86 528e auto trans replacement output shaft different

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Racer 468
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86 528e auto trans replacement output shaft different

Post by Racer 468 »

Greetings, I bought what appears to be the same 4hp-22 trans to replace mine which is caput. I compared the two transmissions for the first time and found the trans output shafts are different. One has three bolts and the other 4. Otherwise they seem the same except one had large RED block letters saying " U P" which is three yoke. and the other has the same red " A C" which is four bolt and in the car. Wondering if the solution is a U joint and 3 bolt driveshaft yoke or should I swap out the "output" shaft and renew the seal. Are the shafts the same size and interchangeable?

Thanks for any help!
Ju@n
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Re: 86 528e auto trans replacement output shaft different

Post by Ju@n »

4hp22-eh have 4 bolts if i'm not mistaken, I THINK non-eh 4hp-22 have the 3 bolt ones
Racer 468
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Re: 86 528e auto trans replacement output shaft different

Post by Racer 468 »

What impact does that have?
Can someone direct me to info on these transmissions. I have read all I can find and still can't get any clarity and direction on what I thought would be simple. Humbled and Begging for help in Virginia.
1st 5er
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Re: 86 528e auto trans replacement output shaft different

Post by 1st 5er »

Racer 468 wrote: Jan 29, 2023 8:22 AM What impact does that have?
Shift inputs.
EH = electronic inputs
___ = mechanical inputs
1st 5er
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Re: 86 528e auto trans replacement output shaft different

Post by 1st 5er »

Racer 468 wrote: Jan 29, 2023 8:22 AM
Can someone direct me to info on these transmissions.
There's this, viewtopic.php?f=3&t=61367
Racer 468
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Re: 86 528e auto trans replacement output shaft different

Post by Racer 468 »

Thanks, I guess I'm out of luck. Does anyone have a NON EH 4 boly output they want to sell. Real shame this EH is fresh.
Mike W.
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Re: 86 528e auto trans replacement output shaft different

Post by Mike W. »

Digging into Realoem.com it doesn't appear that there were any US spec EH trannys for M20 engines. So if it's an EH tranny, it is probably for a M30 engine. The sure way to find out if it's an EH or not is to look for the electrical plug, somewhere on it. I don't recall exactly where or even if it's a little pigtail with a plug, or just a plug.

What car did it come out of? One out of an E30 325e should work, but if it's out of a 325i it might not work well as the torque curve is very different.

Look at the bellhousing. If the holes are a mix of 8MM and 10MM, it's for an M30. If they're all 12MM, it is for a M20.

If it is the correct tranny, just swap the output flange with the one on yours currently. And it does appear E28s and E30s used different output flanges, I don't know what the difference is, but it might be 3/4 bolt.
Racer 468
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Re: 86 528e auto trans replacement output shaft different

Post by Racer 468 »

Thanks! I have asked what specific model the three bolt replacement came from.

I'm on board with you on the simple swap of output flanges and have ordered a new seal.

The two bell housings are identical as far a having connections in common. One concern is that the new trans has the mounts for the two electrical connection on drivers left but maybe it's just cast that way and there is nothing for the sensors to read. If this is the case maybe swapping the bellhousing and flywheel? Getting ahead of myself I know.


I appreciate all help and apologize if I seem frustrated.

More to come as I think photos will help.

Peace and Thanks
1st 5er
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Re: 86 528e auto trans replacement output shaft different

Post by 1st 5er »

The EH tranny has a 7 or 8 pin male connector on the left side down near the oil pan.
All trannies have a 2 spade male connector on the left side near the top for the reverse light connector.
Mike W.
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Re: 86 528e auto trans replacement output shaft different

Post by Mike W. »

Racer 468 wrote: Jan 29, 2023 6:15 PM
One concern is that the new trans has the mounts for the two electrical connection on drivers left but maybe it's just cast that way and there is nothing for the sensors to read. If this is the case maybe swapping the bellhousing and flywheel? Getting ahead of myself I know.
I know M30s much better, but in this regard I think M20/M30 are similar. On M30s, the speed and reference sensors to read the flywheel to run the Motronic system are located in the bellhousing, lower left. My guess is M20 is the same, and that you need them.
Racer 468
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Re: 86 528e auto trans replacement output shaft different

Post by Racer 468 »

Thanks to all for the help. I spoke with the gentleman I bought the trans from and he immediately offered a refund if needed but was confident this will work if I simply swap out the output flange. It did come from an 87 528 (mine is an 11/85 manufactured 86. His confidence is based on 28 years experience with these cars. Stay tuned!
Aldo525
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Re: 86 528e auto trans replacement output shaft different

Post by Aldo525 »

According Realoem the auto gearbox ZF 4HP22 AC was mounted only on e30 325i until 07/88 (part number 24001216571), but no on e28. However, ZF 4HP22 UP and AC have the same output shaft (24211216334) so maybe it can be swaped. (I mean yoke)

But consider MIke's observation: " One out of an E30 325e should work, but if it's out of a 325i it might not work well as the torque curve is very different."
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