If you SSR is an auto and you want to upgrade to the 14bolt rear end with the 4:10 gear raito, good news. The Trailblazer SS rear end is a bolt in. The drive shaft will need to be shortened and the rear yoke/u joint changed. also if you have the Hotchkis sway bar you should order the new one. The rear end comes complete with rotors and calipers which are the same as the SSR. I reinstalled my drilled/slotted/painted rotors and calipers on the new rear end. You will also need to order the U joint strap, the one off the 10 bolt will not work. The stock 10 bolt doesn't have any sensors on it, so the 2 sensors on the TBSS are not used. Also The T/C should work like stock. The P/N is 15796955 with a list price of $2785. Got mine from Frank Belk for $2145. Plus tax -- (Thanks again Frank)
Ya - Joe and I have been talking about me doing the swap for the last 6 months. Had hoped that someone else would have tryed it first. found a few of the 14 bolts from the SSR - all used and pulled from wrecks - with an asking price of $1000. to 1500.. So by the time you swapped the gears the cost would have been about the same. Have to thank Joe for talking me into doing it.
Ross - I didnt have to twist your arm too hard. I cannt wait to see how it will effect traction with your SSR. We need to get together again real soon.
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'07 Black TrailBlazer SS "MP122HH" MagnaCharger
'05 SSR 6 Speed 427 "MP122HH" MagnaCharger Authorized MagnaCharger Dealer/Distributor
My SSR: '06 PB #21661 Born 8/29/05, GHL "Old School" True Duals, ADDCO bars, Eibach rear, Joe's Tune
Physics is fun
Ignoring the robustness change from the Torsen to the beefier Eaton rear axle..... Ross, you really needed that!
If you look at the math involved with the change-over, you will see that this is the simplest and cleanest performance improvement you can make.
The numerical difference between the two is almost exactly 10%. That is (4.10-3.73)/3.73 = 0.0992 or roughly 10%.
Here are some of the results:
1) At any speed in any gear, you will have 10% more RPM showing on your tach. If you look at your tach much, you will find that this is NOT going to tax the engine. (reference my avatar)
2) You will increase the numerical advantage of the ring and pinion by 10%. This means that you will have 10% more rear wheel torque for the same driveshaft torque. Torque is what moves the truck, but if you are hung up on HP..... The horsepower gain at the rear wheels is only a calculation away... HP = (torque x rpm)/5252.
3) The driveshaft and transmission loads are decreased by 10%. This is a no-brainer.
4) The computer won't care. Torque management is focused on limiting the torque through the transmission, not at the rear wheels. It doesn't know you changed the rear torque multiplier.
5) Engine efficiencies will be better. By operating a little closer to the peak efficiency area (usually above 2500 rpm), you may actually see a slight increase in gas mileage..... but you gotta get your foot out of it first.
For performance improvement, I think changing rear axle ratio is the most bang for the buck.
And YES, Jim G. is right ...... the 4.56 calculates to be 20% more torque multiplication than the 3.73. Your main consideration for that change, is to ask yourself if you are willing to have 20% higher engine rpms for any given speed.
My preference is to the 4.10.... but that is MY preference.
Ross, you did a really good thing here!!!
Regards,
Mike
__________________ Trust and Generosity are contagious.
My SSR: '06 PB #21661 Born 8/29/05, GHL "Old School" True Duals, ADDCO bars, Eibach rear, Joe's Tune
Quote:
Originally Posted by Ross
Thanks Mike - Hows the support coming?
I still have not seen the second generation support. I really expected it Thursday or Friday. My supplier was tied up pretty tight in the last week. He's doing me a big favor on the design of this part and I hate to bug him, so I will be patient.
How's the performance difference with the new gears???
MIke
__________________ Trust and Generosity are contagious.
Mike & SSR 05 - thanks for the input - I have the 2005 automatic as well and will start looking for someone in the Portland, OR area to do the rearend mod.
Anyone out there have any recomendations for dealers/speed shops who you have dealt with in the past??
