engine and drivetrain Transmission Options - 4 vs 5 speed

[logume1881]

The 4 speed on my 72 2002 is nearing the end of its life, I fear. The second gear syncro no longer exists, and the transmission whines like a truck transmission with straight cut gears (!) How much could I expect to pay for a good/rebuilt 4 speed unit? Would it be worth the time and money to upgrade to a 5 speed? Thanks for the input.

[JackF]

Don't know the costs, but if you plan on keeping the car, it is definitely one of the best mods you can make. Much more pleasant cruising.

[Mike Self]

Now that I have, I hardly drive my 69 any more--at least on trips--with the four speed in favor of my 73 with its five speed tranny. Drops about 800 rpm at a given speed, and that is significant in terms of noise.

If you take trips in your '02, do the five speed. And find one now as good ones are increasingly difficult to find.

cheers

mike

[rover1]

Rebuild the 4 speed or get another one. the only 5 speeds worth using are C/R 5-speeds wich are available if start looking right now. I must admit that i have (5 speed overdrive Getrag 245/5) in my 76 but i never use 5 gear unless im traveling over the speed of 110mph wich is pretty rare. its a fairly easy conversion but way over rated.

[Guest Anonymous]

The E21 5-speed (over drive) is great for Interstate driving. I am really glad I made the change from a 4-speed. Primarily, the 5-speed reduces engine noise, but also rpm's and therfore improves gas mileage.

____________________________

Roger

'72 Malaga

RBenson685@aol.com

[jrhone]

I'm not sure whats hard about the decision....dump money into a 4 speed, or dump money into a 5 speed. To me its a no brainer...5 speed. Also while you are at it, upgrade the rear diff to a 3.91. This will give you quicker acceleration in gears 1-4 and 5th will give you lower RPMs on the freeway. If you do the 5 speed without the rear diff, your 1-4 gears are the same, you will just have a lower 5th overdrive. 320 5 speeds are out there and not expensive. you just need some other parts for the conversion, driveshaft, tranny mount, shifter, etc...

[ClayW]

+1 on the 5 speed upgrade. Unless you're never going to drive your car above 50 MPH, a 5 speed overdrive is a great option. I really can't imagine ever owning a 2002/1600 without one. Plan on spending at least $250 on a Getrag 245/5 (1980-82 BMW 320i) plus up to $800 for the conversion parts. You can, alternatively, fabricate many of the parts yourself. Search "overdrive AND conversion" for some reading material on the conversion. Also, see the FAQ entry on the matter.

On the other hand, a usable stock 4 speed can be had for less than $100. Hell, I just gave away the original 4 speed from my 1600.

Good luck!

[TobyB]

Also while you are at it, upgrade the rear diff to a 3.91.

Yeah, that's the real winner. Jenn's car has a 3.64- and honestly, unless you're on the interstate at 70, it's not all that useful.

But with a 3.91, now 4th is a great passing gear, and 5th will take

you up a hill without a downshift.

t

[BBL70]

The 4 speed on my 72 2002 is nearing the end of its life, I fear. The second gear syncro no longer exists, and the transmission whines like a truck transmission with straight cut gears (!) How much could I expect to pay for a good/rebuilt 4 speed unit? Would it be worth the time and money to upgrade to a 5 speed? Thanks for the input.

going next month .......

http://www.racetep.com/5speed.html

[logume1881]

Sounds like an all around win for the 5 speed! Sadly, I can't be without the car for more than a weekend, because it is my only car. That, and the money thing of course. Thanks for all the input, fingers crossed it holds together until I can do it properly.

[Guest Anonymous]

Race tep's 5 speed is rather pricey. I was considering it myself. Piecing out a 5 speed swap now. If you are not very technical or good at serious modification it could cost upwards of $2000. I have a 4 speed that was rebuilt 4 months ago that I am selling. Not even broken in yet only 300 miles on it $800 from my buddy's shop. That's like $200 off list

[Gordon]

Search Craigslist for complete E21 donor cars like this one for cheap Just make sure the seller registered the car non-op or DMV will want a lot of back fees when you ask for a junk title.

http://sfbay.craigslist.org/nby/cto/1982222838.html

http://mendocino.craigslist.org/pts/1917598362.html

Study up on the below link for everything you wanted to know about a 2002 5 speed conversion

http://www.lexam.net/peter/carnut/5-speed.html

G-Man

[2002ftw]

Hi folks, I know this is an old topic, but Im looking at the 245/5 transmission swap for my auto 2002 and am intrigued by the 3.91 diff swap - I want to retain as much "snappy" acceleration as possible (as well as upgrading power output on the motor) - as a newbie, is this 3.91 differential an aftermarket part or from another bmw model? Can anybody help me with who might supply these kind of parts?

[Simeon]

The technical articles (FAQ) are always a good place to start. 

 

 

 

 

[Vicleonardo1]

A bit of a surprise looking at a 9 year old thread. I was wondering why everyone was saying that finding a 5 speed was easy as well as a 3.91. 

Not so easy (or cheap) these days.