pcm code is UZF2

I took suzuki's advice and disabled the O/D.

1-2 @ 13 mph
2-3 @ 21 mph

Then NOTHING until a converter lock @ 36 mph. The "bump" @ 31 mph was gone, so unless the converter lock schedule changes when O/D is disabled, this can only mean that the 31 mph "bump" is in fact the 3-4 shift.

So yes, the converter will lock in 3rd gear, but the only way I can make it happen is to force it to stay in 3rd by disabling the O/D.

 

Same here, my TC only locks in 3rd if the O/D is off.

I don't know about the modulation, mines acts like it is locked or unlocked with no middle ground. Unless I cannot tell the difference.

 

If you want to stop out by the shop I can throw my NGS on your truck and let you watch the converter clutch ramp in and out.

Darrin

 

Ahhh... perhaps a refinement to lessen the perception / intrusion of TC lock/unlock by the soccer mom's

 

Nah that's alright I'll take your word for it. I wasn't trying to disprove you, should've worded my responce differently. I don't know squat about autos anyway.(this is the first auto that I have ever owned).

The one thing that I always thought was odd about this truck was the 3rd to 4th gear change with very light throttle. It just makes a thump/jerk with little to no RMP change. It however shifts nice and smooth when applying more throttle. I should be getting my Troyer tunes in a few weeks, maybe the tunes will change this shift?

Do you work at a transmission shop or something? Seems by your post you have alot of knowledge on trannies. If you work at a shop I'll keep you in mind if I ever have any trany issues.

 

That's the "thump" that prompted all of this. It's looking like that really is the 3-4 shift and it actually drops by about 100 rpm, but you're right; it's barely noticeable.