Are These Babbitt Bearings Still Good?

I don't use a chuck for the test, the idea is to try both ends. it is just a lever inside the spindle bore....
what I read when rebuilding my lathe was to just use a bar, not the chuck. It works on a plain bearing shimmed type of spindle.
 
Another way to check how much wear there is in the babbit is to use some Plastigauge. Remove the top cap, clean the debris from the spindle and bearing cap, place a piece of Plastigauge on the spindle, and replace the cap. The Plastigauge will flatten out a bit. Use the gauge on the paper packaging to determine the clearance.

Plastigauge is available at almost any auto parts store. It's commonly used to check bearing clearance when rebuilding engines. Here's a link to some available on Amazon:

Normally there is a stack of shims between the cap and body on babbited bearings when they are new. As the babbit wears shims are removed to maintain the proper clearance. If there weren't any shims left between the cap and the body, and there is excessive clearance when using the Plastigauge, the babbit is near the end of it's life.
 
projectnut said:
Another way to check how much wear there is in the babbit is to use some Plastigauge. Remove the top cap, clean the debris from the spindle and bearing cap, place a piece of Plastigauge on the spindle, and replace the cap. The Plastigauge will flatten out a bit. Use the gauge on the paper packaging to determine the clearance.

Plastigauge is available at almost any auto parts store. It's commonly used to check bearing clearance when rebuilding engines. Here's a link to some available on Amazon:

Normally there is a stack of shims between the cap and body on babbited bearings when they are new. As the babbit wears shims are removed to maintain the proper clearance. If there weren't any shims left between the cap and the body, and there is excessive clearance when using the Plastigauge, the babbit is near the end of it's life.
Click to expand...
wow, plastigauge has changed since I was young. I built a race car back when I was young. back then plastigauge was small piece of plastic, that you stuck on the bearing journal and tightened down on, then you then measured the width of it on and compared to a chart. I look at that and am not sure what that is anymore. looks way more complicated.
 
woodchucker said:
wow, plastigauge has changed since I was young. I built a race car back when I was young. back then plastigauge was small piece of plastic, that you stuck on the bearing journal and tightened down on, then you then measured the width of it on and compared to a chart. I look at that and am not sure what that is anymore. looks way more complicated.
Click to expand...
It's still the same stuff. It now comes in a sleeve that's used for measuring the final width. Now it comes in both Metric and Imperial sizes. It is time sensitive. It only lasts a few months in the package before it gets hard. Once it's hard it cracks and turns to dust rather than spreading out.
 
If you can't torque the two bolts in either bearing cap to 15 to 25 lb-ft, you need to add back some of the missing shims The original shim packs which Clausing still had some of when I checked several years ago were two pieces per bearing cap and were originally if I recall correctly 5 pieces of 0.001" shim stock laminated together. The older MOLO's have a section on how to handle them. Basically, if noticeable clearance was found with the rod and dial indicator, you peeled off one layer from the front pack, and replaced the caps and torqued them down and checked again. If still too loose, you removed one layer from the rear and checked again. But if all four shim packs are missing or removed and it is still too loose, then you must either re-pour the babbit or replace the head stock. If you have to replace the headstock, I would replace it with a Timken headstock. But do run the tests first.
 
I have a babbit lathe and removed shims to eliminate play. BUT the spindle is below the tailstock. I know this by turning a point on a piece of stock and then putting a dead center in the tailstock and then sliding them together. I live with it, this lathe is 16"x120" and only used on monster parts.

Anyway, look at this also.
 
Plasti-Gauge is made for this kind of inspection work. Used lots on engine bearings over the years. I only buy one package per engine as it does age.
Pierre

Hot Rod V6 for a 1986 Jeep Cherokee.
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The rod test may have been valid at the time it was introduced. However like most everything technology moves on. To put things in perspective Plastigauge wasn't invented until 1948. The OP's lathe could have been as much as 18 years old when the new technology came into being.

Personally I would think the Plastigauge would be a far more accurate method to determine where the wear is and the extent of the wear. I' used it on my 1916 Seneca falls star lathe to determine how much shim stock was necessary. As for shim stock sizes they were originally limited to .001" per layer. These days you can but shim stock in .0005" increments. I have several 1" wide and 6" wide rolls of Precision and Trinity brand shim stock. They range in thickness from .0005" to .030".
 
projectnut said:
The rod test may have been valid at the time it was introduced. However like most everything technology moves on. To put things in perspective Plastigauge wasn't invented until 1948. The OP's lathe could have been as much as 18 years old when the new technology came into being.

Personally I would think the Plastigauge would be a far more accurate method to determine where the wear is and the extent of the wear. I' used it on my 1916 Seneca falls star lathe to determine how much shim stock was necessary. As for shim stock sizes they were originally limited to .001" per layer. These days you can but shim stock in .0005" increments. I have several 1" wide and 6" wide rolls of Precision and Trinity brand shim stock. They range in thickness from .0005" to .030".
Click to expand...
actually the rebuild manual by swells documents for the SB 9 , testing that way. The reason, the head caps don't come off. Its a split cap on one side. So yes it's still valid. But for the atlas we are talking about, the plastigage is perfect.
 
With plastigauge you are looking for maybe 0.0005 to 0.001" clearance. 0.002" is on the big side.
Foil Hershey bar wrappers were 0.0005" thick, BTW. Handy for us mechanical types ;-) snack and shim in one neat package...

Sent from my SM-G892A using Tapatalk
 
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