1600 4-speed to 2002 4-speed swap question

[Conserv]

14 hours ago, Alexander said:

… Did they even make the automatic at the time when the 2002s were equipped with the long neck?…

Good question. I would have assumed “no” if @Peter Zettler had not weighed in.

 

Although the U.S.-spec version of the 2002A does not appear to have been manufactured before May 1969, the production of both LHD and RHD 2002A’s s for ROW (Rest Of World) appears to have begun in January 1969, just in time to produce a few 2002A’s with long-neck differentials.

 

Blue highlighted rows below show 2002A LHD and RHD production beginning in January 1969, with VIN 2500001 and 2520001, respectively.

 

Best regards,

 

Steve

 

 

[Peter Zettler]

Mine is a 1602,1968. In order to swap the long neck for the short, you have to swap to entire rear assembly. The mounts are very different. I've done that on a 1967 1602. 2002 trans( fine spline) it all swaps ( driveshaft, guibo,ect). It's a fine upgrade partially because of the 2002 guibo. The so called " Frankenstein " drive shaft is tricky. But, I don't race the car. It was my work car( realestate) ect. I bought  rolling shell and had access to every part used for all 1602's and 2002's. I built the car,  based on what I liked aesthetically and functionally. So my input may be impossible for most at this time. Guess it is a " Frankenstein " car. But, drives like new(120,000) over the last 27 years. One of the best upgrades is a 320 radiator, another is a manual advance distributor with electronic ignition. The Weber 2 barrel is unbeatable! 4piston calipers on the front and big drums on the back. Big sways front and back. Bilistiens all around, Sthal header. My pedal box is from a 2002 as well,brake system and wiring harness. Interior is from a 1974( best aesthetically.) Rotary A/C compressor. These cars are masterpiece of engineering. Drive it till I die I hope! Peter Z

 

 

[Peter Zettler]

On the 4sp output shaft ( course or fine spline). The course spline tended to strip. Particularly if you raced. The course will last indefinitely if installed correctly and not over stressed ( normal street driving). I used loctite and really torqued the nut. It's never moved in over 100k miles. The same goes for the output flanges on the rear end. You have to have the right flange to go from U joints to cv's. PeterZ

[Alexander]

1 hour ago, Peter Zettler said:

The course spline tended to strip. Particularly if you raced.

Yes, it strips with the 2.0L if driven aggressively, but less often, if ever with the 1.6L which produces much less torque. Even the high performance high horsepower 1.6L engines produce less torque.

 

In regards to your sub-frame swap to accommodate the short neck diff and longer driveshaft, it's actually a down grade as far as I'm concerned. The long neck diffs are superior to the short neck diffs because they hold more oil and the crush collar nut is located deep in the neck where it doesn't double as the flange nut like on the short neck. So, you can safely replace the flange and / or oil  seal without affecting the crush collar. Once you loosen the flange nut on the short neck, you got to disassemble the entire diff to replace the crush collar. This is not the case with the long neck. So, the long neck is much easier to service. It's also heavier. This is exactly where you want more weight on an 02.

 

The short 2002 specific driveshaft from the 1968 2002 is also superior to the later long driveshaft on the short neck equipped cars. The 68 driveshaft is both, telescopic and has the u-joints with the grease nipples for maintenance. BMW went to the short neck diff and longer driveshaft because they were cheaper to produce. A lot of builders are swapping out sub frames and switching to the short neck configuration because the 3.90 limited slip short neck diff from the 320i"S" is more readily available, especially here in the US. BMW actually produced the long neck in every imaginable ratio and limited slip action. They were used on early NK  and 02 track cars. But, you got to look for them in Europe. I also have all the parts for the short neck configuration, but I opted to stay with the long neck. I had my 4.11 long neck rebuilt to limited slip. The builder used some of the guts from a 3.90LSD I provided him.