720 rear main seal

[datsunrally720]

so i got a 86 nissan 720 truck automatic  I'm rebuilding the engine i bought  a rebuild kit  ITM  I'm trying to install the ream main and it won't go in it won't fit  

 

[Lockleaf]

You can try lubing it with clean motor oil or rtv. They don't just slip in. They have to be tapped in. I like to use the old seal as a buffer and tap the seal in using a 3/8 inch ratchet extension and a hammer.

[Draker]

Yep, tight fit. 

 

You can buy a felpro from rockauto for dirt cheap if it turns out it's a cheap aftermarket seal. Wouldn't surprise me either.. 

[datzenmike]

Lube the crankshaft side lips on the seal so it doesn't start up and run dry. Place a suitable size block of wood over the seal, line it up evenly and nudge into place with a heavy hammer or sledge tap. Once flush, switch to something like the 3/8 extension and go round and round. tapping it gently in until fully seated.

[Doctor510]

so i got a 86 nissan 720 truck automatic  I'm rebuilding the engine i bought  a rebuild kit  ITM  I'm trying to install the ream main and it won't go in it won't fit  

Have you removed the flex plate adapter?