Alignment Cam Seize Alternative Solution

[Jetboy]

I'm thinking about an alternative option for the common problem of seized cam bolts on the lower control arms. The most typical "fix" is to cut out the lower control arm bushings and then replace all the parts with new. I've been kicking this around in my head and with my experience with the 4Runner and my Tundra.

I don't think there is a need to actually remove or even cause the sleeve to spin. It can stay seized. What we want is to be able to adjust the location of the lower control arm vs the mounting tab. And that does not require the cam to spin. It DOES require the cam to rotate if you have to keep the cam plate (the out of round washer part of the sleeve on the front or bolt on the rear) attached to the sleeve and stay within the cam tabs.

What I did on my 4Runner was simply hammer flat the tab that the cam adjusts against and when you loosen the cam bolt you can still adjust alignment, but you have to do it with a combination of prybars. No need to cut out the lower bushings to get a proper alignment.

The next solution I've been thinking about is why not separate the sleeve from the cam plate? Basically figure out a way to cut them apart to leave the cam sleeve seized in the bushing. Adjustment will be done by adding a new cam ring. It could be done a few ways. The first would be a center drill that would drill out the cam/sleeve centered with a roughly 14mm bit and remove it on the fixed side - on the back side the cam plate ring is just a small tooth key that can easily be removed to spin freely independent of the cam sleeve.

That's how I did it on my 4Runner - I just spun the tooth off the back side and hammered flat the cam tabs on the front side and you could align it without all the effort of cutting it all apart. But I'd rather remove the front cam plate instead of flattening the tabs.

The second thought I've had is to use an annular cutter to leave the front of the seized sleeve in plate but cut it into a nicely machined cylinder and then drop an off-center drilled washer over it to make a new cam plate. Probably just use an OEM one that fits.

Finally - I don't think that the cam tabs should play a meaningful role in fixing the location of the alignment. The friction between the bushing outer plate and the lower control arm mounting bracket should do that function. It's the clamping force that should hold it in place, not a physical barrier of the cam plate against the cam taps. As long as you can locate the lower control arm bushing within its range of motion in the mounting bracket, you should be able to fully clamp it down and have a good alignment that doesn't shift. If it's shifting after clamping - it's a problem with too little clamping force applied by the through bolt or something causing the teeth of the LCA bushing not to engage properly into the surface of the mounting bracket.

If you use poly bushings - you've thrown out the primary source of force locating the front control arms and probably need a different solution. Instead of using the friction between the bracket and the bushing you're relying on the sheer strength of through bolt and some physical keying to keep that in place. Those are two very different mechanisms and this would primarily be for the OEM bushing location mechanism. Not for poly bushing locating.

Just a thought I've been kicking around as I think I probably need an alignment on my Tundra soon at 100k miles and I'm pretty sure they'll be seized. I'm leaning toward the annular cutter, but I need to first verify that they're actually seized first.

 

[jdm-v35]

I would think if clamping force alone was enough to keep it in place, they should not get bent. I ran a curb in the snow and it was enough to bend the tab. I bent it back and got another alignment. I have the marlin crawler reinforcement kit but I did not put it on yet.

The proper way to redo it it would be remove cam tabs, put cam lockout plates in with regular bolts to keep them locked in one spot, then use control arms with adjustable rod ends. besides that I don't see any reliable way to hold and alignment.

 

[slide531]

Having just cut my LCAs out yesterday (needed replacement due to bad bushings and ball joint) I think my alternative solution, if I ever get another new 4runner, will be to pull the cam sleeves out while still relatively new and put some anti-seize on them.

 

[Jetboy]

I would think if clamping force alone was enough to keep it in place, they should not get bent. I ran a curb in the snow and it was enough to bend the tab. I bent it back and got another alignment. I have the marlin crawler reinforcement kit but I did not put it on yet.

The proper way to redo it it would be remove cam tabs, put cam lockout plates in with regular bolts to keep them locked in one spot, then use control arms with adjustable rod ends. besides that I don't see any reliable way to hold and alignment.

The design isn't robust to impacts. No argument about that. It's not intended to take impacts there and they do get bent up. I think the Marlin reinforcement is a great option for that concern. I don't think it is useful for holding the alignment when using OEM bushings. It may even make it marginally worse.

For the OEM design I'm pretty confident that it is purely engineered for tension and compression loads on the bracket, not for any sort of impact. And that the friction and mechanical keying of the teeth of the bushing created by clamping force is the how it is engineered by the Toyota engineers to hold it in place. If they intended to have the cam plate ring hold it in place due to the physical barrier of the small sheet metal tabs - it would look a lot different. I don't think any engineer would put any meaningful value on those tabs for the function of holding the alignment in spec. The only design function of those cam tabs is to be used during alignment to allow for easy controllable adjustment of the alignment. They were never meant to hold it in place.

I do agree that you could re-engineer the design to locate the through bolt as the primary locating mechanism and heavily reinforce the contact points to take the loading on the through bolt. There are other components that are engineered to transfer the load through the through bolt vs use it for its clamping force although it's a rare way to engineer a connection point for an OEM because it tends to be heavier and less durable.

I'm just looking at a way to stick with the OEM engineering principles without having to cut out the LCAs when the only real goal is to adjust their alignment in stock format.

 

[jdm-v35]

The design isn't robust to impacts. No argument about that. It's not intended to take impacts there and they do get bent up. I think the Marlin reinforcement is a great option for that concern. I don't think it is useful for holding the alignment when using OEM bushings. It may even make it marginally worse.

