5th Gear shift point issue. After lift. (1 Viewer)

[valeo175]

All,
My GX 65 percent of the time shifts from 4 to 5 at its normal shift point. The other times it shifts very late, 3k. Has anyone else experienced this after lifting? The Lexus dealership is trying to blame this on the active suspension being disconnected, as well as the tires being the incorrect size. I haven't seen anyone post about this. Any help would be appreciated.

Thanks,

Ben

 

[470SNC]

How much bigger are your tires after lift? With the extra weight/tire size, the tranny may be hunting for different shift points in different conditions. When it would shift late, would it be on a flat surface or incline?

 

[valeo175]

They are 33's. Stock I believe are 30's. Level ground. No load.

 

[Nothinghead]

They are 33's. Stock I believe are 30's. Level ground. No load.

There's your problem. Bigger tires decrease the leverage you have to get that heavy truck moving so you have to stay in a lower gear longer to compensate. It's inconsistent probably because the tranny's "brain" is confused by what it senses as a load and was designed to work with stock gears and 30.5" tires. Change your ring and pinion (4.10?) to undo the leverage you changed. I don't know if the tranny is reprogrammable. I don't think it has anything to do with the suspension except that you ride higher and have affected your aerodynamics a bit.

 

[valeo175]

TOTALLY agree! Nothinghead, have you lifted?

 

[470SNC]

I'm lifted on 285s and my rig occasionally does this, but I just manually downshift and play with the throttle to get it to shift. Used to it since my FJ did it all the time.

 

[valeo175]

Guys thanks so much for the replies. Makes me feel that the stealership isn't full of it.

 

[Nothinghead]

TOTALLY agree! Nothinghead, have you lifted?

Yup. I'm about 1.5-2" up and on 265/70 17 tires and just accept the awkward shifting. I might consider a re-gear if I go up to 285s and add a trailer. It's acceptable for now.

 

[GXO]

I have 285s and find it shifts fine, but I haven't actually driven a stock truck in so long I may be used to it. It is the tire, not the lift, not the suspension. Welcome to the land of bigger meats