And now for something completely differential
Thread Starter
Racer
Joined: Aug 2010
Posts: 349
Likes: 7
From: San Diego CA
And now for something completely differential
I spent my Christmas productively, swapping in a 3.15 diff. I did the job on jack stands with the tilted torque tube method. The whole thing took 14 hours, 2 of which I spent adjusting the front flanges of the exhaust. Maybe I was tired or something but I just could not seem to get them line up properly. The first day I dropped the exhaust, removed the brakes and disconnected everything in 4 hours. The second day I worked for an hour to drop the rear cradle. The third day was another 4 hour session to drop the pumpkin, install a new one and jack up the cradle. The fourth day of Christmas I torqued everything together, installed the pipes, and updated the ECU.
I didn't expect to complete the job alone, but it was actually super easy with a low profile transmission jack. Since there are plenty of write ups, I'm not making my own, but I can answer any questions.
Why 3.15? Well, I got a low mileage 3.15 for $300, and I want to keep the car pretty much stock. The 3.15 feels like the car was designed for it, a perfect compromise for a 4 speed auto. Couldn't be happier with the choice.
I didn't expect to complete the job alone, but it was actually super easy with a low profile transmission jack. Since there are plenty of write ups, I'm not making my own, but I can answer any questions.
Why 3.15? Well, I got a low mileage 3.15 for $300, and I want to keep the car pretty much stock. The 3.15 feels like the car was designed for it, a perfect compromise for a 4 speed auto. Couldn't be happier with the choice.
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Congrats on the upgrade. The 3.15 ratio should give you a bit more SOTP feel.
Thread Starter
Racer
Joined: Aug 2010
Posts: 349
Likes: 7
From: San Diego CA
"I got a low mileage 3.15 for $300, and I want to keep the car pretty much stock. The 3.15 feels like the car was designed for it, a perfect compromise for a 4 speed auto. Couldn't be happier with the choice."
Race Director
Joined: Feb 2004
Posts: 11,039
Likes: 2,591
From: Del Boca Vista FL
I spent my Christmas productively, swapping in a 3.15 diff. I did the job on jack stands with the tilted torque tube method. The whole thing took 14 hours, 2 of which I spent adjusting the front flanges of the exhaust. Maybe I was tired or something but I just could not seem to get them line up properly. The first day I dropped the exhaust, removed the brakes and disconnected everything in 4 hours. The second day I worked for an hour to drop the rear cradle. The third day was another 4 hour session to drop the pumpkin, install a new one and jack up the cradle. The fourth day of Christmas I torqued everything together, installed the pipes, and updated the ECU.
I didn't expect to complete the job alone, but it was actually super easy with a low profile transmission jack. Since there are plenty of write ups, I'm not making my own, but I can answer any questions.
Why 3.15? Well, I got a low mileage 3.15 for $300, and I want to keep the car pretty much stock. The 3.15 feels like the car was designed for it, a perfect compromise for a 4 speed auto. Couldn't be happier with the choice.
I didn't expect to complete the job alone, but it was actually super easy with a low profile transmission jack. Since there are plenty of write ups, I'm not making my own, but I can answer any questions.
Why 3.15? Well, I got a low mileage 3.15 for $300, and I want to keep the car pretty much stock. The 3.15 feels like the car was designed for it, a perfect compromise for a 4 speed auto. Couldn't be happier with the choice.
Thread Starter
Racer
Joined: Aug 2010
Posts: 349
Likes: 7
From: San Diego CA
Out of curiosity I must ask what update was needed on the ECU? I went the other way as my 3.15 took a giant dump and I picked up a low mileage 2.73 to get back on the road while I rebuilt the 3.15. No changes were necessary to the ECU. VSS sends the signal to the speedometer and everything works as well as before. Now the 3.15 sits ready for install.
The speedo is not affected either way.
Race Director
Joined: Feb 2004
Posts: 11,039
Likes: 2,591
From: Del Boca Vista FL
One thing you may notice is that when using cruise control you will get a surge when going down a slight grade. Mine did it with the 3.15 but does not do it with the 2.73.
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Nice job. I am planning on doing the upgrade to the 3.15 too someday. Would like a little more SOTP feel.
Mine has the 2.73's now and really don't care for it that much.
Mine has the 2.73's now and really don't care for it that much.
Pro
Joined: Aug 2010
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From: Indiana
Thread Starter
Racer
Joined: Aug 2010
Posts: 349
Likes: 7
From: San Diego CA
The difference is that 2.73 feels like it's always on the wrong gear, whereas the 3.15 feels it's on the correct gear. No bogging at 1-2 shift anymore. With increased shift points and shift pressure it chirps the tires at WOT shift and kicks the tail easily.
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