trans question

[clancy1920]

I have a 99 F-250 with auto. When I put it in 1 it will idle all day but if I try to move it will go about 10 feet and shut the motor off. It will start right up and do it again. Does fine in 2 and D. Ford had no idea.
Next, every once in a while when I am driving down the road the speedometer will stop working and a few seconds later the od light will start flashing. Any where from 5 to 15 minutes later the speedo will start working and a few seconds later the od light will stop flashing. Any idea anyone
Thanks Clancy

[99Smokin73Stroker]

I would have guessed a cam sensor at first, but since it works fine in 2nd and on up then i'll leave this to marc to try to figure out...

[mschn99]

Originally Posted by clancy1920

I have a 99 F-250 with auto. When I put it in 1 it will idle all day but if I try to move it will go about 10 feet and shut the motor off. It will start right up and do it again. Does fine in 2 and D. Ford had no idea.
Next, every once in a while when I am driving down the road the speedometer will stop working and a few seconds later the od light will start flashing. Any where from 5 to 15 minutes later the speedo will start working and a few seconds later the od light will stop flashing. Any idea anyone
Thanks Clancy

sounds to me like.....A. there is a problem with first in your trans......your truck will usually start out in second unless you are taking off from a hard accell, then it shifts down into first, but since yours is causing a stall, i would guess that it is either not unlocking the converter in first, or there is a clutch problem that is acting up from a takeoff in manual 1......the speedo and OD light sound like a rear diff speed sensor.....or the wiring for it, but where it is intermittant and it comes back, thats probably the sensor.......Marc

[99Smokin73Stroker]

Yeah...my guess was way off.....

[clancy1920]

thanks for the fast reply
Clancy

[Deeno]

Originally Posted by mschn99

sounds to me like.....A. there is a problem with first in your trans......your truck will usually start out in second unless you are taking off from a hard accell, then it shifts down into first, but since yours is causing a stall, i would guess that it is either not unlocking the converter in first, or there is a clutch problem that is acting up from a takeoff in manual 1......the speedo and OD light sound like a rear diff speed sensor.....or the wiring for it, but where it is intermittant and it comes back, thats probably the sensor.......Marc

So if you take off in 2nd gear with the 4R100 tranny, it will downshift into 1st gear if it needs to. Is that right?

[mschn99]

Originally Posted by Deeno

So if you take off in 2nd gear with the 4R100 tranny, it will downshift into 1st gear if it needs to. Is that right?

yes, it generally takes off in second......but if you are on the throttle hard, it will downshift to first to allow the extra acceleration........

[ipz2222]

Marc. A polite correction. The 4r100 does not take off in 2nd unless you select 2. It always takes off in first in the od selection.
The reason the engine dies in manual 1 is because of a cross leak in the pump caused by high line pressure when man 1 is selected. When the pump is perfect, this does not happen, but with time and heat the pump warps and causes these cross leaks. The lock up valve is in the pump and this crossleak causes the valve to move and partially apply the lockup clutch, sometimes lugging the eng and sometimes killing it. Sometimes the converter itself can cause this, hence I always replace them both. Preston

[99Smokin73Stroker]

Marc getting corrected? Whoa! That's new!

[ipz2222]

That's why I said " a polite correction " . He obviously know a lot about these vehicles. Preston