Newly acquired SB 13" back gear problem

I have recently acquired a 13 x 36 or so SB, catalog no. 113A. All works fairly well with the exception of the backgear which kicks out of engagement immediately upon running the machine. The castings in which the back gear pivots have two screws on the backside, and I believe these are to adjust the bushings. They also have holes on their tops which carry screws for attaching the various guards. Beyond these, I see no other holes for any kind of adjustment. I am slow to think that the bushing screws are used to adjust.

Can anyone out there clue me in on how to adjust this back gear?

Thanks,


Glenn

I never saw screws in a back gear for adjusting a bushing. Looking from the front of the headstock on your right there should be a screw on the bottom that will have a spring and brass piece to put tension on the shaft. The one on the left keeps the backgear from moving to far in either direction.

Yes, Tommy's correct. Front screw with spring and shoe adjusts the tension, the rear screw (plain dog head set screw)adjusts the engagement of the gears.

John

Just to make sure, I am working with a 13" lathe, which is quite different from the 9's and 10's. Are you gentleman definitely talking about 13" ones (and this is a single tumbler lathe, so basicly war-time production.

More on 13" back gear

I did some more investigating and have found that the back gear hollow shaft, which carries the two gears as an assembly on the eccentric shaft, is a bit tight feeling. I believe the problem lies in this tightness. So the question becomes what is involved to remove the shaft to free it up, or what is the procedure. I surely don't want to disassemble the whole machine, but I would like to use it for the purpose I originally planned, which requires the back gear.

I've attached photos of the machine and the eccentric blocks on the back gear.

OK...an update for those who may be interested.

Turned out that the backgear rotating shaft was a bit stiff on the eccentric. I oiled her a bit and she is now spinning freely. Yes, I feel a bit stupid.

The eccentric was allowing the assembly to climb out of mesh with the drive end and the chuck due at least in part to the friction in the backgear and afterwards it still tried just a touch but adjusting the tension corrected the situation.

Further, the 13 and 16" lathes (very similar as I undedstand) are quite different from the 9s and 10s, which many of us have and it appears assume are identical to their larger brethern. Fact is that the 13, anyway, does not have a screw with a spring and a brass runner, but the back gear eccentric is carried in split collars which are adjusted through a pair of square head set screws.

Just FYI.

Yahoo SOUTHBENDLATHE group has in the files section: CE3458 Parts Manual.pdf which is the parts manual that should cover your lathe. It also has the back gear adjustment for 10L, 13", 14.5" 16/24" lathes.

Also here at: South Bend Lathe Works - Publication Reprints - South Bend (nearly) Complete Lathe Parts Bulletin Collection - 10-16" Model | VintageMachinery.org

Pages 4 & 5 have your adjustment (they are out of order).

I have them pdf'd on a flash drive, but they don't seem to want to down load, maybe too big.

I have two 9" Model A's and two 13", one with single tumbler gear box, one with the dual tumblers. Forgot about the adjustment differences, last one I was into was the 9 incher.

John

Great link John. Need to print that for future reference.

Just about every old South Bend doc has been scanned and is available for the picking on the net. I have a hardcopy of the that one that came with the old 1956 13 incher I bought. I'm thinking the used machinery dealer put it in, as the lathe is older than the doc. Covers the correct parts though...

John