2.9L Rebuild Questions

[Jspafford]

Hey all,
I have a 2.9L in pieces laying out in the garage. It is down to a bare block with all the components laying in piles.

It was taken out of a Bronco II with an Automatic (Thanks Randy). I am in the process of trying to rebuild it for a new spare if mine ever blows.

The reason it was pulled was because the crank kept walking back and forth and burning out the pump in the automatic transmission.

When I rebuild this, what do I need to pay extra attention to in order to fix the problem and keep this from happening again. What causes the crank to walk? Bad bearings? I was expecting roller bearings but they are just half moon shaped pieces of metal.

This was a project for me to learn on, and man am I ever learning.

Go ahead... Edumicate me!

 

[Mutant Pony]

One of the main bearings is different from the rest, I don't remember which one. It has "sides" on it. That is the thrust bearing. It controls front-to-rear movement. Most of the time people look for auto trans cranks to have turned because manual trans cranks are wore in the thrust bearing area. Every time you push the clutch in you are shoving the crank forward, You let go of the clutch pedal the crank goes back.
Anything else?
Ok, a couple more things. A front end collision or someone hammering a balancer on could crush the thrust bearing.

 

[Jspafford]

Now that you mention it, I think it's the rear bearing. It has a totally different cap. It is part of the back of the block and rear main area.

 

[Mutant Pony]

The rear maincap is different because it houses a slinger and the rear main seal and the rear oil pan seal, they don't usually have the thrust bearing though. It is usually in the center of the engine. If an engine only has 4 main caps, it could be #2 or #3 as there is no center cap. I don't build cologne engines so I'm not familiar with them. Now if it were a 2.3 I could offer slightly more accurate info.