This post is a tutorial on how to replace the con-rod and crankshaft (main) bearings and at the same time replace the front & rear main crankshaft seals. For engines which have been sitting around for long periods of time (such as many japanese import engines), I feel replacing the bearings it's a important repair to do. This tutorial is for the Toyota 4EFTE engine but will work (with exception of torque settings) for most FWD engined cars.
The engine will need to removed from the car, gearbox removed and bolted up to an engine stand. My engine was already on a stand after getting it sandblasted.
Okay - so here we go...
The main crankshaft pulley needs to be removed first. Remove the main pulley bolt first with either a rattle gun; or holding a screwdriver in the flywheel ring gear to stop the crankshaft from moving and a use a breaker bar to undo the bolt. To remove the pulley, clamp the puller around the pulley and tighten the main bolt/shaft.
The main bolt of the puller I had was too small and once tightened, would be forced into and strip the crankshaft bolt thread so I cut a small piece of steel up so that the bolt would sit on top of the end of the crankshaft.
Once the pulley is off, remove the two plastic timing belt covers, loosen the timing belt idler pulley and tensioner pulley, and remove the timing belt (I will have a tutorial on how to change the belt also which will kick of at this point). Remove the bolts and couple of nuts holding the sump on, and lever it off (it will be stuck on with gasket sealer).
Spray some WD-40 behind the oil pump sprocket (as it can sometimes be siezed on the shaft, so leave ir overnight maybe?) and CAREFULLY lever the sprocket off with two screwdrivers.
Undo the bolts holding the oil pump assembly on and remove it.
At this point, you can inspect the oil pump, check for any scoring in the rotor area, or any shaft play. Replace if necessary.
Remove the rear crank seal assembly from the other end of the engine and replace that seal also.
Undo the 3 small bolts holding the oil pickup assembly on and remove the pickup. The crankshaft will be full exposed, so go ahead and undo and remove all the conrod nuts and conrod caps. Be careful not to drop any nuts into the piston bores. It's not like you'll lose them, but it can take a bit of time getting them out again!
and the crankshaft cap bolts and caps. BEWARE - Make sure that you make note of the orientation of the caps for the conrods & crankshaft. I simply wiggled the caps to get them off and placed them on a rag next to the engine in the position. After that, remove the whole crank and make sure that you don't pull the pistons too far out of the bore to expose the piston rings (you'll have a heck of a job getting them back in the bore after that)
Remove all the old bearings from the conrods & cranks and all the caps. They should simply push out by hand.
For the conrods, all the 8 x bearing shells are the same so simply line up the notch in the bearing with the notch in the conrod cap or main conrod and push in the bearing. After that, apply assembly lube to the bearings.
For the crankshaft bearings, the upper & lower bearing shells are different and are marked "U" for upper (fit into the block) and "L" for lower (fit into the caps). As per the conrod bearings, match up the notch in the bearing, insert and apply lube.
The thrust washers are the same as the crankshaft bearings in that they are marked for Upper and Lower fitting. The washers should be fitted with the grooved sides facing OUT.
A trick to getting the washers to stay in place is to apply assembly lube to the smooth side of the washer and it will stick to the block/cap. Fit the two washers to the block and two to the single centre crankshaft cap.
Once all the bearings have been fitted and lubed up, it's now time to bolt everything back together.
Ensure that all pistons are pushed down into the block and place the crankshaft back into the block. Place the two end crakshaft caps on and hand tighten cap bolts (just to keep the crankshaft in place for now). Rotate the crank until two of the journals are at the top piston. In my case it was the end ones. Lift up the piston so it contacts with the journal.
Place the conrod cap over the journal and apply some High Strength Loctite to the threads and tighten (using a torque wrench of course). Torque for these nuts are 40Nm (spec says tighten to 25Nm then turn another 90degrees)
Rotate the crank again, lift up the other two pistons & repeat.
Place the remaining caps in place (make sure the orientation of the caps is correct), insert remaining crankshaft cap bolts, apply loctite to the crankshaft bolts and tighten to 57Nm. The order to tighten them is as below.
Well done! The bearings have been fitted. Clean out the old gasket sealer from the machined grooves in the backs of the oil pump assembly and rear main seal housing. Apply some assembly lube to the oil pump rotor and gasket maker (I used Permatex Copper Maxx RTV silicon gasket maker) to the grooves. I lost my nozzle for the tube of gasket sealer so it's a bit messy here, but it does the job.
Don't forget to install the oil pump rubber O-Ring.
Then bolt them back onto the block. The ideal situation is have just a small amount gasket sealer squeeze out so you know it's got enough to make a good seal.
