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View Full Version : Diffrences through the years



cmitchell17
November 7th, 2007, 04:07 PM
Well after having my trans shift hard for so long I went back to stock settings to try to get back that luxury shift, but still add in a little pressure for the high torque loads.

Anyway the stock 2000 settings just don't seem right. So I have all of the other tunes of truck 4L60s up untill 2007 and none of them are the same.
So I used the 2007 settings assuming they where the best, but they give almost no pressure on the 1-2 shift.

I just don't get the inconsistency? Are all the tunes just tuned for that specific year and they all shift about the same.

It looks like there is only a small diffrence between the force motor current between the years. But would that make a diffrence in shift firmness?

Im guessing the stock settings from 2000 would be the best to use. But the shift times just look so wierd they increase from .3 seconds in the low torque to .5-.6 seconds on the high torque. Then there is a huge dip to .3 seconds then goes back to .6seconds on the 2-3.

My trans seems to like to shift hard on the 2-3 especially on light throttle.
The 1-2 seems like it dosent shift nearly as hard as the 2-3.

It also likes to do the 2-3 3-2 clunk and a little clunk on the 2-1. Which I think just might be something worn on my driveline.

I just don't get the inconsistensy on the settings through the years.Why would GM change there minds so much?

Im using the stock 1-2 and 1-2TR and the 2007 2-3 and 2-3TR becuase it was lower then the stock 2-3 for 2000.
Then im using all the 2007 shift times.

dc_justin
November 7th, 2007, 07:33 PM
A small difference in the force motor current will have a large impact on shift pressures.

cmitchell17
November 8th, 2007, 08:06 AM
Does anybody else notice a hard shift at low tps on the 2-3? I know theres the 2-3, 3-2 clunk that is just becuase the way the trans is, but it shifts normally at higher or really low throttle?

So I guess its best to use the stock 2000 settings then try to adapt a newer tune to mine?

They just seemed like they just randomly made these. On the 2007 the 1-2 shift pressure where perfectly flat and parallel along with the TR. Shouldent the curves be even and pressure curves match the TR curves?

Does diabling the abuse mode TR mess with the timing of the shifting TR?

cmitchell17
November 10th, 2007, 04:39 AM
I just thought of something.

Would my inceased timing at low thottle throw off my delievered torque causing my trans to give wrong pressures.

Is it safe to back off the pressures 10-20% at low tps on the stock settings?

cmitchell17
November 10th, 2007, 10:26 AM
And what about the positive and negative force motor current tables?

Does this have anything to do with anything?