Differential interchangeability

[turbo87adam]

Could anyone verify if a posi carrier out of a 95 roadmaster will fit a grand national? I looked on rock auto and they list the same differential bearing for both but is side to side offset the same?

 

[mikestertwo]

I think the carrier will fit but it may have 30 spline axles instead of 28 spline

 

[ttaowner]

I agree with the above.

 

[TurboTnZ06]

From experience, just buy a new one like an Eaton from Summit etc. I bought a used one once, it shattered the spider gears on the second pass. I've given up buying anything used at the age these cars are.

 

[turbo87adam]

Thanks for the information.I have the opportunity to pull one out of my father car before I send it to the junk yard but I won't bother now.

 

[TexasT]

I am pretty sure those newer diffs are 30 spline.

I spoke to the eaton rep at the power tour and he thought their thorsen type helical diff was worth the extra. I'm not sold but it doesn't have clutches to wear out.

I agree with the buy it knew if you have the coin. No telling what condition the used stuff is in.

I would consider an upgrade to the axles to 30 spline if you plan to upgrade the axles at the same time. It's already apart.

 

[novaderrik]

i think they used a crappy differential in the newer B bodies, anyways...

you should consider grabbing the front spindles off the car- you can swap them onto your car with different upper control arms and lower balljoint.. get a 1LE Camaro rotor and this will give you 12" brakes, and the 94-96 spindle is the lightest and strongest of the "tall" spindles..

 

[ttaowner]

If its free its worth taking out . That car probably has 3.42 ratio and that would be the same

 

[MonstrNrgy]

The roadmaster more than likely has 2.93 gears in it.