[Kevin_The_Clean1]

Originally Posted by Bimma360

It's just the NVH and what I am willing to accept on this particular car. VTT describes the NVH as "little to none," and I think it's more like "little to some." Essentially, their lockdown brace amplifies engine resonance in the cabin. In other words it makes your engine sound louder. At low RPM, its "little." Above 3K RPM its "some." Under deceleration in the 4000 - 3200 RPM range there is a pretty pronounced growl/whine. I drive the car in manual 99.9% of the time, and with the way I drive I tend to decelerate through that range pretty often.

Generally speaking, the NVH is not bad. Hearing and feeling your engine a bit more might be a good thing for some. Especially if you have a louder exhaust. Just depends on what you want out of your car. For me, it turns out, only very little is acceptable on this car. The lockdown brace, to me, makes the car feel a bit more crude. I have plenty of old BMW's, I don't need this one to feel like one too. Haha actually the more I drive this thing the more I can't wait to rip this thing out.

As far as Ryan's solutions go. You just have to reach out to him on Facebook. He doesn't have a website or anything. The 14mm bolt kit I pictured in my earlier post is one of his solutions. It's essentially a stronger than OEM bolt, with a new steel sleeve to further increase strength vs stock. My view on all of this now is that I need to retain the factory bushing. So the only solution left is focus on the bolt itself. And for the sake of argument, let's say this isn't a permanent solution but buys me a few years (not saying that it's not). I would much rather replace or check on the bolt and sleeve every few years, then have to live with NVH.

Thank you for taking the time to explain this. That VTT differential lockdown brace looks awesome & super strong. But because of they way it amplifies drivetrain resonance from the rear subframe into the unibody, it's no wonder their hardly noticeable NVH claims is a touch off the mark.

To be honest, all these kist N new companies with different options gives me a little bit of a headache. I sure would liek to know which option is best in the long run & allows us to make our X3 M's stronger without the sacrifice of more noise & harshness in the cabin. If this were a track machine & didn't spend most of its time on the street, then we would be having a different conversation. I respect VVT & all they make. Just wish someone would make a definitive guide to all this & clearly show all the possible options with their pro's & cons.

[Jnat]

Originally Posted by Kevin_The_Clean1

Thank you for taking the time to explain this. That VTT differential lockdown brace looks awesome & super strong. But because of they way it amplifies drivetrain resonance from the rear subframe into the unibody, it's no wonder their hardly noticeable NVH claims is a touch off the mark.

To be honest, all these kist N new companies with different options gives me a little bit of a headache. I sure would liek to know which option is best in the long run & allows us to make our X3 M's stronger without the sacrifice of more noise & harshness in the cabin. If this were a track machine & didn't spend most of its time on the street, then we would be having a different conversation. I respect VVT & all they make. Just wish someone would make a definitive guide to all this & clearly show all the possible options with their pro's & cons.

I agree with this and i'm frustrated. I orig ordered the Einhorn, it's still on my desk (ordered way too quickly initially). I started to fear the NVH feedback we all were reading about. I then sat around waiting for another solution which i narrowed to the VTT simple bolt insert that i installed a few days ago. Install was straight forward and i was very surprised how tight the insert is when pulling it into the stock bushing. I did not have to lower the diff so i did nothing different then i would do lifting the truck normally. I now have a pretty significant clunk when shifting into gear and when pressing on and off the gas. So i'm now officially confused/disappointed and don't know what to do. I'm actually leaning toward reinstalling a stock bolt and just changing that frequently.

[Max Well]

Given the many available 'solutions' for the rear differential bushing and bolt issue it seemed a list might help organize. If anyone sees errors or omissions - suggest changes in a post and I'll keep it edited for accuracy. I've referenced and linked this post in the OP so it'll be easier to find (just like I did for the 1/4 Mile Leaderboards). Not all forum members use social media so references to those sites aren't available to everyone.

