Inconsistent Highway Transmission Shifts

[04UZJ100]

Typically when passing on the highway, I manually drop the selector into 4 and then begin my pass. The transmission usually locks the torque converter while accelerating.

After I've passed/accelerated, I manually move the gate to the D position and the car shifts into OD. I cannot remember for the life of me if the normal 4-D shift is smooth or firm. It seems to me that the release of 4th into five is firmer than 1-2, 2-3, and 3-4. 5 engages smoothly but the disengagement out of 4 is what I've noticed, if that makes sense.

Nothing feels abnormal but I wanted to hear how your trucks behave? Is the 4-5 shift seamless?
Does it ever feels firm or almost lurch into gear?

I want to be careful with my wording because it is subtle but different than all other shifts.

Thanks

 

[Sandroad]

My '04 has an intermittently firm shift from 4-D, similar to what you describe. It's not all the time and that's the only shift point affected. I've wondered about torque converter lock-up, but haven't explored the behavior in details. I do use 4 when towing, but not for passing like you indicated.

 

[04UZJ100]

Thanks for the reply, I've also noticed it can be temperature dependent. Even cruising at highway speed in cold temps, the fluid sits around 120-135. Above that and the shifts are smoother, particularly the 4-5 one. Perhaps it's the colder weather that's making me notice it more.

 

[Sandroad]

I've got 8 quarts of WS fluid in the garage waiting for a couple rounds of trans drain and refill. Just to be sure......

 

[04UZJ100]

Anyone else have experience with what I described?

 

[Stylo07]

It seems to me that the release of 4th into five is firmer than 1-2, 2-3, and 3-4. 5 engages smoothly but the disengagement out of 4 is what I've noticed, if that makes sense.

Nothing feels abnormal but I wanted to hear how your trucks behave? Is the 4-5 shift seamless?
Does it ever feels firm or almost lurch into gear?

The upshifts from 4 to 5 in my 2006 can occasionally be felt, but the downshift from 5-4 is consistently smooth. Overall operation is smoother after having a fluid exchange performed.

What year and how many miles?

 

[04UZJ100]

The upshifts from 4 to 5 in my 2006 can occasionally be felt, but the downshift from 5-4 is consistently smooth. Overall operation is smoother after having a fluid exchange performed.

What year and how many miles?

I've got ~60k on the fluid now (since my last service). There has been a fair increase in city traffic and stop/go since moving to Chicago. I'm thinking I will do the fluid early.