Rear Spherical Bearings Conversion on Stock Arms

mariusc wrote

The very same thing happened to me today, when throwing the car into a corner at a race track. Bolt snapped.

I recommend that everyone that has installed the McGill washers replace these with something more suitable ASAP.

Damn. I'm sorry to hear that. I've removed references to the McGill washers in the first post.

mariusc wrote

The very same thing happened to me today, when throwing the car into a corner at a race track. Bolt snapped.

I recommend that everyone that has installed the McGill washers replace these with something more suitable ASAP.

That's a bummer. I'm hopeful that the car is alright otherwise? Which arm let go on you?

CHSe92 wrote

That's a bummer. I'm hopeful that the car is alright otherwise? Which arm let go on you?

The car is fine. Rear left wheel rubbed trough the liner in front of the tire. The bolt that broke was the one for the most forward of the two arms, which means the tire would turn left and right when under braking or under power. It felt like a much more expensive damage when it occured.

So there have now been a few failures on the McGill washers but everyone using the original machined ones have been fine?

Looking at the McGill I wouldn't be surprised if that shoulder on the washer is bottoming out on the knuckle before the washer is getting fully seated. You wouldn't know this tightening down and everything I'm sure feels plenty sturdy just bolted up.

"Looking at the McGill I wouldn't be surprised if that shoulder on the washer is bottoming out on the knuckle before the washer is getting fully seated."

I think that's exactly what happened. It never felt completely seated into the cup on the knuckle even holding it there by hand. I just (incorrectly) assumed once torqued down it would clamp down properly

I’m sure that’s the reason. It probably won’t help removing the outer shoulder, except if the angle on the washer itself would be 100% perfect.

So, do anyone have those purpose engineered washers available right now?

mariusc wrote

So, do anyone have those purpose engineered washers available right now?

I think cchen9_ made up a few sets locally in the US. Not sure if he still has any available or not.

mariusc wrote

I’m sure that’s the reason. It probably won’t help removing the outer shoulder, except if the angle on the washer itself would be 100% perfect.

So, do anyone have those purpose engineered washers available right now?

I have a set laying around along with arms and bearing if you're interested.

Hi folks,

I've produced a batch of tapered spacers today as the user ericliew on m3cutters, amongst a few others, mentioned the failures due to using the McGill spacers.
Not to mention due to this guide (and it's cutters counterpart) I needed a set myself as I'm converting to spherical bearings on my own car!

I have 12 sets ready to go out.
Made from 304 stainless on my CNC lathe.

I'm asking £20 delivered in the UK, and £24 delivered worldwide. (Per set of 4)

Best wishes to you all!
Mike

Hi Mike! I'm ericliew on Cutters. Thanks for offering this here. You can ignore my PM in your inbox.

Hey Redd!

For anybody on here that's trying to get in touch, as I only signed up to m3post yesterday I don't have the PM function for another 6 days or so.
You can reach me by email to ow_dont_pull_that@hotmail.com

Thanks!

I had a bolt snap on the right rear with the purpose made washers, not the McGill.

The other 3 bolts that hadn't snapped in the rear were loose.

It destroyed a rear axle which was $$$ to get replaced, and could have sent me into a wall if that control arm had let go on a different part of the track.

I wouldn't push ahead assuming the fault of this mod is only with the mcgill washers.

If spherical bushings in the rear are a must, run them everywhere the conical washers aren't needed and use the SPL arms to replace both upper control arms. The SPL setup is an added expense up front but the failure rate of this washer hack is too high to be worth it.

leftfootbr8king wrote

I had a bolt snap on the right rear with the purpose made washers, not the McGill.

The other 3 bolts that hadn't snapped in the rear were loose.

It destroyed a rear axle which was $$$ to get replaced, and could have sent me into a wall if that control arm had let go on a different part of the track.

I wouldn't push ahead assuming the fault of this mod is only with the mcgill washers.

If spherical bushings in the rear are a must, run them everywhere the conical washers aren't needed and use the SPL arms to replace both upper control arms. The SPL setup is an added expense up front but the failure rate of this washer hack is too high to be worth it.

Do you have any photos of the snapped bolt?
I'm interested to see the failure mode.

The other three being loose is perhaps indicative of incorrect fitment - they'll certainly snap eventually if they're not tightened up as the bearings will be free to move around and bend the bolt side to side.

spikenipple wrote

leftfootbr8king wrote

I had a bolt snap on the right rear with the purpose made washers, not the McGill.

The other 3 bolts that hadn't snapped in the rear were loose.

It destroyed a rear axle which was $$$ to get replaced, and could have sent me into a wall if that control arm had let go on a different part of the track.

