Rear Axle Gear Swap Info

[Achias]

The local mech who installed my Magnacharger was able to do all of those adjustments with his HP tuner on his laptop. It seems to me that there must be somebody in your area that has an HP tuner.

[Topspin]

I guess a little discussion on tuning might be in order, as everyone, at the very minimum, wants to correct their speedometer after the gear replacement. Once again we need to divide the models up into 03/04 and 05/06. The earlier versions present very little problem for the speedo correction, and even the hand held tuners will accomplish the task. Now, with the installation of the LS2s in 05, the ECM was updated to the E40 with the CAN based architecture. The new ECM, at least initially, presented some issues when trying to make the speedo correction. I'm not certain if any hand held micro tuners, to date, will handle the correction. I bought a Flashpaq, from Superchips, that advertised that it would do the speedo correction, and that proved false. They finally offered me a refund, after many phone calls, and claimed they had no solution to the problem. There are newer versions out that possibly have the solution, but I have no personal experience with them. I'm not certain if the 6 speeds are more or less difficult to correct, but I do know Bryan Herter @ PCM4less is able to correct the manual speedo perfectly. I know Jeremy Formato, from Florida, is doing a lot of SSR tuning and possibly he too has a solution? I believe Lyndon Wester, from Canada, may have it figured out also. If Joe Delano happens to read this, maybe he could offer his thoughts on this issue, as he's an accomplished tuner. Anyway not all tuners are equal by any means. Just like mechanics, there are good, average, and bad tuners out there. The really good ones focus on just that as their business, and even travel the country doing custom tunes.

If you have an 05/06 and have had a successful speedo recalibration, maybe listing the tuner here would be helpful to others.

[paulcars]

I have an 06 six speed with 4.10 rear gears. Joe Delano changed the speedo to work correctly with that combination when he reprogrammed the computer for the supercharger. My recollection is that he said that a 6 speed with 4.56 gears is hard to get accurate. Joe??

[Topspin]

Thanks for the info Paul, I may PM Joe to see if he will respond and elaborate some. I think it might be the tire diameter tables that have to be tweaked.

[hdflstf]

Originally Posted by paulcars

I have an 06 six speed with 4.10 rear gears. Joe Delano changed the speedo to work correctly with that combination when he reprogrammed the computer for the supercharger. My recollection is that he said that a 6 speed with 4.56 gears is hard to get accurate. Joe??

HP Tuners software package can't do the 4.56 change correctly, at least the last time I looked into it. We tried to figure out how to do the change with EFI Live and we still unsuccessful though others as mentioned can accomplish the change. I finally sent mine to Brian to get the 4.56 change done.

[Topspin]

Hdfl, when you say we, are you referring to you and Joe D.? Also, are you talking about just 6 speeds, or do the 05/06 autos share the same issues?

[hdflstf]

Originally Posted by Topspin

Hdfl, when you say we, are you referring to you and Joe D.? Also, are you talking about just 6 speeds, or do the 05/06 autos share the same issues?

Yes and yes..

[Topspin]

Thanks, for the confirmation.

At the moment, PCMforless.com is the one known tuner for the 05/06 speedo correction. I sent a PM to Jeremy Formato, and am waiting for his reply as to his capabilities in that area.

[ZsSSR]

I have posted this before...but it might be worth repeating...

The problem with HP Tuners is that there is at least one parameter that they do not adjust right in the PCM Files that must be changed when setting the speedo on the dash. When you do a "Read Entire" they capture all the adjustment parameters and store them in their files (or write them back when you do an update), but then they don't actually bring all of them to a Graphical User Interface (GUI) adjustable 'knob' in their software (or they don't include it in their final adjustments).

For 4.10 gears you can work around the problem by playing with tire size parameters because there is enough "adjustment" left from 3.73. With 4.56 gears the change is to drastic and the "correct" parameter needs to be changed...

When I changed my SSR from 3.73 to 4.56 I went through the excercise of collecting data (at least 10 log files) and sending it to Bill@HPTuners to get to the bottom of this.

Ultimately, I sent my SSR PCM and TCM (My truck is an Automatic) to Bryan Herter at PCM4Less in PA. He uses LS2 Edit to make the changes (per an email from him). The speedo was dead on after he made the change.

