New Member in California

[e9orama]

Hello e9ers,

Thank you all for putting this forum together and contributing so much to it. I've read few strings as a guest on and off, and enjoy all the great stories, photos and so on. I hope I can contribute some worthwhile stuff too.

I've had my '74 coupe for at least 20 years (gee, maybe a lot more). When I bought it, there was no internet. Buying locally was the only decent option. I drove a number of Los Angeles area cars over a period of at least a year before choosing this one.

I'm a bit outside the mainstream (if you can call it that) regarding my preferences. I chose a big bumpered '74 because the brakes were better assisted, and just seemed nicer than any of the earlier cars (I seem to recall a larger booster). And I preferred the inertia reel seat belts. Seems like small stuff now, but back then it made a difference to me. This car seems more quiet and refined somehow than the earlier ones I drove, but maybe that's because it was generally better kept than most of them.

Also - and here's where I expect some heat - my car's an automatic. I drove a few sticks and thought the auto, as bad as it is, was more suited to the nature of the car. Now, with traffic as bad as it has become around here, the auto seems an even better choice.

So here's the thing that really has me ambivalent about the car. Even though the trans is in fine condition, these early 3 speeds are certainly a disaster. Between the massive loss of power and the horrific fuel economy, there are times when I'd throw this thing out the window, if only I had it out of the car and a convenient window. I think the car would be just right with a more efficient, later trans like, perhaps, the 4 speed ZF that has been mentioned on this forum and elsewhere. However, I still haven't found anyone who has made that conversion and wonder if it can be done without major surgery. Also, I wonder if there'd be any real improvement. Or, perhaps there's another auto trans out there that could do the job. If anyone has some experience with this, I'd love to hear from you. The trans issue is the only thing that makes this anything other than my idea of one of the all time greatest cars around.

Thanks again to all of you!
-Dave

 

[CSteve]

I swapped out a slush pump for a four speed in my 2800CS. An enormous difference.

Then in my second coupe, a euro CS, I swapped an a reworked injected motor and five-speed. The gearing, I believe is the same, but the fifth gear quiets the car down and probably improves gas mileage, but who cares about that.

I would not recommend the close ratio five speed. I understand you will be shifting constantly. With a stick shift I drive the car, with an automatic I aim.

Steve

 

[jmackro]

I think the car would be just right with a more efficient, later trans like, perhaps, the 4 speed ZF that has been mentioned on this forum and elsewhere. However, I still haven't found anyone who has made that conversion and wonder if it can be done without major surgery. Also, I wonder if there'd be any real improvement. Or, perhaps there's another auto trans out there that could do the job.

Are you asking if there is a different/better automatic transmission that can be swapped?

 

[Stan]

someone once told me that anything can be done given enough money.
I would ask sfdon or Coupe King or La Jolla Independent

 

[Arde]

Where in California? Here in the Bay Area I can send you to a ZF guru that can figure out what can be done if you want to stay with the automatic.

The wholesale swap to the 635 type engione will improve fuel efficiency I hear.

 

[e9orama]

Thanks for the replies and input.

To clarify, Jay, I want to keep an automatic in this car. So yes, I'm asking if there's a better one available. The original 3 speed auto that's in the car now (I don't know if it's a Borg Warner or a ZF. I have read on this forum that both were used in these cars.) is horrible. It sort of reminds me of those old 2 speed Power Glides used in GM cars from the 60's. In both cases, the first gear is too high, the high gear is too low. And the loss of power going through is substantial.

I'd like to find out what is the best auto-to-auto swap. Ideally, I'd like to maintain the shifter and other interior pieces as all of that is still in nice condition and I want to maintain that original look. It seems to me that there must be a fair number of options out there, either from a later BMW or from some other car.

If anyone out there has found a good replacement - especially one that helps with the fuel economy - and has actually installed and used it, I'd like to hear from you.

Steve, it sounds like you've been there with your 2800CS. Could you elaborate a bit on that, please?

Stan, I talked to both Peter (Coupe King) and Carl (La Jolla Independent) about this about 10 years ago. Neither of them seemed particularly, well, interested in this idea. I didn't get any advice from them. I think they both figured the only option was to go to a 5 speed. But that was a while ago. Maybe they can appreciate my perspective now though.

I'm in L.A, Arde. But if you have a guy in the Bay Area who knows about ZFs, and wouldn't mind my bending his ear for a few minutes, I'd certainly appreciate getting hold of him.

Again, thanks to all of you for the help.

-Dave

 

[CSteve]

Dave, I understand your desire for originality. Why not rebuild your current automatic? Or there must be later autos, perhaps from a 5 series that would rob less power and give better mpg. I can only talk about my great results with automatic to four speed in my 2800 and four speed to five speed in my 3.0CS.
Steve

 

[Luis A.]

Dave,

Welcome to the forum. I'm interested in what you find out as I'm restoring a 3.0 Si (E3) which has the ZF 3HP22, which by some accounts, is not as bad as the BW. I drove for about 40 miles prior to dismantling teh car and it was well suited to the character of the car and how I'll be using it: enjoyably the yuppie-retro-luxo-cruise 70's style... So even though I'd like to keep it an automatic and very original I wouldn't be adverse to upgrading to a 4 speed auto and/or one w a lock-up torque converter. Keep us posted.

 

[e9orama]

Steve, the trans in the car only has about 15,000 miles on it and works as well as intended. But the ratios are lousy and it transmits power very poorly. It's just a bad design.

