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MitchaPaLoOza88

Early vs Late Transmission 1600-2

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I know there’s a lot of stuff dedicated to this but...

I have an early drivetrain (68) in the car with the long nose final drive and trans and I have an entire late year drivetrain from a 70. Which is better?

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(edited)

There are two different drive-train set-ups for the long neck diff:

1. The 1600-2 (1966-MId 69)

2. The 2002 (1968 - Mid 69)

 

I'm assuming  you have the 68 2002. If you do, that is the best driveshaft and diff used in any 2002. The driveshaft has the serviceable u joints with grease nipples and is telescopic. The long neck diff is superior to the later short neck versions for several reasons:

1. It holds more oil and stays cooler.

2. It is heavier. And, that is exactly where you want more weight in an 02, at the rear axle, resulting in better balance.

3. You can loosen the hex nut at the front and remove the yoke to get to the seal when you need to replace it without worrying about the crush collar. That's because there is another hex nut deep in the neck which torques down the crush collar. This is not the case with the short neck diff where there is just one hex nut at the front which holds the yoke and torque on the crush collar. Once you loosen the nut to replace the seal you need to also replace the crush collar which requires further disassembly of the diff. The later design is cheaper to manufacture. But, it is certainly not the better of the two. Short neck diffs and drive train layouts are popular with the 02 community because they are more plentiful and also available in the limited slip versions (3.64 & 3.90) as used on the 320i "S" package cars. During the early years BMW produced long neck diffs in every imaginable ratio and limited slip action for the race cars. They are easier to locate in Europe, though.

 

Each corresponding diff version requires a specific rear sub frame. You can't simply swap the diff styles without also swapping the rear sub frame. Many people have swapped to the later style sub frame, driveshaft and diff so they can drop in the popular 3.90LSD from the 320i while doing their 5 speed OD conversion. But, I would never choose this route. Your long neck is superior. If you want another ratio in the long neck, you can find it if you look. And you can always have it rebuilt to include the limited slip. There are a few very competent people in the 02 community who are good at building diffs.

 

BMW moved to the later short neck design because it was cheaper to produce, but it wasn't better.

 

 

 

Edited by Autostrada
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9 minutes ago, Autostrada said:

There are two different drive-train set-ups for the long neck diff:

1. The 1600-2 (1966-MId 69)

2. The 2002 (1968 - Mid 69)

 

I'm assuming  you have the 68 2002. If you do, that is the best driveshaft and diff used in any 2002. The driveshaft has the serviceable u joints with grease nipples and is telescopic. The long neck diff is superior to the later short neck versions for several reasons:

1. It holds more oil and stays cooler.

2. It is heavier. And, that is exactly where you want more weight in an 02, at the rear axle, resulting in better balance.

3. You can loosen the hex nut at the front and remove the yoke to get to the seal when you need to replace it without worrying about the crush collar. That's because there is another hex nut deep in the neck which torques down the crush collar. This is not the case with the short neck diff where there is just one hex nut at the front which holds the yoke and torque on the crush collar. Once you loosen the nut to replace the seal you need to also replace the crush collar which requires further disassembly of the diff. The later design is cheaper to manufacture. But, it is certainly not the better of the two. Short neck diffs and drive train layouts are popular with the 02 community because the are more plentiful and also available in the limited slip versions (3.64 & 3.90) as used on the 320i "S" package cars. During the early years BMW produced long neck diffs in every imaginable ratio and limited slip action for the race cars. They are easier to locate in Europe, though.

 

Each corresponding diff version requires a specific rear sub frame. You can't simply swap the diff styles without also swapping the rear sub frame. Many people have swapped to the later style sub frame, driveshaft and diff so they can drop in the popular 3.90LSD from the 320i while doing their 5 speed OD conversion. But, I would never choose this route. Your long neck is superior. If you want another ratio in the long neck, you can find it if you look. And you can always have it rebuilt to include the limited slip. There are a few very competent people in the 02 community who are good at building diffs.

 

BMW moved to the later short neck design because it was cheaper to produce, but it wasn't better.

 

 

 


Wonderfully articulated!
 

Thanks and regards,

 

Steve

 

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7 hours ago, Autostrada said:

There are two different drive-train set-ups for the long neck diff:

1. The 1600-2 (1966-MId 69)

2. The 2002 (1968 - Mid 69)

 

I'm assuming  you have the 68 2002.


Sorry late night post should have been clearer.

- I have a 68 1600-2 original setup in the car right now. Getrag 232?

 

- I also have a 70-71 entire drivetrain (engine, trans, diff, driveshaft, F&R Subframes) from another 1600-2. Getrag 242?

 

Thank you so much for that response. My original inclination was to run that early setup and if it dies then swap to the later one.

 

It seems like you’re mostly talking about the final drives but what about the transmission differences?
 

