The Ultimate 5-speed Conversion Page for Getrag 245

[CubbyChowder]

[Edit 2018] PLEASE NOTE: This is an old thread with broken pictures and unfinished info. Unfortunately, I can't bring old pictures back and this is the extent of information I gathered for this swap. There are helpful links provided on page 3 of the comments section to help steer you in the right direction. Good luck!

 

 

Since I am in the process of converting to 5-speed, I've found that there are plenty of helpful write-ups with loads of information, but they all lack some detail or another. This means I spent a lot of time searching through different threads trying to find each bit of information that I need.

I would like to fill this page with every possible bit of information that one would need to successfully complete a 5-speed conversion from a 4-speed manual, but I need your guys' help on certain things. This page is a work in progress!

Please feel free to correct me if I provide wrong information or if you feel there is a better process to something. I am very new to this so some of my advice might not seem valid. There are a few steps which I personally haven't reached yet so I am basing some of this article off previous research and not by experience. Areas written in red are indication that I am unsure and need clarification or more info

First off, the Getrag 245 overdrive 5-speed manual transmission can be found in a 1980-83 e21 320i and looks like this (release fork/throwout bearing not pictured):

It bolts directly to the M10 block, but is about 3.6" longer than the original 4-speed, meaning the shift platform, shift linkage and driveshaft will all need to be shortened, but more on that later.

It is smart to replace all the seals and fluid in the Getrag 245 before installing it. This includes:

Input shaft seal - 30mm X 42mm X 7mm - Part #: 23 11 1 228 314

Output shaft seal - 40mm X 55mm X 8mm - Part #: 23 12 1 205 340

Selector shaft seal - Part #: 23 12 1 282 394 (or 23 12 1 228 443)

Output flange locking ring - Part #: 23 22 1 201 330

To access the rear seal, you must first remove the output flange. This will either be of 3 or 4 bolt design. Pictured below is a 4-bolt flange, so you can imagine what a 3-bolt flange would look like:

Whether you are using a 3 or 4 bolt flange, you must make sure you purchase a corresponding guibo (flex disc). 3-bolt flanges use a 6-hole guibo and 4-bolt flanges use an 8-hole guibo.

6-hole guibo part #: 26 11 1 225 624

8-hole guibo part #: 26 11 1 106 113

In order to remove this flange, you will need a long reach, thin wall 30mm socket, like so:

You will need to figure out how to keep the flange steady while you impact the 30mm nut off. This is kind of a bad picture but gives you an idea of what needs to be done. I feel it'd be pretty easy to make one:

Once you get that off, pull the flange off and you will have access to the rear output seal, which looks like this:

You can either attack the seal directly or remove the rear seal cover which consists of 5 bolts. Take caution when removing the rear seal cover as one bolt (namely the one in 1 o'clock position) is a shorter bolt and if it doesn't go back in the same spot, you will lose 5th gear until you get it back in there. 

Here's a good way to get that sucker out without having to remove the rear seal cover. Drive a screw into it and pull it out!:

Make sure you spread some sealant around the outside of the new seal and press it in with a large socket hammering gently or some other creative way (anyone know which specific sealant to use?).

Once that is done, re-install the flange with the new locking ring you ordered (torque spec? more info?).

The front seal can be replaced by removing the 6 bolts around the cover, once they are removed you will have this:

Replace the seal, re-install the cover and torque the 6 bolts down to recommended spec (does anyone know this?)

The selector shaft is located directly above the output shaft. This seal can easily be replaced by taking a small pipe which is the same diameter as the seal and lightly hammer the seal into the transmission. There is room for a few seals in there so don't be nervous, or try to remove it if you want. Either way. Replace and you're good to go.

As for fluid, it is recommended to use Redline MTF. Buy 2 quarts, it won't use everything but most of it:

Once you have all the seals and fluid replaced, it would be a good time to consider clutch options. There are two different flywheel/clutch sizes which were used on 2002's (228mm and 215mm) so it's important that you know what to get.

From the factory, all round taillight 2002's used a 228mm clutch/flywheel. All square taillight 2002's used a 215mm clutch/flywheel EXCEPT for Turbo's and 1974 Tii's, they used the 228mm.

It is possible that at some point throughout your '02's existence, the clutch/flywheel was swapped to a different size, meaning your original 215mm clutch/flywheel was swapped for a 228mm or vice versa. It is important to know what size flywheel you will be using so you can base your clutch kit purchase off that.

If you plan on using a 228mm flywheel, it is recommended to use the following clutch/pressure plate/throwout bearing combo:

228mm clutch disc - part #: 21 21 1 223 097 (or 21 21 1 223 174)

228mm pressure plate - part #: 21 21 1 251 248

The throwout bearing must be from an e21 323i - part #: 21 51 1 204 525

If you plan on using the 215mm flywheel, it is recommended to use the following clutch/pressure plate/throwout bearing combo:

215mm clutch disc - part #: 21 21 1 223 575 (or 21 21 1 223 083)

215mm pressure plate - part #: 21 21 1 225 865 (or 21 21 1 225 207)

The throwout bearing must be from an e21 320i - part #: 21 51 2 226 729 (or 21 51 1 223 366)

When getting the flywheel resurfaced, make sure they know to leave a .020" lip for the clutch disc to ride on. As quoted from another member "The clutch disc rides on a raised platform. The mounting for the pressure plate sits .5mm "below" the central wear surface." Apparently any reputable shop should know this spec. It should look like this when complete:

It is also smart to replace the flywheel bolts. Like the flywheels, there are two different sizes of bolts to use. There are 8 bolts total.

