MTFCA Forum

Hi,
i have a question about the 4th Main.
When you pull the Motor or the Rear end, you have to unscrew the 4th Main. What is your recommendation so the 4th Main does not shift downwards?

Regards
Markus

After you remove the fasteners to drop the ball joint retainer, you can then reinstall at least the bottom 2 to hold it in. I am sure more than a few engines get pulled with it removed.
One reason to keep it semi installed, helps keep any oil that is still in the engine when tipping at such a steep angle to remove from the car, in the engine and not on the floor, or to a minimum.

Hi Markus,
The fourth main should fit snug in the pan & hogs head so it should not fall down but will sometimes slide out. Mark it with something so if it doe's slide out you can install it in the same orientation so the oil hole stays up when you secure it with the two bottom bolts.
Craig.

Unless someone has installed it wrong or has rotated it to get less oil through the hole, there is only one orientation, the oil hole should face up.

Mark,
Does turning the fourth main hole down help to get it to leak less?
Craig.

Craig Leach wrote: ↑

Wed Jun 15, 2022 6:58 pm

Mark,
Does turning the fourth main hole down help to get it to leak less?
Craig.

Yes. Its helpful to slow grease thinning, especially when using the modern oil screen.
This screen concentrates extra oil right to the oil hole in the 4th main.

I wouldnt turn it over with a new, tight, to spec 4th main.
There is also the assumption that the 4th main was machined on center & rotating doesnt change its proper fit.

Wish I had thought of that on a tour one of the guys fourth main started leaking and he decided it leaked less with the oil level lower. Wrong answer!!!
Craig.

Some will turn so the hole is on the side. Don't think I would face it down in any case. You are still getting a good amount of oil at the front. Assumption would be that the person machining the 4th would where/know how to center it for boring, but wear patterns can change that center over time.

The 4th main is held in place with RTV or Permatex. It should not move when you pull the engine or pull back the rear axle. The screws hold the rear axle in place.

Mark,
This one was leaking pretty bad I don't think turning the hole down would have been a issue getting oil to it. May have not even helped. I think more oil & more often would have saved the engine. But if you are going to end up on the trailer sooner or later sooner is better & less expensive & time consuming.
Craig.