I wouldn't push ahead assuming the fault of this mod is only with the mcgill washers.

If spherical bushings in the rear are a must, run them everywhere the conical washers aren't needed and use the SPL arms to replace both upper control arms. The SPL setup is an added expense up front but the failure rate of this washer hack is too high to be worth it.

Do you have any photos of the snapped bolt?
I'm interested to see the failure mode.

The other three being loose is perhaps indicative of incorrect fitment - they'll certainly snap eventually if they're not tightened up as the bearings will be free to move around and bend the bolt side to side.

This is what I have for pics from last fall. The rest of what I have is video.

I didn't do the install on these since the car was in for rear subframe bushings anyway. Work was done by a reputable race shop. Not saying they couldn't have messed the install up but 3 reported failures, 3 different shops in a just a few months. The consequences of failure are not insignificant.

Fwiw: BFG R1, Moton CS 2WR, big brakes, etc. The car was getting pushed pretty hard and made it through 1.5 days around VIR before letting go, so if you're into hard parking on street tires this washer hack might suit you just fine.

I've reached out to vtl, the guy who designed this mod, to see if he knows anything about this failure. Will update when I get more info.

Below are replies from vtl.
Some friends had sent me some links to forum threads where people had not followed the original design and subsituted their own variations of washers. In some cases looked completely wrong where the face of the washer wouldn't have proper contact with the coned face of the knuckle. The washer design while looking simple was actually very specific to allow proper contact to the face.

Yes locally we did have an instance of a snapped bolt and a couple cases of the bolts backing out. In my experience the bolts to the knuckle with the washers are prone backing out if they were not torqued up correctly. The factory spec is actually 100Nm + 90. I have found anything less than 100Nm (with no angle) will result in loose bolts (once its loose theres movement and youll get a snapped bolt). I do not beleive it is related to the thread engagement of the bolt, as the engagement with the knuckle is well over 1x the diameter (12mm)

I really dont like doing torque angles as the bolts have to be replaced every time. I personally put on 100Nm with no angle on my car and have not had any issues. Ideally I would like to simply use a higher static torque, but I have found a lot of times the bolt to the knuckle will simply not allow you to torque it up to a higher torque like 120nm (the bolt just stretches). Have personally installed these monoballs on i think around 7-8 cars and have not had issues if everything was torqued up correctly with a digital torque wrench. These days I just do 100Nm with loctite.

My own car is running fine with the upgrade and have taken it on interstate drives on fast tight roads and multiple track days (on 200TW tyres though, not slicks).

When I originally did the mod, custom washers were a last resort. I had a quick look at the mcgill washers but the face was simply wrong being a high misalignment washer and would not give proper contact (and be quite dangerous if used).

Redd wrote

Below are replies from vtl.
Some friends had sent me some links to forum threads where people had not followed the original design and subsituted their own variations of washers. In some cases looked completely wrong where the face of the washer wouldn't have proper contact with the coned face of the knuckle. The washer design while looking simple was actually very specific to allow proper contact to the face.

Yes locally we did have an instance of a snapped bolt and a couple cases of the bolts backing out. In my experience the bolts to the knuckle with the washers are prone backing out if they were not torqued up correctly. The factory spec is actually 100Nm + 90. I have found anything less than 100Nm (with no angle) will result in loose bolts (once its loose theres movement and youll get a snapped bolt). I do not beleive it is related to the thread engagement of the bolt, as the engagement with the knuckle is well over 1x the diameter (12mm)

I really dont like doing torque angles as the bolts have to be replaced every time. I personally put on 100Nm with no angle on my car and have not had any issues. Ideally I would like to simply use a higher static torque, but I have found a lot of times the bolt to the knuckle will simply not allow you to torque it up to a higher torque like 120nm (the bolt just stretches). Have personally installed these monoballs on i think around 7-8 cars and have not had issues if everything was torqued up correctly with a digital torque wrench. These days I just do 100Nm with loctite.

My own car is running fine with the upgrade and have taken it on interstate drives on fast tight roads and multiple track days (on 200TW tyres though, not slicks).

When I originally did the mod, custom washers were a last resort. I had a quick look at the mcgill washers but the face was simply wrong being a high misalignment washer and would not give proper contact (and be quite dangerous if used).

I'm confused why folks don't torque to yield when instructed just to save a few bucks? Especially in track applications… It's a frustrating investment, but a spares package for the common yield bolts is worthwhile!

I actually did not replace those bolts that go into the spindle. But now I will be ordering new bolts and making sure they are torqued correctly with loctite.

At the moment with the washers that I put I have not had problems. I will report as I go on trackdays

leftfootbr8king wrote

spikenipple wrote

leftfootbr8king wrote

I had a bolt snap on the right rear with the purpose made washers, not the McGill.