Clean up the sump of old gasket/sealer, apply a more liberal line of gasket maker and bolt the sump on.
And that's pretty much it. From here, I moved on to fit the new timing belt.
The engine will need to removed from the car, gearbox removed and bolted up to an engine stand. My engine was already on a stand after getting it sandblasted.
Okay - so here we go...
The main crankshaft pulley needs to be removed first. Remove the main pulley bolt first with either a rattle gun; or holding a screwdriver in the flywheel ring gear to stop the crankshaft from moving and a use a breaker bar to undo the bolt. To remove the pulley, clamp the puller around the pulley and tighten the main bolt/shaft.
The main bolt of the puller I had was too small and once tightened, would be forced into and strip the crankshaft bolt thread so I cut a small piece of steel up so that the bolt would sit on top of the end of the crankshaft.
Once the pulley is off, remove the two plastic timing belt covers, loosen the timing belt idler pulley and tensioner pulley, and remove the timing belt (I will have a tutorial on how to change the belt also which will kick of at this point). Remove the bolts and couple of nuts holding the sump on, and lever it off (it will be stuck on with gasket sealer).
Spray some WD-40 behind the oil pump sprocket (as it can sometimes be siezed on the shaft, so leave ir overnight maybe?) and CAREFULLY lever the sprocket off with two screwdrivers.
Undo the bolts holding the oil pump assembly on and remove it.
At this point, you can inspect the oil pump, check for any scoring in the rotor area, or any shaft play. Replace if necessary.
Remove the rear crank seal assembly from the other end of the engine and replace that seal also.
Undo the 3 small bolts holding the oil pickup assembly on and remove the pickup. The crankshaft will be full exposed, so go ahead and undo and remove all the conrod nuts and conrod caps. Be careful not to drop any nuts into the piston bores. It's not like you'll lose them, but it can take a bit of time getting them out again!
and the crankshaft cap bolts and caps. BEWARE - Make sure that you make note of the orientation of the caps for the conrods & crankshaft. I simply wiggled the caps to get them off and placed them on a rag next to the engine in the position. After that, remove the whole crank and make sure that you don't pull the pistons too far out of the bore to expose the piston rings (you'll have a heck of a job getting them back in the bore after that)
Remove all the old bearings from the conrods & cranks and all the caps. They should simply push out by hand.
For the conrods, all the 8 x bearing shells are the same so simply line up the notch in the bearing with the notch in the conrod cap or main conrod and push in the bearing. After that, apply assembly lube to the bearings.
For the crankshaft bearings, the upper & lower bearing shells are different and are marked "U" for upper (fit into the block) and "L" for lower (fit into the caps). As per the conrod bearings, match up the notch in the bearing, insert and apply lube.
The thrust washers are the same as the crankshaft bearings in that they are marked for Upper and Lower fitting. The washers should be fitted with the grooved sides facing OUT.
A trick to getting the washers to stay in place is to apply assembly lube to the smooth side of the washer and it will stick to the block/cap. Fit the two washers to the block and two to the single centre crankshaft cap.
Once all the bearings have been fitted and lubed up, it's now time to bolt everything back together.
Ensure that all pistons are pushed down into the block and place the crankshaft back into the block. Place the two end crakshaft caps on and hand tighten cap bolts (just to keep the crankshaft in place for now). Rotate the crank until two of the journals are at the top piston. In my case it was the end ones. Lift up the piston so it contacts with the journal.
Place the conrod cap over the journal and apply some High Strength Loctite to the threads and tighten (using a torque wrench of course). Torque for these nuts are 40Nm (spec says tighten to 25Nm then turn another 90degrees)
Rotate the crank again, lift up the other two pistons & repeat.
Place the remaining caps in place (make sure the orientation of the caps is correct), insert remaining crankshaft cap bolts, apply loctite to the crankshaft bolts and tighten to 57Nm. The order to tighten them is as below.
Well done! The bearings have been fitted. Clean out the old gasket sealer from the machined grooves in the backs of the oil pump assembly and rear main seal housing. Apply some assembly lube to the oil pump rotor and gasket maker (I used Permatex Copper Maxx RTV silicon gasket maker) to the grooves. I lost my nozzle for the tube of gasket sealer so it's a bit messy here, but it does the job.
Don't forget to install the oil pump rubber O-Ring.
Then bolt them back onto the block. The ideal situation is have just a small amount gasket sealer squeeze out so you know it's got enough to make a good seal.
Clean up the sump of old gasket/sealer, apply a more liberal line of gasket maker and bolt the sump on.
And that's pretty much it. From here, I moved on to fit the new timing belt.
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