[matty2244]

So, back in November I bought a 2021 M550i from a BMW dealership in Nebraska. I had been looking for a bit and this one fit what I wanted, however in hindsight I would have looked for one with the B&W system - I am not a fan of the HK, but that said the car is amazing.

Anyways, this thing has the 20s, so when i got it home I went to discount tire and got a set of 19s with whatever the awesome snow tires that everybody uses some Scandinavian company.

Anyways, I threw those on and have put a few thousand miles on the car since November. The other day I heard a hum, which I thought was odd, kind of sounded like a wheel bearing. Brought it to BMW last Friday, and got it back last night. They replaced the front diff, as well as the rear propeller shaft flex joint.

The tech said it would have been between 7 and 8k if I had to pay for it. I bought it used, off lease with 29k. The car went to Florida and came back to Nebraska when the lease was up. The service tech was leaning towards rolling circumference possibly contributing to it, my snow tires checked out perfectly though he said and asked that I bring my summer rims and tires up to him when it is time to throw them on (a month or so I suppose). The summer rims have brand new tires on them that they put on before turning it over after the lease. I obviously can't speak to the initial 30k miles, but god this is kind of concerning this thing has broken that bad with this low of miles.

Thoughts anybody?

lol I forgot to add that I asked my loaner not be a 4 cylinder anything, and the only 6 cyl they had was an 840i convertible with AWESOME black 20s and huge blue brakes. It was in the 70s all weekend, so I was rolling that around for 5 days. It is way too slow and handles way too poorly for me, but it is pretty cool. Sticker said 107k, no thanks.

[G30M]

do you recall the sizes of the 19" snow tires - were the front tire size different from rear tire size?

i've also got 20" tires and i'm thinking of going to 19" square.

people have said the 20" staggered setup is already 1.1% difference to start with, outside of the 1% tolerance

[matty2244]

The snow tires and wheels are square, 245 all around. Indeed my summers are staggered,now I'm kind of worried about it when I put them on...

[430Scud]

Wear and cracking on the rear guibo is sort of normal to occur, but a little early if only 29k miles. The failure of your front transfer case is unusual and I would call it a fluke. I have not seen nor heard of any other failures on the forums since I purchased my 2018 in late 2019.

[Joe-BMW33]

430Scud beat me to it, I was literally typing the same exact reply.

My guibo was done at 30k miles, but I wasn't experiencing any symptoms. Since it is so common, dealers look for stress fractures. Easy 4 hour warranty money done in 1.5 hours tops.

I think your front diff issue is a fluke or related to the prior owner (lease). It's the first case I have seen with a front diff failure in following the G30 for four years.

[matty2244]

Ok good to know on both fronts. I'm still going to bring my summers up and have them do their thing before throwing them on. Just wanted to make sure these diffs can't be broken by launching it here and there, hard accelerating, etc.

[HerkHealer]

I was going to joke that someone in the Mafia named this part...........and it's sort of true.
The Guibo was designed by an Italian Engineer, and modified the Italian word Guinto, which means "a joint or coupling".

[G30M]

Originally Posted by matty2244

Ok good to know on both fronts. I'm still going to bring my summers up and have them do their thing before throwing them on. Just wanted to make sure these diffs can't be broken by launching it here and there, hard accelerating, etc.

my M340i had a broken front diff from new, just got it fixed under warranty

[ezaircon4jc]

Originally Posted by HerkHealer

I was going to joke that someone in the Mafia named this part...........and it's sort of true.
The Guibo was designed by an Italian Engineer, and modified the Italian word Guinto, which means "a joint or coupling".

I thought Guibo was the dude that broke delinquent's legs, er, collected overdue debts!

[HerkHealer]

Originally Posted by ezaircon4jc

I thought Guibo was the dude that broke delinquent's legs, er, collected overdue debts!

Exactly !
Unfortunately, he was cut from the Goodfellas movie.

[BMW012]

not that i care, but proper spelling is GIUBO. however it seems like GUIBO is used more often anyways

[Joe-BMW33]

Originally Posted by BMW012

not that i care, but proper spelling is GIUBO. however it seems like GUIBO is used more often anyways

Flex Disc is easier to remember how to spell.

[Chappers 71]

I’ve always known it as a prop shaft coupling

[G30M]

so how is the M5 different? they don't seem to have this issue, or do they?

[Joe-BMW33]

Originally Posted by g21

so how is the M5 different? they don't seem to have this issue, or do they?

I can’t imagine they are any different. Flex Disk failures or wear and tear are across all lines for the last 20 years, well maybe not the new golf cart models with no drive shaft or soul.

[Sam_M550i]

I was having a slight vibration when starting from a stop and the dealership checked maybe 4 times and said it was fine. I only have 29k miles on my 2018 but seems to be hit or miss even at low miles. From what I've seen. The exhaust has to be dropped to do the job.

[Joe-BMW33]

Originally Posted by Sam_M550i

I was having a slight vibration when starting from a stop and the dealership checked maybe 4 times and said it was fine. I only have 29k miles on my 2018 but seems to be hit or miss even at low miles. From what I've seen. The exhaust has to be dropped to do the job.

They can inspect the flex disk without dropping the exhaust, but it does need to be dropped for the repair, which really isn't a big deal.