Splitting the Type IV Case

by John Anderson

You NEED to remove up to 18 (count them) 8mm nuts or bolts to split a Type IV case. Often there are only 17, but occasionally one will be in place at the very top tab on the flywheel end.

Among the hardware to be removed are:

• Two 6mm nuts from the breather area
• Six 10mm case through bolts to split a T4 case (don't actually remove those 10mm bolts just take off the nuts)
• Three often overlooked are: one behind the flywheel, one in the center of the lifter bores, and one below the oil filter.

Count them, if you don't have 18 yet, keep looking.

Even then the Type IV can be a hard case to split. Last week I ruined a nice 1700 case--broke the tang up at the breather clean off on my second tap with a wooden mallet. I've hit harder on others with even steel hammers, so I figure someone else had already nearly broken it.

It is usually the 2 dowels that hang it up, particularly if they are rusted. To make it easier I recommend using one of the studs below the oil pump (which has already been removed) to tap on. Sometimes it is easier to first remove all the parting line and through hardware then the pump will slip right out. Put an old nut on the stud about halfway on, and tap gently with a hammer on the nut. This will concentrate the force right at the dowel below the pump. Once that starts, judicious tapping with soft mallets up on the front top (flywheel end) will usually break the other pin free and then you can pull it apart by hand. Also, no need to remove the oil seals. Don't beat that stud so much to damage it--light tapping will get the case going.