i'm removing the oil pan to replace gasket, oil pump, mains/rod bearings. will i have to pull the motor out to get the oil pan off? or maybe remove dizzy/fan unbolt motor mounts and exhaust and jack it way up?

 

i would pull the engine out to freshen it up, IMO it would be easier if you did. Also you should plasti-gage the bearings for clearance just to make sure that all is good. i think its cheap insurance.

 

Myself, I would yank the motor to be doing anything like main berrings on an engine. They need to be pretty clean, and thats a filthy area around the bottom and crossmember. Its probably in your best interest and cheap insurance to pull the engine out and do the jobs with more room to work and cleaner results. I think you could jury-rig a gasket change on it without pulling the engine, but I dont think you can get the pan out of the way. Im not sure if you can even get the pan off a 4x4 without some serious moving of engine... My older S10 has a smallblock, and there is NO WAY that oil pan can come off without the engine coming out, and its a 2WD model.

 

The book says to pull the engine on a 2 wheel drive. Fir what you're doing I can't see why you wouldn't.

 

I had to pull my engine on my 2.8L 4x4. I was able to get to all the bolts with the engine ine, but no way to remove the pan.

 

I have seen someone take the motor mounts off and than using a hoist to lift it up and he had enough room to take the pan off and work at it. But he only replaced the gasket and the oil pump while he was at it.

 

well it's not a guaranteed thing that i'm replacing the bearings, i'm going to check one main and one rod for wear. the blazer has over 230k miles. the oil pan gasket started leaking ALOT after i replaced the timing chain. it has good oil pressure 55 psi cold and 40 when warm but has a weird problem, when you are stopping the oil pressure drops and if you stop to hard the oil pressure will go all the way to 0 and the oil light will come on, but as soon as you come to a complete stop the oil pressure goes right back up, doesnt do it when you accelerate.

 

Check and see if your oil pressure sender is leaking. It's right next to the oil filter if my old brain remembers correctly. Might not be the pan gasket after all. My 84 Jimmy (2.8L) did pretty much the same thing and it was the sender/ I thpught it was the pan gasket too.

 

now this is regarding what i first read (in the first few post).

how the hell would you hold that crank up in there, while trying to get the mains on without screwing anything up? are you related to Superman or The Flash ('cause you'd have to be super fast to acomplish it that way IMO).

now after reading the rest, have you thought about checking the actual pump? (providing the sending unit checks out ok) @ 230K, the pump might be pretty worn out.

but if you feel that the any of the mains or throws need to come of, personally, i'd just pull 'em all, polish the crank, and throw in a new set of bearings, 'cause the chances of getting the same load back on a main or throw is gonna be a crap shoot @ best.

 

If you can get the pan off, the rest can be done and done quite easily. Should it be done, not really since you cannot measure anything properly to determine if the journals are the proper size and actually round. This is especially true if there is damage to the crank which is quite likely regardless of how quick you got it shut down. Damage can be done in a fraction of a second.

I have helped in the replacement of main and rod bearings in a Detroit Diesel from the bottom end. It was in one of our dump trucks on the farm. We needed the truck to haul grain and did not have the time to do a proper rebuild. Replacing the bearings got the oil pressure back up where it needed to be and lasted the month that we needed it to last. We then tore the complete engine down over the winter. But that was out of immediate necessity with the express knowledge that it was time and money wasted.