SMG transmission

[Mpopaj]

I am swapping my z3 to a 6-speed on as tight a budget as possible. Considering I could get an smg for half the price of a manual and just put a self centering shifter on it, I was wondering what I am better off doing. I donÂ’t want to swap the transmission out again anytime soon. I know of the smg pump issues that I obviously wouldnÂ’t have to worry about, but how does the actual gearbox hold up. Is the smg rough on the gears or should it be in the same condition as a manual with the same mileage

[Liquidity]

It’s the exact same transmission except the selector rod can’t accept decent pins and the case isn't machined for them. It will definitely last longer than a used manual because the synchros won’t be all beat up from years of missed shifts.

[Mpopaj]

I figured that the quick shifts of the smg might have the same effect as power shifting every shift in a manual transmission.

[eacmen]

I havedriven an SMG conversion with self centering shifter and no detents. If it were my car I would spend the money to get it machined for detents.

Does it work? yes

Does it feel good to shift? no.

[jclausen]

Don’t do an smg trans

[Mpopaj]

Don’t do an smg trans

Because of the feeling or because of the reliability? It would save me a lot of money.

[Liquidity]

Dude. They’re the same transmission. How would reliability be different? The way this should be done is to get yourself a regular manual 420G and then when you blow up the 3rd gear synchros like we all do, you buy an SMG transmission and swap your selector rod and bell housing onto it and then repeat process until the world is depleted of 420G’s because Getrag doesn’t sell rebuild parts for these. They’re also ridiculously difficult to rebuild because they require a special jig to hold everything in place as you assemble it. As far as I know, Turner Motorsport is the only company that has the ability to rebuild these - and it’s a $5k price tag.

[Mpopaj]

Dude. They’re the same transmission. How would reliability be different? The way this should be done is to get yourself a regular manual 420G and then when you blow up the 3rd gear synchros like we all do, you buy an SMG transmission and swap your selector rod and bell housing onto it and then repeat process until the world is depleted of 420G’s because Getrag doesn’t sell rebuild parts for these. They’re also ridiculously difficult to rebuild because they require a special jig to hold everything in place as you assemble it. As far as I know, Turner Motorsport is the only company that has the ability to rebuild these - and it’s a $5k price tag.

I know they’re the same gearbox but like I said above. It seems that the quick shifts of the manual would be like power shifting into every gear for the last 100k miles. Unless I’m missing something, I can’t imagine that would be good for the transmission. I’m hoping I’m wrong this way I can buy the smg and save close to $1k

[Liquidity]

What you “seem” doesn’t mean anything. You don’t know anything about these cars or these transmissions or how the SMG unit even works.

[Mpopaj]

What you “seem” doesn’t mean anything. You don’t know anything about these cars or these transmissions or how the SMG unit even works.

You sound like you’re a fun guy to be around at parties

[Kevin2772]

Not every SMG shift is banging gears. I doubt most people who use these cars turn DSC off, and SMG 6 on that often. I usually keep mine in SMG 4 or 5 and unless im hammering the throttle the shifts are still smooth and easy.

[180SXTCY]

You sound like you’re a fun guy to be around at parties

It sounds like you've already made your mind up and are trying to justify it albeit others are trying to give you adequate advice.

As Liquidity said, the SMG and the 6 Speed are the SAME gearbox, its just how the gear changes are performed that differ.

I've never had my SMG miss a gear shift for what its worth, so the synchro's are more than likely not flogged from human error smashing gears.