Cadillac Owners Forum banner
  • Hey everyone! Enter your ride HERE to be a part of JUNE's Ride of the Month Challenge!

21 - 28 of 28 Posts

·
Registered
Joined
·
629 Posts
KensCTS said:
I finally installed the gears today! Went from 3.42 to 3.73. No issues with computer or ABS. Car feels quicker. It was worth it. I got the complete carrior from online wrenching yard. It took me about 4 hours. Getting the exhaust out of the way might be the hardest if you try this. I have a flowmaster bolt on exhaust so I just unbolted to get it out of the way. Next I removed 2 X 6 Allen bolts holding the rear axles to the carrior. No need to take the rear wheels or axles out. Then I removed three bolts holding the drive shaft to the pinion flange on the carrior. Then there are three big bolts holding the carrior in place, remove and lowered the carrior with a flour jack. Install was the reverse.
This is very very good news. Thank you for posting your results.
 

·
Registered
07' CTS-V | 07' Lux 3.6 Volant-Borla-Vsways | 08' CTS 3.6 DI Performance
Joined
·
970 Posts
KensCTS that's awesome news!

Can you please post some more information when you get a chance, I'm looking for the following:

New 0-60 time
New MPG at a flat stretch of highway at 70MPH & 80MPH
Crusing RPM at 70 MPH, 75MPH & 80 MPH
 

·
Registered
CTS 2011
Joined
·
29 Posts
Discussion Starter · #23 ·
CTSM, I'll try to get some of this for you. But never recorded my 0-60 time. Also didn't check the MPG before so only could give you after. But for RPMs and MPH it is very linear calculation. The gear change is 3.42/3.73-1=8.31%. So your MPH are always off that much. At 2000RPM let's say was 70MPH with the 3.42 gears. With the 3.73 or 8.31% reduction the RPMs at 70MPH will now be 2000X108.31%=2166. So today my speedo is off by 8.31%. When is shows 70MPH is really going 70MPH-70MPHX8.31%=64MPH. Next trick is find a way to fix the speedo, any ideas. I think some tuner kits can do it.
 

·
Registered
2008 STS LLT 3.6DI RWD
Joined
·
64 Posts
"Next trick is find a way to fix the speedo, any ideas. I think some tuner kits can do it."
Madtuner can fix it. I swapped my broken 3.23 open to 3.42 LSD and then replaced gears to 3.91. With Performance engine and transmission tuning package from Madtuner everything works correctly.
 

·
Registered
09 CTS 3.6di 1994 Eldoardo Touring
Joined
·
29 Posts
Hey what is the part number for that. I am almost sure mine is open diff would love this change. I also say mpg should not be too diff, maybe better! (not counting your 0-60 runs non stop) bc most cars hunt lower gears for high mpg in tests or granny driving. I would love to do this mod but how much ? Anybody in NC that can help me or geting rid of a good 3.7+ lsd ?

PS junk yard parts ? if all of us here were that bad that we only want new and factory we would all buy 2016 ats-v and cts-v's! But we tune and customize bc of budget and preferences, so like your mom should have told you: dont have anything nice to say go do donuts with your open diff and if your junkyard diff does not work just buy another or a different one its just a part, wont blow up your car if it brakes, it just metal why pay 4 times the price ? so that the diff dragging 2 or 3 inches above every shit you drive over is shinny for 2 days? F that sell me your used 3.7 lsd when your ego makes you crash bc of the blindspot it creates
 

·
Registered
Magoo—2012 Cadillac CTS Luxury
Joined
·
47 Posts
Shakey no race car. Just lowing gears a little. Makes it jump off the line a little harder. Also the 3.73 has a limited slip for better traction.
I'm curious what the donor for this was?

The parts catalog shows 3.73:1 gears came in some CTS Wagon models, but without the Limited Slip. I can't find a service part for a differential carrier assembly with both 3.73:1 gears and limited slip. I don't think GM ever used that combination in a production CTS.
 
21 - 28 of 28 Posts
Top