93 YZ25 bearing installation

TORQUE SPEC FOR ROD BEARING BOLTS 19 - 24 FT LBS TORQUE SPEC FOR MAIN BEARING BOLTS 60 - 70 FT LBS, CRANKSHAFT PULLEY BOLT 85 - 100 FT LBS. MAIN BEARING OIL CLEARANCE .0005 - .0022 CONNECTING ROD OIL CLEARANCE .0008 - .0015 / SHAFT END PLAY .004 - .008 / AND ROD SIDE CLEARANCE IS .004 - .011 HOPE THIS HELP THIS INFORMATION I GAVE YOU IS INLINE 6 -200 AND INLINE 6 - 250 ENGINES

If you have a connecting rod problem then you have a serious problem. This is the rod that hooks the piston to the crankshaft. Get it looked at before you send a piston through the side of the engine. I will cost more to replace the entire engine. Most reputable mechanics can replace the rod, bearing, and related parts for a reasonable cost. Good luck, do it soon

remove engine from car and install on an engine stand, remove head and oil pan, disconnect lowe rod bearing cap and remove piston through the top, measure crank with a micrometer to get proper bearing size, install rod onto piston and install using ring compressor then install on crank shaft, lube well, reassemble engine and install in car

It can be time consuming and the end result may not be desirable if you haven't done it before.
--- The following is just a sample of what to do once the engine is torn down: Pistons and Connecting Rods

1. Before installing the piston/connecting rod assembly, oil the pistons, piston rings and the cylinder walls with light engine oil. Install connecting rod bolt protectors or rubber hose onto the connecting rod bolts/studs. Also perform the following:
   1. Select the proper ring set for the size cylinder bore.
   2. Position the ring in the bore in which it is going to be used.
   3. Push the ring down into the bore area where normal ring wear is not encountered.
   4. Use the head of the piston to position the ring in the bore so that the ring is square with the cylinder wall. Use caution to avoid damage to the ring or cylinder bore.
   5. Measure the gap between the ends of the ring with a feeler gauge. Ring gap in a worn cylinder is normally greater than specification. If the ring gap is greater than the specified limits, try an oversize ring set. Fig. 5: Checking the piston ring-to-ring groove side clearance using the ring and a feeler gauge
      
      
   6. Check the ring side clearance of the compression rings with a feeler gauge inserted between the ring and its lower land according to specification. The gauge should slide freely around the entire ring circumference without binding. Any wear that occurs will form a step at the inner portion of the lower land. If the lower lands have high steps, the piston should be replaced. Fig. 6: The notch on the side of the bearing cap matches the tang on the bearing insert
      
   
   
2. Unless new pistons are installed, be sure to install the pistons in the cylinders from which they were removed. The numbers on the connecting rod and bearing cap must be on the same side when installed in the cylinder bore. If a connecting rod is ever transposed from one engine or cylinder to another, new bearings should be fitted and the connecting rod should be numbered to correspond with the new cylinder number. The notch on the piston head goes toward the front of the engine.
3. Install all of the rod bearing inserts into the rods and caps. Fig. 7: Most rings are marked to show which side of the ring should face up when installed to the piston
   
   
4. Install the rings to the pistons. Install the oil control ring first, then the second compression ring and finally the top compression ring. Use a piston ring expander tool to aid in installation and to help reduce the chance of breakage. Fig. 8: Install the piston and rod assembly into the block using a ring compressor and the handle of a hammer
   
   
5. Make sure the ring gaps are properly spaced around the circumference of the piston. Fit a piston ring compressor around the piston and slide the piston and connecting rod assembly down into the cylinder bore, pushing it in with the wooden hammer handle. Push the piston down until it is only slightly below the top of the cylinder bore. Guide the connecting rod onto the crankshaft bearing journal carefully, to avoid damaging the crankshaft.
6. Check the bearing clearance of all the rod bearings, fitting them to the crankshaft bearing journals. Follow the procedure in the crankshaft installation above.
7. After the bearings have been fitted, apply a light coating of assembly oil to the journals and bearings.
8. Turn the crankshaft until the appropriate bearing journal is at the bottom of its stroke, then push the piston assembly all the way down until the connecting rod bearing seats on the crankshaft journal. Be careful not to allow the bearing cap screws to strike the crankshaft bearing journals and damage them.
9. After the piston and connecting rod assemblies have been installed, check the connecting rod side clearance on each crankshaft journal.
10. Prime and install the oil pump and the oil pump intake tube.
11. Install the auxiliary/balance shaft(s)/assembly(ies).

OHV Engines CAMSHAFT, LIFTERS AND TIMING ASSEMBLY

1. Install the camshaft.
2. Install the lifters/followers into their bores.
3. Install the timing gears/chain assembly.

CYLINDER HEAD(S)

1. Install the cylinder head(s) using new gaskets.
2. Assemble the rest of the valve train (pushrods and rocker arms and/or shafts).

