What's new
What's new

L&S 1408 noisy bearings

borne2fly

Hot Rolled
Joined
Feb 7, 2008
Location
California
I recently picked up this 1965 L&S 1408. Seems to have been well maintained, not much wear to be found. But the headstock seems a little noisy and I get that howling "spalling" sound coming from the left side of the headstock at higher speeds. Bad bearing? Possibly the bearing at the left end of the spindle?

If so, how does that bearing come out? Seems like it's pressed onto the shaft. If I need to pull the spindle, is it a straightforward procedure (meaning, if the bearing retaining bolts are loosened up should the spindle assembly basically slide out of the right side of the housing)? I've pulled spindles on mills before, but never a lathe.

Thanks in advance,
-Don

(Pictures are all rotated 90 degrees. Doesn't seem to matter what the orientation is in the original file. That's something else I need to learn how to fix)

L&S.JPGheadstock_left.JPGbearing.JPG
 
The left spindle bearing looks like it was drawn into position by the adjusting nut. This bearing would have to come off before the spindle could be removed out the other side (bearing can’t pass through some gears on the shaft), and I am most reluctant to attempt tapping it out. The inner race is almost the same diameter as the shoulder it butts up against. Any ideas?
 
Go down to the local auto store and buy a auto mechanics Stethoscope and listen for the nosiest places at high speed. Have you checked the headstock lubrication passages? It maybe OK and just gear noise. Squirt some way oil in the bearing and see if it gets quieter. I have found a rule of thumb Most headstocks will last 2 to 1 on the bed ways, so if the ways look good then the bearings should be OK. Have you checked the spindle thrust or run-out? Maybe it needs to be tightened? That bearing back there generally are only radial and not thrust bearings. The bearings are usually a light press and trying to only tap it out is something I would never do.

Also buy an info-red temp gun and check the bearing temp. it should be between 120 to 140 F when hot.


Read the first section on spindle bearings. It's older, but the basic design and maintenance should be the same

http://vintagemachinery.org/pubs/2104/15228.pdf
 
Last edited:
Oil passages are all working properly. Squirted oil on the left-side spindle bearing and that made no difference. Spindle bore shows around 0.0004" runout, just under half a thou. That seems a little excessive, doesn't it? I'll check the spindle end-play tonight. Maybe I'll get lucky and all it needs is a little tightening as you suggested.
The ways have a few scratches, looks like normal wear to me (not abuse), if I run the carriage back and forth it doesn't drop more than one or two tenths. Ditto for the rest of the machine, looks to be in good shape.

I recently changed the spindle bearings in my mill, and that really made a difference .... went from noisy to a quiet turbine-like whine. I could be wrong, but I always thought that these things ran smooth and quiet when everything was working right.
 
Just noticed that the balls in the spindle bearing (left side) intermittently stop moving even though the spindle continues to rotate. I'm turning it by hand when I see this. That can't be good ...
 
Got it out, and with only a slight push. Amazing. I'm use to having to fight these things tooth & nail to get them apart. Bearing number 3L12, with a small "3" handmarked on the edge of the outer race. Spinning it by hand you can hear things rattling in there.

left_bearing_3L12.jpg
 
It's been a few years since I've worked on a L & S lathe. I recall the spindle rides on a set of zero precision tapered roller bearings on the front end of the spindle. The bearings, as your describing, is on the tail end of the spindle. This bearing "floats" in the housing bore and probably is a close or snug fit to the spindle originally. Be real careful on replacing bearings on the L & S. They used lots of ball bearings where the inner race was wider than the outer race. Your bearing appears to be one of those. Looking at the bearing interchange guides out there, this width will vary with bearing manufactures. So choose carefully. As for the class of the bearings, that '3" may be the fit of the bearing balls and not the quality class of the bearing. Ken
 
Ken,

>> They used lots of ball bearings where the inner race was wider than the outer race

Glad you mentioned that, it is something I never would have noticed! I called Monarch and they also said that it is a grade(?) 3 bearing.

>> This bearing "floats" in the housing bore ...

Yes, and the outer race "creeps" around in the housing bore (ever so slowly) as the spindle rotates. Is that normal? I'm wondering if this constitutes a loose fit, and if it could be the cause of the wailing noise I hear when the spindle runs at the higher rpms?
 
I have attached some pages from my 1954 New Departure Hand Book that had belonged to my father in case the information might be helpful .
There may be other cross references to other bearing makers somewhere on line if you look for them
Regards,
Jim
 

Attachments

  • Image (246).jpg
    Image (246).jpg
    95 KB · Views: 71
  • Image (242).jpg
    Image (242).jpg
    101.5 KB · Views: 81
  • Image (243).jpg
    Image (243).jpg
    99.1 KB · Views: 70
  • Image (244).jpg
    Image (244).jpg
    97.8 KB · Views: 73
  • Image (245).jpg
    Image (245).jpg
    99.1 KB · Views: 66
Jim,

I have that same book somewhere around here.Have to see if I can find it. Good information there.