For the OEM design I'm pretty confident that it is purely engineered for tension and compression loads on the bracket, not for any sort of impact. And that the friction and mechanical keying of the teeth of the bushing created by clamping force is the how it is engineered by the Toyota engineers to hold it in place. If they intended to have the cam plate ring hold it in place due to the physical barrier of the small sheet metal tabs - it would look a lot different. I don't think any engineer would put any meaningful value on those tabs for the function of holding the alignment in spec. The only design function of those cam tabs is to be used during alignment to allow for easy controllable adjustment of the alignment. They were never meant to hold it in place.

I do agree that you could re-engineer the design to locate the through bolt as the primary locating mechanism and heavily reinforce the contact points to take the loading on the through bolt. There are other components that are engineered to transfer the load through the through bolt vs use it for its clamping force although it's a rare way to engineer a connection point for an OEM because it tends to be heavier and less durable.

I'm just looking at a way to stick with the OEM engineering principles without having to cut out the LCAs when the only real goal is to adjust their alignment in stock format.

I think the easiest/only way is to cut them out if they are bad and during replacement, liberally apply marine grade anti-seize.

 

[Jetboy]

Having just cut my LCAs out yesterday (needed replacement due to bad bushings and ball joint) I think my alternative solution, if I ever get another new 4runner, will be to pull the cam sleeves out while still relatively new and put some anti-seize on them.

I think that's a good idea. I'm not sure exactly what would be the best solution for it a far as an anti-seize product. I don't know what anti-corrosion product Toyota uses for those parts. Something is mismatched chemically though causing the rapid corrosion and has been for a long time.

I've considered whether it might make sense to fully coat the bushing in grease instead, or maybe even in some form of anerobic sealant like loctite purple that is easy to break free, but provides a full seal out of oxygen and water. Just not getting anything lubricating on the bushing mounting surface. That's where it needs max friction and you don't want it lubricated.

I've also thought about whether it might make sense to drill some relief holes in the bushing. Maybe 5 or so 1/8" dia holes all the way through down the barrel of the bushing. That way if it was seized in you could remove the through bolt and fill the bushing with a penetrating oil that could flow through those holes into the area where it seizes a lot. I think it's an issue with aluminized hardware in contact with zinc coated steel.

It's pretty frustrating that it's such a PITA to fix something that doesn't need to be a problem with better corrosion protection.

 

[jdm-v35]

I think that's a good idea. I'm not sure exactly what would be the best solution for it a far as an anti-seize product. I don't know what anti-corrosion product Toyota uses for those parts. Something is mismatched chemically though causing the rapid corrosion and has been for a long time.

I've considered whether it might make sense to fully coat the bushing in grease instead, or maybe even in some form of anerobic sealant like loctite purple that is easy to break free, but provides a full seal out of oxygen and water. Just not getting anything lubricating on the bushing mounting surface. That's where it needs max friction and you don't want it lubricated.

I've also thought about whether it might make sense to drill some relief holes in the bushing. Maybe 5 or so 1/8" dia holes all the way through down the barrel of the bushing. That way if it was seized in you could remove the through bolt and fill the bushing with a penetrating oil that could flow through those holes into the area where it seizes a lot. I think it's an issue with aluminized hardware in contact with zinc coated steel.

It's pretty frustrating that it's such a PITA to fix something that doesn't need to be a problem with better corrosion protection.

I dont think they use any antiseize product, and the combination of the steel bolts/frame and aluminum bushing sleeves/inserts cause it to seize up.

 

[Jetboy]

I dont think they use any antiseize product, and the combination of the steel bolts/frame and aluminum bushing sleeves/inserts cause it to seize up.

No. But as a mfg they shouldn't have to. They should have material science experts and software that checks every component combination to verify the galvanic imbalance and in places with issues, they should fix them by specs on the corrosion resistance of the components. It's not Toyota's first time building cars. Toyota should fix the issue with proper hardware coatings so we don't have to put anti-seize on.

I think it's pretty important to understand the issue because copper based anti-seize in this case may accelerate the corrosion rather than reduce it. There's a lot going on between the aluminized anti-corrosion coating on the cam sleeve and the zinc coating on the bushing. Maybe a non-metalic anti-seize like LOCTITE 567 would be best. I don't know what the best anti-sieze to use is. Only that I've generally seen rapidly increased corrosion with copper anti-seize on aluminized OEM hardware on Toyotas.

These were only 4 years old OEM hardware from my 4Runner in a dry climate. I suspect copper anti-seize i used played a significant role in why they deteriorated so quickly. It might just be really crappy metallurgy of the fasteners. I don't know. Wish I had more expertise in this and the testing equipment to do some useful A/B testing to compare outcomes.

 

[jdm-v35]

I don't use the normal copper stuff. I only use this; Amazon.com

 

[El Dusty]

These were only 4 years old OEM hardware from my 4Runner in a dry climate. I suspect copper anti-seize i used played a significant role in why they deteriorated so quickly. It might just be really crappy metallurgy of the fasteners. I don't know. Wish I had more expertise in this and the testing equipment to do some useful A/B testing to compare outcomes.

See the photo attached for your rule of thumb on fasteners to base metal reactivity.

Galvanic Reaction Chart - All Points Fasteners

Im not metallurgist but from my experience in structural fasteners I have never seen copper anti-seize used on zinc or galvd parts. We see a lot of stainless cotter pins rust to shit paired with galvanized base metal, C scenario. Your picture is likely pushing the D & E reactions where the plating of the fastener deteriorates pretty quickly, leaving a fully rusted POS.

 

[Jetboy]

I almost only use Loctite purple now for fasteners that don't need a higher grade of loctite 222. I find that sealing threads has been almost foolproof vs anti seize. It doesn't have the issues with torque adjustment from the lubrication, is cleaner, and I haven't found any issues with any fastener type or material. I'm sure there are plenty of other options, but it's my go to for threaded fasteners.