BMW F97 X3M/F98 X4M Rear Differential Bushing/Bolt Fix Options

Bolt only options
-BMW OEM
-Belmetric bolt

Bushing only options
- Vargas Turbocharger Technologies [VTT] Rear Differential Bushing Insert

Bushing and Bolt combination options
-BMW OEM
-Einhorn Industries Unicorn Egg – Billet Aluminum Rear Differential Rear Bushing and Belmetric M14 Bolt with matching washers and lock nut
-Vargas Turbocharger Technologies [VTT] Rear Differential Bushing Insert Kit (also available for the front bushings)
----
-Ryan Morard Facebook bolt, sleeve and collar solution – apparently he has 3 solutions per Bimma360 (“a 12mm bolt kit (the original), a 14mm bolt kit, and a full urethane bushing kit” – as he described in post 92 @ https://x3.xbimmers.com/forums/showp...9&postcount=92 )
-Clint Hightower YouTube Rennfix.com Bolt Saver Solution
-FJ MotorWerkes Rear Differential End Bushing, Bolt, and Collar Upgrade

Bracing only options
-JXB Performance Driveshaft Center Support Bearing Carrier Upgrade
-Vargas Turbocharger Technologies [VTT] Billet Differential Lock Down Kit

[TacosRule!]

Originally Posted by Bimma360

Haha I guess I can't argue with that. Here is Ryan's profile...

https://www.facebook.com/ryan.morard1

Another favor, does he have an email listed? A free gmail account? The link forces me to sign in, aint creating an account on that shit.


Thanks

[TacosRule!]

Originally Posted by Max Well

Given the many available 'solutions' for the rear differential bushing and bolt issue it seemed a list might help organize. If anyone sees errors or omissions - suggest changes in a post and I'll keep it edited for accuracy. I've referenced and linked this post in the OP so it'll be easier to find (just like I did for the 1/4 Mile Leaderboards). Not all forum members use social media so references to those sites aren't available to everyone.

BMW F97 X3M/F98 X4M Rear Differential Bushing/Bolt Fix Options

Bolt only options
-BMW OEM
-Belmetric bolt

Bushing only options
- Vargas Turbocharger Technologies [VTT] Rear Differential Bushing Insert

Bushing and Bolt combination options
-BMW OEM
-Einhorn Industries Unicorn Egg – Billet Aluminum Rear Differential Rear Bushing and Belmetric M14 Bolt with matching washers and lock nut
-Vargas Turbocharger Technologies [VTT] Rear Differential Bushing Insert Kit (also available for the front bushings)
----
-Ryan Morard Facebook bolt, sleeve and collar solution – apparently he has 3 solutions per Bimma360 (“a 12mm bolt kit (the original), a 14mm bolt kit, and a full urethane bushing kit” – as he described in post 92 @ https://x3.xbimmers.com/forums/showp...9&postcount=92 )
-Clint Hightower YouTube Rennfix.com Bolt Saver Solution
-FJ MotorWerkes Rear Differential End Bushing, Bolt, and Collar Upgrade

Bracing only options
-JXB Performance Driveshaft Center Support Bearing Carrier Upgrade
-Vargas Turbocharger Technologies [VTT] Billet Differential Lock Down Kit

Great post, appreciate the summary. What I think I found out is that after reading all the kits and watching videos from renfixx, FJ werks kit is a combination of Ryan's bolt and renfixx's kit. He even mentioned on one of his vids that he drilled out one kit, which is what FJ does. I still want to see Ryan's bolt kit to confirm.

I think I will replace my OEM bushing and OEM bolt, then use renfixx's kit. Only need to figure out the OE part numbers. Can someone confirm I'm looking at the correct parts?

The bolt is obviously #11, is the bushing #10?

[Max Well]

Originally Posted by TacosRule!

Great post, appreciate the summary. What I think I found out is that after reading all the kits and watching videos from renfixx, FJ werks kit is a combination of Ryan's bolt and renfixx's kit. He even mentioned on one of his vids that he drilled out one kit, which is what FJ does. I still want to see Ryan's bolt kit to confirm.

I think I will replace my OEM bushing and OEM bolt, then use renfixx's kit. Only need to figure out the OE part numbers. Can someone confirm I'm looking at the correct parts?