When I say "float", probably no more that a half thousandth loose at max. Shaft fit would be to the dimensions given in the above book. It shouldn't be loose at all on the shaft. I don't claim to be an expert at this stuff since I haven't dealt with bearing fits in many years. There's others here that have much more experience at this stuff than me. I'm just going by what I've learned over the years listening to others, including my dad who have torn into many L & S's back in his days. Wish he was still alive at times. Ken
 
Before I replace that end bearing I'm wandering around the rest of the machine doing a general inspection/cleanup. Might as well replace the way wipers and all the oil.
Without that end bearing, the spindle is sitting cantilever on the two main Timkens at the other end of the headstock. And if I grab the loose end of the spindle I find that there's no discernable "wiggle" at all. Tight as a drum. And it rolls smoothly. I'm trying to convince myself that the main bearings are ok :)
 
Ok, the rear spindle bearing is now replaced. No difference, .... it's still very noisy in top gear. I'm figuring that if the rear (left?) spindle bearing wasn't the problem then the one I pulled out is probably still good. And I'd also guess that the big Timkens at the big end of the spindle are in good shape as well. At this point, the only things moving in the headstock are the spindle and input shaft. All the other shafts are out of the picture. And when I put it in neutral, only the input shaft spins, and it's QUIET.
Could all the noise simply be normal for big spur gears? There are certain speeds where it's noisy as hell, but at full speed it seems to quiet down a lot.
 
On the Model X I had, one of the intermediate shafts had a noisy gear when put in a certain gear group. Didn't really notice any bearing noise from that shaft. I just did not run it in that range. I didn't want to open up a can of worms tearing into the head stock of that lathe. There was a thread here in late 2017, early 2018 of a guy up in the News Brunswick Canada, that had a Model X, with a similar problem where he found sever damaged gears along with bearings that needed to be replaced. Even though, it's a Model-X, the Powerturn has basically the same head stock on the inside, just a little different shifting mechanism for changing speeds. Ken
 
I had Ken's X before he had it. :D

It has two strikes against it even if it is brand new.

All straight cut gears and a very high input shaft speed

In a small close quarters shop it is just plain too noisy

Count your blessings if you have the 1160 top - some were sold with either 1740 or 2000 top ends - and that is just about the speed of the input shaft
 
On that Model X, did the spindle Timkens need to be replaced, or was it some of the ball bearings on the other shafts?
This 1408 makes a loud "chirping" sound at high speeds, and I can't tell if that's the sound of ball or roller bearings. I can't find any play in the spindle, but it does have a very slight "stiction" when I roll it around by hand .... it takes slightly more of a push to get it moving than to keep it moving, if that makes any sense.
 
I checked the spindle bearings again by prying up (gently) the chuck with a 2x4. Only a few tenths of radial movement. That looks good to me, but I don't know how tight these old L&S machines are suppose to be.
Moved to the left end of the spindle, did the same thing, and found .004" of radial movement. And that's a new bearing! The OD is loose in the housing. Now what? I wrapped some .002 brass shim stock around the OD and it all goes back together nice & tight. Is shimming the thing the right solution or is there a better way? Besides re-boring the headstock, that is.
 
it would not surprise me one bit that L & S engineering bought off on that rear bearing bore being a couple thousandths over just to save a casting with lots of machine work into it. As long as that .002" shim does not walk out over time run with it. Something else is causing the chirping noise. Could be a bent shaft, something trapped in a gear tooth. Generally these two usually create some kind of thumping noise. Could be a missing gear tooth?

Did I change out the spindle bearings in my model-X. No. I did not touch anything in the head stock. It was definitely a ball bearing and bad gear causing all of the noise in that one gear cluster. Not anything to do with the spindle.

Ken
 
Started taking the input shaft apart. The ball bearing right at the pulley is a snug fit in the housing but the inner race spins on the shaft. There are two more bearings on the input shaft ... a ball bearing in the center and a roller bearing (?) on the other end. The shaft deflects up & down about .0015” right at the center bearing. This bearing shows no slippage of either the inner or outer races, all the play appears to be from the actual ball bearings. I’d like to pull the shaft out but the roller bearing on the right side won’t clear the bull gear on the spindle (it appears to be a good press fit to the shaft with no obvious way to press it off). Do I need to pull the spindle to get the input shaft out?
 








 
Back
Top