Observatuon about new spindles and bearing torque (1 Viewer)

[Rusty Marlin]

Curious here.
The FSM specifies 9.5-15lbf of preload. Since the fish scale is not pulling 1 foot from the rotational center, shouldn't one do some measuring & math using this method?

(Which would reduce the assumed force many people are using. I'm going to stick with Tools' method.)

Its not a torque value, force * distance, it's a straight load value pulled on a stud 90 degrees to rotation.
I thought seriously of converting the spring scale load to a torque value, it would be 5.5/2"x9.5# to 5.5/2" x 15# = 26in-lbs to 41in-lbs. It would be a spanner tool that would go across a couple of lugs and have a 3/8 drive in the center. You would measure the torque with a beam type torque wrench. It would make for a large SST that is of dubious use over a simple fish scale. But it would make the FSM more consitant on how it wants mechanics to measure bearing preload.

 

[Mighty690]

Its not a torque value, force * distance, it's a straight load value pulled on a stud 90 degrees to rotation.

I agree with your above statement in that's how I see people measuring, but the FSM states foot/lbs (and kg/f too), not simply lbs in a linear pull from a lug. It's pretty clearly a torque value at a given distance from center. I'm not trying to refute you, or be difficult, but this does throw a wrench in the spokes, so to speak, regarding the fidelity to the FSM. No?

 

[BILT4ME]

I agree with your above statement in that's how I see people measuring, but the FSM states foot/lbs (and kg/f too), not simply lbs in a linear pull from a lug. It's pretty clearly a torque value at a given distance from center. I'm not trying to refute you, or be difficult, but this does throw a wrench in the spokes, so to speak, regarding the fidelity to the FSM. No?

Also realize that the Aussie version of the FSM reads completely different for the same axle assembly.

 

[Mighty690]

Also realize that the Aussie version of the FSM reads completely different for the same axle assembly.

Ah, interesting! Thanks for that.

 

[mudgudgeon]

Also realize that the Aussie version of the FSM reads completely different for the same axle assembly.

I don't think so. I believe it's the same.

 

[BILT4ME]

I don't think so. I believe it's the same.

Please confirm to your manual:
This is from the 1996 USA version.

 

[Rusty Marlin]

Top image looks like a linear load of kgf and lbf (kilograms force and pounds force) to me. No offset at distance given.

 

[Mighty690]

Top image looks like a linear load of kgf and lbf (kilograms force and pounds force) to me. No offset at distance given.

View attachment 2543287

I see the problem; it's not "pounds force" but a given weight at a given distance, a lever, and in this case it's one foot. Am I wrong?

 

[Mighty690]

I see the problem; it's not "pounds force" but a given weight at a given distance, a lever, and in this case it's one foot. Am I wrong?

Looking at the FSM picture, perhaps the scale is not a fish scale but is calibrated to foot pounds. That's the only way I can make logic of the fish scale linear pull perspective.

 

[Rusty Marlin]

I think its a translation thing.
lbf =pounds force, no distance involved.
ftlb or lbft = foot pounds or pounds feet (interchangeable) and there is a distance involved (1ft implied)
The manual does say ft-lbf foot pounds force, which is a little confusing, in physics and engineering we leave out the "force" at the end, it's implied.

Now where the manual does want you to measure bearing preload as a measure of torque is in the section on the Steering Gear Assembly. The input shaft bearings are tightened until the proper input torque is registered on the input shaft through a beam type torque wrench and a splined socket that fits the input shaft.

 

[Mighty690]

I think its a translation thing.
lbf =pounds force, no distance involve
ftlb or lbft = foot pounds or pounds feet (interchangable) and there is a distance involved (1ft implied)
The manual does say ft-lbsf foot pounds force, which is a little confusing, in physics and engineering we leave out the "force" at the end, it's implied.

Okay, then it (the use of lbf) would be consistent elsewhere in the FSM. Is that the case?

 

[Rusty Marlin]

Yes, please re-read my post I was editing for additional content when you quoted it... my bad.

 

[mudgudgeon]

Please confirm to your manual:
This is from the 1996 USA version.
View attachment 2543288

The Aussie manual is written slightly differently, but all the values are the same.

 

[BILT4ME]

The Aussie manual is written slightly differently, but all the values are the same.

View attachment 2543603

I'm gonna have to find the thread discussing this previously. It's probably in a TOOLS R US thread.

 

[VivaToy]

Rebuilt the knuckles about a month ago and haven't touched the LC since. I didn't see this thread and torqued it to the FSM manual at about 4 ft/lbs for the inner and 65 ft/lbs for the outer. After 20 miles of driving the driver side was considerably loose. As in, really loose. I took it apart, am trying to use TOOLS R US specs but when I get it to 25 ft/lbs it barely spins at all. At 50 ft/lbs it's frozen solid.

