1983 FJ60 - Differing front wheel bearing specs in FSM's.

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fjgdk

10 Year
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May 8, 2011
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I am rebuilding the front axle and when I finished doing the pre-load procedure per publication 36262E my pre-load is around 20-22 Ft. lbs.

My questions is two-fold, the details of which I will explain:
1) Is my pre-load OK (seems heavy) ?
2) Why are there seemingly two different specs in two different FSM's, one of which my measurement would meet spec and the other it would not ?

Let me explain:
"Manual 1" = Toyota publication 36044E = Aug 1980 Land Cruiser = says it applies to FJ60 (and 40's, BJ's etc.)

"Manual 2" = Toyota publication 36262E = Production Dates 10/84 thru 1/90 = Does NOT specify it can be used with an FJ60.

"Manual 3" = Toyota publication #unknown (Front page not scanned on document I saw" = "1985 FJ60 Toyota Landcruiser Chassis & Body supplement" = Says to use manual 2 EXCEPT for the certain items contained in the supplement.

Regarding the front axle bearing pre-load:
Manual 1 =
tighten adjuster to 43 ft-lbs -> loosen adjusting nut -> retighten adjuster to 35-60 in-lbs -> measure preload at 6.2-12.6 ft-lbs -> tighten locker to 58-72 ft-lbs -> preload should still be at 6.2-12/6 ft-lbs

Based on what I did, I would be well out spec with this.

Manual 2 = tighten adjuster to 43 ft-lbs -> turn wheel to and fro -> tighten adjuster to 43 ft-lbs again -> loosen adjusting nut -> measure preload and define this value as the "frictional force"
-> retighten adjuster to 35-60 in-lbs -> measure preload at "frictional force" + 0.9 - 7.3 lbs -> tighten locker to 58 ft-lbs -> preload should still be at "frictional force" + 0.9 - 7.3 lbs

Based on what I did, I would be in spec as my "frictional force" was around 15ft-lbs which gives a final max acceptable range of 15.7 -22.3 lbs. Also note the typo of 0.9-7.3 pounds and NOT ft-lbs.. I am assuming they meant ft-lbs.

Manual 3 = says to refer to manual 2 for this part (the front axle is unmentioned except for alignment specs.



Confusing ?
I will post pictures.
 
Here are the pages from Manual 1, publication 36044E

IMG_4297.webp
IMG_4295.webp
IMG_4296.webp
 
Regarding manual 3, I think it is publication number 36274A. I have seen screen shots of the front axle part where it refers back to manual 2
for this part of the front axle job. I don't have photos at the moment.
 
Ft-lbs is a combination measurement of force(lbs) and distance from the point of rotation(ft) so in regard to the possible typo, the distance from rotation is already specified as the wheel stud so the leftover measurement is only lbs which is measured on a fish scale.

I too am having an issue coming up with the right preload, unfortunate no one has responded to this thread.
 
The spec is different for new vs used bearings. Used bearings set up looser than new ones. Perhaps that's the source of your confusion.
 
Ok, also my preload is coming up way under spec. Do I just keep torquing the adjustment nut incrementally and measuring until it's in range?
 
No need to go crazy with trying to set the exact preload. If the hub doesn't have any free play against the bearings when rocking it from top to bottom, the preload is fine. When it's not fine is when the bearings are crushed too tight w excessive preload. You can tell if it's too tight cuz wheel will have way too much drag- and you might hear squeaking of the bearings when driving.

I always set my preload by feel and never had a problem in 30 years /290,000 miles.
The one time I did run into a problem was when I believed I had set the preload to spec very carefully with a tension scale - only to find out a thousand miles or so later on a long trip the bearing was squeaking. After that incident I never "measured" the bearing preload again during service- just went by feel
 
The way I think about measuring frictional force and pre-load, it is not about the inital force required to overcome the inertia of the rotating assembly, but the force required to keep it in motion. Using the fish scale, the fish scale should be tangent to the circle defined by the wheel studs. So as you rotate the wheel hub, you need to rotate the non-hook-end of the fish scale around in a larger circle to keep the wheel moving. Then you should get an accurate pre-load measurement.

As tangocircus says, the fish scale is measures force, not torque. Therefore the units are lbs or N. You could calculate torque by multiplying the force by the distance from the axis of rotation, but the FSM gives you the spec in the measurement units.
 
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