The bolt is obviously #11, is the bushing #10?

Thanks. Will be interesting to read some feedback from those who have installed one of the 3 'bolt sleeve collar' variations with regard to NVH and clunking as some have described with the other more solid bushing choices. I suspect those protect that key 1-1/2" zone where the bending and fracturing seems to be occurring on our bolts and appears to be a more directed approach at the problem while still allowing some motion in the bushing.

We're not on social media either, so maybe some from our forum here can comment if they get some experience with them.

And I can confirm from my BMW Svc Ctr invoice from late Feb '24 when I had my OEM bushings/bolts replaced, that the part numbers are as your png illustrates. Mine listed the combination nut (12 in your diagram) as well, and since you didn't highlight just wanted to make sure you're also getting that.

[TacosRule!]

Originally Posted by Max Well

Thanks. Will be interesting to read some feedback from those who have installed one of the 3 'bolt sleeve collar' variations with regard to NVH and clunking as some have described with the other more solid bushing choices. I suspect those protect that key 1-1/2" zone where the bending and fracturing seems to be occurring on our bolts and appears to be a more directed approach at the problem while still allowing some motion in the bushing.

We're not on social media either, so maybe some from our forum here can comment if they get some experience with them.

And I can confirm from my BMW Svc Ctr invoice from late Feb '24 when I had my OEM bushings/bolts replaced, that the part numbers are as your png illustrates. Mine listed the combination nut (12 in your diagram) as well, and since you didn't highlight just wanted to make sure you're also getting that.

Thank you sir, much appreciated.

[Stereolab42]

Originally Posted by Bimma360

I saw some pics of the revised bolts. Visually you can spot them as they are fully threaded vs the old bolts. Don't know if that's a fix or not. Some people say its not, but I take everything online with a giant grain of salt.

Has anyone with an LCI X3M had their bolt fail or bend?

[Max Well]

Originally Posted by Stereolab42

Has anyone with an LCI X3M had their bolt fail or bend?

Yes – D-Pat Murph shared an image of his 2022 Malachite Green X3MC’s failed bolt in his thread I linked in my OP. He said it was OK to share that image here (thanks,D-Pat Murph!), so I’ve added it to my previous compilation image.

As he ordered his X3MC 9 Mar 2022, and I think it was delivered week 22 of that year, if FJ MotorWerkes comment about a new OEM bolt being introduced in 2021/22 is true, then surely his would’ve been the upgraded one? As I’ve not seen anything definitive regarding if/when BMW did a bolt upgrade I’m not accepting as fact yet…

Does anyone know if the Morard, Hightower, and/or FJM solutions protect that 1-2" apparent flex zone, or is their structural improvement distal to that area?

[TacosRule!]

Originally Posted by Max Well

Does anyone know if the Morard, Hightower, and/or FJM solutions protect that 1-2" apparent flex zone, or is their structural improvement distal to that area?

The FJ Motors works the same as rennfix, they add the last 1" or so poly "collar" that fills in the gap in the OE bushing.

[Max Well]

Originally Posted by TacosRule!

The FJ Motors works the same as rennfix, they add the last 1" or so poly "collar" that fills in the gap in the OE bushing.

Yet Clint indicates in his video, 'BMW X3M and X4M Differential Solid Bushing Review and Installation by Einhorn Industries.', that he's tried solutions before the Einhorn including his own (if I'm understanding correctly) and they "also fail"... Review the time segment 1:07' to 2:17' in that video

Some cursory thoughts:
-would like to compare images of the 'failed bolts' with those collar, sleeve concepts which he indicates still occur to the OEM ones which have fractured. Do they look the same?
-I've done over 40 stock launches at the Strip and always drive in Sport/Sport+ (never Comfort), and my X3MC was 4-1/2 years old, yet my bolt was just mildly bent, so surely there must be other variables leading to complete failures, such as just variations in metal structure during manufacturing which leads to some bolts failing more quickly?

