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It might be worth setting the pre-load again and then leaving it overnight or a few days. If it changes again, sit and wiggle it for a while (changing hands for cup of tea occasionally) and see what happens. It may take several cups of tea.Quote:
Originally Posted by turkeybrain
John
That sounds like a good plan. There's definitely a temptation to set the pre-load low too. I'll have another go early next week when I get a chance.
Cheers,
Martin
After much exercising of the hub, it still sat at 23 lb.
I've pulled it apart, absolutely smothered it in oil, and put it back together. The initial reading sat at 12 lb (noting I didn't touch shims, the previous initial reading was 12 lb).
Having left it for half an hour, it's already up to 16 lb.
I tightened the bolts up in a diagonal/long/diagonal/long pattern, starting at 20 ft.lb, then 30, 40, and finishing at 50 ft.lb. It doesn't seem like the shims are settling as the bolts are not becoming loose as the preload increases.
Sigh. I'll check it again tomorrow. Does anybody know if this will cause issues?
Cheers,
Martin
Perhaps consider fiction,
Friction is an issue with preload in engineering situations. High friction can lead to over torquing.
Ensure the threads and bolts are clean and lightly lubricated.
The other issue I had was the measurement device and the initial inertia when it is first used.
Thank you for the suggestions!
I'm using new bolts (part number 237357) and have run a 7/16-BSF tap through the threads in the swivel casting prior to reassembly. I'm using Loctite C5-A copper anti-seize as a thread lubricant.
I don't have another measurement device to compare to, but it's at least the same device making the measurements each time. The extra force required to overcome initial friction is relatively minor when first assembled, but I've seen over 40 lb once it has settled with time. The numbers I'm using are what I'm reading off while in motion, rather than the ultimate force required. I'll see if I can get a video of it in action when I have a second set of hands in the shed this evening.
Cheers,
Martin
The initial inertia will always be high, it’s the secondary movement which is the real measure but it sounds as though you are doing that.
An increasing preload would come from either friction, heat or possibly something in the bottom of the hole.
Thought would be too maybe torque to 75%, leave overnight and final torque the next day.
I rebuilt all of mine and had the right preload. When I first drove Sid the steering was tight, but after 20-30 miles it loosened up beautifully. There will be a certain amount of bedding in with new stuff
Sitting at 24 lb dynamic friction this evening, a 100% increase over what I measured last night.
https://youtu.be/KHPbCp9r3TQ
With this in mind, I think I might leave it be and hope it settles down once it has a bit of weight and a few miles under its belt.Quote:
Originally Posted by Cadas
Onward with installing the diff!
Cheers,
Martin
Well, that being the case, it sounds like there's only one rational explanation:Quote:
Originally Posted by turkeybrain
Aliens.
P.S. Yep, quite likely it will settle in alright with use.
Cold lubricant overnight. It’s going sticky.Quote:
Originally Posted by turkeybrain
What are you using as assembly lube