Advantages of 5-Speed Conversion?

[ATLBMW]

My 4-speed manual tranny is shot, and some have suggested replacing it with a 5-speed instead of another 4-speed. I won't be doing the work, and the 5-speed conversion is about 3 times the cost of just replacing the 4-speed.

What are the advantages to the 5 speed, other than driveability?

[Rocan]

My 4-speed manual tranny is shot, and some have suggested replacing it with a 5-speed instead of another 4-speed. I won't be doing the work, and the 5-speed conversion is about 3 times the cost of just replacing the 4-speed.

What are the advantages to the 5 speed, other than driveability?

The 5th gear is an overdrive, so cruising on the highway is far better and fuel milage is improved (although not really enough to switch to a 5 speed solely for the improved mpg). Also any transmission in good condition is going to feel way nicer than an old and worn transmission. Top speed also increases (if you have the cajones and extra power to take your 2002 over 120mph, that is, on a CLOSED COURSE, of course).

If you're doing the work, just go for it. you won't regret it.

[Mikesmalaga72]

It is subjective:

When coupled with a preferred ratio of 3.90 diff

Lower revs at cruise speed top gear, quieter engine, slight mpg improvement, close ratio, or overdrive choices.

If you have the bucks and price is right and the right person helping you do the 5 speed conversion it may be a great idea.

I dont have issues with the four speed myself. Im keeping mine pretty much stock though.

Hope you are getting some deserved help! Good luck with your trans adventure!! Keep us posted.

[Mike Self]

a 5-Speed conversion is the trick. Drops engine revs about 800 at a given speed (70 mph is around 3200 rpm vs 4000)--this makes a big difference in noise level. This of course is only true if you keep the original 3.64 diff.

The overdrive 5th doesn't really hurt highway performance either. I've pulled some pretty steep grades without having to downshift, and if I have to, so what? That's the fun of having a stick shift.

I take quite a few long trips in my 02, so I'll have to say it's been about the best single improvement I've made to the car.

cheers

mike

[ATLBMW]

Seeing as how this is a 3rd "fun" car that I rarely drive on highways, I'm thinking I will stick with the four-speed and save the money for the next repair.

[duckdudess]

The change is not a small project, but not a difficult one either. Transmission, slave cylinder, back up light switch, shortened drive shaft, new or shortened shift platform, new transmission mounting bracket(s), new speedo cable...all well documented. Also, the gear ratios are slightly different in gears 1-4 between the two transmissions but the biggest difference was changing the differential from 3.64 (open) to 3.91 (LSD). The result of this change was that the 1st gear acceleration was improved and the 5th gear cruising RPMs remained about the same as with the 4 spd. This was worth doing, but required the LSD which in my case was 3x the price of the 5 spd transmission. It required 320i CV joints on the LSD, which also requires a spacer with the right number/size of bolt holes. And while everything was apart, half shaft rebuild kit was installed, transmission seals replaced, LSD seals replaced, etc. Anyway, I felt all of this, while not cheap (~$2K+), was worth it. I would not simply do the transmission swap, especially for around town driving. Save the dough for something else.

[nbristow01]

The complete swap with all parts, shaft included, for a 5 sped swap runs over $1000.00. Guys locally have gievn away 4 speed trannys. So if it is just a 3rd fun can stick with the 4 speed I would think