In the past when I've had the bearings out I just went by feel when retorquing, but this is the first time putting in new ones, and seeing how expensive they are I really want to get this right. Plus, then I can blame the Mexican manufacturers if they blow out.

Using the FSM method with the spring scale, the figures they give, regardless of year, are in ft/lbs. But spring scales only measure lbs, and every writeup here uses only lbs pull at the wheel stud.

The lug bolts are only a few inches from the hub center. 5 lbs pull at the wheel stud is going to be much less than 5 ft/lbs, which would be 5 lbs pull at 1 ft from the center (as anyone who has put a pipe on their breaker bar knows, it doesn't take much extension to really multiply the torque.

Not trying to split hairs, but seems like it could be quite a difference, and really curious. It seems like to use the FSM figures we would need to rig up an extension to get 1 ft from the hub center and measure lbs pull there, or figure out the torque multiplier 3" from center. Am I mistaken in this? Is the FSM worded incorrectly? Or is everyone using spring gauges actually setting their preload lower than Yota specs?

 

someone put a video up on how to properly preload those bearings. Not sure if it was brake related or not. Might wanna dig around for that.

If I get it correctly, the ft-lb with a torque wrench is the hub nut torque and is completely unrelated to the spring pull. If I am right you torque the nut to spec rotate wheel a few times retorque and then use the spring scale to measure rolling resistance of the wheel and loosen tighten the hub nut to get your spring rate lbs correct.

Please someone correct me if I am wrong here.

 

Trunnion bearings or wheel bearings?

New wheel bearings torque to seat at like 40 ft-lbs
Spin, loosen, retorque at like 20 ft-lbs. Repeat.
FSM has actual settings but that's close.
Use a torque wrench and a 54mm socket, not a chisel and feels tight.

I use a fish scale for fishing.

:wabbit2:

 

^^^^ that's how I did mine using my old bearings. No problems yet.

 

Same here, but for my peace of mind at spending $150 for both sides, I was hoping to finally follow the FSM. See a lot of writeups using the scales too.

http://www.ncttora.com/fsm/1990-1995...l/frontaxl.pdf

So, even if only for curiosity's sake, if the wheel stud is 3" from the hub center, isn't the FSM spec of 12ft/lb drag, the equivalent of 48ft/lb when measured only 3" from center? And then which would be the correct preload figure to use, ft/lb like they say, or lbs drag on the wheel stud, which I can't see being the same?

 

oh and keep in mind if your actually gonna measure the drag, make sure you do it with the calipers off. One would also think the amt of drag is gonna be somewhat variable anyway based on what type and how much grease and how it was applied. Not sure if it's negligible though.

 

Done this a baxillion times and I use a torque wrench, not a fish scale.

Fish scale is more to measure resistance turning it to get a feel for what you've already done with a torque wrench.

:wabbit2:

 

Oh, and wheel bearing. Is the trunion part of the steering knuckle?

 

Good point, pretty sure the ADD like I have are measured after getting an initial reading of "oil seal drag" and then adding preload on top of that. Maybe that's why.

 

hehe yet another reason to have manual hubs. forgot all about the add system. So that brings up another point on the ADD system, what happens when you go and try to do this with a front locker? It's not like you can do this by the book and would have to use wabbit's method.

 

True, I guess even if you disengaged it there would still be additional drag on the hub. You could probably still do the 'intial reading+bearing preload' method though I'd imagine (all I can do, until I can afford a locker someday...)

I'm definitely going to use a torque wrench to get in the neighborhood but there were several threads where guys were trying that and then not getting the readings they thought they should have when checked with the spring gauge. I was just hoping to have some extra assurance so as not be worrying that I'm going to be spending another $150 for new bearings anytime soon.

 

Well the answer is FSM is right, Haynes is wrong. FSM uses "lbf" to measure drag, Haynes says lb/ft. I thought maybe lbf was a Japanese way of saying lb/ft (so did Haynes apparently?) but according to Wikipedia it is 'pound-force' and... "In most contexts, the shorter name "pound" is used, but this can introduce confusion with the mass unit of the similar name."

So plain old pounds it is. Just in case any other slightly anal retentive people were losing sleep over this...

 

you shouldnt have extra drag even on an ADD system because when you tightening the wheel nuts you have the flange off which disengages and lets the hub free wheel. same as for a manuel lock you have the lock part off so same thing. now when you put it all together then you will have a difference with the manuals and the ADD.

 

There are two different procedures for checking preload depending on ADD or not. I've never done a conversion, but wouldn't Manual and ADD hub bodies be a different part number, or can you just slap a manual hub right on an ADD setup? If they're different, something in there is affecting drag, if not, maybe the different preload settings are just taking into account the different needs after it's all back together.

*Edit* Emm, nevermind that last bit, I was looking at the Auto-locking hubs, not ADD. Guess ADD uses the same procedure for checking preload as Manual hubs. Still measured in pounds though.