5-speed vs 6-speed dimensional differences

[senorcarey]

Hi All,

I was wondering if one of you either knew of the dimensional differences between the five and six-speed trannies. I am not concerned about weight, but mostly in what makes them different through the bell housing region. I'd specifically like to compare them to the G265 that's currently in my car.

I'm trying to decide between the two and am wondering if I will be able to get away with subtle massaging from a BFH or if I'll need to do more invasive tunnel reconstruction.

I have a 5-speed available to me for $150 (with PP) that needs the shifter boss welded back on. Six-speeds are also readily available for 4-5 times the price.

My car is a DD, and I'm concerned that the 5-speed will get tiresome after a while.

Thanks in advance.

[dirty30]

In an E30 Im guessing?

Honestly the problems with these S6S420G's aren't so much fitting in the tunnel as the transmissions themselves malfunctioning internally. These S6S420G's are notorious for a number of problems, mainly sticking in gear or not going into gear at all. If you are buying one second hand I would make sure you know the history of it. If its a DD I would go with the 5 speed just from a reliability standpoint. You don't want to have to pull that trans back out. Its a tight squeeze.

[Jonsku]

5-speeders are more reliable and can withstand lots of power.

I'd say that the only notable difference in size between the boxes is the length. The bellhousing is of course the same as they bolt on to same engines..

[nrubenstein]

Yes. The issue is length.

And while reliability and shift quality are worse with the 6spd, usability of the car is much better.

[bmwmech1]

I've been down this road before with other forum members about the dimensional, weight and drivability differences between these 2 transmissions. 2 things to remember...

1. If you use the 6 speed, you'll need to have a custom driveshaft made and also fab a trans mount, so add those to your dollar figure differences. The driveshaft can get salty... I think Frank paid around $600 for his.
2. IIRC, the gear ratios are exactly the same, excluding the overdriven 6th. Unless you do a ton of freeway driving or plan on driving at twice the legal speed a lot, the car will be the same, no matter which transmission you use. Especially if you choose a 2.93 LSD...

Garey

[mutty]

Which 6-speed you are referring to? E46 M3 or E46 330i [ZHP]? My understanding is that the 330i [ZHP] has the much stronger and more sought after 6-speed box.

[dirty30]

Which 6-speed you are referring to? E46 M3 or E46 330i [ZHP]? My understanding is that the 330i [ZHP] has the much stronger and more sought after 6-speed box.

We are referring to the getrag six speed S6S 420G in the V8 configuration.

[iamsam]

Looks like the 5-speed is the winner all around from what I am reading, as long as you can live without the extra gear.

[senorcarey]

Thanks for the replies. I realize that both have the same bell housing diameter at the end, but I thought that the 6-speed had less of a slope, so to speak, as it runs towards the back of the tranny, necessitating more severe tunnel mods.

The 5-speed looks to be just slightly shorter than a G265. That works out perfectly, as well.

Thanks for the info, guys. This section contains a ton of great info as well as help.