Engine/trans swap drive shaft too short!

E92inAZ · 10-28-2018, 03:33 AM

Swapping N52 with trans from a 2011 328i wagon into my 2007 328i coupe and everything seemed to measure out the same, all the mount points line up, but the driveshaft is about 25 mm too far away to attach to the flex disc. Should I go back to the salvage yard and get the drive shaft from the wagon? I'm having a tough time finding stats online about driveshaft lengths - also, I've just spent an entire day wrenching on this damned thing so I'm about to pass out. I'll uncover the rest of the drive shaft tomorrow and investigate further.

E92inAZ · 10-28-2018, 03:51 PM

ooohhhhhh,
never mind.
i have determined, after exhaustive research, that i'm an idiot.
they're all the same. thing is: we hadn't pried the flex disc loose. we took the bolts out, but it came apart on its own as we pulled the engine. obviously, the engine had moved backwards first, retracting the drive shaft and disengaging itself. then, we didn't touch anything rear of the flex disc so we didn't know it is a two piece driveshaft which, therefore, must extend and retract, plus we have enough oomph in our fingers to pull it to extension.
after pulling the cross brace, pulling the exhaust, and pulling the heat shield i was able to put two hands on the driveshaft and it stretched right out.
when things like this happen at the end of a 10 hour session wrenching, its best to sleep on it. it'll look different in the morning.

Phyrexia · 10-28-2018, 04:22 PM

I was thinking this was going to be the outcome. Glad you got it sorted.

Twoforty · 10-28-2018, 08:11 PM

Sleeping on it is like rebooting a computer ....
It generally solves most problems.

Efthreeoh · 11-04-2018, 10:15 AM

Quote:

Originally Posted by E92inAZ

ooohhhhhh,
never mind.
i have determined, after exhaustive research, that i'm an idiot.
they're all the same. thing is: we hadn't pried the flex disc loose. we took the bolts out, but it came apart on its own as we pulled the engine. obviously, the engine had moved backwards first, retracting the drive shaft and disengaging itself. then, we didn't touch anything rear of the flex disc so we didn't know it is a two piece driveshaft which, therefore, must extend and retract, plus we have enough oomph in our fingers to pull it to extension.
after pulling the cross brace, pulling the exhaust, and pulling the heat shield i was able to put two hands on the driveshaft and it stretched right out.
when things like this happen at the end of a 10 hour session wrenching, its best to sleep on it. it'll look different in the morning.

I'd like to comment here. So I have an April 2006 build E90 325i. I replaced the driveshaft in June 2017 at 324K. I was chasing a driveline vibration. It probably was just the center bearing (which I had already replaced at 250K), but I figured the price of a re-manufactured drive shaft was about $100 more than a center bearing and comes with new u-joints and a fresh balance. What I noticed is the early driveshafts do not have a locking bolt for the slip-joint section and the later driveshafts have a locking bolt. Also, my driveshaft used to "tink" when unloading the drivetrain. There are two internal nylon bushings on the slip-joint splines that I guess are designed to prevent noise. My original driveshaft did not have them (I added them when I did the center bearing at 250K).

Anyway, just some info in people read this thread.

10-28-2018, 03:33 AM	#1
E92inAZ Private 39 Rep 74 Posts Drives: 2007 E92 coupe Join Date: Jul 2015 Location: Glendale, AZ iTrader: (0)	Engine/trans swap drive shaft too short! Swapping N52 with trans from a 2011 328i wagon into my 2007 328i coupe and everything seemed to measure out the same, all the mount points line up, but the driveshaft is about 25 mm too far away to attach to the flex disc. Should I go back to the salvage yard and get the drive shaft from the wagon? I'm having a tough time finding stats online about driveshaft lengths - also, I've just spent an entire day wrenching on this damned thing so I'm about to pass out. I'll uncover the rest of the drive shaft tomorrow and investigate further. __________________ 2007 E92 328i coupe. 19" staggered VMR v710, front: 19x8.5 et35 continental 235/35 19, rear: 19x9.5 et33 continental 265/30 19; 1 inch front lowering perches; Msport rear bumper; roof spoiler; trunk lip; Bavsound UF110; carbon fiber wrapped interior trim; 3 stage BMW intake manifold; aFe magnum force stage 2 si pro 5R cold air intake; active autowerkes catless header; active autowerkes gen 2 signature exhaust; BPC stage 2 header tune
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10-28-2018, 03:51 PM	#2
E92inAZ Private 39 Rep 74 Posts Drives: 2007 E92 coupe Join Date: Jul 2015 Location: Glendale, AZ iTrader: (0)	ooohhhhhh, never mind. i have determined, after exhaustive research, that i'm an idiot. they're all the same. thing is: we hadn't pried the flex disc loose. we took the bolts out, but it came apart on its own as we pulled the engine. obviously, the engine had moved backwards first, retracting the drive shaft and disengaging itself. then, we didn't touch anything rear of the flex disc so we didn't know it is a two piece driveshaft which, therefore, must extend and retract, plus we have enough oomph in our fingers to pull it to extension. after pulling the cross brace, pulling the exhaust, and pulling the heat shield i was able to put two hands on the driveshaft and it stretched right out. when things like this happen at the end of a 10 hour session wrenching, its best to sleep on it. it'll look different in the morning. __________________ 2007 E92 328i coupe. 19" staggered VMR v710, front: 19x8.5 et35 continental 235/35 19, rear: 19x9.5 et33 continental 265/30 19; 1 inch front lowering perches; Msport rear bumper; roof spoiler; trunk lip; Bavsound UF110; carbon fiber wrapped interior trim; 3 stage BMW intake manifold; aFe magnum force stage 2 si pro 5R cold air intake; active autowerkes catless header; active autowerkes gen 2 signature exhaust; BPC stage 2 header tune
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10-28-2018, 04:22 PM	#3
Phyrexia Resident Pedant 503 Rep 792 Posts Drives: '15 335i 8AT Join Date: Nov 2017 Location: Limbo iTrader: (1)	I was thinking this was going to be the outcome. Glad you got it sorted. __________________ '15 F30 335i 8AT Estoril II/Black (12.218 @ 114.94mph) MHD Stage 2+ 93 / XHP Stage 3 / M-Goodies / K&N Filter / ER CP / CSF IC / NGK 97506 / ER DP / Michelin A/S 3+
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10-28-2018, 08:11 PM	#4
Twoforty Private First Class 29 Rep 145 Posts Drives: F30 LCI 330i Msport Join Date: Mar 2015 Location: Newcastle, Australia iTrader: (0)	Sleeping on it is like rebooting a computer .... It generally solves most problems.
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