e36 M3 vert w/ 6 speed manual swap ? driveshaft ?

[imaiami]

Howdy,

I just recently converted my auto m3 vert to manual 6 speed getrag box,
Used the usual inter web skowering, which made it seem like the auto m3 driveshaft was a direct fit....
I guess it "works" if you don't mind only having 1" of spline connecting the two parts of the driveshaft.

My question here is what are my best options: (and most cost effective)

Is there a thicker giubo than the e36 m3 one?

extend front portion of the e36 vert driveshaft?

Shorten front portion of e36 m3 manual driveshaft?

spend bucks and buy a evo front half? where to get cheapish?

Use a e46 m3 front half of driveshaft (do the splines match that of the e36 rear?)

btw, this swap is as budget as one can do for a 6 speed, so looking for budget driveshaft option. I couldn't bare the auto and had a full s54 w/ 6 speed awaiting this car in the future. S54 needs some love, so rather than doing the full thing, why not do a quick manual swap to play with the healthy s52. (not so quick lol)

modded a stock e36 manual trans bracket,
modded e46 m3 shift linkage (shifter is 1.5" rearward, but works fine)
Used the stock e46 m3 starter, clutch and flywheel, slave cylinder
routed e36 master to slave hardline without removing abs or booster along with not touching intake manifold.
I did have to connect the clutch master to the hardline with the master disassembled from the pedal assy inside the car. (not so fun laying on my back assembling the whole pedal assembly under the dash), but it worked.
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Any help?


Thanks

[pbonsalb]

Hope this is a track car. I doubt you will like those red poly trans mounts in daily driving. They look pretty, though.

[imaiami]

She’s slowly on her way, but with how nice it is on the inside, it’ll retain daily amenities. Me ol racecar recently got totaled, So all the parts are slowly moving over.

[Tapanui]

one of two options.

1: Get a manual drive shaft which is longer than an auto shaft.

2: Or take it to a drive shaft shop and get them to lengthen it.

I wouldn't go swapping slip joints in a driveshaft as it can throw the shaft out balance.

[imaiami]

I do have a manual shaft as well, But it’s too long. To shorten or to lengthen that is the question? I haven’t even gotten with a shop to see my options yet.
And of course I’ll have the whole shaft balanced no matter what I do. I’ve been through tearing up center support bearings, No fun.

[Tapanui]

Cost wise, shorting the shaft would be cheaper as you cutting and re-welding the shaft. lengthening means they cut the ends off and weld in a new tube.

[M3AN]

It's also much easier to (re)balance a shorter shaft than it is to balance a lengthened one.

[imaiami]

Thats what I'm thinking as well.

and even if I were to get a correct length front section (evo or e46 m3((assuming the spline matched))), I'd still have to get it balanced.

Off to a drive shaft shop.

I usually have no problems doing what needs to get done, but after reading so much about the auto driveshaft being a direct fit, it left me a bit perplexed when I saw how sketchy the end result was.

Thanks for chiming in

[lbennyboobool]

I would go with shortening the driveshaft.

seems to be cheaper to go shorter than lengthening

I'm curious on the dimension once you have it done if you don't mind sharing

[imaiami]

not having time to tear my exhaust and heat shield out to get some measurements, and then wasting the time in front of the computer, I found some lengths.

e36 evo shaft is 1376mm-54.17in
e36 manual shaft is 1492mm-58.7in
e36 m3 auto is 1342mm-52.8in



Auto trans is 1.5" shorter than the 420g, which is about the variance of the auto to evo shaft.
by those numbers, if I were to shorten the manual front section 4.5" I'd be in the ballpark. (it seems like a lot of shortening)

Trans lengths
zf5 is 21"
zf6/ getrag is 25"
that tells me 4" to shorten

All rear ends are the same lengths, so modification is only needed to the front shaft.

I don't trust it enough to mess up a driveshaft, so prior to taking it to the drive shaft shop (which was to be tomorrow), I'm going to get actual measurements of my own.

I'll let ya know what I find.

[imaiami]

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there's roughly 6" difference in the front section of the auto to manual e36 shaft, so needing 1.5" more on the auto end, I shortened the manual 4.5".
They ended up re-sleeving the whole front section, so if you were to take the auto and have them lengthen 1.5" it would be the same as shortening the manual 4.5". It cost me 160.00 to shorten the front and balance. I feel much better about beating on the car now