Front Spindle nut tightening. Need help please

[72Z/28]

Ok guys, finished packing my new Wilwood bearings with grease but I am a bit confused about how to properly proceed with the tightening of the spindle castle nut as I have read so many posts in different forums about the tightening, and not sure what is the correct method. I torqued the nut to 12 ft-lbs while spinning the rotor but confused about the following statements I read in some forums:


- torquing the nut to 12ft. Lbs while spinning the rotor, then back off the nut to the nearest slot to put the cotter pin.


- Torquing the nut to 12ft. Lbs, then back of the nut by “one flat”, not sure what this means,


-or torque the nut to 12 ft. Lbs. Back off the nut till bearing gets unloaded, then hand tighten the nut till snug and put the cotter pin.


Could someone guide me please how to proceed with this because when I torque the nut to 12ft. Lbs, the castle nut slot sometimes is aligned with the hole for the cotter pin or sometimes covering half of the hole. Of course, there is resistance in rotating the rotor at this stage.


If the castle nut is aligned with one of the holes on the spindle, shall I back of the nut by. 1/4 of a turn to get to the other hole to insert the cotter pin or backing it off by full turn and hand tighten it get the castle nut aligned to insert the cotter pin?




Thanks in advance

[79T/Aman]

Unfortunately these days there are too many key board experts, the smartest way to get correct info is to go back to reading books/service manuals.

[72Z/28]

Unfortunately these days there are too many key board experts, the smartest way to get correct info is to go back to reading books/service manuals.

Unfortunately, I do not have any reference from service manuals or books.

[raustinss]

Tighten to 12 ft lbs ... then spin it back one flat of the nut. The nut has 6 "sides " aka flats . Really what it means is spin the nut loose until you can insert a cotter pin . Having said that sometimes that might mean going a lot more loose than necessarily needed . My hot take ... no torque wrench ... spin until tight ish while spinning the rotor . Back off a touch put in cotter pin... recheck after maybe 50 100 miles ... or kms . Really you just want to take the bearings and grease up to temp a few times and bed themselves in . If you find the bearings loose at said time .. give them a tighten and insert a new cotter pin

[72Z/28]

Tighten to 12 ft lbs ... then spin it back one flat of the nut. The nut has 6 "sides " aka flats . Really what it means is spin the nut loose until you can insert a cotter pin . Having said that sometimes that might mean going a lot more loose than necessarily needed . My hot take ... no torque wrench ... spin until tight ish while spinning the rotor . Back off a touch put in cotter pin... recheck after maybe 50 100 miles ... or kms . Really you just want to take the bearings and grease up to temp a few times and bed themselves in . If you find the bearings loose at said time .. give them a tighten and insert a new cotter pin

Thanks Ryan for the input. Really informative.
I have just found a thread in chevytalk, where they were referring to some manuals about tightening procedure for the wheel tapered bearings.

The procedure is similar to what you mentioned.

The nut needs to be torqued to 12 ft-lbs while the rotor. Then it says to loosen the nut and again hand tighten it till snug. Lastly back off the nut as you mentioned to align the cottor pin with the hole.

[raustinss]

Good glad you found something "official"lol ... 12 ft lbs really isnt much , this was why I said dont use one . If you do you'll see how little torque it is . Plus I guess I've done it enough I have calibrated hand lol

[TheBandit]

The way I did it was to use a smaller 3/8 drive torque wrench which I set to 144in-lb (12ft-lb) to tighten the spindle nut, then I rotated the rotor a bit, then re-torqued and repeated a few times to make sure the bearings were fully seated. Then I backed the nut 1/8 turn looking for the nearest cotter pin hole. The goal is to have zero preload on these bearings with minimal axial play. I have seen a spec of 0.003in maximum axial play.

Torquing the nut to 12ft-lb helps establish where the bearing has just slight preload. Then backing off by 1/8turn provides the axial endplay required to ensure it's not overly preloaded when things heat up under use & braking.

