FJ40 Disc Brake Conversion

RicardoJM

Hard Core 4+
Joined
Jul 18, 2007
Messages
2,582
Location
Centennial, CO
Wheel Bearing Preload

With the exception of installing the proportioning valve, I finally have the conversion buttoned up. I did have a challenge regarding my wheel bearing preload. When I put the hub and rotors on my pre-load was well over 20lbs. The spec should be much closer to 12. I took the rig for a short ride (maybe 5 miles) and when I put my hand to the hubs they were hot, very hot. I was very certain that I had all the parts in the right place, I had checked and rechecked everything when I encountered the high pre-load.

I was a bit stumped, but the more I thought about the parts involved it occured to me that I had reused the claw washer and nuts from the FJ60. At one point I had considered getting new ones, because it was clear someone had used the chisel method of removal/tightening - but decided they were ok. In retrospect, it should have been obvious these needed to be replaced with new. Here is a picture of the old claw washers.
w_badclaw.jpg


Notice the groove made by the old bearings. This groove is what was causing my tight bearing pre-load. The groove allowed the washer to put more inward pressure on the bearings. After replacing the claw washer and nuts with new ones, my pre-load is right on spec. If you do a front axle job and replace your wheel bearings, I would recommend you also get new claw washers.
 

Rzeppa

Rising Sun Member
Joined
Aug 24, 2005
Messages
8,723
Location
Kittredge CO, USA
If the groove was only on one side you could have just turned them around so the non-grooved side was against the inner race. But new ones never hurt. Glad you got that sorted out.
 
Back
Top