In the 4 spd world is a Getrag much better than a ZF?
- Thread starter Nicad
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The Getrag is supposedly more durable but I've never driven a sweeter trans than the ZF in our 2800! The shifter is integral to the trans housing meaning no slop, just snick, snick, snick between gears.
Good to hear that Chris. I'm hopefully going to drop the trans to rebuild the shift bushings and seals in the next month or so.
Chris is spot on... the ZF 4 speed just "feels" better and I would not change it over for another 4 speed as long as it's serviceable.
My bronze bushing upgrade with uuc shifter rod will give the getrag the snick snick desired
Steve, I beg to differ. There are no bushings to wear in the ZF, the lever acts directly on the shift rod and no sheet metal platform that can move. Come out for a visit!
Something is wrong, when you get it out you can see that the lever just sticks into the trans, maybe it is the ball in the tunnel.
Chris is right. The ZF is so nice.
Good, looking forward to more time spent on my back with dirt in my face.
Wow, I wish I had a ZF 5 speed now. Since we can only go about 130 KMHr without getting beat up and having our faces in the newspaper, I don't think I will need or want the lowering of revs at this speed. A close ratio 5 speed might suit my engine very well though .
one comment,..
you should not use a 4 spd zf in a 3.0 car, probably it wont last long
always talking 4 spd, bmw changed the zf for the getrag a few cars after the production of the 3.0 began, this is a fact
rumour has it that the increased power of the 3.0 was not getting in good terms with the zf
i recall reading that explanation in a period magazine
not to mention those vitamined swaps of bigger engines that some people love
my 02
rgds
you should not use a 4 spd zf in a 3.0 car, probably it wont last long
always talking 4 spd, bmw changed the zf for the getrag a few cars after the production of the 3.0 began, this is a fact
rumour has it that the increased power of the 3.0 was not getting in good terms with the zf
i recall reading that explanation in a period magazine
not to mention those vitamined swaps of bigger engines that some people love
my 02
rgds
Perhaps the euro 3.0 had too much power for the ZF The euro 2800 CS with 9:1 compression pistons (and a ZF) is only a few HP off from a USA 3.0 CS with 8:1. Not doubting the factory decision, but I think a ZF would be fine in a US 3.0
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I agree, stock US or Euro 3.0 should be fine... the popular 3.5 torque motors are probably another story.
So many opinions, . . . so little data?
Much of what has been mentioned in this thread has been addressed before, including Murray's take on the subject: http://www.e9coupe.com/forum/threads/when-did-bmw-switch-from-zf-to-getrag-gearboxes-in-e3-9s.4024/
In the linked thread, there are a number of probable reasons offered for BMW’s change from ZF to Getrag. I suspect the answer is still rooted more in economics with a tilt toward transmission durability rather than refinement. The reason for change may be analogous to the factory’s decision to change the M30's cam drive from a double row chain to a single row. One seems more durable,yet the other is not necessarily more prone to failure and is presumably less expensive and perhaps even consumes less energy. So, is one cam drive more desirable than another?
To the best of my memory, in the early ‘70s, BMW and Volvo were two primary users of Getrags. Early ‘70s Mercedes used ZF and eventually their own transmission design. Competitive cost was a likely factor, and that probably included something about which, I have little knowledge: relative availability and/or ability to meet anticipated production (- before any fuel crisis). After the ‘73 fuel crisis, there was probably some scrambling to provide transmissions that were lighter in weight and had better (lower) ratios, “geared” more toward fuel economy. If I am not mistaken, the same scenario led to the smaller displacement 2.5L E9.
Neither transmission type has a monopoly on indestructibility. Rumor regarding one transmission design's strength and ability to reliably handle torque - is not he same as proven fact. Probably, the biggest wear items in either transmission are synchronizers. The linked-thread mentions different synchronizers. I can't recall whether this is a change from Porsche style versus Borg Warner style synchronizers, the former being arguably less rugged than the latter. Next on the list might be the main and layshaft bearings. When these parts wear, both transmissions can make plenty of undesirable noise. Manufacturers’ statistical analysis and/or racing results might be the final determiners as to whether one transmission type was more prone to failure and needed more frequent repairs than the other. (Frequent inexpensive repairs - versus - infrequent expensive repairs, is another consideration for historical statisticians. Hint: the labor for replacing synchronizers under warranty is probably not cheap, and not every E9/E3 driver probably treated each shift as though he/she was driving with a wedding cake balanced on the roof.)
Whether one transmission design is more refined than another, I am not so sure. Revisit the linked thread ^^^^ and it is apparent that the ZF is not immune from criticism. Chris has a good point with the ZF’s gear shift action being superior to the Getrag’s. It has fewer moving parts and the shifter platform is not isolated from the transmission body. The Getrag, on the other hand, has metal/rubber spacers PN25111202842. Some may argue that there is no need to isolate the shifter from the transmission housing and therefore from other drive line vibrations. Then why were they used? Intuition alone suggests the factory may have considered that the two piece driveshaft and all of its related components may not have remained perfectly balanced and there may have been an anticipated need for additional vibration suppression. Still, drive shaft vibration is a definite possibility regardless of transmission type. So, were these metal/rubber spacers used to correct a problem that many of us never experienced? All things being equal, the ZF-design, while being superior in shifting, is arguably inferior to the Getrag in shifter vibration suppression. (I have no idea whether one transmission vibrates more than another.)