OHC Engines CYLINDER HEAD(S)

1. Install the cylinder head(s) using new gaskets.
2. Install the timing sprockets/gears and the belt/chain assemblies.

Engine Covers and Components Install the timing cover(s) and oil pan. Refer to your notes and drawings made prior to disassembly and install all of the components that were removed. Install the engine into the vehicle. Engine Start-up and Break-in STARTING THE ENGINE Now that the engine is installed and every wire and hose is properly connected, go back and double check that all coolant and vacuum hoses are connected. Check that your oil drain plug is installed and properly tightened. If not already done, install a new oil filter onto the engine. Fill the crankcase with the proper amount and grade of engine oil. Fill the cooling system with a 50/50 mixture of coolant/water.

1. Connect the vehicle battery.
2. Start the engine. Keep your eye on your oil pressure indicator; if it does not indicate oil pressure within 10 seconds of starting, turn the vehicle OFF. WARNING
   Damage to the engine can result if it is allowed to run with no oil pressure. Check the engine oil level to make sure that it is full. Check for any leaks and if found, repair the leaks before continuing. If there is still no indication of oil pressure, you may need to prime the system.
   
3. Confirm that there are no fluid leaks (oil or other).
4. Allow the engine to reach normal operating temperature (the upper radiator hose will be hot to the touch).
5. At this point any necessary checks or adjustments can be performed, such as ignition timing.
6. Install any remaining components or body panels which were removed.

no-sorry to tell u but need to pull engine to access crank shaft have to drop oil pan and u have to break down engine to block[ rod bearing might be part of problem wrist pin also may be damaged even side wall of cylinder may be damaged ] piston and rod go in from top of cylinder

MAKE SURE THE CRANKSHAFT IS NO DAMAGED.IF IT IS THE NEW BEARINGS WILL GO BAD QUICKLY

You need a spindle nut, a bearing puller and a tie rod puller. Get a Haynes manual and it will walk you through the installation.

Lots of clanking when first started sounds like a worn rod bearing. Check the engine compartment and rev engine to listen for knocking. It will get progressively worse as time goes by. Nothing to do except buy/install new crankshaft kit from autozone, about $300+.

In the mean time, just change oil and put in some oil additive to lessen the knocking. High speeds will accelerate the wear of the rod bearing. The rod bearing is installed inside of the piston rod. This bearing goes around the crankshaft. It has very tight tolerances down to the thousands of an inch. When it gets worn, metal will flake off of the soft bearing material and contaminate your oil more. If you catch it early enough, you can replace the bearing without too much trouble. Here is what you need to do.

Find the bad bearing. If you hear the knocking with the engine on and under the hood, disconnect a sparkplug. If the knocking goes away, that is the bad bearing. Do this disconnecting/reconnecting until you identify the bad bearings. Now disconnect battery. Next loosen drive belt- done from steering pump. Loosen 2-13mm bolts on back, one on top and one on bracket on bottom. On bottom right-hand side of pump will be a long adjusting bolt. Loosen turn this bolt counter clockwise to loosen drive belt. Now jack vehicle from the frame, vehicle will raise but tires will remain on ground. keep going as high as your jack will go. Install jack stands on frame. This extends your suspension and keep body raised. Drain oil, remove steering damper. It's the shock absorber looking thing connected to your tie rods/center link. The easiest way to remove the oil pan is to get a 3/8 inch socket adapter for a cordless drill. The bolts will come out in a hurry if you do this. Keep track of where the double sided bolts are, they secure the fuel line brackets. After all are removed, wiggle, tug, and pull pan out. Now you will see the large main caps and the rod caps. The mains are bolted to the block and the rods will rotate up and down with the spinning of the crankshaft. Spin the crankshaft to see. Each bearing cap needs to be marked. Use a center punch and hammer to mark from front to rear. 1 mark for rod cap 1 and so forth. You should end up with 6 marks on rod cap #6. Do the marking on the front side of the cap so you know how it fits back. Remove the rod caps that corresponded to the bad bearing identified earlier. Remove nut on cap. Wiggle cap back and forth until it comes loose. It will eventually come out. Inside the cap, you will see the bearing. It is basically a liner for the cap that rides on the crankshaft. there is one on the top of the rod too. Remove it by pushing rod up into cylinder and pulling it out with your hand. Ensure you remember the orientation of the bearings. One side has a notch, the other has a key that fits into a hole on the rod. Now you have the bearing in hand, check for scoring, or wearing on the face. Check the web for a nice color picture. Feel the crankshaft bearing area with your finger nail. It should be smooth and not ridged. Purchase some plastigage along with a standard .000 bearing. Clean rod surface, install new bearing and plastigage. Tighten to torque. Remove cap and measure plastigage for your oil clearance. Now you can purchase the correct bearing to match your oil clearance. If you don't have a repair manual, now's a good time to get it. It has bearing tolerances for you to get the correct bearing. After you have the correct bearings, use oil additive to grease up the new bearing/crank surfaces. Put everything back together, put some quality magnets inside of your oil pan near the drain hole and cross your fingers.

The oil clearance for a rod bearing was probably not done correctly allowing excess slapping. Check by unplugging your sparkplugs one at a time to see if the noise goes away. If it does, then the corresponding rod bearing is probably the cause. Check utube for videos of rod bearing noises and see if yours sound like those. That's how I found out my rod bearing was bad.