Help - positive camber (1 Viewer)

[juaclark]

OK, so I've looked long and hard and cannot find anything definitive on this subject.

My FJZ80 seems to have positive camber.

Both front tires have worn at an angle starting with very little wear on the inside and increasing to almost worn out on the outer edge.

Pretty darn frustrating given they only have about 20k on them and they are 315 Cooper ST's that were definitely not cheap. I have let them go for the past 10-12k with no rotation, because I didn't want to also wear out the other two tires.

Since she was due an axle rebuild anyway, I was hoping to find some reason for this as I got into it - like shot trunnion bearings or something, but everything still looks pretty darn good from the last rebuild about 70k miles ago (I did this about 10 years ago when I bought it). The bearings and races show very little wear - trunnion or wheel.

When I took a very rough measurement of the tires with everything on the ground I was seeing close to 1 degree positive (top of tire tilted out), but it was a very rough measurement and I could have been seeing what I expected to see.

When I got down to the just the knuckles left on the axle housing, I measured the face of the knuckles and got about 0.5-0.7 degrees positive on each side of the truck. I placed the angle finder on both the rear and the front edge of each knuckle to confirm. I could affect this reading by rotating the knuckle left or right, but these measurements were taken with the knuckles pointing basically straight ahead, or as close to zero toe as I could eyeball. Either side of this position was still a positive camber.

The truck is lifted about 3" in the front and caster corrected with Slee plates to about +4 degrees. This was confirmed by the alignment shop when I last took it in (about 3 years ago after I put the plates on) and by a simple measurement across the two upper kingpin (trunnion bearing plate) bolts below:

I cannot tell if I am I really seeing what I think I am seeing? Should I be trying to correct this via adjustable trunnion bearings, or is there something else going on here? Or is it all in my head and I just need to rebuild it and rotate my tires way more often? Has anyone else seen this? Could this just be due to a bad toe in or toe out? I have to admit that I didn't have an alignment or check it myself since these tires were installed - and I am kicking myself for that now...

By the way, I quickly test fit new trunnion bearings and measured again - same answer - apparent positive camber.

Thanks for any help!!

 

[jfz80]

Toe in would cause similar outside wear too it seems. You can clamp a straight edge to each knuckle face and measure as far out as possible in front and compare to same distance behind the knuckle to get an idea of toe and adj from there if needed.

 

[juaclark]

yeah - I realize that (now), but I failed to measure before disassembly and whatever the toe was, I won't be able to measure it now, as I'm replacing all the tie rod ends and the links have been pulled from the truck and disassembled.

I will be using this method to set the toe with the new parts installed.

Still interested to know if anyone else has measured the flange surface of the knuckle before. Should it be closer to 90 degrees, or is closer to 91 still OK?

 

[satchel]

Not sure I saw in your post but what did you zero the angle finder out on? For camber I don't guess I know what your zero measurement would be, somewhere on the axle housing maybe? Anyway, just curious what that 90.7 and 90.5 measurement is based on. If it's the floor, meaning zero is the floor, then I wouldn't trust that measurement as it would be off depending on how you lifted the truck up, and most floors are not completely flat anyway especially over the entire surface the truck is sitting on.

 

[juaclark]

The measurements are relative to true horizontal, so 90 is true vertical. The angle finder was calibrated at a true zero Horizontal using an accurate bubble level. The flange surface of the knuckle is what the spindle bolts to, so it dictates the angle of of the spindle. The axle is suspended on jack stands that are set on an even floor and raised to the same level. They may be sitting a little higher than normal, but not much. If the axle was tilted (and therefore causing the measurement to be something other than 90), then I should expect the opposite knuckle to indicate negative or something smaller, but it doesn’t. It also measures 90.6 degrees +/- 0.1 degree.

 

[satchel]

Understood, sounds like you got it zeroed true then. My thought was that, let's say one jack is slightly higher than the other, your whole axle, knuckles and all, would be tilted away from true zero even though nothing on the actual axle would be off, would be the jack causing it, but sounds like you have everything perfectly level and zeroed so I'll shut up .

 

[UTkruzer]

Maybe spindle/axle flex under load will negate that 0.5 degrees.

 

[satchel]

Most people tend to show 0 on camber when getting an alignment but the spec is something like .3 - 1.8 degrees positive camber each so if it eases your mind any, I believe you are right on for what Mr. T wants.

 

[juaclark]

Most people tend to show 0 on camber when getting an alignment but the spec is something like .3 - 1.8 degrees positive camber each so if it eases your mind any, I believe you are right on for what Mr. T wants.

