G260 misalignment Help! For everyone that uses this box with M5X, please educate me

[btec116]

Does anyone know the distance between the input and output shaft axes on the Getrag G260's?
Does anyone know what I'm getting at?

The gearbox output shaft is -obviously- not on the same axis as the crank.
Tilting the gearbox the extra 10-or-so degrees from the M20 to M5X, assuming crank axis stays in the same position as the M20 (which it DOES), will swing the output shaft off the drivetrain centreline.
If you try to bring the -end- of the output shaft back on centre (where guibo sits), then you're just pushing the whole engine/gearbox off the drivetrain centreline, at a (small) angle.

The only way I can see to avoid this is either use the M42's box, or the E36 box. I am one of the many swappers sticking with the G260 off an M20.

So Obviously people are doing it, and assumedly have been for a while, but I'd really like to know how much these distances are, and what effects this is likely to have, on which components.

Has anyone previously considered this?

[turboeta]

What mount are you using for the trans?

[golde30]

uhhh, what? there are more than a dozen guys running the getrag260 with their swap, and this is the first time any1 has posted this problem. you are doing something wrong. good luck.

[Teaguer]

What mount are you using for the trans?

Buckethead rulez ! :bow:


And yes , the Aussie is thinking too hard and fucking things up hardcore . :D

[Garageaholic]

I've never done an M50 swap, but I intend to do one soon. Is it really this difficult?

[etxxz]

^^depends on what you can do....not that hard, lots of hours req. i'm upwards of 90hours on my s52 obdii and have another 10-15 to go.


NOW


he is not messing anything up...and i don't think anyone has undestood his theory...cauase its not a problem, and since people do it all the time.

if i read correctly he's refering to this in a geometric sense since the input shaft (clutch side) is not on the same axis (so its either ontop or below) as the ourput shaft, meaning if you move the engine whatever degrees difference exists b/ M20 to M50, this output shaft will be a little offset, and so the driveshaft now points at an angle towards the CSB

my thoughts: i agree, i could see how it happens, but people run it with no problems....if this were true, there is still no problem since there's a u-joint before the CSB. i think the e36 driveshaft has the u-joint after the csb but you're not gonna use that so you're good.

[btec116]

^

if i read correctly he's refering to this in a geometric sense since the input shaft (clutch side) is not on the same axis (so its either ontop or below) as the ourput shaft, meaning if you move the engine whatever degrees difference exists b/ M20 to M50, this output shaft will be a little offset, and so the driveshaft now points at an angle towards the CSB

Spot-on.

Well, thanks, at least its nice to know I'm not delusional!
I know people do it, but that doesn't necessarily make it right. And the thing that bugs me bout it most is that I dont know what/how much these angles are. And I don't like saying "I don't know"!

Like you say, the misalignment will be taken out at the UV joint before the centre mount, so thats OK, but it still puts a deflection through the rubber flexjoint (between output shaft and tailshaft), this angle will be the same regardless of how you line the thing up.

The flexjoints are designed to flex (obviously), but as they do, the torque they can transmit, as well as their lifespan decrease. Again, considering this was a part designed to work with zero angular deflection, it'd just be nice to know. ANd to know that, you need to know the distance between the in/output shafts!

But then since everyone does do this without a second thought, has anyone ever run into any drivetrain troubles? Flexjoints or CSB's wearing faster than they should???

[FredK]

I think Stu Mc has run an M/S50 for the longest out of most people on this board, and he's had no issues after like 30k miles using a G260, and he's done a few auto-x and track events.

[Drew325is]

Bence, seeing as my engine and tranny aren't in the car yet, I can probably try and take some measurements for you. I'll see how I go. There'd be a bit of time in mesing with it to get accurate numbers.

I'm not sweating over it though...even if it halved the life of the flex joint I'd be looking at well over 50000km before replacement...I do like 5000km (tops) per year...and if does give me problems, sounds like a good excuse for my missus to let me put a 6 speed in there :D.

[btec116]

Cheers guys, thats what I need to hear!

Drew, just a rough idea would be great, my box is already in, so it makes measuring anything (esp. input shaft!!!) a bit hard.
I'll figure it out and post the data (if anyone else cares!)

But road k's speak alot, and 30,000 of them (miles) is pretty confidence inspiring!

Thanks,
Bence

[Brew]

I've done about 40k miles with the 260 on an M50 and modded S50. No issues with burning up u-joints, or flex discs.

[FredK]

Um, yeah, I totally forgot about everyone's favorite lurker, Brew. :mrgreen:

[turboeta]

Buckethead rulez ! :bow:

:up: Do you play?