How does the ZF gearshift operation really compare with a well-lubed Getrag equipped with new (unworn) bushes? Admittedly, it has been a long time since I have shifted a low mileage ZF 4-speed, but I was never awed by its shifting operation versus the Getrag. Perhaps I should have paid more attention, but I never had any concerns with the latter style transmission. To be sure, I have experienced my fair share of sloppy shifters. However, bushing (rubber/spacer) replacement was never the biggest ordeal, and fortunately, it is an infrequent occurrence. Of course, neither transmission is a pleasure to shift, if the rubber transmission mount is kaput.
Bottom line: Just like the choice of the cam drive chain, be it single or double row, it probably makes the mos sense to keep what you have. The pros and cons of each transmission do not necessarily warrant a complete change, except to maintain originality.
Much of what has been mentioned in this thread has been addressed before, including Murray's take on the subject: http://www.e9coupe.com/forum/threads/when-did-bmw-switch-from-zf-to-getrag-gearboxes-in-e3-9s.4024/
In the linked thread, there are a number of probable reasons offered for BMW’s change from ZF to Getrag. I suspect the answer is still rooted more in economics with a tilt toward transmission durability rather than refinement. The reason for change may be analogous to the factory’s decision to change the M30's cam drive from a double row chain to a single row. One seems more durable,yet the other is not necessarily more prone to failure and is presumably less expensive and perhaps even consumes less energy. So, is one cam drive more desirable than another?
To the best of my memory, in the early ‘70s, BMW and Volvo were two primary users of Getrags. Early ‘70s Mercedes used ZF and eventually their own transmission design. Competitive cost was a likely factor, and that probably included something about which, I have little knowledge: relative availability and/or ability to meet anticipated production (- before any fuel crisis). After the ‘73 fuel crisis, there was probably some scrambling to provide transmissions that were lighter in weight and had better (lower) ratios, “geared” more toward fuel economy. If I am not mistaken, the same scenario led to the smaller displacement 2.5L E9.
Neither transmission type has a monopoly on indestructibility. Rumor regarding one transmission design's strength and ability to reliably handle torque - is not he same as proven fact. Probably, the biggest wear items in either transmission are synchronizers. The linked-thread mentions different synchronizers. I can't recall whether this is a change from Porsche style versus Borg Warner style synchronizers, the former being arguably less rugged than the latter. Next on the list might be the main and layshaft bearings. When these parts wear, both transmissions can make plenty of undesirable noise. Manufacturers’ statistical analysis and/or racing results might be the final determiners as to whether one transmission type was more prone to failure and needed more frequent repairs than the other. (Frequent inexpensive repairs - versus - infrequent expensive repairs, is another consideration for historical statisticians. Hint: the labor for replacing synchronizers under warranty is probably not cheap, and not every E9/E3 driver probably treated each shift as though he/she was driving with a wedding cake balanced on the roof.)
Whether one transmission design is more refined than another, I am not so sure. Revisit the linked thread ^^^^ and it is apparent that the ZF is not immune from criticism. Chris has a good point with the ZF’s gear shift action being superior to the Getrag’s. It has fewer moving parts and the shifter platform is not isolated from the transmission body. The Getrag, on the other hand, has metal/rubber spacers PN25111202842. Some may argue that there is no need to isolate the shifter from the transmission housing and therefore from other drive line vibrations. Then why were they used? Intuition alone suggests the factory may have considered that the two piece driveshaft and all of its related components may not have remained perfectly balanced and there may have been an anticipated need for additional vibration suppression. Still, drive shaft vibration is a definite possibility regardless of transmission type. So, were these metal/rubber spacers used to correct a problem that many of us never experienced? All things being equal, the ZF-design, while being superior in shifting, is arguably inferior to the Getrag in shifter vibration suppression. (I have no idea whether one transmission vibrates more than another.)
How does the ZF gearshift operation really compare with a well-lubed Getrag equipped with new (unworn) bushes? Admittedly, it has been a long time since I have shifted a low mileage ZF 4-speed, but I was never awed by its shifting operation versus the Getrag. Perhaps I should have paid more attention, but I never had any concerns with the latter style transmission. To be sure, I have experienced my fair share of sloppy shifters. However, bushing (rubber/spacer) replacement was never the biggest ordeal, and fortunately, it is an infrequent occurrence. Of course, neither transmission is a pleasure to shift, if the rubber transmission mount is kaput.
Bottom line: Just like the choice of the cam drive chain, be it single or double row, it probably makes the mos sense to keep what you have. The pros and cons of each transmission do not necessarily warrant a complete change, except to maintain originality.
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well elaborated, thanks