Someone wanted to know if they were really babbitt

Looks like babbitt, weights like babbitt, fractures up like babbitt....now Smokes like babbitt...and drips like babbitt....must be babbitt


And for those who run with one side of the babbitt gone........see what happens to pinion and ring gear mesh....I'll say this pinion gear has gone south!

Randall, pot metal melts very much like that, but it is much more brittle. Just sayin'. Dave

Drop a piece of it on the floor. If it rings, it's probably zinc (Pot metal). If it 'thuds', it's probably babbitt.

Good babbitt doesn't thud.....it rings as does zinc.
Lead thuds.

Will the real Ford drawing for the thrust washers please stand up? Otherwise this question may continue forever.

Actually it doesn't make a hoot, original Ford thrust washers fail at the most unexpected time, and any car that is to be driven should have them replaced with bronze washers.

Could you get a few more miles from that pinion if you welded it and filed to teeth back to shape?

Babbitt comes in many varieties.. http://en.wikipedia.org/wiki/Babbitt_(metal)
"There are many Babbitt alloys in addition to Babbitt's original. Some common compositions are:

90% tin, 10% copper
89% tin, 7% antimony, 4% copper
80% lead, 15% antimony, 5% tin
76% copper, 24% lead
75% lead, 10% tin
67% copper, 28% tin, 5% lead
Internal combustion motors use Babbitt metal which is primarily tin-based because it can withstand the pounding. Lead-based Babbitt tends to work-harden and develop cracks but it is suitable for constant-turning tools such as sawblades."


Ford used a composition of 86% tin, 7% copper and 7% antimony in the engine, but since tin is more expensive than lead, he likely used a cheaper composition with more lead in it where he thought he could get away with it.

I think I've read somewhere about the assembly process for rear ends at the factory - Ford didn't have time to measure and pick different thicknesses for each differential, so all thrust washers were a little thicker than the thickest needed, then the axle halves were put together with force while the differential and axles were turning. Lead babbitt was soft enough to conform to the available space and keep that thickness for many miles (but not as many years as we would have liked).

Maybe this can be confirmed or refuted.. Those of you with NOS babbitt thrusts - how thick are they?

Pinion looks beyond repair since they are readily available. I agree with Ted, Babbitt, pot metal, or Zink, a poor choice on Ford's part... A poorer choice when rebuilding a rear end!

John, I'll disagree on your statement that it was a poor choice on Ford's part. If, as Roger stated above, Ford used thicker soft babbit washers and pressed them into conformity on assembly, he saved lots more time and money than trying to assemble 15 million rear ends by individually fitting the correct sized thrust washers. The problem only seemed to occur as the babbit got old, when most cars were well out of service. This is an interesting topic. Thanks all.