putting in new piston rings

87hilux7mge · 05-06-2011, 07:14 PM

problem here. as far as i tried and seen, you cannot get pistons in or out of the bottom of the 7m block.

the main girdles get in the way. also you do not have to pull the crank to put new piston rings in.

pull the motor. pull the head and oil pan. remove oil pump. remove rod caps. take vacuum plugs and cover rod cap bolts. push pistons out the top of the block. remove old rings. clean rods/piston. hone/deglaze cylinders with a honing brush. install new rings, careful not to break them. make sure everything is very clean before reassembly. using a ring compressor and wooden handle or rubber coated handle (NO METAL), tap pistons back into block, be very careful not to ding anything. seat rods back onto journals. install caps and check clearances. if it all check out, torque to spec. reinstall everything and your good to go.

i wouldnt recommend just doing rings cuz theres prolly other things wrong if its old. a full rebuild would be best. just check your bearing clearances and youll be fine.

one more thing, the old addage that removing pistons from the top is bad due to ring wear ridge, is almost unapplicable to most toyota l4 and l6 motors. toyota uses high nickel content blocks, adding greatly to wear resistance from the rings. this is not bullet proof, but when tearing a motor down, it takes 2 seconds to check. ive never had a problem with any rings or pistons breaking when removing them from a block.

ive pulled apart 3 M series block and 2 R series, and all of them had well over 180k. the ring ridge was almost non existant. the most pronounced was my 22r from my pickup which had 240k on it (still ran great, just replaced the rings while i was doing the clutch for some extra insurance. guy i sold it too still runs it to this day and gets 25+ mpg and has 145-150 compression all across the board.

05-06-2011, 07:14 PM	#7
87hilux7mge walbro fp Join Date: Dec 2010 Location: spokane Posts: 479	problem here. as far as i tried and seen, you cannot get pistons in or out of the bottom of the 7m block. the main girdles get in the way. also you do not have to pull the crank to put new piston rings in. pull the motor. pull the head and oil pan. remove oil pump. remove rod caps. take vacuum plugs and cover rod cap bolts. push pistons out the top of the block. remove old rings. clean rods/piston. hone/deglaze cylinders with a honing brush. install new rings, careful not to break them. make sure everything is very clean before reassembly. using a ring compressor and wooden handle or rubber coated handle (NO METAL), tap pistons back into block, be very careful not to ding anything. seat rods back onto journals. install caps and check clearances. if it all check out, torque to spec. reinstall everything and your good to go. i wouldnt recommend just doing rings cuz theres prolly other things wrong if its old. a full rebuild would be best. just check your bearing clearances and youll be fine. one more thing, the old addage that removing pistons from the top is bad due to ring wear ridge, is almost unapplicable to most toyota l4 and l6 motors. toyota uses high nickel content blocks, adding greatly to wear resistance from the rings. this is not bullet proof, but when tearing a motor down, it takes 2 seconds to check. ive never had a problem with any rings or pistons breaking when removing them from a block. ive pulled apart 3 M series block and 2 R series, and all of them had well over 180k. the ring ridge was almost non existant. the most pronounced was my 22r from my pickup which had 240k on it (still ran great, just replaced the rings while i was doing the clutch for some extra insurance. guy i sold it too still runs it to this day and gets 25+ mpg and has 145-150 compression all across the board. __________________ 87 toyota 4x4 single cab short box pickup, 7MGZE. Last edited by 87hilux7mge; 05-06-2011 at 07:34 PM.