The other 3 bolts that hadn't snapped in the rear were loose.

It destroyed a rear axle which was $$$ to get replaced, and could have sent me into a wall if that control arm had let go on a different part of the track.

I wouldn't push ahead assuming the fault of this mod is only with the mcgill washers.

If spherical bushings in the rear are a must, run them everywhere the conical washers aren't needed and use the SPL arms to replace both upper control arms. The SPL setup is an added expense up front but the failure rate of this washer hack is too high to be worth it.

Do you have any photos of the snapped bolt?
I'm interested to see the failure mode.

The other three being loose is perhaps indicative of incorrect fitment - they'll certainly snap eventually if they're not tightened up as the bearings will be free to move around and bend the bolt side to side.

This is what I have for pics from last fall. The rest of what I have is video.

I didn't do the install on these since the car was in for rear subframe bushings anyway. Work was done by a reputable race shop. Not saying they couldn't have messed the install up but 3 reported failures, 3 different shops in a just a few months. The consequences of failure are not insignificant.

Fwiw: BFG R1, Moton CS 2WR, big brakes, etc. The car was getting pushed pretty hard and made it through 1.5 days around VIR before letting go, so if you're into hard parking on street tires this washer hack might suit you just fine.

This is concerning, wish I saw this sooner before I gathered all the parts. Has anyone actually done multiple track days without any issues?

CAF80 wrote

leftfootbr8king wrote

spikenipple wrote

leftfootbr8king wrote

I had a bolt snap on the right rear with the purpose made washers, not the McGill.

The other 3 bolts that hadn't snapped in the rear were loose.

It destroyed a rear axle which was $$$ to get replaced, and could have sent me into a wall if that control arm had let go on a different part of the track.

I wouldn't push ahead assuming the fault of this mod is only with the mcgill washers.

If spherical bushings in the rear are a must, run them everywhere the conical washers aren't needed and use the SPL arms to replace both upper control arms. The SPL setup is an added expense up front but the failure rate of this washer hack is too high to be worth it.

Do you have any photos of the snapped bolt?
I'm interested to see the failure mode.

The other three being loose is perhaps indicative of incorrect fitment - they'll certainly snap eventually if they're not tightened up as the bearings will be free to move around and bend the bolt side to side.

This is what I have for pics from last fall. The rest of what I have is video.

I didn't do the install on these since the car was in for rear subframe bushings anyway. Work was done by a reputable race shop. Not saying they couldn't have messed the install up but 3 reported failures, 3 different shops in a just a few months. The consequences of failure are not insignificant.

Fwiw: BFG R1, Moton CS 2WR, big brakes, etc. The car was getting pushed pretty hard and made it through 1.5 days around VIR before letting go, so if you're into hard parking on street tires this washer hack might suit you just fine.

This is concerning, wish I saw this sooner before I gathered all the parts. Has anyone actually done multiple track days without any issues?

Zero issues over 15-20 track days on R7s with reasonable aero.

DRLane wrote

CAF80 wrote

leftfootbr8king wrote

spikenipple wrote

leftfootbr8king wrote

I had a bolt snap on the right rear with the purpose made washers, not the McGill.

The other 3 bolts that hadn't snapped in the rear were loose.

It destroyed a rear axle which was $$$ to get replaced, and could have sent me into a wall if that control arm had let go on a different part of the track.

I wouldn't push ahead assuming the fault of this mod is only with the mcgill washers.

If spherical bushings in the rear are a must, run them everywhere the conical washers aren't needed and use the SPL arms to replace both upper control arms. The SPL setup is an added expense up front but the failure rate of this washer hack is too high to be worth it.

Do you have any photos of the snapped bolt?
I'm interested to see the failure mode.

The other three being loose is perhaps indicative of incorrect fitment - they'll certainly snap eventually if they're not tightened up as the bearings will be free to move around and bend the bolt side to side.

This is what I have for pics from last fall. The rest of what I have is video.

I didn't do the install on these since the car was in for rear subframe bushings anyway. Work was done by a reputable race shop. Not saying they couldn't have messed the install up but 3 reported failures, 3 different shops in a just a few months. The consequences of failure are not insignificant.

Fwiw: BFG R1, Moton CS 2WR, big brakes, etc. The car was getting pushed pretty hard and made it through 1.5 days around VIR before letting go, so if you're into hard parking on street tires this washer hack might suit you just fine.

This is concerning, wish I saw this sooner before I gathered all the parts. Has anyone actually done multiple track days without any issues?

Zero issues over 15-20 track days on R7s with reasonable aero.

That's very reassuring. Thanks for the feedback!