Alternative, DIY refresh Model X rear camber correction

I was thinking about this over coffee. Anybody who is considering spending $400 for the Macsboost kit could DIY this for next to nothing. I need somebody to confirm the relationship between the spacer thickness and the camber, but I don't have a refresh X. If anybody is in the Bay area I'd be down to shim and measure the camber and toe values so we can share the data freely.

Some notes:
- Another member has already confirmed the $400 shims are off the shelf 2.9mm (approx 1/8").
- Factory hardware appears to be M12

To do this at home you will need four M12 (metric, so the nominal diameter is 12mm) washers, approx thickness of 3mm; 1/8" is a close standard equivalent. A correctly sized washer will work in pinch.

If we can measure the factory arm's flange, I can draw a simple square part that others can customize for their desired thickness, if they want to hit a target alignment. There are plenty of shops that will mill these for you

Quick mock up with a non-standard thickness that I priced through Xometry. I quoted laser cut 6061 below but other materials are available for an additional cost. Grade 5 Titanium will double the price...to a whopping $11.

If you are happy with the alignment from the 1/8" thickness there is no reason to have a spacer machined.

Of course, the cost goes way down with volume and we can do cool things like anodize or powdercoat. There are also other manufacturing options available with volume.

If none of these options speak to you grab some 1/8" stock, a hacksaw, and a drill!

 

[bradthebold]

I'm planning on lowering and it doesn't look like the 3mm shims will be enough. You can get a set of .190" (4.83mm) shims from send cut send for $29. Should these be fine with the stock bolts?

Send cut send is the same price for 10 actually, so you could try 2 sizes for free or they also make a 6.3mm one and it's $4 more to get 12 and have a set in each size of 7075.

Edit: I found a local place that has 50mm 10.9 M12 yellow zinc bolts for $1.73, so I'll probably try those if they're in stock and the 4.83mm shims.

 

[towndrunk]

I'm planning on lowering and it doesn't look like the 3mm shims will be enough. You can get a set of .190" (4.83mm) shims from send cut send for $29. Should these be fine with the stock bolts?

Send cut send is the same price for 10 actually, so you could try 2 sizes for free or they also make a 6.3mm one and it's $4 more to get 12 and have a set in each size of 7075.

Edit: I found a local place that has 50mm 10.9 M12 yellow zinc bolts for $1.73, so I'll probably try those if they're in stock and the 4.83mm shims.

If the 3 mm shims need longer bolts, I would think the 4.8 mm definitely will.

 

[bradthebold]

If the 3 mm shims need longer bolts, I would think the 4.8 mm definitely will.

It seems like the consensus is the 3mm don't, but the 6mm do, so these are something in the middle. I think I read with the 3mm shim there was still like 6 threads of engagement. If I had to order them it would just be inconvenient, but If I can just go pick some up for $7 I will do that. 50mm bolts should put 4.8mm shims <1mm shorter than stock.

 

[towndrunk]

It seems like the consensus is the 3mm don't, but the 6mm do, so these are something in the middle. I think I read with the 3mm shim there was still like 6 threads of engagement. If I had to order them it would just be inconvenient, but If I can just go pick some up for $7 I will do that. 50mm bolts should put 4.8mm shims <1mm shorter than stock.

I bought the 3 mm shim kit from Thadeus Strong on FB and they came with longer bolts.

 

[Tiger]

It seems like the consensus is the 3mm don't, but the 6mm do, so these are something in the middle. I think I read with the 3mm shim there was still like 6 threads of engagement. If I had to order them it would just be inconvenient, but If I can just go pick some up for $7 I will do that. 50mm bolts should put 4.8mm shims <1mm shorter than stock.

Does it requre special spec bolts or simply sufficient torque-spec aluminium compatible bolts from local hardware store?

 

[ngng]

Does it requre special spec bolts or simply sufficient torque-spec aluminium compatible bolts from local hardware store?

you want the correct grade hardware

 

[Tiger]

you want the correct grade hardware

Sure. What are the specs to order that off shelf for these circumstances?

