[KristinaV]

My '30 Ford Rat Rod is leaking rearend fluid out of the main seal. After I change the main seal, what kind of gear oil should I use?

It is a 9" ford rearend with an unknown gear ratio.

Please help!

 

[lmsport]

Any GL5 should work. For something I dont want mess with again, I would use synthetic. If it has a clutch type posi you will need to add some friction modifier also. If you dont know what diff it is, you can add the modifier just in case, it wont hurt anything.

 

[big gear head]

80W90 GL4 or GL5

 

[KristinaV]

Rearend Gasket?

ok, cool.

Do you know how to determine what type of 9" Ford rearend I have in order to figure out the exact gasket I need for the Rearend axle housing?


Thanks

 

[big gear head]

A 9 inch Ford is a 9 inch Ford as far as the center gasket goes.

 

[KristinaV]

That's what I thought, but when I look it up there seems to be quite a few different versions of that gasket. How do I figure out which one is correct?

 

[BuzzLOL]

You can find the gear ratio by counting how many driveshaft turns it takes to rotate both rear tires exactly one rotation... 3 1/2 turns = 3.50 ratio... etc... Or count the number of gear teeth on pinion and ring gears and divide if you have it apart...

With one rear tire jacked up and one still on the ground and the tranny in neutral, you can effortlessly spin the one up tire and driveshaft by hand with an open rear end... it will be difficult to impossible with a posi rear end...

 

[lmsport]

FEL-PRO RDS55074 Differential Gasket should fit all Ford9

 

[rip-tide]

You can find the gear ratio by counting how many driveshaft turns it takes to rotate both rear tires exactly one rotation... 3 1/2 turns = 3.50 ratio... etc... Or count the number of gear teeth on pinion and ring gears and divide if you have it apart...

With one rear tire jacked up and one still on the ground and the tranny in neutral, you can effortlessly spin the one up tire and driveshaft by hand with an open rear end... it will be difficult to impossible with a posi rear end...

ROTFLAMO ......... that's pretty true .............. hilarious !


Just having fun...

Greg