Help! Driving in 4 vs D

Check fluid level and leave it in D while driving. It should be allowed to go in/out of lockup as it sees fit, even with 285s.

Towing or going up steep hills (like over a pass) you could experiment with 4th, other than that leave it in D

 

This is what you're feeling. Probably exacerbated by the bigger tires, etc. The tranny gets jerky right at 34/35 mph if you're light on the gas and then give her a little. Mine does the same thing. Feels "clunky" as it hunts and locks/unlocks the converter.

 

Just because it is an automatic doesn't mean you're not in control. If I'm driving consistently at speeds under 50 mph I use 4th gear. In mountains I shift out of D and use 4th gear going up hill and let the truck downshift on it's own as needed. Downhill I use 3rd, 2nd, or even 1st gear as necessary to maintain safe speeds without touching the brakes. If on the road and cruising above 50 I put it in D. When towing or hauling even light loads I default to 4th gear, but if on level ground and feel it isn't a strain on anything may go to D.

 

Damn, brother! You know all the tricks!

 

It may be possible! I always had this clunk since day one but has being way more perceptible after the lift and bigger tires.

 

So, guys, another stupid question; can I change the shift position from 4 to D while the vehicle is on moving or it has to be completely stopped?

 

Mine had done it from day one as well.

You can change it from 4 to D and back while driving. I do this all the time when towing in hilly areas so it doesn't downshift so hard when using cruise control.

 

Thanks a lot, brother! I drive 90% of the times in heavy traffic (South Florida, I tell you that much) so I will drive the truck in 4 for a while and change it to D if I need to take a highway.

 

Have you checked the transmission fluid? If it had enough the next thing I would do if have it power flushed IF the fluid is not burned.

My truck used to shift "firmly" but after the power flush she's been baby soft. (Except for 1st to 2nd axle wrap)

If this fixes it then I would say the gears are not damaged, if it does not help at all then that would make me think that either a gear or a synchronizer is damaged...or perhaps a solenoid valve.

does anyone else know if the torque converter won't lock in 4th gear? Or will it only do it in D while it's in 5th gear?

 

https://www.tacomaworld.com/threads/how-to-drain-refill-automatic-transmission.63851/

 

This is a good question, I was wondering about that. If the torque converter isn't allowed to lock up it can make the tranny fluid run hot. When it locks up it stops being a fluid coupling and becomes a mechanical (locked) connection. I'm pretty sure that is to give the fluid a chance to cool.

 

The lockup is for fuel efficiency, I don't think it helps with cooling haha.
The only thing that makes it get hot is shifting, going faster or driving very hard.

 

Pretty sure it's for fuel economy and to prevent overheating

 

Looks like you are correct sir!!!

"With a lockup clutch in the torque converter, engineers can use an impeller and turbine with slightly less fluid-coupling between them, allowing more slip, more torque multiplication and, as an unintended side effect, more heat. Turbulence in the torque converter is almost the only heat source in an automatic transmission, other than the momentary temperature buildup as the clutches engage and disengage.

As a result, a number of automatic transmissions and transaxles will engage the torque converter lockup in manually selected lower gears to keep the transmission from overheating during extended steep hill climbs or while towing. Some control systems will engage the lockup clutch in most gears above a certain speed if the transmission gets too hot."

The more we know!

This is definitely weird though because I had a Honda Accord that almost would never engage the lockup lol. Perhaps it was malfunctioning

 

You can be going 100 mph and put it all the way in 1st and its only gonna go into a gear that it sees fit.

 

Yup lots dont understand that Brakes are meant to STOP you, gears are there to hold your speed.

 

The converter will only lock in 4th and 5th (4 and D) it always stays unlocked in 1st,2nd,3rd.

 

I just did that recently on my mountian trip, was very impressived my tranny did so well holding lower gears

 

I will say that mine shifts hard and doesn't like it if I go from D to 4 while 5 is locked, if I give her enough to unlock 5th gear and then move to 4 it is butter smooth.