 

[ngng]

Sure. What are the specs to order that off shelf for these circumstances?

no idea, the facebook guy is including 10.9 bolts, but you'd want to verify because you don't want to be guessing

 

[Tiger]

no idea, the facebook guy is including 10.9 bolts, but you'd want to verify because you don't want to be guessing

How wrong can you go if material is compatbile and strength is sufficient (matching torque spec), what other criteria are there in "bolt order book(s)"?

 

[ngng]

How wrong can you go if material is compatbile and strength is sufficient (matching torque spec)?

catastrophic. if the bolt shears your suspension will not be attached to your subframe. you don't have to worry about material "compatibility". it's going to be a high grade bolt into aluminum. torque is dictated by the fastener.

 

[Tiger]

catastrophic. if the bolt shears your suspension will not be attached to your subframe. you don't have to worry about material "compatibility". it's going to be a high grade bolt into aluminum. torque is dictated by the fastener.

Yes, but what bolt spec guarantees sufficient shear rigidity for suspension use so I can ask for that? Chatgpt answer:

In the automotive industry bolts for suspension components need to meet standards of safety and performance, e.g., SAE J429 which defines requirements for threaded fasteners.

Grade 8 bolts are made of medium carbon alloy steel to provide high 150,000 psi tensile strength and greater hardness. They are commonly used in critical applications such as suspension components.

They are typically marked with six radial lines on the head for easy identification.

 

[bradthebold]

Yes, but what bolt spec guarantees sufficient shear rigidity for suspension use so I can ask for that? Chatgpt answer:

In the automotive industry bolts for suspension components need to meet standards of safety and performance, e.g., SAE J429 which defines requirements for threaded fasteners.

Grade 8 bolts are made of medium carbon alloy steel to provide high 150,000 psi tensile strength and greater hardness. They are commonly used in critical applications such as suspension components.

They are typically marked with six radial lines on the head for easy identification.

It's just a bolt. It's not torque to yield, other's have said it's 10.9, it's nothing special. Search for the torque of an M12 bolt. A grade 10.9 bolt can be torqued to 105ft lbs and this is only being torqued to 63 ft lbs. I was more worried about less thread engagement.

 

[ShawnA]

Hi All,

WRONG.
A bolt is not just a bolt…
Standard of the shelf hardware store bolts are usually Grade 5.
In the Tesla part number description the 10.9 indicates the grade of the bolts.
They are special.

The proper torque spec. is 80 ft/lbs.

Six threads of engagement is pitiful for what these bolts need to do…

Trust your life to Chatgpt - Good luck with that.

Shawn

 

[ngng]

It's just a bolt. It's not torque to yield, other's have said it's 10.9, it's nothing special. Search for the torque of an M12 bolt. A grade 10.9 bolt can be torqued to 105ft lbs and this is only being torqued to 63 ft lbs. I was more worried about less thread engagement.

you are confusing the class with the torque value. the class is going to have a tensile strength. the cross section of the bolt will ultimately determine the yield.

Hi All,

WRONG.
A bolt is not just a bolt…
Standard of the shelf hardware store bolts are usually Grade 5.
In the Tesla part number description the 10.9 indicates the grade of the bolts.
They are special.

The proper torque spec. is 80 ft/lbs.

Six threads of engagement is pitiful for what these bolts need to do…

Trust your life to Chatgpt - Good luck with that.

Shawn

the proper torque is 63 (62.7) ft lbs, not 80.

i agree with you re: chatgpt.

i hesitate to people asking about what grade hardware because i don't want to be responsible if somebody sees 10.9 but orders something else.

 

[Tiger]

i agree with you re: chatgpt.

i hesitate to people asking about what grade hardware because i don't want to be responsible if somebody sees 10.9 but orders something else.

https://twitter.com/x/status/1734615940648579248

Thanks y'all.

 

[bradthebold]

you are confusing the class with the torque value. the class is going to have a tensile strength. the cross section of the bolt will ultimately determine the yield.



the proper torque is 63 (62.7) ft lbs, not 80.

i agree with you re: chatgpt.

i hesitate to people asking about what grade hardware because i don't want to be responsible if somebody sees 10.9 but orders something else.

