New rear end in but!!
 

Well my new 1LE rear end has been installed in my car. Only one problem, GM does not have the calibrations yet for the normal SS TR6060 for the speedometer. Should be out in about 3 months or so. So how many miles over or under am I at 35MPH and 65MPH?

Also my tach would still be the same right, so I know if I am redlining my engine?

Ok figured it out with a online tool, about 5 under what the speedo says at low speeds and 8 under at when it says 65.

I don't believe your trans has anything to do with what is showing up on your speedo. You changed your gears, so really the only thing you need to do is go to a tuner and have him calibrate the computer to reflect the new gears.

No the speedo has changed. Radar checked it with one of our patrol cars. The speedometer gets it info from the TCM which is in the transmission, when GM release the program for the stock SS TR6060 then it will have the gear change info in it from 3.45 to 3.91

You can flash the computer via HP Tuners, EFI Live, or one of the hand held units that have the capability to modify the gear ratio to correct the speedo. Of course you have to own one of those or go to a tuner and have them flash the computer with the right gear ratio.

That would void the warranty. I will wait for GM Calc.

Did not know the dealer was updating tunes because of gear/diff swaps, interesting. your speedo will be about 6 or so mph off and you will rack up mileage quicker with the speedo being off too.

Do a handheld, and before you go to the dealer, swap it back to stock.

The tune for the GM 1LE rear end is supposed to be certified for a normal SS in 2-3 months. Since we went around and around for the last couple of days since the rear end was put in the car hopefully it will be sooner than latter.

They can still tell the ECM's been flashes.

I'm out of ideas...lol

So GM is releasing a calibration for a regular SS with 3.91 gears? Wouldn't that be a normal calibration for a 1LE? Couldn't you just go to a mod friendly dealer and have it flashed with a 1LE calibration. Seems to me like you might be getting a load of:bs:from your current dealer.

No this is not from the dealer, the 1LE transmission is different part than the SS transmission and the Calc's for each part has to meet EPA approval. That Calc is being tested now. Believe me it is not my dealers fault all. If you go to a normal dealer they can only load programming GM gives them and that programming is kept in a database for each VIN. Since I want to keep my drivetrain warranty that is why I will wait for the Calc. That is why also I bought the entire rear end from the dealer for a 5 year 100,000 mile warranty to not be voided.

Basically the part we bought will be up coming upgrades from GM, if you remember the 1LE announcement they said that older SS's can be upgraded to 1LE. We got approval to get the part and keep they warranty but no one new that Tach did not have the Calc yet.

I just wanted to know what would be off and that is why I posted. I have since found gear calculators on the net so I know what I go at what speeds now. None of this was posted to pick on my dealer or GM so please do not spin it like that.

And as far as calling dealer BS, well the dealer does not even want a dime from me for the work or the rear end until the Calc comes out and is installed on my car. I call that a good dealer in my book.

Be careful how far you drive before retuning the speedo, because your odometer is off too.