The passenger side torques to 25 ft/lbs great. Spins with some friction but overall looks good. Even spins at 50 ft/lbs to seat properly.

Another note is that the axle shaft for the snap ring that sits on the very end beneath the dust cap has BARELY enough groove to fit. But it does seat properly, and it spins freely when the snap ring is seated.

What is going on with my driver side hub? Should I torque it to 10 or 15 ft/lbs and see what happens? 4 ft/lbs is a no go.

(Axles are currently open so any quick responses would be much appreciated!)

 

[AussieHJCruza]

Rebuilt the knuckles about a month ago and haven't touched the LC since. I didn't see this thread and torqued it to the FSM manual at about 4 ft/lbs for the inner and 65 ft/lbs for the outer. After 20 miles of driving the driver side was considerably loose. As in, really loose. I took it apart, am trying to use TOOLS R US specs but when I get it to 25 ft/lbs it barely spins at all. At 50 ft/lbs it's frozen solid.

The passenger side torques to 25 ft/lbs great. Spins with some friction but overall looks good. Even spins at 50 ft/lbs to seat properly.

Another note is that the axle shaft for the snap ring that sits on the very end beneath the dust cap has BARELY enough groove to fit. But it does seat properly, and it spins freely when the snap ring is seated.

What is going on with my driver side hub? Should I torque it to 10 or 15 ft/lbs and see what happens? 4 ft/lbs is a no go.

(Axles are currently open so any quick responses would be much appreciated!)

Are the bearing races seated properly in drivers side? I wouldn't torque it to 10 ft lbs and call it good, something isn't right there.

 

[motormayhem]

I just threw new bearings / spindles into my front end. Noticed the same thing with the fish scale kind of leveling off after a certain torque on the inner nut. Ran the inner at 30ft*lbf since the fish scale wasn't terribly high (I believe it was about 13.5 lbf, so a little higher than spec). Hubs ran warm and were not cooling down after a few thousand miles. So I pulled it apart and sure enough neither the bearings nor grease were thrilled with it (note these were new bearings). The torque on the outer nut also plays a role since it's higher than the inner nut and therefore pushes the inner nut thru the thread clearance once its loaded. The torque to turn (fish scale) is essentially an indication of the bearing preload (plus grease drag + seal drag, etc). Just because it stops climbing rapidly with nut torque doesn't mean you want to keep going tighter (assuming you did a proper pre-seating of everything). Once you first get torque to turn to the specified value you likely are pretty close to the 0 / slightly preloaded area of the curve and continuing up in inner nut torque is working towards the cliff.

This is a good illustration of bearing life vs preload. Much steeper drop off in life on a tight bearing vs a loose bearing.

 

[VivaToy]

Are the bearing races seated properly in drivers side? I wouldn't torque it to 10 ft lbs and call it good, something isn't right there.

I am very confident the races are seated. I couldn't fit a fingernail beneath the race and the seat in the hub when I was done pounding them in. Can it be anything else?

For now, I think I'll torque them the old fashioned way (by feel) and drive for another 20 miles and see if it's loose again.

 

[Mighty690]

Question: When you initially set it at 30lb/ft, what did it feel like as you turned the hubs?

I just threw new bearings / spindles into my front end. Noticed the same thing with the fish scale kind of leveling off after a certain torque on the inner nut. Ran the inner at 30ft*lbf since the fish scale wasn't terribly high (I believe it was about 13.5 lbf, so a little higher than spec). Hubs ran hot and were not cooling down after a few thousand miles. So I pulled it apart and sure enough neither the bearings nor grease were thrilled with it (note these were new bearings). The torque on the outer nut also plays a role since it's higher than the inner nut and therefore pushes the inner nut thru the thread clearance once its loaded.

This is a good illustration of bearing life vs preload. Much steeper drop off in life on a tight bearing vs a loose bearing.

View attachment 2550556

View attachment 2550560


View attachment 2550562

View attachment 2550563

View attachment 2550564

 

[motormayhem]

Question: When you initially set it at 30lb/ft, what did it feel like as you turned the hubs?

Spinning the hub by hand didn't feel much different than it did at 15 ft*lbf or 25 ft*lbf inner nut torque. It certainly spun without feeling like the bearings were bound up, but with the grease in there and the new seals its a little hard to feel small changes the bearing preload is making. Once you are to the point where the bearings are dragging you are way too tight. I'd guess that's in the 40-50ft*lbf type range. Probably still work, just at a reduced life (both bearing and grease). I suspect the above bearings probably would have worn in a and eventually loosened up and run for a long time, but in doing so lost some life. You can see the difference in the grease. Pink grease on the right vs the grease from around the bearings on the left. 2k miles in an they are already running in their own filth. Still lots of pink grease in the center cavity.