transmission wf

[Peck]

ok this is a strange problem in drive i have no first gear at all if i put it in =to 2nd i can start off fine been doing it for 5 months if i manually put it in first i have 1st but its is terrible weak can idle moving in 1st on flat ground it will move if i touch the gas it just slips hard but if i am driving and shift into first as i slow down the 1st gear will actually slow the truck down it jus wont move it forward this is theb stock trans and its auto 98 exploer sport with sohc any help would be awesome (i have a replacement trans just if i dont need to swap it i wont)

 

[imp]

One-way sprag clutch slipping? imp

 

[2000StreetRod]

"2" is third speed

On the 5R55E when "1" is selected the transmission is in 1st speed and gear (2.47:1). When "2" is selected the transmission is in 3rd speed and 2nd gear (1.47:1). Second speed (1.86:1) is a combination of 1st gear and overdrive (2.47 * .75).

 

[Peck]

lol ok any idea whats wrong i got 1 vote for a bad 1st gear sprag

 

[2000StreetRod]

table data

I know very little about how an automatic transmission works but I have an ATSG 5R55E manual. There is a table of data that may be useful.

In Man 1st Low/Reverse Band is applied but not in Drive 1st
In Man 1st Front One-Way Clutch Coast is hold but in Drive 1st is overrunning
In Man 1sr Rear One-Way Clutch Drive is overrunning but in Drive 1st is hold

I don't know what the above means but I suspect that imp does.

 

[Peck]

ohhh ya maybe i should say reverse works completly fine

 

[Winniethepooh]

possibly blown gasket of the valve body....

 

[kindred4x]

Overdrive drive light flashing? That indicates trans problems.
Sounds like you need to adjust your bands, or you have a broken band. That happened to me.. Broke the band anchor in half and lost first gear. Did a complete tear down and rebuild

 

[kindred4x]

possibly blown gasket of the valve body....

This is also very common, vb gasket is paper thin. When i rebuilt my trans I slapped in a rebuilt VB from Central Valve bodies, great customer service and product

 

[Peck]

if the band had broke i would have lost reverse to and no i have no flashing lights and i know the o/d light works i can push the button and make it come on
asi said first u can feel it engage but will not move the truck 2nd and all other gears are fine there are no flashing lights and no codes in the computer i have a scanner

 

[2000StreetRod]

low/reverse band

if the band had broke i would have lost reverse to . . .

I agree. According to the chart low/reverse band is applied in reverse and manual 1st.

The clue is probably that you have engine braking in manual 1st but no drive capability. I just don't know how to interpret the chart. According to the chart in manual 1st the front one-way clutch is in hold for drive and coast and the rear one-way clutch is overrunning for drive and coast.
Does the TCIL make any difference when Drive is selected and the transmission is in 1st? According to the chart the coast clutch is applied when in manual 1st and in Drive 1st when overdrive is cancelled but not applied when overdrive is enabled.

 

[kindred4x]

Whoops, my bad... it has been a few years since I did my rebuild, I lost second gear I believe.

 

[Peck]

in drive i can not feel first at all in manual 1st i can creep along the gear moving the truck but if i touch the gas it just slips and revs