difficulty installing 3.73

[MustangLx90]

Im looking into switching out my gears to 3.73. my car is a 1990 lx with a 93 cobra in it, I see all these posts about 31 spline being better, but not sure at which hp rate i need to convert, And also was wondering how difficult it is t0do a traction-lok and 3.73, on my own.

 

[njoliver]

setting rearends is usually pretty easy to do, just need the time, tools and patients sometimes. IMO 28 spline is usually fine for street cars it is hard lunching and axle tramp that kills them most of the time. I think cars with 400hp 3.73's and 28spline should be ok long as you don't lunch hard.

 

[MustangLx90]

ok forsure,i have been trying to find which tools i would need but i just cant find anything, You have any idea?

 

[94GTCoupe]

You would need an inch pound torque wrench,bearing race/seal installer,bearing seperator,a press,and a slide hammer with attachments to remove the axle bearings,and a quality 2 jaw puller,dial indicator and magnetic base.

You can rent the slide hammer/attachments,race seal driver,and 2 jaw puller from your local Autozone.

Take your time,and don't cut corners,and it will be fine.
I rebuilt mine not too long ago,first time doing it.
Came out awesome!
No noise,and looks great.
Had my rear open this past weekend to install the cobra rear brakes.
Ring and pinion look perfect.

 

[94GTCoupe]

Almost forgot.
You'll also need a micrometer,or dial caliper.

 

[NIKwoaC]

You don't need to upgrade your axles unless you plan to launch hard on sticky tires. You could have 800 hp and get away with stock axles if you never launched hard with drag radials or slicks.

Rebuilding the rear end isn't exactly easy, but if you have patience and do things right, you'll be fine. It is absolutely KEY to make sure your backlash is in spec and that you break in the gears properly.

I'll add to davis3's list and say you NEED an impact wrench. As for the axle bearings, I got the new ones in using the hammer and socket method, but, of course, never hurts to use the right tools.

 

[90lxcoupe]

Another route would be to buy a rear that someone else put alot of money into for 1/2 price, If you never plan on setting up another rear end then it is alot of money in tools to do something once.

you could probably get a rear with 31 spline axles, and the gear you want for 4 or 500 bucks.

 

[MAC'n89Blckstng]

I cut 1.69-1.71 60 foots with Moser 28 spline axles. They say you want the smallest size axle that will handle your power to get the most efficient power transfer to the wheels. 28's should be alright for you.

 

[NIKwoaC]

I cut 1.69-1.71 60 foots with Moser 28 spline axles. They say you want the smallest size axle that will handle your power to get the most efficient power transfer to the wheels. 28's should be alright for you.

I have a hunch that aftermarket 28 spline axles are much stronger than stock axles of the same size. I know that sometimes they are advertised as "25%" stronger bla bla, but have you ever looked at them side by side? My Yukon axles maintain thickness all the way down to the splines, where stock ones are thinner. Not to mention that they're probably made out of stronger material.