If you search this forum and any others that discuss these early cars, there's a fair amount of help regarding conversions to 5 speeds. That's great if you want that sort of thing but I drive a lot in town, with stop and go traffic. I need air and automatic (and a good cooling system). If I can get this issue sorted out, my next project will be a proper conversion to R134a. I don't know how much of a performance improvement will come from another, slightly later BMW automatic (or even complete drivetrain). Going by the fuel economy numbers that the government provides, they aren't a lot better than what I get from this car (about 13 - 16 mpg). Obviously, there's not much sense in spending months of spare time and 1000s of bucks to gain 1 or 2 mpg and little more torque (a 1990 535i gets 14 - 20). But a newer (and heavier) 2000 528i gets 16 - 24, which might be worth trying to duplicate. The thing is, I can't find anyone out there who's succeeded in doing that.

Luis, thanks for the welcome! Years before I had this car, I had a '71 2800 sedan, also with an auto. I seem to recall that transmission was a bit nicer (maybe it was a ZF?) but at the time, fuel economy wasn't as much a concern (I think gas was, like, 65 cents a gallon and I didn't drive that much. Also, I just don't recall the ratios, shifting, and so on to be as annoying as they are in this car. Of course, that was long ago and maybe I expected less. All European automatics were horrible then.

Anyway, good luck with your restoration. The sedans are lovely cars. I think they're actually a little better made than the coupes and I like the way they drive. Also, a door for each man (or woman) is good policy.

If I find a suitable answer to this, I'll be sure to post it here on the forum.
-Dave

 

[Stan]

From Vintage Sports & Racing

Basically yes they all do fit mechanically. The bigger challenge is with the latter transmissions that are electronically integrated with the engine Wiring and electronic switching for sport mode and normal driving.
Simply put if someone wants an automatic transmission to replace an original automatic the early 1980s automatic is a fully mechanical transmission.
I have never installed one of these in a CS coupe I do happen to have a good use automatic transmission removed from a car recently

 

[rb1971]

This is an interesting thread even if it's not something most of us would be interested in. Please keep us updated on what you find and make a build thread if you go through with this - you never know what might be helpful at some point.

Since the S38 from the E34 M5 fits in the coupe with not that many changes, I would strongly suspect that the automatic transmissions from the E34 series would be a good place to start for fitment. I think they used an M30 variant up through 1992 or 1993, and if I remember correctly they were available with 4 and 5 speed ZF transmissions at various points. You could probably get bell housing and transmission tunnel clearances from your car, and get the same information on the automatics from the E34.

One thing I don't know is how integrated those transmissions are with the other electronics in the car. With the motor, you can relatively easily integrate the "brain" - not sure about the trans.

 

[DougE]

It's Can Be Done

Hi Dave I have a 1972 3.0cs, I've done exactly the opposite of what most have done in that I converted a 4 speed to an auto. My conversion was a necessity in that I have MS, after I finished restoring the car I couldn't operate the clutch as such I installed a ZF-3 from a 1979 528i.

I looked into the idea of installing a ZF-4 but there are number of problems that I didn't feel the extra gear justified. The first 5, 6 & 7 series [1983 & 1984] had non electronic ZF-4's. These transmissions do not have speedometer drive. That's not an insurmountable problem the big problem for me was the lock-up converter. That’s great for getting more power to the rear wheels and lowering rpm’s but it's also much thicker therefore you need to modify the tunnel to accommodate the larger bell housing.

That said I had a friend rebuild the 528i ZF-3 using Kevlar clutches and I'm okay with it although nothing beats a 4 or 5 speed transmission when it comes to getting power to the rear wheels.

I remember sometime back there was a fully restored coupe for sale that had a ZF-4 installed. I tried to get more information on that conversion to no avail. I understand the purchaser bought the car provided the seller would install a 5 speed.

I've attached an interior shot of my coupe, it's kind of small but you might be able to see that I kept the manual console; the shift position box is on the left side of the console right beside the seat.

Doug

 

[e9orama]

If I'm reading the replies correctly, it seems there's a little contradiction. I'm curious as to whether or not the more efficient transmissions will fit without body mods. Stan, you say that they can but DougE says not - at least insofar as the ZF's are concerned.

I'm not particular to the ZF trans though. I figure if I'm going to install something that's not original to the car, it doesn't matter who makes it. I'd be fine with a Mercedes or old American box, if one of them worked. As I've already mentioned - and I don't think there's much disagreement - European automatics (at least the older mechanical ones) are pretty lousy. I'd be fine with something from the U.S. or Japan. If it were a matter of welding different tabs onto a bell housing to make one work, that would be fine. But I don't think I'm going to go so far as to start abusing the car's tunnel to get something to fit.

Then, there's still the question as to whether any of this will make a substantial difference. It seems that the transmission is the culprit as far as power loss and poor fuel economy are concerned. But maybe the engine is just as much to blame. Mine has the two downdraft Webers, replacing the original Zeniths. The old 2800 I had kept the Zeniths and I don't remember having any problems with them except a slight lope to the idle. It also had an auto and I don't recall the fuel economy or power being as much of a problem (but again, that was a long time ago). After the 2800, I had a carbureted '77 XJ6 with a TH400 (which was what they came with). It weighed almost 800 pounds more than an E3 or E9. Yet, it still had good power, got almost 20 mpg on the highway, and worked flawlessly.

I realize I'm a bit outside of the mainstream with my concern about fuel economy, but I don't see the point of owning this (or any) car if the milage is so poor that I'm disinclined to drive it.

DougE, do you have any sorts of numbers to describe how your car performs (mileage, 0-60, etc.) with the ZF3?

 

[DougE]

No I'm sorry I don't but I feel pretty good about the cars performance. You have to keep in mind that unless you've done engine mods this is 40 year old technology.

Doug