[smlblcks10]

quick question for you guys: i was wondering if you have to remove the intake and therefore the distributor to replace a rear main seal on a sbc ('66 283 block). the timing marks are off or something on it and i have spent a good amount of time timing it by ear and feel and have definitely got it in the sweet spot. Now my rear main seal needs replacing and im woried the distributor will have to be removed and ill have to start from scratch timing it. the motor is in an s10 by the way. thanks a bunch

[bracketeer]

You do not have to remove the intake. It will be quite difficult (but not impossible) to line up the oil pump shaft with the distributor with it in the engine. It is easier to put the oil pump in first, then the distributor.

[smlblcks10]

im not sure i understand bracketeer (youll have to bear with me i have no idea how to go about changing the seal). does the oil pump need to be removed or something?

[larryblack]

I could not pull the pan on my 2.8 to change the rear main seal with the engine in the truck. There was no room to drop it down. I really do not think you will get a sbc pan off either.

The pan must come off first before the oil pump could be removed. The oil pump must be removed to take the rear main cap off to replace the seal.

It is easier to stick the dist into the pump shaft slot than putting the pump shaft into the dist slot. It can be done.

You may find pulling the engine out will allow you to more easily replace the rear main seal. Then there is the oil pan seals which need to be replaced too since you pulled the pan. .

[smlblcks10]

so how hard exactly is it to line up the oil pump shaft with the distributor? could a good mechanic do it without too much trouble? if i cant do it that means ill have to take the distributor out, correct? also, if the rear main is in fact the culprit then where exactly will it be leaking from? im pretty sure thats what it is but dont want to tear into it until im sure...

[bracketeer]

Oil leaking from the rear can be coming from the distributor hole, valve pan cover, rear of intake, or rear seal.

Not sure about an S10, but on most vehicles you have to raise the motor to get the oil pan out from between the crank and the cross-member. Once the pan is out, you remove the oil pump, then the rear main bearing cap. The seal is in two halves. One in the cap and one in the block. You remove the two halves and re-install the new one. You then put the main cap back on and just snug the bolts. Pry the crank towards the front of the motor and wedge it in place with a screw driver. Then pry the main cap towards the rear on the motor. This sets the thrust bearing in place. Torque the main cap bolts and remove the screwdrivers. Then re-install the oil pump. The pump shaft has a fork on the end that has to slide up into the distributor shaft. This is the tricky part. Torque the oil pump bolt and replace the oil pan and gasket. You can purchase a one piece rubber oil pan gasket for around 45 bucks from MR Gasket or Felpro. I can't remember which one is cheaper but they are worth the money.

[jimfulco]

Originally Posted by bracketeer

Oil leaking from the rear can be coming from the distributor hole, valve pan cover, rear of intake, or rear seal.

Or maybe the oil pressure sender.