Should piston spin freely on shaft?

[Steave]

Picture #1 looks like the threads on the shaft stop before the nut could pull tight. So was there a spacer on? or the nut was cut so fits over the shafwasher to be put t to pull tight to piston. What ever motion will cause added wear beating forward or backward before fluid pressure took up the space.

Try to locate manufacture of cyl. or book on the back hoe for information.
I just hate to locate a spacer after the machine is working in the bottom of the container for washing parts.
ken

In the picture I just didn't have anything tight. Bad pictures anyway plus the junky back ground.

There were no spacers but I have been known to clean out the parts washer and WHOA where did this suppose to go.

I got it torqued and everything appears OK. I'll stick it back on maybe tomorrow. Thanks.

 

[SPYDERLK]

Torque specs for piston nut. Again, the piston is not supposed to move on the shaft given the torque specs. The figures are in ft lbs.

Locknut Size
½ - 20
5/8 - 18
¾ - 16
7/8 - 14
1 - 14
1 1/8 - 12
1 ¼ - 12
Clamp Load (lbs)
8,997
14,398
20,979
28,658
38,244
48,134
60,353
Torque Min (ft-lbs)
32
64
111
178
271
384
534
Torque Max (ft-lbs)
43
86
151
240
367
519
723
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Awfully loose. I would expect nearer twice those figures.
larry

 

[J_J]

I am thinking those torque values was using lubed threads, IE liquid red or blue Loctite.

If using dry values, you might strip out the nut or shaft threads.

Dry threads torque would probably be more.

Use this torque calculator.

eFunda: Estimanation of Torque Required to Fasten Bolts

http://www.almabolt.com/pages/catalog/bolts/tighteningtorque.htm

http://my.opera.com/3sails/albums/showpic.dml?album=811446&picture=11271228

 

[Steave]

I agree there's a lot of confusing info on torque settings. It seems like every chart is a little different and most of them will say there info is approximate and to always check with the manufacturer. Well since I haven't had any luck finding the manufacturer I'll go by the charts available.

The one I used is from MTI ( Torque Chart ) and at the bottom of the list it says add 33% for dry or deduct 45% for lubricated threads. It come up somewhere close to 700 ft lbs and that is what I used.

I was assuming the shaft was equal to a grade 5?? and I don't have a torque wrench to read this high so it's all an estimate anyway, I estimated the weight applied to the cheater bar and the distance to get my torque. At my weight only a short cheater is needed