King pin preload

[jhoag]

So, Im reassembling my front axle and I've got the left side knuckle completed.  I was able to get the preload on the king pin set at 8 lbs before I installed the seals.  On the right side I can only get 5 lbs, and that is with no shims.  The Mechanics manual I have says to get 6-9 lbs, Vernco says to get 12-16 lbs.  My question is, is 5 lbs good enough, if not, how can I increase it without removing anymore shims?

[Doug]

See this page from Novaks. �If all shims are removed and still not sufficient preload, you can add a washer under top bearing cap. �Read paragraph no 5 under reassembly. � �:)

http://www.novak-adapt.com/knowledge/steering_knuckle_repair.htm

The washer would put additional pressure on the bearing and give you sufficient preload. � The addition of the washer on top of the bearing below the cap will in all likelihood result in too much preload. � You will have to then probably add some shims to back off to the proper preload.

Otherwise, if you do not wish to try the washer trick, you would probably have to try a different brand of bearings and races to see if they are thicker.

[jhoag]

Thanks Doug, I was not aware of the info on the Novak site, Im gonna bookmark that one.  A follow up question for anyone, I have now seen it written in one place that suggests 6-9 lbs and two places for 12-16 lbs, which one is right?  The Willys manual I have is the one that says 6-9 but I have heard that there were further revisions from WO, is that where the 12-16 came from?  Secondly, does anybody know what the preload should be after the seals are installed?  I have them installed on one of mine and I am getting about 20 lbs, all I can find written is that it will increase considerably with them installed.  Im sure Im being to matter of fact on this matter, bare with me, this is the first part of my frame off restoration.

Jeremy

[Doug]

I have never seen a spec for the preload after the seal was installed.  I do not think that would be a very practical spec because as soon as the seal broke in the resistance would drop some.  

As to the 8 or 12 lbs preload, this is just a guess.  Someone else may think otherwise but here is my two cents.   Willys changed the way the kingpin were shimmed.  Earlier they shimmed both top and bottom. Then later Willys started installing a spacer on the bottom and all adjustments were then done on top.    The Willys also experienced a lot of problem with willys death wobble which was attributed to worn knuckle bearings.   I assume that early on the spec may have been 8 but then after they had some experience with the civilian jeeps it went to 12.   I would trust that Novaks site.   Those guys have tons of experience with clearances, bearings, adapters, trannys, engine swaps, etc.   I would guess if anyone would know, they would.    

[jhoag]

Thanks again Doug, I tried putting a washer in today but it would not fit.  Im gonna have to see if I can find a thinner one.  I re-torqued the bolts to 40 lbs as stated by Novaks instead of the 30 lbs I had done before and was able to increase the preload to 10 lbs.  If I cannot find a thinner washer I might just call well enough alone, Im above the original spec and below the the new one.

[Doug]

You should be able to find a  pretty thin washer.  But remember, if the washer makes the preload too high, you can then shim the king pin upper cap to lower the preload.       However, truth be know, you are probably close enough if you are in between the two specs.  Although you may wish to make sure both sides are similar or the same.    The whole idea is to get the bearings tight enough so that they do not bounce and gall out.  Once the bearing races gaul out, you then get the wheel shimmy.    

[jamesr]

fRemeber to pay attention to the length of the bolts you use.  If they are to long, they will hit the edge of the bearing. Jim