It definitely is an M12 bolt, so the cross section is the same no matter what.

If we're at least trusting whatever other vendors are sending, then it's class 10.9 which has much higher tensile strength than the off the shelf grade 5 bolt, but a class 10.9 bolt is not special. A torque to yield bolt or some cryotreated bolt that you can't get from a hardware store is what I would consider 'special'.

6 threads seems like the rule of thumb for enough, but isn't that the result of this whole thread? Your 3mm spacer with the stock bolt leaves 6 threads of engagement? (I might be wrong, I've been reading a lot of threads, something said 6 threads somewhere) Or at the very least, leaves 3mm less thread engagement than there was. Otherwise the whole argument should be tesla used just enough thread so any spacer is a dumb idea. And if you try to make the bolt longer for the spacer, that's a dumb idea because you don't know what the bolt is.

I'm definitely not some bolt expert, but it looks like a class 10.9 bolt that's torqued to nowhere near its limit, so it seems easy to replace with a longer bolt.

The shear strength for a M12 class 10.9 bolt (that does appear to increase with class) looks like 34-50kN or 7,600-11,200 pounds of force. Times 2 of them. I think if you break them you'll have other issues.

I may be wrong though, which is why discussion here is good, it just seems like a simple thing.

 

[Tiger]

It definitely is an M12 bolt, so the cross section is the same no matter what.

If we're at least trusting whatever other vendors are sending, then it's class 10.9 which has much higher tensile strength than the off the shelf grade 5 bolt, but a class 10.9 bolt is not special. A torque to yield bolt or some cryotreated bolt that you can't get from a hardware store is what I would consider 'special'.

6 threads seems like the rule of thumb for enough, but isn't that the result of this whole thread? Your 3mm spacer with the stock bolt leaves 6 threads of engagement? (I might be wrong, I've been reading a lot of threads, something said 6 threads somewhere) Or at the very least, leaves 3mm less thread engagement than there was. Otherwise the whole argument should be tesla used just enough thread so any spacer is a dumb idea. And if you try to make the bolt longer for the spacer, that's a dumb idea because you don't know what the bolt is.

I'm definitely not some bolt expert, but it looks like a class 10.9 bolt that's torqued to nowhere near its limit, so it seems easy to replace with a longer bolt.

The shear strength for a M12 class 10.9 bolt (that does appear to increase with class) looks like 34-50kN or 7,600-11,200 pounds of force. Times 2 of them. I think if you break them you'll have other issues.

I may be wrong though, which is why discussion here is good, it just seems like a simple thing.

How about if I were to trim a new 10.9 bolt to suitable length using a angle grinder, would the dissipated heat (treatment) spoil it? I'm thinking if I add a spacer I would insert a replacement bolt somewhat that much taller than the original bolt.

 

[bradthebold]

How about if I were to trim a new 10.9 bolt to suitable length using a angle grinder, would the dissipated heat (treatment) spoil it? I'm thinking if I add a spacer I would insert a replacement bolt somewhat that much taller than the original bolt.

That sounds more questionable. I would guess it would be fine, but a band saw would probably be better. I would definitely just get a shorter bolt though.

 

[Tiger]

That sounds more questionable. I would guess it would be fine, but a band saw would probably be better. I would definitely just get a shorter bolt though.

Yeah. Depends on what the availability is, hand saw makes sense but does make the cost of time invested higher

Does anyone have a picture of whta the car looks like on the 3mm and 6mm spacers? Even better if pictures at medium ride and low ride (the available default heights (is other than low even available automatically at any normal speeds?))?

 

[ngng]

Yeah. Depends on what the availability is, hand saw makes sense but does make the cost of time invested higher

Does anyone have a picture of whta the car looks like on the 3mm and 6mm spacers? Even better if pictures at medium ride and low ride (the available default heights (is other than low even available automatically at any normal speeds?))?

You can order the correct hardware from McMaster.