[Ryanfknt]

1-2 synchros are thrashed on my car. 2014 f30 335i. (GS6-45BZ tranny)
Is there a transmission available that has stronger synchros?

From what I understand, it is basically the same transmission used in the m2/3/4. BUT the m2/3/4 transmission has beefed up 1-2 and 2-3 synchros.

For some reason I can’t find a single forum or person that says yes they bolt up!!

Can I bolt the 6mt transmission from the m2/3/4 on to my f30 n55??

Or is there is there any sort of upgrades transmission that someone can recommend? I see everybody has the same issue in the f30 335i. but nobody has a solution??? I’ve got 120k miles on my car with no warranty of course and I don’t want to just put another junk transmission in it and pray my 1-2 synchro holds up better.

[thejeremyman9]

The 1-2 synco issue has been discussed that there is indeed no rebuild kit or anything for the 6MT, so the "fix" is a new transmission.

As far as the ///M transmission fitment I am not sure so can't comment on that.

[Ryanfknt]

The only upgrade I was able to find after extensive research is to bolt in the n54 tranny (GS6-53BZ)

Here is a good link that explains a few people doing the swap.
https://www.1addicts.com/forums/show....php?t=1386237

[Ryanfknt]

As I’m learning more about the swap. I just wanted to post the absolute most helpful link I’ve found so far.
This link shows in detail every obstacle you will run into with bolting the n54 tranny to the n55

https://www.1addicts.com/forums/show....php?t=1632598

[Salty B.]

Originally Posted by Ryanfknt

1-2 synchros are thrashed on my car. 2014 f30 335i. (GS6-45BZ tranny)
Is there a transmission available that has stronger synchros?

My trans was replaced under warranty at 22K miles. Same reason, model, and year.

Now the replacement is crunching after only 10K miles. Car only has 32K on it, I'm never home.

Class action time? Did they make that 2nd gear synchro out of glass? Do I suck at driving manuals? Only been doing it for decades and have never broken a transmission or burned a clutch.

[N55E90toF30]

In the shop right now, for synchro and possibly new second gear... depends what it looks like once it’s pulled and inspected... 🤦🏼*♂️ I’ll follow up, I asked for upgraded parts where available and pricing beforehand.

[thejeremyman9]

Originally Posted by N55E90toF30

In the shop right now, for synchro and possibly new second gear... depends what it looks like once it’s pulled and inspected... 🤦🏼*♂️ I’ll follow up, I asked for upgraded parts where available and pricing beforehand.

In BMW dealer or indy? Interested to hear what they say because AFAIK no one produces a rebuilt kit/syncros/parts for the 6MT. Warranty repairs result in a complete new transmission.

[N55E90toF30]

It’s at an Indy transmission shop, but he has supra photos on the wall and dirt track race car photos on the walls and my bmw aftermarket parts installer referred me to him, so we will see. 🤞🏼

[phat8186]

Originally Posted by N55E90toF30

It’s at an Indy transmission shop, but he has supra photos on the wall and dirt track race car photos on the walls and my bmw aftermarket parts installer referred me to him, so we will see. 🤞🏼

Any insight or updates

[Boostedphil698]

Pure Drivetrain Solutions does offer a trans rebuild for 4k on the manual transmissions.

[-Eidos]

Originally Posted by Boostedphil698

Pure Drivetrain Solutions does offer a trans rebuild for 4k on the manual transmissions.

The site says it's for the 6-speed automatic transmissions. Unless you contacted them directly for that information?

[Boostedphil698]

Originally Posted by -Eidos

The site says it's for the 6-speed automatic transmissions. Unless you contacted them directly for that information?

I think you have to call. I saw something where they said they do them.

[terryd5150]

Originally Posted by Boostedphil698

I think you have to call. I saw something where they said they do them.

Is that stock rebuild or will they upgrade internals?

$4K is roughly the price of a new one from BMW.

If you're just going to get "stock", you might as well just buy a new one from BMW.

[Boostedphil698]

Originally Posted by terryd5150

Is that stock rebuild or will they upgrade internals?

$4K is roughly the price of a new one from BMW.

If you're just going to get "stock", you might as well just buy a new one from BMW.

Probably upgraded but I'd call.