Getrag 420g 6 spd

[tommy1394]

I am running a Getrag 420g that was setup as a SMG from an e46 M3. I have converted to a standard 6 spd and was wondering if there are any other maintenance/upgrades that are possible on the transmission while it is out of the car...like upgraded or new springs etc? My car is running >450whp and just what to deal with as much as possible before I reinstall the trans.

Thanks, Tommy

[e30kid89]

I am running a Getrag 420g that was setup as a SMG from an e46 M3. I have converted to a standard 6 spd and was wondering if there are any other maintenance/upgrades that are possible on the transmission while it is out of the car...like upgraded or new springs etc? My car is running >450whp and just what to deal with as much as possible before I reinstall the trans. Thanks, Tommy

Can you point me to any links that describe in depth the conversion? If it helps I have the bell housing from an already standard 420g I can use.

[tommy1394]

If you have the bell housing you just bolt it up.

This is all I have seen.

http://www.m3forum.net/m3forum/showthread.php?t=475959

[tofunin]

Input shaft seal, selector shaft seal, and pins/springs #2 and #6 on this page http://www.realoem.com/bmw/enUS/show...diagId=23_0887 the springs tend to break over time.

[dburt86]

Couple more threads like this and 420s are gonna be 4500$

[geargrinder]

There are no service parts available for 420Gs. The only way they get rebuilt is via buying BMW official remans for 20gazillion eurodouchemarx. Which nobody does.

Aside from parts impossibilities they need some specialty jigs and seriously heavy presses to take apart and reassemble.

A very very few shops in the US know how to do this, not many. The one I talked to explained some of the problems with working on them and said they had to use used trannies as parts donors for repairs. He'd service one but he'd require a fixed min payment up front and couldn't guarantee hed have the parts needed,once it was open.

Supposedly a couple shops used to rebuild them for race teams (aka Turner or whoever) but this seems like it was never available to normal humans. I'm gonna guess maybe some of those shops fabbed custom replacement or race upgrade parts but that those would cost also gazillions if they'd even do it.

[chikinhed]

420g's have weak syncros and are much heavier than the ZF 5 speeds.

[e30kid89]

420g's have weak syncros and are much heavier than the ZF 5 speeds.

I knew the syncros were very temperamental beforehand but what does that mean? We should shift like grandmas? Lol

You had your 6spd for awhile so you have a good idea what they're made of

[geargrinder]

I think "weak" is a little overstated, normally "weak synchros" is applied to far more fragile boxes - it's not like one or two gear-grinder shifts will totally blow a synchro with no prior history, and there are trannies like that, but I take your point and indeed they get balky with age and abuse, and aren't nearly as slick shifting as ZF's. From what I do know of them from seeking out the guys who've been inside them, the bigger weakness is in shift forks that deform and a few other obscure issues with shafts binding up. The day you go into reverse and can't get it out again, that's when yer 420G-forked. They also seldom totally blow up the big parts tho... Not a silky shifter but not super a fragile one either.

Neither a great choice for hard use big power build cars though... No parts or reasonable rebuildability, not cheap used, heavyish, balky as well when cold and will get worse as they are beat on... I keep a spare in the basement for a rainy day emergency but if I did a new project car I'd be looking at ZF options.

[someguy2800]

There are no service parts available for 420Gs. The only way they get rebuilt is via buying BMW official remans for 20gazillion eurodouchemarx. Which nobody does.

Aside from parts impossibilities they need some specialty jigs and seriously heavy presses to take apart and reassemble.

A very very few shops in the US know how to do this, not many. The one I talked to explained some of the problems with working on them and said they had to use used trannies as parts donors for repairs. He'd service one but he'd require a fixed min payment up front and couldn't guarantee hed have the parts needed,once it was open.

Supposedly a couple shops used to rebuild them for race teams (aka Turner or whoever) but this seems like it was never available to normal humans. I'm gonna guess maybe some of those shops fabbed custom replacement or race upgrade parts but that those would cost also gazillions if they'd even do it.

this is exactly why I never considered a 420g a viable option. It's just idiotic that they won't sell you parts. A t56 comes apart in 30 minutes with a pair of snap ring pliers and a brass drift, and tremec is more than happy to sell you every part for a very reasonable price.

[tommy1394]

this is exactly why I never considered a 420g a viable option. It's just idiotic that they won't sell you parts. A t56 comes apart in 30 minutes with a pair of snap ring pliers and a brass drift, and tremec is more than happy to sell you every part for a very reasonable price.

Now if you would just sell me the adaptor for a t56 at a reasonable price.

[Butters Stoch]

We just need a GB on T56 magnums. Simple enough.
Then we can save a $100 on a $3000 trans. We will all go nuts for that.

[Fender13Bender]

Lol

[Fender13Bender]

My car will have a T56, but only because I'm LS swapping it and putting the S50 with a big turbo in my E30.

[someguy2800]

Now if you would just sell me the adaptor for a t56 at a reasonable price.

Quicktime is making the bellhousings. Mine is for sale for the first person that wants it.

[Jsnmagana]

Does anyone know of a reputable source to machine the 420 g bellhousing?

[pbonsalb]

Lang Racing does it, but it's not cheap.

[e46black]

this is exactly why I never considered a 420g a viable option. It's just idiotic that they won't sell you parts. A t56 comes apart in 30 minutes with a pair of snap ring pliers and a brass drift, and tremec is more than happy to sell you every part for a very reasonable price.

I have a 2003 e39 m62tu, my 3rd gear synchro is bad.
Does anyone know if we have any other transmission options?

Will other transmission fit with minimal modification?

It sucks when I can see the Lexus trying to zip in front of me at the last minute, and I couldn't use my 3rd gear to prevent him.

[ltpickles]

There is no proper replacement for these boxes. only option is to swap in another one with less mileage. If you are interested, I have a 420 sitting around with 125,000 miles on it. shifts great.

[geargrinder]

Correct. The overseas V8 535 came w a 5sp ZF so its theoretically a possibliity and i think i remember at least one oerson doing that but itd technically be underrated for the 4.4 TU, not to mention losing a gear...

[busterhax]

How do these compare to the ZF gs6-37?

[Butters Stoch]

I'm thinking I'm going to sell this euro 420G. I have the mount and selector rod and trans. Only need DS. So, if someone is interested, send an offer.

[XAlt]

Correct. The overseas V8 535 came w a 5sp ZF so its theoretically a possibliity and i think i remember at least one oerson doing that but itd technically be underrated for the 4.4 TU, not to mention losing a gear...

E34 530i/5

http://www.realoem.com/bmw/enUS/show...diagId=23_1168

[lbennyboobool]

I'm thinking I'm going to sell this euro 420G. I have the mount and selector rod and trans. Only need DS. So, if someone is interested, send an offer.

How much sir?

[mboor]

E34 530i/5

http://www.realoem.com/bmw/enUS/show...diagId=23_1168

This. A stock M62/M62tu wont break it. $100 at the junk yard.