Why won't my trans kick down????

[hquick]

Hi All,
I can't seem to figure out why my trans won't kick down to second when I'm on the freeway doing 100 or so kph.
If I want to overtake and put my foot into it...it just won't shift. It just loads up and I get KR (due to the load I expect).
At lower speeds it shifts fine.
The attached log shows the issue at around frame 1700 and also 7000 or so.
Any thoughts?

[ChipsByAl]

It appears to me as if the TPS% never achieved enough % to kick it down. The Kickdown {D1206} never got near 87% and the 3->2 downshift table was already out of range. {D0907}
Al

[limited cv8r]

Does your vehicle use the performance tables, or just the normal ones? Also table D0961, I have these set at 90% normal, 75% performance in my own vehicle so you don't have to completely mash it to the floor to get a kick down.

[hquick]

As far as I know I'm using the 'normal' table.
How can you specify one or the other?
Al, what do you mean by the 3-2 downshift table was out of range?
Do you mind altering that tune to what you would expect to be correct?
I'm just trying to learn how to tune this trans.
This is the EXACT problem I'm having. Not kicking down and just loading up causing KR.

http://forum.efilive.com/showthread.php?t=3336&highlight=kickdown

[hquick]

PLease have a look at frame 5636 onwards. I just 'stomped' the pedal. Didn't drop into 2nd and TC didn't unlock (should it?).

[limited cv8r]

Try this, but I can't guarentee it will work for you.

[hquick]

Thanks....I'll give it a try this arvo.
This log shows the problem pretty well (frame 6600+).
Should the TC unlock when I stomp on the pedal?

[limited cv8r]

It would be better for you if it does. Hopefully if it unlocks for you on your 3-2 downshift it will stay unlocked in second as apply speeds are set to 410 in every box,so in theory the only lock up you should get in second is when your convertor reaches its stall speed.

[limited cv8r]

I noticed you were in 3rd gear for your logs. Do you normally cruise in 3rd? If not you could also raise D1002 TCC Apply in Gear to lock up later and adjust D1003 to suit your cruising.

[hquick]

Apparently these transmissions don't generally last as long as they could/should if OD (4th) is used regularly. Although....I have the 80E so maybe that's more directed towards the 60E.
Cruising in 4th seems to effect my AFR's also.
Usually on longer drives I'll kick it into OD.

[limited cv8r]

I'll swap you your one 4L80E for the two dead 4l60(65's) I've got anyday.
I believe 4th is ok as long as you dont give it a hard time or are towing regularly.

[hquick]

Lol!
My trans came all the way from Beaver Creek (I think it was)...somewhere in the US...all the way to Melbourne. No way it's EVER leaving my Burb. Lol!
Don't know what GM were thinking when they put 60E's in 3 tonne vehicles. They're only good for boat anchors!
I'll be heading home in about 2hrs. I'll let you know how those adjustments go.

[hquick]

Well...that was night and day difference! :rockon:
Thanks heaps for that.

[limited cv8r]

Glad to help out :cheers:, there's still probably a bit more tweaking you could do,all depends on your driving style.Trannys are a lot of trial and error :secret:. Have fun.

[hquick]

Thanks again.
What do you mean by 'tweaking'?
I drive it pretty hard....but I don't want neck snapping shifts. Lol!

[limited cv8r]

You don't need to have neck snapping shifts to have a nice feeling tranny. Even something as simple as raising your up shift speeds by 10% can make your driving experience so much better.

[hquick]

That drive on the way home was very smooth. The nicest I've felt from this trans.

[limited cv8r]

Couple more tweaks if your game!!!:hihi:

[hquick]

Lol! I'm always game.
My Burb is an International test vehicle. LOl!

[limited cv8r]

Not big changes, but see what you think.

[hquick]

I noticed you put the kick downs back to 100%?
Any reason for this?

[limited cv8r]

Simple answer for the 100% change was I applied the "dickhead" factor and adjusted the wrong tune.:bangin:

Try attached tune instead.

[hquick]

Just tried that tune. Trans shifts nicely. Fairly smooth.
Kicks down well...which was the main issue.
Thanks again

[limited cv8r]

As long as there's a smile on your dial, it's all good:grin:.

[joecar]

Howard, what changes would you say account for the difference (I haven't had time yet to compare all your files)...?

[hquick]

Main would have to be the kickdown I guess Joe.
Also...unlocking the TC as it kicks down. Seems to free it up so I don't get KR as it loads up.
It has made a hell of a difference.