Rear main questions 29 engine

[old31]

I suspect a rear main leak.

What am in for if I take off the rear main?

Once I have it off, then what? What do I check for and what needs to be looked at and or fixed.

[Tom Wesenberg]

Look for a missing or plugged drain pipe on the rear main cap.
Look for cracked or missing babbit.
Look for excess clearance.

[old31]

Originally Posted by Tom Wesenberg

Look for a missing or plugged drain pipe on the rear main cap.
Look for cracked or missing babbit.
Look for excess clearance.

OK, thanks.

[old31]

I have been reading as much as I can on rear mains.

Please bear with me on this, as I have never worked on this before.

1: One thread said to drill out the 5/16 oil tube and re-thread to 3/8. Is this necessary?

2: Another thread mentioned, and I did not understand what they meant. If the rear main was removed it could not be installed properly because the alignment will not be correct.

[tbirdtbird]

let us know how you make out

[aermotor]

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Don't do anything until you have gone through tbirdtbird's link.

[old31]

Please let me know what you think of the rear main. I have looked at it but it doesn't tell me anything.

Notice the small chip that kind of fits like a puzzle. One picture I have it out and the other I have it in. Would I be able to JB that piece in place?

What should my next step be? If it is to use plastigauge, I will need help as I have not done that before.

[George Miller]

Originally Posted by old31

I have been reading as much as I can on rear mains.

Please bear with me on this, as I have never worked on this before.

1: One thread said to drill out the 5/16 oil tube and re-thread to 3/8. Is this necessary?

2: Another thread mentioned, and I did not understand what they meant. If the rear main was removed it could not be installed properly because the alignment will not be correct.

It is not a 3/8 thread. It is a pipe thread, also the pipe is on a little angle.

[FRANK PKNY]

By the looks of that bearing I would pull the engine and re-Babbitt it! Once that the Babbitt starts to break up it doomed to fail soon. Depending on the condition of the rest of your engine you may want to consider rebuilding while you have it out. JMHO

[J Franklin]

That babbit could last a long time if the clearance is reset to good specs. That chip isn't a killer and could be replaced or left out. Take up all the bearings to around 11/2 thous. Rebuild your engine when it really needs it.

[40 Deluxe]

Originally Posted by J Franklin

That babbit could last a long time if the clearance is reset to good specs. That chip isn't a killer and could be replaced or left out. Take up all the bearings to around 11/2 thous. Rebuild your engine when it really needs it.

Just do not try JB Weld or any kind of adhesive on that piece. Doing so will raise that little piece above the surrounding Babbit and pinch the crank, resulting in you erroneously adding more shims. Just reassemble, drive and enjoy!

[tbirdtbird]

"Don't do anything until you have gone through tbirdtbird's link."

[James Rogers]

Originally Posted by George Miller

It is not a 3/8 thread. It is a pipe thread, also the pipe is on a little angle.

George, the thread on the rear cap is a standard thread. It is just a bastard size, it is a 3/8-32.

[FRANK PKNY]

If you want dependability rebuild it correctly. JMHO That Babbitt looks to be crystallized, it may have been a cold poor or the receiving parts not properly prepared. Do the job right and you will have a fine engine for many years to come.

[Kurt in NJ]

To me the Babbitt looks original. The cap never filed, but it looks to have absorbed a lot of debris, this can make it abrasive and wear the crankshaft, have you measured the crankshaft to see how round it is

[Tom Wesenberg]

I had the same thought as Kurt. Someone didn't keep clean oil in the engine.

[Kohnke Rebabbitting]

Originally Posted by old31

Please let me know what you think of the rear main. I have looked at it but it doesn't tell me anything.

Notice the small chip that kind of fits like a puzzle. One picture I have it out and the other I have it in. Would I be able to JB that piece in place?

What should my next step be? If it is to use plastigauge, I will need help as I have not done that before.

That is not ford Babbitt.

It has cast in oil wells. Not Fords

It has 45 Degree Radius. Not Fords

Kurt is right, dirt in Babbitt, no good.

George is right, caps have pipe thread. Repro pipes made wrong.

Herm.

[old31]

Originally Posted by Kurt in NJ

To me the Babbitt looks original. The cap never filed, but it looks to have absorbed a lot of debris, this can make it abrasive and wear the crankshaft, have you measured the crankshaft to see how round it is

Kurt, have not measured the crankshaft. I would not know how to measure it.

George, the reason I mentioned 3/16 vs 3/8 is due to me having a 28-29 engine it has a 3/16 oil pipe. If the 3/16 was removed and drilled for a 30-31 3/8 oil pipe it would be able to move to a all around quicker movement of oil? True not true?.

The engine is not out and I would not want to do a rebuild now.

How do I go about checking clearances.

[VFRhugh]

Here's a good place to start.
http://www.sacramentocapitolas.org/s...Clearances.pdf

[old31]

Originally Posted by VFRhugh

Here's a good place to start.
http://www.sacramentocapitolas.org/s...Clearances.pdf

VFR, that's a great article thanks.