Before I sent the PCM/TCM to PCM4Less, I did a "Read Entire" with HP Tuners. When I got my PCM and TCM back I did another "Read Entire" with HP Tuners. I then copied over the changes from the PCM4Less Tune to the Tune I saved before I sent the PCM/TCM to PCM4Less, and saved it as another file. So at that point I should have had identical tunes. (The compare function in HP Tuners showed they were identical)

Then I uploaded the copied one (created with HP Tuners) to the SSR. The speedo was wrong, just as before the PCM/TCM was sent out. I then re-loaded the PCM4Less tune. The speedo was dead on per GPS. This simple test shows that HP Tuners is missing something in the background.

I sent both files to Bill@HPTuners. He confirmed they were missing some parameter that is saved in the tune files, but not adjusted with their GUI.
He later assured me that it would be fixed in later versions. However, in the latest beta (Version 2.23) that I have recieved (about 2 mos ago), it has still not been fixed. I went through the speedo issue with them in Dec 2007.

You can make adjustments in HP Tuners such that the logged values in HP Tuners scanner, or the values shown on an Aeroforce Gauge or Dashhawk match GPS Exactly and are dead on. But the Speedo won't match the ODB-II/CAN port scan/log data. It is the value that affects the Speedo on the dash that HP Tuners does not correctly update. HP Tuners is not the only software with this issue for the affected vehicles. Super Chips, and Diablo MicroTuners are also known to have the same problem.

[Topspin]

Many thanks Zs, for that in depth explanation. It confirms the issue I had with my Superchips Flashpaq tuner. I could read the speedo correction on the tuner, and it would be accurate, but the SSR speedo would never reflect the change.

So, to condense Zs post, the only shot you have is finding someone that tunes with "LS2 Edit" and is VERY sharp! So far, it would seem, Bryan Herter @ PCMforless is the only known source?!

[bgetz]

Well, i'll jump in...
456 gears
Custom cam and heavier springs ( thank you Ken)
2800 stall converter
All is wonderful

Now... If i can talk Mom into a supercharger... Ill need to change the cam and gears...

If i dont change the gears a little lower first gear will run out REAL fast, it will be virtually worthless. Im dynoed by Jeremy at 300. Gas milage = smilage. I can cruise her and get good milage.

Ill tell you the honest to goodness truth: if it's gas milage your concerned about, let it stock. Its easy to get drawn in to upgrades. I red this forum for months on each upgrade. I live in the steep mountains of central Pa. 456 gears help me allot but at the same time i have my foot in her. She is not a daily driver.

I love working on it, but im careful of the changes as this 2004 has the smaller LM4 engine.
Have fun and do your research. I knew everytthing i was running into BEFORE I did it.
No question is a dumb one. Buy Jim G's book. Topspin is an excellant resource, he knows his stuff!!! Dont fall for the cheap hop'ups you read about on the internet. If its too good to be true...it is, follow your gut.

[waysouth6speed]

4.56 and a 6 banger...

To add to the list of can't do's - diablosport (and I went up there in person to have them try) and EFI Live which ended up burning up my PCM (although they sent me a new one)!

Bryan Herter is the man pcm4less.com

[Dicktator]

I changed to 4:10 in my 04 about 5 years ago. Jeremy did the speed-0 calibration along with the tune. Includes drop of throttle delay, shift pattern changes, temp changes for fan, air/fuel of course. Picked up about 30 hp.

I increased my in town mileage by close to 3 miles per gal and then the Gov. added ethanol and I lost one mile per gal.

I average, according to my CID, 16.9/17.2 in City. Where I do most of my driving anyway. Highway, 19 is where I am now.

At 26/2700 rpm on the highway, my engine smooths out real nice, problem is, that is 82 mph.

If I had a six speed, 4:56 is the way to go.

Auto, four speed, 4:10 is the way to go.

Your Permagrin will be much, much bigger!!

That, of course, is my opinion.

Dicktator

[REBEL]

HP tuner DID work for me on a 2003.

Lm4 with 4:56 and taller tires. speedo matches GPS perfectly now.

SCT tuner, did not work for me.

