[Mike]

This is just my opinion but I would not worry. When the bearings get to the point of needing replacement I suspect you will be seeing low oil pressure. Unless that is what is happening now, keep on trucking.

[Archived]

Thanks Jon. Oil pressure is still good so that is not a problem.

[Andre]

Tom I would change the bearings,the thrust bearings wears you will not see a oil pressure drop, the 92 is a strange duck all the journals are drilled for oil passage with the expection of the rear main and when they get to much ware it will spend the rear bearing then it will cost you big time to line bore the engine.

The rear main on a 92 series is the weak link on the engine I could never understand why DD increased the hp and more cubic inches and used the same bearing as the smaller 8V71.

It’s a 1 day job just remove the pan, the oil pump pickup tube,remove the block supports from the mains and start removing the caps all the bearing are easy to replace except the rear main that one you have to roll the engine over to remove the bearing .The fun part is the 250 ft of torque laying on your back be sure you have a good 12 point 15/16 socket a 6 point is worthless good luck

[jack]

Thanks Clifford. That is good information.

[Archived]

Is it agreed then that 200,000 miles is the point of action based on mileage even though oil pressure is still good ?

We have a little over 123,000 miles but try to plan ahead for such pricey maintenance issues.

I monitor the engine vitals religiously and thought as Jon said the oil pressure would gradually get lower, flagging the main wear issue. I also understand Cliffords statement about the rear main concern and possible issues with spinning it.

Is 200,000 miles a safe and proven point of action to prevent the possible rear main spinning ? And is it a Detroit mandate or a seat of the pants observation by experienced mechanics, (sometimes better than factory)?

[Archived]

I ran mine 250,000 and when I started getting coolant in the cylinder I opted to do a complete in-frame.

Wasn’t needed. everything was line new and the problem was a crack in the head but we didn’t know it until we had the engine apart.

[Clifford]

The 20000 miles was based off the 5000 hr bearing replacement for the off hiway engines some manuals state 200,000 miles in the preventive maintaince sections some don’t,sorta like the vibration damper replacement at 300,000 miles or must be replaced at overhaul.

Tear one down the rod bearings will look new on the lower shell and lots of ware on the upper shell as the upper carries all the load then on the mains the upper shell will look new and the lower shell carrying the load will be wore

[John]

The 20000 miles was based off the 5000 hr bearing replacement for the off hiway engines some manuals state 200,000 miles in the preventive maintaince sections some don’t,sorta like the vibration damper replacement at 300,000 miles or must be replaced at overhaul.

Tear one down the rod bearings will look new on the lower shell and lots of ware on the upper shell as the upper carries all the load then on the mains the upper shell will look new and the lower shell carrying the load will be wore