got a 78 supercab 1 ton. has a 400. and the rear mains outta it. whats the best way to go about replacing it?
thanks.

 

The easiest way to change it would be to drop the trans, you may want to find a trans jack to give a helping hand.

 

EMAIL MY HUSBAND HE HAD TO REPLACE 3 REARS AFTER YOU DROP YOUR TRANS YOU HAVE TO USE THE PLASTIC COVER TO HELP INSERT IT ANS YOU SHOULD USE GASKET SEALER IF YOU PUT IT IN DRY YYOU MAY TEAR THE RUBBER AND IT WILL LEAK AGIAN

 

if He is installing the seals correct an there still leaking , its possibly that the main brgs are worn out allowing excessive play in the Crankshaft.