[Double-L]

Well TS I could have helped you out but the racing is over, A friend that does most the work on my SSR was wanting to take the 430 center out of his super pro 68 Camaro and try it in the SSR, I could have made a a couple runs with the 411's and then the 430 and see the difference and take it on the highway and check the mileage drop and so on

[Topspin]

2LL, that would have been interesting, but not real relevant to the average SSR, as yours is so far removed from stock.

As Rebel and Dicktator mentioned, there's no problem with recalibrating the 03/04 speedos, as even the micro tuners will accomplish the task.

[Double-L]

True but it would still be interesting, I am thinking about maybe just putting a cam in the 5.3 and putting the 122 on it and putting it back in the SSR, Will know more by spring

[RLCulster]

Greetings Gear Group:
I have an 04' and installed a 411 gear set some years back.. I love the change.. at 80MPH it's reving at 2650 RPM and I am really comfortable with not too revvy at highway speed and good performance around town.. My milage was on the level 20 to 21 mpg at 80 (in Nevada at around a mile high)Elko area. after 410's it dropped around 1 mpg to 19/20 at the same speed. So NO biggie.. big difference in seat of the pants feel at low speeds however.. Anyway for What is worth dept.
Regards..
RLCulster, Elko NV.

[ssr_u4ia]

Great info here, but I'd like to build on it...

Can someone weigh in on the combination of 4.30 or 4.56 gears and a (slightly) higher stall converter?

I have a bone stock '03 LM4 and am pinching pennies toward a gear ratio change (leaning toward 4.56 personally). It's such a long haul from a dead stop to the start of the power band and I've never been able to break the tires loose. I'm thinking a higher stall converter (I saw 2800 rpm mentioned in this thread) will get me to the power band more quickly. I should mention, a Formato tune will also be part of my build, too.

So if I were to install a higher stall converter, what should I be considering regarding the gear ratio change? Would I put a higher priority on the 4.30's for all-around driveability since I'd be getting more power to the wheels more quickly? Or stick with 4.56 for a good, hard launch? Has anyone with the 5.3/Auto done 4.30 or 4.56 gear change with a higher stall converter?

Thanks.

[Topspin]

U4ia, I can only offer an opinion, as mine is a stick. I'd think 4.30s with the convertor you mentioned would work great with the 5.3 motor. That would still give you reasonable cruising rpm, too. Those two mods along with a good tune should really wake your R up!

[ssr_u4ia]

Originally Posted by Topspin

U4ia, I can only offer an opinion, as mine is a stick. I'd think 4.30s with the convertor you mentioned would work great with the 5.3 motor. That would still give you reasonable cruising rpm, too. Those two mods along with a good tune should really wake your R up!

Thanks Topspin, that's what I'm thinking is the way to go. Great thread!

[RedlinedSSR]

can someone give me some part numbers for 4.56 for a 05 auto...

[daboxerred]

thanks topspin u were alot of help and im sure to use 456 on my 05 stick for the kicks

[Topspin]

Redlined, Summit sells Motive gears Part#MGR-G885456 and also Richmond gears Part# RMG6901671 both for your axle.

Dabo, I'm glad the info was useful, and Welcome aboard!

[RedlinedSSR]

Topspin which out of the 2 would you recommend ?

[Topspin]

I've got Motive gears in mine and have had good luck with them. They are quiet and have performed well.

[spook]

One point to make stock 03/04auto tranny won't bear up much to full throttle launches. After I did my motor work it wasn't long before I started to slip. I have an 04 UV SSR. Greg Ducato took care of that for me back in about 2007. Been wonderful every since. Barking in 1st and 2nd is no problem with just medium throttle.

[yellochevy02]

Thanks for all the info here. I have been thinking of doing this for a while. I have an 04 auto, do i need to get it tuned by a professional or is it easy enough for me to do it? Ill also be installing them myself, so advice would be good. Ill be searching that later, but it would be nice to have that on once place as well.

[CJ]

so i have an 05 auto i bought used and previous owner did alot of mods but i didnt get to meet him
how would i know what gears i have in mine?
could i tell by what speed i am going in a certain gear at a certain rpm?

MGR-G885456 is the gear i would use in my 05 auto?
Summit has them for 170.96
what is normal install cost to put these in?