Well, at 180K I decided to do the rear axle service on my 80. Pretty straightforward stuff, especially since I had done the front axles a little over a year ago. The parts have been sitting in my garage for awhile, and I had the time so why not.
Digging into the axle, it was clear that the oil seals were shot and I had mixing of grease and oil. However, the bearing and axle shafts looked great. I replaced the oils seals and paper gasket but I decided to reuse the bearings (minimal to no wear at all).
Putting everything back together was going fine until I got to setting the bearing preload. I followed the FSM...tightened the lock nut to 43 lbf while spinning then loosen, then tighten, etc. My problem came when I used a fish scale (yes it is calibrated) to set the preload. Holy cow! To get the into the correct preload range (5.7-12.8 lbf), I really had to crank the lock nut down!
I was not comfortable with it being that tight. In my experience tight makes heat and burns the bearings. I asked a buddy of mine that works on commercial trucks (not Toyotas) about this and he felt the same way. The way our axle is designed, you really have to crank it or loosen it so the holes line up. It's a little different from other vehicles I (or my friend) have worked on in the past.
Another observation that has me guessing...during the job I compared the side I was working on to the other side of the vehicle and that side was pretty loose; maybe 2 lbf...so I just set both loose as compared the FSM. This is where I think they were before I did the service.
After torquing everything else, along with the tires, I checked for play in the wheels, but didn't feel any. If there is going to be a problem, maybe it will show up later?
I read this thread, and it seems that others have noticed the same thing with having to really torque down the lock nut in order to get the right preload.
https://forum.ih8mud.com/80-series-tech/212472-has-anyone-tested-torque-rear-axle-lock-nuts.html
I guess I am just questioning myself now and maybe should dig back into the axles and torque down until I get the right preload setting per the FSM.
Thoughts? Thx
Digging into the axle, it was clear that the oil seals were shot and I had mixing of grease and oil. However, the bearing and axle shafts looked great. I replaced the oils seals and paper gasket but I decided to reuse the bearings (minimal to no wear at all).
Putting everything back together was going fine until I got to setting the bearing preload. I followed the FSM...tightened the lock nut to 43 lbf while spinning then loosen, then tighten, etc. My problem came when I used a fish scale (yes it is calibrated) to set the preload. Holy cow! To get the into the correct preload range (5.7-12.8 lbf), I really had to crank the lock nut down!
I was not comfortable with it being that tight. In my experience tight makes heat and burns the bearings. I asked a buddy of mine that works on commercial trucks (not Toyotas) about this and he felt the same way. The way our axle is designed, you really have to crank it or loosen it so the holes line up. It's a little different from other vehicles I (or my friend) have worked on in the past.
Another observation that has me guessing...during the job I compared the side I was working on to the other side of the vehicle and that side was pretty loose; maybe 2 lbf...so I just set both loose as compared the FSM. This is where I think they were before I did the service.
After torquing everything else, along with the tires, I checked for play in the wheels, but didn't feel any. If there is going to be a problem, maybe it will show up later?
I read this thread, and it seems that others have noticed the same thing with having to really torque down the lock nut in order to get the right preload.
https://forum.ih8mud.com/80-series-tech/212472-has-anyone-tested-torque-rear-axle-lock-nuts.html
I guess I am just questioning myself now and maybe should dig back into the axles and torque down until I get the right preload setting per the FSM.
Thoughts? Thx
