biopete said:
thanks jetta 97. i've made up my mind to do the swap.
I used the below instructions from user QuickTD(?).
To change the crank bearings you will need:
Rod bearing shells std size
main bearing shells std size
thrust bearings
rod bolts
main cap bolts
torque wrench
service manual
Lots of time and patience, this is critical
The rod bearings can be replaced without much trouble with the engine in the car. Rotate the crank so that the rod you are working on is at BDC. Do them one at a time and make sure the caps go back on in the correctorientation.
Mark the installed position if they are not already clearly marked. Use care to avoid nicking the crank journals. Lubricate the shells thoroughly with clean engine oil. Use new bolts and torque them to spec. Keep everything is spotlessly clean.
The main bearings will be somewhat more difficult. It is possible to very slightly loosen all the main caps and the crank will drop far enough (you only need a few thousanths of an inch) to ease the removal of the main bearing shells. Again, only remove one cap at a time and make sure to reinstall it in the correct orientation. The main caps are a light press fit into the block, it will take some wiggling to get them out. The #3 main is particularly nasty because it carries the thrust washers and has very little wiggle room.
The term "rolling in" refers to the method of installing the upper bearing shells. To do this you must fabricate a tool to insert into the oil hole in the crank. The "head" of the tool must be large enough that is does not fall into the oil hole completely, that would be extremely bad, but low enough that it can fit between the crank and the block. An aluminum roofing nail can be fashioned into a suitable tool, and is non-scratching to boot. The tool is inserted into the oil hole and the crank is rotated with a wrench (remove glow plugs to make it easier) to to push to old bearing shell out.
The new shell is then laid on the crank journal and rolled as far as possible into the block. It is then pushed to its final position with the tool. Be careful. If anthing binds up stop and back up. You don't want to shear off your tool in the oil hole or bend a bearing shell.
The rearmost bearing shell cannot be removed/replaced in this manner as it does not have an oil hole in the journal. This shell must be pushed out using a non scratching flexible sheet metal strip. Aluminum sheet about 3/4" wide and .040" thick works well. The aluminum strip method may also work for some of the other bearings, YMMV. You may have to fab up more "special tools" as you work. There are no off the shelf tools for this job. The shells can be stubborn and it can be very difficult to get the locating tabs in the shells to align properly with the grooves in the block. Try to start the bearings as centered as possible as this will help with final alignment.
When you are doing this kind of work be prepared to spend a couple of days at it. Rent a car if you need to. It is very frustrating work. Be prepared to walk away from it a few times to cool off.... I'll admit it, it is sometimes easier just to pull the motor. If you have never changed bearings on an engine, I wouldn't recommend you attempt the job for the first time on an engine installed in the car.
Cleanliness is of the utmost importance. Have plenty of clean rags and solvent (brake clean) available in case something gets dropped and needs cleaning. Dip the new shells in clean engine oil before installing them and crank the engine for at least 30 seconds with the fuel cutoff solenoid disconnected to prime the oil system once the work is complete.
Do an internet search for "main bearing replacement" and "rod bearing replacement" and you may find some additional info. I'm a little afraid of what you might find when you get in there. The overlay metal on the bearings is very thin. If the overlay wears through the crankshaft journal will be tore up. If this is the case you will need to pull the motor and either get the crank reground and undersize bearings installed or just get a new engine, which would probably be the easier route to take. New bearings will not last on rough crank journals. Even worse, one or more of the bearings could have stuck to the crank and spun in the rods or in the block. If this has happened you will need a new engine for sure.