Front Hub torque values
hondaraybo
03-04-2007, 01:25 AM
First time poster so here goes, I am replaceing both front hubs on my 2003 Alero and need to know the torque values for the 3 bolts that hold the hub on and the 36mm axle nut. Any help would be appreciated. P.S. I hear these cars are notorious for eating front hubs.
BNaylor
03-04-2007, 08:32 AM
Welcome to AF.
There are two different axle nut designs, therefore the possibility of two different torque values. There is a PAC Nut which most '99 and up Aleros should have but also, there is a second design. First design (Black PAC Nut) is 284 ft-lbs with a new axle nut. The old axle PAC Nut should not be reused. Second design (solid gray) is 173 ft-lbs.
http://i5.photobucket.com/albums/y186/lizzywiz/pacnut.gif
1st Design PAC Nut
Pac Nuts are laminated lock nuts designed to internally deflect as torque is applied. This deflection or spring loading occurs below and through the bolt stretch or elastic range, adding to the bolt's capability to maintain preload. Preload maintenance is fundamental to preventing joint loosening.
Advantages of a PacNut®
Joint loosening prevention - The internal deflection of the conical laminations in the nut result in a reduction of hole size or pitch diameter eliminating designed clearance between the nut and bolt. This also produces mechanical pressure to the flanks of both male and female threads. The spring pressure and mechanical interference results in locking or resistance to loosening.
Torque/Tension - Solid nuts characteristically concentrate the majority of loading at the bottom one and one half to two threads. This eccentric loading causes the nut to dilate and increases friction in the highly loaded thread contact area. This results in increased torque/tension. Torque/tension relationships with the Pac Nut are maintained through controlled spring deflection, resulting in uniform thread loading form bottom to top of nut. Pac Nut laminations are specifically designed with varied thickness and crowned configuration of the laminations bottom to top to allow equal thread load distribution.
There are two different axle nut designs, therefore the possibility of two different torque values. There is a PAC Nut which most '99 and up Aleros should have but also, there is a second design. First design (Black PAC Nut) is 284 ft-lbs with a new axle nut. The old axle PAC Nut should not be reused. Second design (solid gray) is 173 ft-lbs.
http://i5.photobucket.com/albums/y186/lizzywiz/pacnut.gif
1st Design PAC Nut
Pac Nuts are laminated lock nuts designed to internally deflect as torque is applied. This deflection or spring loading occurs below and through the bolt stretch or elastic range, adding to the bolt's capability to maintain preload. Preload maintenance is fundamental to preventing joint loosening.
Advantages of a PacNut®
Joint loosening prevention - The internal deflection of the conical laminations in the nut result in a reduction of hole size or pitch diameter eliminating designed clearance between the nut and bolt. This also produces mechanical pressure to the flanks of both male and female threads. The spring pressure and mechanical interference results in locking or resistance to loosening.
Torque/Tension - Solid nuts characteristically concentrate the majority of loading at the bottom one and one half to two threads. This eccentric loading causes the nut to dilate and increases friction in the highly loaded thread contact area. This results in increased torque/tension. Torque/tension relationships with the Pac Nut are maintained through controlled spring deflection, resulting in uniform thread loading form bottom to top of nut. Pac Nut laminations are specifically designed with varied thickness and crowned configuration of the laminations bottom to top to allow equal thread load distribution.
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