RTS bus part number help

[Scott Crosby]

I'm helping a guy with an rts bus.  I believe he said its a 1980 RTS II.  He has a bad seal leak on his radiator fan drive output shaft.  He has the manual but it shows a fluid fan drive like a regular gm bus, however his is a large belt driven fan so his parts book does not show this setup.  There is a pulley on a shaft that comes off the crank maybe 6". The seal is the one where it hooks to the block crank output.  Anyone know that part number?  It looks to be about a 4" diameter seal.  I can see the entire seal and it looks like maybe once the pully is removed the seal can come out over the shaft?  Hopefully they make a wear sleeve and seal kit?  Anyone know the part number and or the way to replace it? 

[luvrbus]

When you remove the 6 pulley bolts there is a bolt on the end of the crank you remove it and pull the drive to replace that seal if you talking about the fan drive that has a serpentine belt with a idler,fan pulley and drive pulley.

I don't have the seal number but it's standard DD issue and I never saw a wear sleeve on 1 you replaced the drive if worn  that one can be fun without a good puller 

[Scott Crosby]

thanks.  I'll try to pull it tomorrow.  I was hoping for a part number to get it ordered or pick it up on my way at the local two stroke shop if they had it in stock.  They had the 2 valve head and cylinder kits for it in stock that we put in on Friday for the guy.  That seal is leaking pretty massively like maybe 1/2 to 1 pint per minute.  They do more industrial engines so if it's a bus specific part they won't have it.   

[luvrbus]

Wonder who changed the heads to a 2 valve a 80 model shouldn't be a 2 valve head

[Scott Crosby]

Is that big bolt on the crank regular right hand thread? 

[luvrbus]

Yep, tight huh

[Scott Crosby]

It was snug.  I got it though.  The seal was a son of a b to remove but it's out too.

[luvrbus]

 I take self tapping screws and force the seal out or they can be a PITA