Front crank seal

#1

Ok, I will admit, I have not taken the front of the engine apart yet, nor have I changed the timing belt. The issue is the car seems to spray some oil during a race/session out of the front of the engine. I don’t really know what all seals are in the area. I assume a crankshaft seal, but there appears to be a timing cover seal as well, but I kind of doubt that is the culprit.

If it is the crank seal on the front, how hard is it to replace? I just did the rear main and that is nicely sealed now with no oil leaks.

Looks like I need to order a driveshaft support bearing cradle so I could just buy this seal as well and a timing belt to do this all before the next race.

I am tempted to just let it spray oil until the end of the season where I may pull the engine apart…

#2

Possible front leak points:

  1. Rocker arm shaft end rubber seals. These are thumbnail size pieces of rubber and you’ve got 2 in front and 2 at the rear of the head. They sit just below the rocker arm cover gasket. The trick to making them seal better is remove them, clean the surfaces, and put some goobage under them before reinstalling. Be sure to bonk them in all the way so they don’t push the rocker arm cover gasket up.

  2. Valve cover gasket. Inspect rocker arm cover carefully for cracks. A tiny crack in the rocker arm cover can behave devilishly like a gasket problem. If the rocker arm cover is ok, put some goobage under the gasket at the front and the rear of the head so that the rocker arm shaft end seals mate with the rocker arm cover gasket better. Then some more goobage on top of the gasket all the way around and fasten it down. Do all of this in one fell swoop so the rocker arm cover shoves down on the shaft seals while everything is still wet.

  3. Cam shaft end seal. You must remove the tbelt and the head’s tbelt gear in order to get to this. This is a little rubber o-ring that is easily pinched during installation. Per Chuck Baader’s advice, I no longer use that o-ring. Instead I just put some goobage in there.

#3

Those points all seem pretty high up on the engine. The top side isn’t wet, only the bottom where it appears to be spraying on the plastic just below the oil pan.

#4

Ah so. That would be either the front crank seal as you suggested or, less likely, the intermediate shaft seal. Both of those are pretty reliable. It’s usually the rear one that leaks.

#5

So, since I just replaced the rear one and that is nice and tight, how difficult is it to replace the front one? Is this something I can do without a lot of teardown?

#6

The only difficult thing about it is getting the Jesus nut off the front of the crank. Before you start to tear everything down put a socket on the nut and see if you can wedge a breaker bar or pipe against the frame rail, then bump the starter, hopefully that will break it loose. If you can get an impact in there it might work, but my ingersoll rand gun wouldn’t budge it. If neither the starter method of the impact work you will need the crank holding tool and one huge cheater bar.

#7

This is a standard thread and not a reverse, correct? I can’t remember which way this engine rotates.

#8

Yes, the crankshaft bolt is standard thread direction.

#9

Standard thread.

If you go to my build thread for New #6 you’ll see the parts I fabbed to get the Jesus nut off and on (to correct torque) in a jiffy. You’ll need some angle iron and a spare harmonic balancer.

Later edit. Here you go.