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Discussion Starter #241
Alright, this thing again. Basically I think I'll be pulling off the solenoid plate from the top of the new trans and putting it on the old one. Will take pics and advise the hive as I do...
 

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Discussion Starter #243
Did that at lunch. ...or at least flipped all the forks back into center position and trans turns just dandy.

How much of a wear item are the piston seals? Wondering if I really need to do them. Was going to do all the solenoid o-rings (clutch and shift).
 

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I only did the clutch and the other 2 at the top (unclear at the moment what they are called), those had visible tearing.
 

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Discussion Starter #245
Ok, here we go aaaaagain. Gotta add fluids, plug it in and make sure gear tracks and plcd read. I don't plan on pressurizing hydraulics until trans in, don't want to have issue with clutch slave cylinder.
940033
 

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Discussion Starter #246
So. I am posting this from the damn asylum where mein BMW therapist has allowed me use of ze internet.
****.

Got the mongrel trans all together and schlepped it up near the car enough to plug in everything to check gear position tracks in INPA as well as everything I could without powering up the hydraulic pump (remember that).

R/1st track ****ed just like the other trans. Hydraulic pressure read 70 bar (WTAF) which was interesting considering it was 1) depressurized before removal and 2) all solenoids were removed and re-o-ring-ed. F.F.F.

Please recall I checked the controller on my other car and all good. That leaves just the damn wiring harness.

Will plug another harness in tomorrow and ve vill see.
 

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So you’re saying the pressure somehow reads 70 bar, but the SMG motor never ran???
Perhaps you have a bad or shorted wiring for ze pressure transducer and this the computer is getting a false value and then doing something to move one of the gear solenoids. You can remove that Transducer easily and see what the ref voltage is what it is under pressure. Not hard to create a V vs. pressure graph.
 

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Discussion Starter #250
Think engine is ok, didn't see bad pins but will try to sort that out today. No way 70 bar is right. Zomezing ist nein right mein Herr...
 

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Discussion Starter #251
Ok, so there are basically three parts on the SMG: controller, wiring harness and ze transmission.
Controller confirmed good on the other car, had to change the original trans gear position sensor plate out and thought that was it. The replacement gear position sensor plate read ok on INPA, so I went ahead and heat-shrunk the wiring on the sub harness.
Re-oringed all the solenoids, and assembled the trans.
Before installing the trans though, got it up into position with a trans jack and connected everything all together. No joy on 1st/R gear position sensor track. F-u-k! Also what looked odd was hydraulic temp/pressure didn't look right (reading 7 bar when it wasn't pressurized).

Sooo, took the harness that the replacement trans came with and plugged it into the E-box with the trans now alongside the car. A-ha.

All sensor tracks started to read reasonably, and also the temp/pressure looked right.
Then disconnected the replacement gear position sensor connector and connected the original (insulation repaired) gear position sensor (plate off trans so could wiggle hydraulic pistons), and bingo all tracks read and reacted to movement on the piston.

Looks like... while yes the gear position sensor had the wiring insulation issue, the sensor itself is ok.
The original problem (or perhaps a secondary failure) is the harness itself. I'll rip apart the harness to see if I can find any damage but it sure looks like the harness at present.
 

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Nice progress. Remember gear position sensors cannot be swapped - they are matched (programmed) to each individual smg unit. While swapping may work, Jim described other issues when doing so.
 

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Discussion Starter #253
Pretty sure they are matched to the 'hydraulic unit' which really is the top plate/sensor/solenoids as relates to the shift piston position sensor function.

At least the posts of Jim's that I could read alluded to the sensor having to be matched to the plate/pistons/cylinders if I understood Jim's posts correctly.
 

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Pretty sure they are matched to the 'hydraulic unit' which really is the top plate/sensor/solenoids as relates to the shift piston position sensor function.

At least the posts of Jim's that I could read alluded to the sensor having to be matched to the plate/pistons/cylinders if I understood Jim's posts correctly.
Correct, mated to the hydraulics (what I called smg unit), not the trans itself.
 

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Wow bizarre, my only guess is someone "repaired" the harness before, regular mechanical damage would just mean no continuity on whatever wires.
 

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These issues are worrying. The wire insulation on these harnesses is worse than paper, so I’m not surprised.

If he was seeing a 70 bar value, when he knows the system is not pressurized. 70 bar is like 1000 psi.

that’s likely a sign of an issue somewhere in the circuit where the signal short to power (vs. short to ground). Usually pressure transducers have a signal line that is expecting a positive voltage, which is proportional to positive pressure. Short to ground would result in a pressure reading on the low side.

Seems like we can conclude that there was a short in the harness. based on sh*t like this, these are the things that worry me about these cars over the next decade. Electrical shorts are really hard to diagnose, DTCs (codes) are often useless since shorts cause false signals (and fires too)

940197
 

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Discussion Starter #258
I have a harness. I suspect that the clutch was done as clutch looks 'newish', and it is earlier car with the delrin release bearing.
during that deal harness was possibly damaged?? No idea really.

Anyhow I will be pulling apart the existing harness in effort to confirm damage/some short internal to harness. Also to splice in the tailshaft speed sensor wiring (replacement harness has damaged connector).
 

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Discussion Starter #259
Ok, tailshaft speed sensor wiring spliced in to the 'new' harness. I'll sling the trans alongside the car and plug in to make sure everything coming across in INPA then install harness, then trans.

Given the other thread (engine swap) looks like I need to cast a suspicious eye to the engine harness as well.

And now, of course, the other car seems to have shat a throttle actuator(s). Sigh.
 

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Discussion Starter #260
Ok, test fit up the repair harness and all systems seem to read normal values. Trans goes back in soon. Got a damn dental implant in work, and had to get a bigger healing screw put in. Feeling that now, so probably not much more progress today!
 
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