If you are using a 228mm flywheel, you must purchase 8 of the 28mm bolts - part #: 11 22 7 805 885

If you are using a 215mm flywheel, you must purchase 8 of the 22mm bolts - part #: 11 22 0 616 143

Use RED LOCTITE on all the bolts and torque to 75 lb.ft.

Once you have everything purchased and installed, it'd be a good time to mock-up the transmission so you can figure out exactly how much to shorten the shift assembly and driveshaft by. You will need to pound in a small section of the transmission tunnel to allow room for the clutch slave cylinder, don't worry, this will not be visible from the inside. 

Since the Getrag 245 is longer than your original 4-speed, you will also need to either buy a pre-made transmission mount made specifically for 5-speed conversions or make your own. There are a few different ways people have done this. I would suggest buying a pre-made U-shaped one which allows you to utilize the existing transmission mount bolt holes.

Here is another way to do it that I found:

Once you have the mount figured out and the transmission is straight, now would be a good time to get your driveshaft measurement. Carefully measure the distance from the output shaft on the transmission to the input shaft on the differential. It is IMPORTANT that you take the guibo thickness into consideration when measuring (the 6-hole and 8-hole guibos have different thicknesses). Either measure the thickness of your guibo and subtract that from the overall distance between both flanges or install the guibo onto your output flange and measure from there. This is the final length that your driveshaft will need to be, so measure carefully, double check, and have it shortened to that length. It should be about 3.6" shorter than it originally was but every car is different so MAKE SURE you measure your own distance. It is also recommended to purchase a new driveshaft center bearing and install that before final installation.

Driveshaft center bearing part #: 26 11 1 206 502

You will also need to shorten your shift platform and shift linkage so the shifter lines up in the original hole on the transmission tunnel or buy a pre-shortened kit such as this one from Ireland Engineering: http://www.iemotorsport.com/mm5/merchant.mvc?Screen=PROD&Store_Code=ie&Product_Code=025spplate&Category_Code=2002-clutch-driveline

A longer speedometer cable is also needed. One from an automatic 2002 can be used. As quoted "Two versions of this cable are available. For pre-'75 cars, the cable is one long piece. For '75-'76 US models that still have the EGR/Reactor Service mileage switch box, only the lower half of the cable needs to be replaced. Of course, the earlier cable can be used to

bypass the switch box altogether.

Cable, pre-'75 models: 62 12 1 351 720

Cable, lower half, '75-'76 models: 62 12 1 359 333"

 

[nbcbird]

You need to provide a detailed pic of the output shaft flange and indicate the location of the shorter bolt (about 1 or 2 o'clock). This was discussed about a day or two ago on the forum.

[CubbyChowder]

You need to provide a detailed pic of the output shaft flange and indicate the location of the shorter bolt (about 1 or 2 o'clock). This was discussed about a day or two ago on the forum.

sorry, I am unfamiliar with this shorter bolt, care to elaborate so I can post it in the article?

[Taymar]

Thanks for taking the time to put this together, it's going to be a huge help. Including part numbers was a really nice touch.

If you need any photos modified (arrows, annotations, highlighted areas etc.) I'd be happy to help. Perhaps pointing out which bolt is shorter, and where the lip is on the flywheel.

[Koblenz]

This is shaping up nicely. It is giving me a great amount of insight. Great job.

[CubbyChowder]

Thanks guys, honestly if you have any ideas on how to make this more informative or more simple feel free to just do so and I will edit the post. Also, if you guys have better pictures or descriptions just let me know.

Are there any areas that I am missing or where I should elaborate more?

[JerryC]

I vaguely recall that the differential mounts allow a small amount of adjustment front to back. Would you want to center the differential housing before taking the driveshaft length measurement?

[M3M3]

jgerock had a long 5spd conversion thread that has tons of pics and a complete list with part numbers of all the needed brackets, seals, bushings, bolts, etc.

[Gre@semonkey02]

Hey does anyone know if the 4 speed 4 bolt flange fit on the 5 speed I wana use my driveshaft

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[John_in_VA]

Other resources:

http://www.bimmers.com/02/upgrades/transmission.html

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

[M3M3]

Hey does anyone know if the 4 speed 4 bolt flange fit on the 5 speed I wana use my driveshaft

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there was just a thread on that topic two days ago....

 

you are going to have to send the ds off to be cut anyway.

[Gre@semonkey02]

Ya I know I gota send it away to be shorted but I'm asking my 4 speed has a 4 bolt flange can I transfer that to the 5 speed did anyone do that or they go buy one

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[pehlivanov_tii]

I have Getrag 245, but it's a CR dogleg, not an overdrive. Is everything the same with the conversion?

[jgerock]

I have Getrag 245, but it's a CR dogleg, not an overdrive. Is everything the same with the conversion?

The close ratio 5 speed is shorter than the overdrive version so the mount, shift tower, shift Rod and driveshaft will have different measurements. I believe the BMW blue book describes the CR 5 speed installation.

[Gre@semonkey02]

Well I just need a 4 bolt flange for the 5 speed or 3 bolt flange off a drive shaft

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