That does ease my mind. Maybe I should put her back together and focus more on making sure the toe is really set right.

 

[juaclark]

Maybe spindle/axle flex under load will negate that 0.5 degrees.

Not exactly sure I agree with that. At least not normally loaded rolling down the road. I have the axle supported nearly at the ends, so there isn’t much length to bend from there and that would be a fair amount of flex - but maybe.

 

[lumbee1]

To reduce the wear on the outer edge and fix your camber, you could install offset trunion bearings.

Cruiser Outfitters

Cruiser Outfitters

Caster/Camber Adjusting Front Axle Knuckle Bearing Sets
2 sets per axle, Koyo Bearings. These unique bearing/race combos allow caster and camber adjustments without expensive axle modifications and repairs. Can be used to improve caster without decreasing pinion angle. Can also be used to reduce interference issues with tie rod on the 80 Series while increasing caster following a suspension install.

Early - 1990 4x/5x/6x/7x Axle Applications:
Part# FA88901 - 1.2* Caster/Camber Adjustment - $97.50
Part# FA88902 - 1.5* Caster/Camber Adjustment - $97.50
Part# FA88903 - 1.8* Caster/Camber Adjustment - $82.50
Part# FA88904 - 2.2* Caster/Camber Adjustment - $82.50

1/1990-1997 80 Series Applications:
Part# FA88915 - 1.0* Caster/Camber Adjustment - $112.50
Part# FA88920 - 3.0* Caster/Camber Adjustment - $112.50

Note: Caster/Camber adjusting bearings are sold as a pair, including two bearings and two corresponding races. You must order two pairs for a complete axle retrofit.

 

[juaclark]

To reduce the wear on the outer edge and fix your camber, you could install offset trunion bearings.

Cruiser Outfitters

Cruiser Outfitters

Caster/Camber Adjusting Front Axle Knuckle Bearing Sets
2 sets per axle, Koyo Bearings. These unique bearing/race combos allow caster and camber adjustments without expensive axle modifications and repairs. Can be used to improve caster without decreasing pinion angle. Can also be used to reduce interference issues with tie rod on the 80 Series while increasing caster following a suspension install.

Early - 1990 4x/5x/6x/7x Axle Applications:
Part# FA88901 - 1.2* Caster/Camber Adjustment - $97.50
Part# FA88902 - 1.5* Caster/Camber Adjustment - $97.50
Part# FA88903 - 1.8* Caster/Camber Adjustment - $82.50
Part# FA88904 - 2.2* Caster/Camber Adjustment - $82.50

1/1990-1997 80 Series Applications:
Part# FA88915 - 1.0* Caster/Camber Adjustment - $112.50
Part# FA88920 - 3.0* Caster/Camber Adjustment - $112.50

Note: Caster/Camber adjusting bearings are sold as a pair, including two bearings and two corresponding races. You must order two pairs for a complete axle retrofit.

Thanks. Yes, I’ve been looking these and trying to determine if they are warranted. That’s why I am asking about the camber measurements I am seeing. If I install the smallest of them oriented for camber gain, I will end up with a net negative camber on each side, which might be just as bad. If I rotate them part way between camber and caster, I will have more positive caster than recommended - not sure if that’s bad or not. Either way, I’d be stuck using these special bearings forever - meaning I’d have to buy a new set of these at each axle rebuild, right? And I’d probably need to get the Toyota SST (or make my own which is difficult without a machine shop) for centering the knuckle since they aren’t standard bearings. That’s another big investment and a pain I’d like to avoid if I can. Am I wrong about that?
Maybe they are still the right way to go though.
Anybody else have any thought on that? Has anyone ever used these for camber correction? I can’t find a single thread on that.

 

[satchel]

I had them installed on one of my knuckles to get them to basically where you are saying you are currently (wanted positive camber cause of a pull). Not a big deal to go a little over on caster to get camber wherever you are wanting, a lot of people like the feel of more caster than stock once the tires get bigger anyway. If I were in your shoes I wouldn't mess with it.

 

[juaclark]

I had them installed on one of my knuckles to get them to basically where you are saying you are currently (wanted positive camber cause of a pull). Not a big deal to go a little over on caster to get camber wherever you are wanting, a lot of people like the feel of more caster than stock once the tires get bigger anyway. If I were in your shoes I wouldn't mess with it.

I think I’ll abide by that and move on then. Thanks Satchel.