A typical GM spindle nut has a 3/4-20 thread, which is a pitch of 0.05 (one revolution will move the nut 0.05in). To get 0.003in axial play, you can rotate the nut 0.003/0.05=0.06 times which is about 1/16 rotation. With 3 options on the nut and 2 options on the spindle, you should find a nearby position that allows the cotter pin to go through.

Also don't forget to install the tabbed washer that must sit under the spindle nut. The tab keeps the washer from rotating which is important to make sure the nut doesn't try to back off.

[GoodysGotaCuda]

Not sure I am much help here, but my fixed Wilwood front calipers were seeing some decent pad knockback when the spindle was torqued with a beam wrench. My front bearings are quite a bit tighter than they "should" be in order to offset the bad knockback.

I'll trade replacing bearings for braking performance.

[72Z/28]

The way I did it was to use a smaller 3/8 drive torque wrench which I set to 144in-lb (12ft-lb) to tighten the spindle nut, then I rotated the rotor a bit, then re-torqued and repeated a few times to make sure the bearings were fully seated. Then I backed the nut 1/8 turn looking for the nearest cotter pin hole. The goal is to have zero preload on these bearings with minimal axial play. I have seen a spec of 0.003in maximum axial play.

Torquing the nut to 12ft-lb helps establish where the bearing has just slight preload. Then backing off by 1/8turn provides the axial endplay required to ensure it's not overly preloaded when things heat up under use & braking.

A typical GM spindle nut has a 3/4-20 thread, which is a pitch of 0.05 (one revolution will move the nut 0.05in). To get 0.003in axial play, you can rotate the nut 0.003/0.05=0.06 times which is about 1/16 rotation. With 3 options on the nut and 2 options on the spindle, you should find a nearby position that allows the cotter pin to go through.

Also don't forget to install the tabbed washer that must sit under the spindle nut. The tab keeps the washer from rotating which is important to make sure the nut doesn't try to back off.

Thanks for the input. I am using the a small torque wrench as well in in-lbs. i have been the same thing with spinning the rotor and maintaining the torque at 144 inch. Lb.

I did back off the nut 1/8 of a turn but still there was a preload on the bearing.

[CarlC]

I've tried every method and only one offers a consistent preload setting, the Kore3 solid bearing spacer with shims. When properly set up the 0.0015" end play wheel movement is minimized and and bearing life maximized.

1) Install the hub + bearings on to the spindle without grease or the inner seal.

2) Using the provided shims, adjust until an end play of 0.0015" is met.

3) Disassemble and pack the bearings full, internal housing and cap 1/3 - 1/2 full of grease, install the seals, and reassemble using the same shim and spacer pack.

[TheBandit]

I've heard about the solid spacer, but haven't seen much information online. It sounds very similar to using a solid spacer for pinion bearings in a differential (instead of a crush spacer), although in this case it seems no preload is desired (I assume due to the lack of cooling from recirculating gear oil). Out of curiousity Carl, what lead you to using that setup? Were you having issues with wheel bearing life or was this to minimize knock back?

[CarlC]

It was to both minimize caliper piston knockback and to have real control over the bearing preload. The OE turn-of-the-nut method lead to a wide range of variances. By using the solid spacer + shims the nut can be torqued down hard and still maintain the desired 0.0015" end play. Being able to control the preload leads to better bearing life and overall control of the wheel assembly. It works really well with hardly any noticeable wheel movement (grab tire top/bottom and feel for clearance).

The differential crush sleeve is quite different, though some elect to eliminate it in favor of a solid spacer. Setting the preload on tapered roller bearings has to be done very carefully due to the fine line between too much, and not enough, internal clearance and the changes that occur due to thermal deltas. Pinion gear mesh requires firm control over the rolling element surfaces or else excessive wear and noise will occur. Hence, negative clearance preload and oil lubrication. For front wheel TRB's, no gears, and the much more common servicing needs involved, a small range of +IC is fine and will have little affect on overall use for normal driving. Put big sticky tires on the front and beat on the car, it's usually best to try and control the IC.

[TheBandit]

Thanks for the additional info Carl. Do I remember correctly that your day job has something to do with bearings?

[CarlC]

Yep on the bearing gig, but only for the last 28 years ;-)