briansgonnawin

Im going to replace my diff and axle to a 31 spline. and want to know do i need new bearings and seals or can i just use the stock ones? and if any, which axle would you guys recomend?

SINISTER

Since you are already going to be in there, you might as well go ahead and replace the bearings and seals.

MU71L4710N

and the gears for another 150$ :-)

wont you need a 31 spline LSD also?

TheCrimzonKnight

moser axles, auburn lsd, ford racing bearing kit

2abouAziza

I want to replace plaintary gears to LSD do i ahve to change the axles? i bought a 3.73 ring n pinion and thought those would be the 3 things to switch out other then the seals and bearings. I was told that i have to change the whole differntial housing in order to switch my 99 gt to have LSD due to axels and other issue?

GodAmGT00

If I'm not mistaken, you WILL need new bearings and seals, since 31 spline axles I believe are thicker.. On top of that, your center section is 28-spline, if it's OE, therefore you'll need to replace that as well.. I mean, at this point, you're going to have to rebuild the entire rear diff, if you plan on making it last.. Not cheap, but definitely worth it...



JT

Pest007

Axle seals are good idea since you have everything out, bearing depends on miles and stuff, but might as well since you doing everything else. They should be same size tho.

2abouAziza

So what im understanding is28 spline and 31 spline are both LSD. What is the difference to the 2 options i found on ebay and what do they each ask of me to replace... axels, ring and pinon,..etc? The reason i say axel is because i was told that the 99-04cobra have LSD not knowing that the GT has LSD and that their whole differential housing is different and so the routing of the exhaustwill change also. This is to my knowledge and im hoping to be corrected. I found these 2 products and do i just slap on the ring n pinion, seals and bearings and then im good to go or is there much to be added or changed? what is the difference between the 2 if there is any. I really appreciate the help

Ford Racing 8.8" 31 Spline Traction Lok Differential

OBX LSD DIFF POSI MUSTANG 79-05 31 SPLINE 8.8"







[/align]Thanks [/align]

TheCrimzonKnight

The difference is that the 31spine is stronger and can handle more power. So if you dont plan on making alot of rwhp you really dont need 31 spines. Also if you do change it get the ford racing one i believe that is the one in the 03-04 cobra.

Pest007

You do know that the Cobra's have IRS and not a solid rear axle like the GT's right, that is why the exhaust stuff is different. I they both have differentials (not the same ones) but the IRS and solid rear axle are 2 completely different things.