Just from my research, it seems like parts for the early Getrag 232 are NLA (or is that just synchros are NLA)? While it’s out I was honestly just gonna change the oil and the throw out bearing and slap it back in. But is there any thing I could look for to diagnose it?

 

Thanks for all the responses, when I dig into things I like to gather as much knowledge as I can, relevant or not

E8F2AE65-E9AD-417F-99FC-ED8AEE0AC617.jpeg

6853A174-E299-48FC-862B-59A25EB4E42B.jpeg

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I thought that parts for both the 232 (Porsche synchros) and 242 (Borg Warner synchros) were growing difficult to source...

 

The Borg Warner synchros, however, tend to hold up a bit better than the Porsche synchros. Not wildly better — for cars that are driven hard — but better.

 

I’ve worn out both types multiple times, despite always double-clutching on downshifts. I don’t pause, however, on upshifts, as kinder owners often do!

 

Regards,

 

Steven

 

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(edited)

I don't know exactly when they changed the designation of the 4 speed from 232 to 242 as there were several changes made to the 4 speed during the production run (1966-76).

My answer to your question depends on what you are planning to do with your car and also on your personal preferences.

 

The 232 first appeared in the 1600-2. It remained essentially unchanged until the factory started equipping the 1600-2 with the short neck diff and corresponding sub frame and driveshaft at some time around 1970. These early 1600-2 transmissions have the following features:

1. Smoother case

2. Porsche synchroes: Resulting in silk smooth shifts, but supposedly weaker than the later Borg Worner synchros which are not as smooth. I prefer the Porsche synchros. And, I've never had a problem with them while clocking Hundreds of thousands miles on 1600-02s. But, I don't drive my cars like a Gremlin. And, they may be more prone to wear with the more powerful 2 liter.

3. 3 bolt yoke with 6 bolt flex disc (A slightly smaller 6 bolt flex disc than the one on the 320i):

The shift fork mating point to the linkage is immediately above the flex disc. While the 3 bolt yoke is interchangeable with the 4 bolt yoke of the 2002, there is no way you can install the 8 bolt guibo of the 2002 on this transmission due to the location of mating junction for the linkage. There isn't enough room.

 

BMW had two different drive trains for the 02s equipped with long neck diffs.

1. 1600-2

2. 2002

 

They differed primarily in the driveshaft. The factory redesigned the driveshaft while trying to account for the additional torque of the 2 liter motor. So, they replaced the 3 bolt yoke and 6 bolt flex disc at the transmission with a 4 bolt yoke and 8 bolt flex disc at the transmission. In doing so they had to include a longer shift fork on the transmission (the only, but very important modification to the transmission at this point), moving back the mating junction for the linkage aft of the 8 bolt guibo, otherwise the guibo wouldn't fit in its location. You can tailor most 2002 coarse splined 4 speed transmissions to fit the early 1600-2s, but the early 1600-02 transmissions can't be mated to the 2002 unless you disassembled them to include the longer shift fork). The early 1600-02s had 3 flex discs on the driveshaft and u joints while the 2002 had a larger 8 bolt flex disc at the transmission end and two joints ( one at the center and one at the diff end of the driveshaft. I've also heard that the 2002 driveshaft was better balanced. It is rated for higher torque. But, many people have installed 2 liter engines in their early 1600-2s and had no problems with the early driveshaft.

 

When BMW switched to the short neck design they essentially just extended the length of this drive shaft and did away with the grease nipples at the u-joints which were a cool feature on the 68 2002. The factory also simplified things and included the same driveshaft for the entire 02 range.

 

So, my answer to you is: If you plan on installing a 2 liter motor in your car at some point in the future and in keeping with the factory philosophy necessitating a driveshaft redesign for the 2002 to accommodate the additional torque of the 2 liter motor, you may opt for the later 70-71 set-up. But, as I mentioned, many people have ran 2 liter motors with the early 1600 driveshafts with no problems. And, as I've mentioned in my earlier post, the short neck diff is more readily available in different gear ratios and limited slip variants. But, I personally feel that the long neck is a better design.

 

One additional important matter:

The sub frame for the short neck diff has wider spaced mounting ears for the trailing arms. The trailing arms are all the same, though, but the bushings in the trailing arms used for the later sub frames are wider, protruding slightly out of trailing arms to accommodate the wider spacing of the mounting ears. These wider bushings are common. The earlier narrower bushings are difficult to obtain. BMW starting manufacturing them again, but they screwed up and made them slightly too small in diameter. So, they really don't work. Some people have simply modified the later bushings by cutting them to fit the earlier mounting ears. This is another important matter to keep in mind. It is very easy to obtain the later style bushings while you have to get creative in replacing the early ones.

 

 

 

 

 

Edited by Autostrada
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(edited)

Damn just seeing this now. Too late to put the late one in now. I'll keep it in mind if I ever decide I wanna switch.

 

As for how am I gonna drive it... Like a 1600-2 and wink at hunnies as I pass by

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Edited by MitchaPaLoOza88

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