Wheel Bearing preload and fsm
01-09-2011, 11:53 PM
#1
Registered User
Thread Starter
Join Date: Aug 2010
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Wheel Bearing preload and fsm
Just finished a cv boot and bearings on my 1991 4runner, and I had some questions regarding setting the preload on the axle.
I went ahead and set it exactly as toyota mentions in the fsm , first tightening the adjustment nut down, then loosening, then tightening slightly, and checking the preload. Then I placed the locking washer and the locking nut onto the axle. Once I tighten the locking nut down to the set torque setting the preload goes through the roof.
I then took everything off and tried to set it again, with the same results.
The only way I can keep the preload in spec is to literally just hand tighten the locking nut. I'm not exactly worried that it's going to spin off by itself since it has a the locking washer, but I am a little confused on why I can't set it to what the fsm is stating.
When I spoke to one of my friends who did this before he did it without the 54mm socket and just hand tightened the locking nut. I was a bit hesitant so I went out and bought the socket, but it almost looks like you might not need it.
I went ahead and set it exactly as toyota mentions in the fsm , first tightening the adjustment nut down, then loosening, then tightening slightly, and checking the preload. Then I placed the locking washer and the locking nut onto the axle. Once I tighten the locking nut down to the set torque setting the preload goes through the roof.
I then took everything off and tried to set it again, with the same results.
The only way I can keep the preload in spec is to literally just hand tighten the locking nut. I'm not exactly worried that it's going to spin off by itself since it has a the locking washer, but I am a little confused on why I can't set it to what the fsm is stating.
When I spoke to one of my friends who did this before he did it without the 54mm socket and just hand tightened the locking nut. I was a bit hesitant so I went out and bought the socket, but it almost looks like you might not need it.
01-10-2011, 06:49 AM
#2
Done this dozens of times.
It depends if the bearings are new or used.
Are you spinning the wheel hub after torquing and then checking preload?
Hand tight won't get it and you will have issues sooner or later.
Torque specs are there for a reason and you need a 54mm socket.
:wabbit2:
It depends if the bearings are new or used.
Are you spinning the wheel hub after torquing and then checking preload?
Hand tight won't get it and you will have issues sooner or later.
Torque specs are there for a reason and you need a 54mm socket.
:wabbit2:
01-10-2011, 07:28 AM
#3
Registered User
Thread Starter
Join Date: Aug 2010
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
Done this dozens of times.
It depends if the bearings are new or used.
Are you spinning the wheel hub after torquing and then checking preload?
Hand tight won't get it and you will have issues sooner or later.
Torque specs are there for a reason and you need a 54mm socket.
:wabbit2:
It depends if the bearings are new or used.
Are you spinning the wheel hub after torquing and then checking preload?
Hand tight won't get it and you will have issues sooner or later.
Torque specs are there for a reason and you need a 54mm socket.
:wabbit2:
The bearings are new on the inner and outside sides. I've put on the hub, put the adjusting nut on and torqued it to 45 lbs.
Loosened the adjusting nut completely
Spun the entire hub 2-3 times
Retightened the adjusting nut to I think 18 lbs
Check preload think it was 6-12 lbs
Put the lock washer on and tightened the lock nut to 35 lbs
Check preload and now it's consistiently above 20 lbs
Scratched my head and redid the entire process, only to find that the preload is over 20 lbs again.
Last edited by ultimase; 01-10-2011 at 07:31 AM.
01-10-2011, 09:30 AM
#5
Registered User
Thread Starter
Join Date: Aug 2010
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
See that's what I was thinking, but according to http://www.ncttora.com/fsm/1990-1995...l/frontaxl.pdf page 6
the only torque rate that I remembered wrong was the initial 43 lbs for the adjustment nut. Everything else is as I remembered it.
the only torque rate that I remembered wrong was the initial 43 lbs for the adjustment nut. Everything else is as I remembered it.
01-10-2011, 09:37 AM
#6
This is the technique I use (gleaned from the old toy4x4 mailing list many moons ago):
http://www.4crawler.com/4x4/CheapTri....shtml#Rebuild
http://www.4crawler.com/4x4/CheapTri....shtml#Rebuild
The second method seems to produce similar results and is a bit more straight forward:
* Torque spindle nut to 43 ft. lbs.
o Spin hub right 4-5 rotations
o Spin hub left 4-5 rotations
* Loosen inner spindle nut
o Spin hub right 4-5 rotations
o Spin hub left 4-5 rotations
* Torque spindle nut to 43 ft. lbs.
o Spin hub right 4-5 rotations
o Spin hub left 4-5 rotations
* Loosen inner spindle nut
o Spin hub right 4-5 rotations
o Spin hub left 4-5 rotations
* Torque spindle nut to ~21 ft. lbs.
The idea behind the second method is to ensure the bearing is fully seated in the grease and then the final torquing sets the pre-load fairly accurately. I used the second technique on my first rebuild (I didn't have a spring scale then) and I found the bearings a bit tight. In fact they seemed to be getting a bit hot on a highway trip to go wheeling. However, after two days crawling rocks, they seemed to settle right in. When I got back, I picked up a scale and measured the bearing drag and both sides were about 8 lbs. total (don't know what the oil seal drag was and I wasn't about to find out :-), so I guess it worked OK.
* Torque spindle nut to 43 ft. lbs.
o Spin hub right 4-5 rotations
o Spin hub left 4-5 rotations
* Loosen inner spindle nut
o Spin hub right 4-5 rotations
o Spin hub left 4-5 rotations
* Torque spindle nut to 43 ft. lbs.
o Spin hub right 4-5 rotations
o Spin hub left 4-5 rotations
* Loosen inner spindle nut
o Spin hub right 4-5 rotations
o Spin hub left 4-5 rotations
* Torque spindle nut to ~21 ft. lbs.
The idea behind the second method is to ensure the bearing is fully seated in the grease and then the final torquing sets the pre-load fairly accurately. I used the second technique on my first rebuild (I didn't have a spring scale then) and I found the bearings a bit tight. In fact they seemed to be getting a bit hot on a highway trip to go wheeling. However, after two days crawling rocks, they seemed to settle right in. When I got back, I picked up a scale and measured the bearing drag and both sides were about 8 lbs. total (don't know what the oil seal drag was and I wasn't about to find out :-), so I guess it worked OK.
Thread
Thread Starter
Forum
Replies
Last Post
altydog
86-95 Trucks & 4Runners
1
07-28-2015 10:20 AM