Solutions are present, but choice comes down to protection from high power forces vs NVH? Seems its up to us to decide where we land on that scale...

[TacosRule!]

Yeah I was also confused by Clint's video you posted. His review vid on the einhorn was also what drove me to get it. Honestly I trust all the guys on this thread in particular.

I think the variation you allude to is the "revised" bolt whose picture was posted here, and based on the info from FJ.

I'm getting the FJ Kit. I like Clint's since its cheaper but using the OE bolt (again) is a turn off. The FJ kit seems simpler to install, which means faster which means cheaper to run.

Wish me luck

[Diskz]

Originally Posted by TacosRule!

Yeah I was also confused by Clint's video you posted. His review vid on the einhorn was also what drove me to get it. Honestly I trust all the guys on this thread in particular.

I think the variation you allude to is the "revised" bolt whose picture was posted here, and based on the info from FJ.

I'm getting the FJ Kit. I like Clint's since its cheaper but using the OE bolt (again) is a turn off. The FJ kit seems simpler to install, which means faster which means cheaper to run.

Wish me luck

Looking forward to your review of the FJ kit. Debating picking one up as well

[Bimma360]

Got Ryan's kit in the mail today. Already ripped out the VTT brace. I'll have the new bolt and sleeve installed tomorrow most likely.

[Jnat]

Removed the Vtt insert kit due to clunking when shifting park to gear and simply on / off pedal to maintain speed, constant clunk. For me there was too much of an increase in deceleration whine from diff also. I re installed a new factory bolt and all noises are gone. I'm now looking for another solution. I don't launch often but want some protection. I could have dealt with the diff whine (not terrible) but the on / off pedal clunk along with the into gear clunk to a lessor degree was a deal breaker. i think it's too sophisticated of a vehicle and too well designed to have drive line clunks all the time. Btw, i think the Vargas insert would be effective if you can deal with the NVH...

[TacosRule!]

Originally Posted by Bimma360

Got Ryan's kit in the mail today. Already ripped out the VTT brace. I'll have the new bolt and sleeve installed tomorrow most likely.

Can you post pics of the kit please? Also does he have an email or is possible to coax him into posting here so that we can look at/order his kits?

[Rwdyx3]

Hey Gus, somebody said that there were some questions about the polyurethane bushing kit that I make. Feel free to contact me or message me for details.

[TacosRule!]

Originally Posted by Rwdyx3

Hey Gus, somebody said that there were some questions about the polyurethane bushing kit that I make. Feel free to contact me or message me for details.

Ryan this you? Thanks for chiming in (and whoever told him to swing by).

1) can you please post pics of your kits? I understand you have several.
2) do you reuse/use a new OEM bolt in any of the kits?
3) do you replace the metal sleeve in the OE bushing?
4) Costs

Thank you for dropping by. Looking forward to the info.

[Stereolab42]

What a mess... decided to bite the bullet and just get the Einhorn installed next week (along with low-dust brake pads). Seems to be reports of noise with all of these solutions so I may as well use the strongest one. And noise doesn't bother me unless it's really bizarre. Guess we'll see.

[TacosRule!]

Originally Posted by Stereolab42

What a mess... decided to bite the bullet and just get the Einhorn installed next week (along with low-dust brake pads). Seems to be reports of noise with all of these solutions so I may as well use the strongest one. And noise doesn't bother me unless it's really bizarre. Guess we'll see.

Good luck, keep us posted.

[Max Well]

For those changing out their OEM bolts - if you share a side image of your bolt as I've shown in the comparison photo I can size it and add to the compilation.

To be more useful as reference it would probably be helpful to also keep track of: pre-LCI vs LCI, total mileage, bolt/vehicle age, power output (stock, St1, St2, St2+) and rough idea of launches (none, few, moderate, a lot).

For my image as example - pre-LCI, 40K miles, 4-1/2 yrs old, stock, a lot

[TacosRule!]

Originally Posted by Max Well

For my image as example - pre-LCI, 40K miles, 4-1/2 yrs old, stock, a lot

That's pretty bad...