Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

1 - 7 of 7 Posts

·
Registered
2008 chevy trailblazer_lt
Joined
·
2 Posts
Discussion Starter #1
Hello all-

I am looking to change the axle ratio on my 08' Trailblazer LT from a 3.42 to a 4.10. I found a cheap low mileage SS axle and wa swondering if anyone has done the swap.
I think everything will bolt in, rotos are the same, calipers etc-but I am concerned about the driveshaft. I realize I will need to reprogram my VSS etc.

Does anyone have any information to make this effort less?

Thanks in advance!
 

·
Banned
2003 gmc envoy_slt
Joined
·
7,190 Posts
:iagree: Front and rear ratios must be the same.

The only other option would be to use smaller tires on the front.

Good luck figuring out how much smaller.
 

·
Registered
2008 chevy trailblazer_lt
Joined
·
2 Posts
First things first. I noticed you have 4WD. What are you planning to do with your existing front axle since the ratios are different?

I am not worried about the front axle, that is easy. All the cases are the same, the only difference is part time or AWD. According to the parts catalog, they offer a 4:10 with part time.

I was looking for information on the REAR axle. My understanding is that the SS axle is a 9.5" rather than the 8.625 I have now. I was wondering about the pinion flange being the same or if the L6 driveshaft has a different style due to the different frequencys between the 6 and 8 cylinder.

:iagree: Front and rear ratios must be the same.

The only other option would be to use smaller tires on the front.

Good luck figuring out how much smaller.

The formula is simple. Using smaller tires on the front to change the gear ratio is not what I or any other person should recommend.
 

·
Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
Joined
·
3,700 Posts
FWIW, the 8.6 is in the SWB 5.3L and all of the EXT models... You should have the 8.0"

http://www.compnine.com/index.php?u=1&year=2007&artnbr=TS05-012&artsfx=NULL&supplgroup=NULL&catcode=56S&modelcode=T&makecode=LC&modelseries=100&uid=1&modelid=2000000813&capuid=1&majorgroup=05&grouptype=B

The 4.2, 5.3, and 6.0 all have different rear prop shafts. The 4.2 and 5.3 are only different because of length (the V8 engine is shorter, so the engine/trans/t-case are farther forward, so the fan is in the same place as the I6, so the rear prop shaft for the 5.3L has to be longer). The cardon joints for the 4.2/5.3 are the same as one another, and the 6.0 has larger (or at least "different") joints.

So in short, you'll probably have to have a driveshaft made, or at the very least, get new ears/end put on yours.

Mike
 

·
Registered
2006 chevy
Joined
·
157 Posts
THe TB SS rear axle is a bolt in for any 2002-09 TB. In order to connect the rear drive shaft you must NAPPA uv joint # 447.
I know this because I have done the swap 3.42 to 4.10 so much better especialy with SS wheels and tires.
 
1 - 7 of 7 Posts
Top