I used the fish scale method also, like the factory service manual says (I used a digital bow scale). I was inching up on it with a torque wrench and the torque on the adjusting nut ended up being a wopping 42 ft/lbs or torque to get the scale up to the specified range of 9.5 -15 lbs. And I was just getting into the low end of the range at that. Kind of scary but I guess that's what it takes. I was thinking, WOW, this must be really good grease! On all my other vehicles I always just tighened the nut until no more play was felt while wiggling the tire.
Hmmm... seems like there's a common issue with the preload as described in the FSM. Here's one of those threads:
https://forum.ih8mud.com/100-series-cruisers/420496-wheel-bearing-fsm-torque-light-just-right.html
This probably should be in a different thread, but since you started on the topic I'll dump my thoughts since it's on my mind. This is a summary of all the issues surrounding adjusting nut that I came across, apologize if it's overload.
To summarize:
FSM states that after getting the bearing to settle (tighten adj nut to 43 ft/lb then turn hub etc...) you loosen and then retighten to JUST 38-57 IN/lbf - that's in/lbf not ft/lb. That's ~3-5 ft/lb. Then with the tension gauge/fish scale you should get 9.5-15 lbs on preload (starting).
The problem is that many (most?) people can't get that 9.5-15 lbs preload without torquing the adjusting nut to upwards of 35 ft/lbs which horrifies many folks.
So you have some that go by the book with just 4-6 ft/lbs on the adjusting nut and are able to get the proper preload with that.
Some go with 18-21 ft/lbs (with and without fish scale method).
Some go with 35-40 ft/lbs (with and without fish scale method).
Some don't use the fish scale method at all.
Some just do it by feel.
Some use a method whereby they tighten the adjusting nut until the claw washer doesn't move (or just barely moves with force).
Also - people distinguish b/w the torque when parts are 'wet' vs 'dry' with grease. (At first I had a hard time understanding what they mean by dry given the amount of grease all over the place - believe this just means they wipe off all grease from nuts/claw washer, spindle threads, lock washer etc).
This issue is discussed a lot in the 80s forum.
I have lots of questions but hard to find definitive answers:
- for example how reliable is the fish scale method - does it vary with the type of grease being used and the temperature
- also, is it possible that torque needed for new bearings/races vs. repacking old (but presumably not damaged) bearings/races is different?
- is it possible that people who can't get the proper preload with 3-5 ft/lbs of torque have worn spindle or worn bearings/races?
Some point out that the adjusting nuts tend to loosen - obviously if the lock washer tabs weren't forced down on the adj. nut AND the lock nut it could loosen. However I suspect this could also be due to the lock washers not being fully down on both nuts - in other words one can easly just bend it down halfway without it fully being seated on the nut. I was to knock the tabs ALL the way down to contact the nut to keep them in place tight (I noticed how carefully it was done on mine when removing the lock washer). I'm guessing that's standard procedure, but guys just learning and doing this for the first time may not know and the FSM doesn't say it prolly 'cause it's a given to those with experience.
Some folks have noticed that their claw washers have wear - presumably from adjusting nut not being tight enough, or also possible from the spindle being worn which prevents ever having proper preload. I personally had a little wear on both claw washers so this time I turned them over (next time will replace them). Hoping not to see it next time around - I'm at 90k and have no idea if my bearings were ever repacked prior to my ownership (bought at 70k).
I did my PS and tried following the fish scale method but that led me to ~37 ft/lbs before I got to ~10 lbs of preload. During my test drives, I believe I could feel some drag on that wheel while driving and was a tad nervous about it although temps on the hub and flange were fine even a little lower than the left side after driving. So after further reading and pondering, I decided to tone it down a bit to 21 ft lbs (and to test out the approach of tight enough that the claw washer barely moves with force). So on the DS I just went with 21 ft lbs (claw wouldn't move at all so it was a little tighter than that approach would have dictated). B/c of the issue in this post I redid the passenger side and this time was very careful to knock down the tabs on the lock washer all the way and I did 21 ft lbs etc. Initial thoughts are that it's right - but really only time (and inspection) will tell, right...
