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Mendocino
01-18-2010, 06:18 PM
The FSM says to torque the knuckle bearing caps to 43-54 ft lbs for bearing preload. The preload is checked with a fish scale and should read not more than 5 lbs. When I toque the bearing caps to 43 lbs the fish scale says ~8.5 lbs. I tried to reduce the torque to 38 lbs on the bearing caps but I am still reading about 8 lbs on the fish scale.

So, do I 1) try to reduce the bearing cap torque, 2) run it as it is, or 3) do something else that my friends will tell me about?:thumb::)

Air Randy
01-18-2010, 06:49 PM
Try removing 1 shim, re-torque then check the pre load again. The idea is to have the right number of shims in that when you torque to proper values you get the 5 lbs on the scale

Mendocino
01-18-2010, 06:54 PM
Try removing 1 shim, re-torque then check the pre load again. The idea is to have the right number of shims in that when you torque to proper values you get the 5 lbs on the scale


Argghhh!!! I went to protracted effort with the SST to get the right shim thickness:(...any other suggestions? Thanks for helping.:)

Shark Bait
01-18-2010, 07:01 PM
Argghhh!!! I went to protracted effort with the SST to get the right shim thickness:(...any other suggestions? Thanks for helping.:)

Try a different scale. :eek::D

nakman
01-18-2010, 10:14 PM
Try a different scale. :eek::D :lmao: yeah I've got a couple you can borrow, one of them you can bend the little needle a little if you want.

But what's at risk here, just the load on the trunion bearings? I would toss the fish scale back in the tackle box and torque those boys back to 54.. but that's me. :D

Air Randy
01-18-2010, 10:40 PM
:lmao: yeah I've got a couple you can borrow, one of them you can bend the little needle a little if you want.

But what's at risk here, just the load on the trunion bearings? I would toss the fish scale back in the tackle box and torque those boys back to 54.. but that's me. :D

I would tend to agree, but he did imply he wanted to be anal and get it exactly right.

Also, if you used the SST to get the top/bottom centering correct, the truely correct way (I think) would be to remove equal shims top/bottom so the centering is exact. That sounds like a real pain to me, I would take an extra shot or two of whiskey, check it again and I'll bet the pre-load will be perfect :hill:

Mendocino
01-18-2010, 10:43 PM
I ended up adding shims to reduce the preload on the trunion bearings at torque. It now works fine. My extreme frustration was that I used the SST. I had to replace the Marlin Seal (the seals removal was a PITA) so I figured I would just take it apart the entire way and use the SST again to get a better measurement. When I assembled it with the STT measurements I got excessive preload. After adding shims i got the preload and torque to where it needed to be. Good grief, want a pain.:p:

rover67
01-18-2010, 10:47 PM
Torque the nuts to what the spec says.. the preload is determined by the TOTAL shims thickness.

First step to use that SST is to assemble it all together with the bearings in place and tighten it down untill you get the specified preload (appropriate reading on the fish scale). Once you set that you measure the SST with calipers, record the number, measure the Knuckle housing with Calipers, and subtract that number from the SST size. That gives you the TOTAL shim thickness.

The rest of the procedure just tells you ho many to put on top and bottom to center the knuckle housing on the axle.

So.... if yo uhave too much preload on the bearings at the final step.. you need to add some shim thickness and go back through the centering calculations (even though that probably is not needed.) .

For what it's worth... my FJ60 factory service manual calls out a bearing preload of 4-8.4Lbs...

If I were you I'd leave it. you're done...

rover67
01-18-2010, 10:48 PM
wow, a lot happened while I wrote that...

sounds like ya got it :)

Mendocino
01-18-2010, 11:00 PM
...First step to use that SST is to assemble it all together with the bearings in place and tighten it down untill you get the specified preload (appropriate reading on the fish scale). Once you set that you measure the SST with calipers, record the number, measure the Knuckle housing with Calipers, and subtract that number from the SST size. That gives you the TOTAL shim thickness. ...

Interesting. I don't remember the FSM saying to torque the trunion bearing caps to spec and test with fish scale THEN measure when using the SST. This makes a lot of sense to me.

Too late now. I'm putting the thing together and driving it. I will change methods the next time I have to take it apart.:rolleyes:

EDIT: Now that I think more about this if I would have torqued the SST (not the Trunion bearing caps) this would have resulted in an increased SST measurement and therefor more rotational torque as measured on the fish scale and not less.:confused: I am still missing something...:hill:

In any case the knuckle is on and I will asemble the rest wehn i get home tonight.

nakman
01-18-2010, 11:06 PM
..I'm putting the thing together and driving it.

Oh come on, we don't get to second guess your wheel bearing preload now? what fun are ya, geez. :(

Shark Bait
01-18-2010, 11:27 PM
For what it's worth... my FJ60 factory service manual calls out a bearing preload of 4-8.4Lbs...



My point was that a fish scale isn't necessarily a precision measuring tool. :thumb:

Mendocino
01-19-2010, 06:08 AM
Oh come on, we don't get to second guess your wheel bearing preload now? what fun are ya, geez. :(

Guess away Nak.:) BTW-Its Trunion preload now wheel bearing; or maybe that's what you meant.:eek:

nakman
01-19-2010, 09:08 AM
Obviously a failed attempt at humor, sorry- putting it all back together implies you'll be putting the hub back on, which could imply that the fish scale is coming back out. :)

rover67
01-19-2010, 09:14 AM
Hey wait a minute!! my fish scale IS a precision peice of equipment!!!! I bought it at Harbor Freight!!! It must be good right???

:D

subzali
01-19-2010, 07:30 PM
and it's been bouncing around in my toolbox for almost 5 years!

Old40Dog
01-19-2010, 08:07 PM
Take it from an expert!:D The handle says it all:lmao:

My point was that a fish scale isn't necessarily a precision measuring tool. :thumb:

Sorry Chris, I just couldn't resist.....I've been watching this thread for several days.:cheers:

Shark Bait
01-19-2010, 09:03 PM
Good one, Dave! :lmao:

Old40Dog
01-19-2010, 09:20 PM
Good one, Dave! :lmao:

Your welcome!:hill: And thanks again for the tank! Really got me going again on the "72-40. Got the frame in the garage this weekend and made some real progress.:weld: