ideas??

Start by changing the VSS. located on the rearend. This part will make the tranny go into limp mode. Flashing OD light and hard erratic shifting is the result.

 

[95talon]

ok thanks for the suggestions... i traded the truck back in to the dealer and bought a different one.. spending 18k on a truck i want to just get in it and drive... not have to fix things... for details on the new one i got go to "New to a 7.3" thread