Is this normal engine braking

Today while driving down a straight mile long descent my engine brake kicked on when I was going about 50mph. When I was near the bottom of the hill I hit the accelerator to continue onto the straight away. The engine brake didn't turn off when I hit the accelerator gently and my rpm's went up to about 2500 and stayed in the same gear. When I let my foot off of the accelerator it switched gears and my rpm's went to about 1800. Normally I drive this stretch at about 75mph but the popo was behind me so I just let off the gas going down the hill.

Is this how the engine brake should work? I also changed my differentials and transfer case oil yesterday is this related to that in any way?

 

Engine brake? What engine brake???

 

It's not an engine brake. It just down shifts to slow the truck down. Mine occasionally doesn't shift back up to 5th. Usually I throw it in 4th, then back to 5th and it shifts it back to 5th.

 

Engine braking isn't really a brake. The resistance of the engine is used with a lower gear to slow the truck down. What you described is normal and nothing to worry about.

 

Is there any way changing the differential oil or transfer case oil would make this feature work differently. It feels like it is more sensitive now after those changes. They may have never been changed up till now 47,000 miles. I should have did it right when I bought it

 

This is normal (and desired) operation - the transmission stays in a lower gear to keep the revs up (and the engine in the powerband) when it senses you want to accelerate, then upshifts when the truck reached cruise speed.

A little revving is nothing to worry about. You can hammer it at redline all day without causing damage. You should see how rev-happy the 5.7L V8 is in the Tundra.

 

Have you ever greased the driveshaft u-joints?

 

X2 Since buying the truck 9k miles ago this was my first maintenance project. I drove around most of the day slower than I normally do without the radio on just listening to it which is very rare. At least when I was under there I saw where the oil drain plug was so I don't make that mistake

 

I did those yesterday for the second time while I was under it waiting for the diffential oil to drain. 4-5 pumps until grease came out except for the hidden one which took 7 before grease came out. I don't think the dealership greased that one or changed the front diff because it was worse than the rear which seems opposite to how it should be.

 

Sweet.

 

Engine/transmission braking is not ‘desired’ when not towing or hauling a load and should have the option to disable it like every other truck on the market.
Why is it not desired?
It’s more wear & tear on the .....
-Engine &
-Transmission.
-It kills MPG.
-More failure possibilities (mechanical & electronics)
-It’s a helluva lot cheaper to replace brake pads then a torque converter, transmission control module, etc.....

 

I have to say that I couldn't disagree more with your post. Everything you said is pretty much incorrect. Including disabling the engine braking feature. You can disable it quite easy. Just slip the transmission manual or automatic into neutral. Easy Peasy.

 

These trucks do not have engine brakes. You're experiencing a downshift which is normal.

 

was the cruise control engaged?

 

Engine braking will not prematurely wear out an engine or the diffs. Maybe the tranny will be carrying more load, but not more than it can handle. Engine braking down a slope is way better for your vehical than using the brakes

 

I thought engine braking was going down a hill in low gear letting the engine slow the decent instead of brakes...?

 

its the trans downshifting and that revs the engine. Not the other way around.

 

I have not it changed my diff or trans fluids in 215k miles. My truck behaves like yours going down hills. I put it in even lower gear until RPMs hit around 5k so I don't have to use brakes going down steep mountain passes in the blue Ridge Mountains.

This truck is like a mini tank. Runs great and takes everything I toss at it.

 

My trans only down shifts when I move the stick.

 

you could let off the gas and it will slow the truck down