the1998sr5

Hi Guys,


I have a 1998 t4r with almost 170K. I read in the manual that it is a 3 speed with overdrive. Being that I am anal about my car, I pay close attention to my truck and noticed something:


accelerating from 0-65, I feel like the trans shifts 4 times- when in my head, I think it should only be three-1-2,2-3,3-OD. It does not feel like it is slipping, actually quite smooth, but if I watch the rpms and the I feel for shifting- it seems to change 4x.


Any ideas? Is this normal and perhaps it is just-readjusting electronically within one of the gears before going into OD?

millball

Torque converter lock-up. All good!

the1998sr5

Millball, So the torque converter lock up is different than over drive? meaning 1-2,2-3,3-OD then lock up?

2kT4R

Yeah the 4 speed auto tranny (3 speeds + OD) is separate from the torque converter lockup. When you get up to a cruising stable speed, ie no acceleration/deceleration, the torque converter locks up automatically to increase efficiency.

So don't count it as another gear .

millball

Is'nt the auto tranny in a '98 a 4 speed + converter lockup??


I guess so, I failed to see the previous post.

R.DesJardin

iTrader: (1)

Look at the trans and post what it says on the ID tag. My guess it is a 4sp auto, yes OD is a gear and the TC lock does not feel like a shift but you do see rpm drop. The TC should lock in 3rd and 4th depending on speed and driving terrain.
The trans is most likely the A340F used until the 5spd autos were released around 2005.

Texas_Ace

Yep, just the converter lockup. You can really tell when this happens if you are towing and forget to turn OD off.