Frank's E30 M60 V8 Swap Build Thread

[Jonsku]

Hummm, how the hell I've managed to miss that spline in M60 'shaft... well, you learn something new every day :)



Good that you got new options/ideas, many ways to do same things :)

[Garageaholic]

Update:

I've decided to use complete E30 driveshaft and have them weld the (smaller diameter of the M60 Front half) onto the front half of the E30 as well as shorten it to the same dimensions as mentioned a few posts ago.

One thing to note, The M60 and E30 driveshafts are NOT plug and play. In fact, they are polar opposites in terms of spline-male/female joints, spline size, and center bearing installation orientation.

With that being said, this new installation methodology is more factory-like, maintaining the E30 driveshaft. It requires just the front half to be shortened, and I get to keep the "sliding characteristics" of the spline. Perfect.

FYI: the E30 Front half diameter is 60.00mm. The "small sections" of the M60 front half diameter is 60.00mm. Perfect cut and weld compatibility.

Thanks so much for all of your help. you likely saved me some money and alot of potential compatibility heartache.

See pictures below of both driveshafts side-by-side for reference. E30 on top, M60 on bottom.





Spline size differences. M60 is much bigger.

[Garageaholic]

It is rather strong!!!

I just got my 18mm boxwrench this afternoon, so when I get home tonight ill disassemble the m60 shafts and try to piece it together as garey and jonsku suggests. Front half will still need to be shortened, but it might save me a little money because I wont then need to shorten the rear half......just rebuild.

[CoreyZ]

Do any of the high HP turbo guys have issues with stock driveshafts? I was under the impression the stock DS was pretty damn stout.

[Garageaholic]

No 1 piece driveshaft. I like jonskus approach. However because the 6spd tyranny is so much longer, the front half needs to be shortened no matter which front half you use .....

im going to explore using the shortened m60 front end mated to the e30 rear end (same length). That way, I maintain the slider in the middle and can have the beefier m60 front half.

Will report back tonight.

[iamsam]

What about a one piece driveshaft? I know you would have to remove the diff everytime you wanted to pull the driveshaft but has anyone done it with the M60 swap yet?

That just doesn't sound like a good idea, i dunno. You'd have to remove the diff every time you need to replace the guibo too.

I'm getting more and more glad that I have the ZF 5-speed.

[dirty30]

What about a one piece driveshaft? I know you would have to remove the diff everytime you wanted to pull the driveshaft but has anyone done it with the M60 swap yet?

[bmwmech1]

Soooowait.......6sp driveshaft, front half, mated to e30 driveshaft, rear half, will fit a M60'd 6sp, e30?

Is it really that easy?

They don't just bolt together, though... the front halves of each respective shaft has to be "cut down" on a lathe and then welded together at the specified overall length. This, combined with new parts/balancing will cost in the neighborhood of what Frank is talking. Not many driveshaft shops here in the States will even listen to you when you mention BMW and driveshaft in the same breath...

Garey

[slammin.e28]

Who has said it's hard in the first place?

IDK, lol, just seems that everyone saying, "It needs a custom made DS, etc, etc" would have figured out the e30/540 DS combo before hand. I considered trying it, but haven't gotten my 540 DS yet.

Seems kinda neat that it ends up being the correct length and all...like it was meant to be.... ;)

[Jonsku]

Soooowait.......6sp driveshaft, front half, mated to e30 driveshaft, rear half, will fit a M60'd 6sp, e30?

Is it really that easy?

Who has said it's hard in the first place?

[slammin.e28]

Soooowait.......6sp driveshaft, front half, mated to e30 driveshaft, rear half, will fit a M60'd 6sp, e30?

Is it really that easy?

[Jonsku]

Are you suggesting that I reconsider my driveshaft rebuild technique to utilize e30 front AND rear half and simply weld the m60 front flange to the e30 front half?

Doing it that way, perhaps just the front half would need to be shortened, but since the front half diameters are different, you couldn't weld the front half m60 to the front half e30. That was my problem.

I see how it would be easier through maintaining the center spline sliding for easy install, but since the front half diameters are different, I don't think that configuration will work.

Go and measure the front diameters ... ;)






That's one example. E30 shaft with M60 front part (the largest diameter "bulge" from M60 shaft was left out as it'd have been so short).

(the part just in front of the U-joint in M60 shaft is exactly same diameter as in E30, only difference is the gearbox flange and the largest diameter part.

Actually that begs the question....when that e30 spline nut is fully tightened to spec, is the design intended to allow the 2 halves to slide?

Of course, the rubber mounts are not that rigid. That's why it's always bit questionable to use "rigid" driveshaft. It works, but reduces the rubber-joint lifetime quite a lot..

[iamsam]

Actually that begs the question....when that e30 spline nut is fully tightened to spec, is the design intended to allow the 2 halves to slide?

I think so, yes. The nut only tightens the squeeze of the rubber sleeve on the splined shaft, so it still moves with more force. It would have to, the motor/trans moves on its rubber mounts, and the diff moves (a little) on its mount. Of course polyurethane everywhere would greatly limit these movements, and the guibo itself can take some flexing up to a half inch or so if it needs to.

[Garageaholic]

Actually that begs the question....when that e30 spline nut is fully tightened to spec, is the design intended to allow the 2 halves to slide?

If not, then im sticking with my original plan.

If so, then I will reevaluate my options to accommodate both halves of the e30 driveshaft.

[Garageaholic]

Are you suggesting that I reconsider my driveshaft rebuild technique to utilize e30 front AND rear half and simply weld the m60 front flange to the e30 front half?

Doing it that way, perhaps just the front half would need to be shortened, but since the front half diameters are different, you couldn't weld the front half m60 to the front half e30. That was my problem.

I see how it would be easier through maintaining the center spline sliding for easy install, but since the front half diameters are different, I don't think that configuration will work.