Trans Output Flange Mis-match

#1

In the final stages of finishing my car. Just before installing the engine & tranny I did a mock up of the driveshaft. Well, i see that the output flange of my recently purchased tranny does not line up with the flex disc.

It appears that the output flange is approx 4" across the holes. The old tranny (auto) has approx 3.5" across.

What are my options?

Do I need a new driveshaft to match the output flange?

Can I change output flange?

Is there a flex disc that fits 4.5" output and 3.5" driveshaft spacing?

I need this like another hole in my head…

Your thoughts please!

#2

IIRC, you need a manual trans drive shaft and the corresponding flex disk. I did a auto/manual swap a few years ago as well.
Ed

#3

Been there… I bought a manual driveshaft… The length is correct.

#4

If you are certain that this is the drive shaft from a manual transmission car, I’d swap the output flange.

Hint; thread locker was used on the flange nut. So application of heat will make it much easier to get the nut off. Replace the seal along with the flange.

#5

Thanks,But… I’m definitely confused; are there two different size output flanges for manual transmission cars? And if so, there must be two different driveshafts…

If the driveshafts are the same then I would guess that there is a flex disc that reduces from the large output shaft size to the driveshaft bolt spacing size?

HELP!!!

#6

I have 2 spare trannys - both measure ~ 2.75" between holes. Same for the spare drive shaft I have.
Ed

#7

Thanks for the reply…

The ID # on my tranny #260.0.1270 90…

Can anyone confirm that this is a proper E30 tranny?

#8

PDS wrote:

[quote]Thanks,But… I’m definitely confused; are there two different size output flanges for manual transmission cars? And if so, there must be two different driveshafts…

If the driveshafts are the same then I would guess that there is a flex disc that reduces from the large output shaft size to the driveshaft bolt spacing size?[/quote]
I remember there being a large and small guibo, but I’ll confess to not remembering what production they were used on. So yes there are large and small flanges and , as I recall, matching drive shafts.

#9

If you have 11 numbers for your part you can look it up on RealOEM.com.

Jason

#10

Jason,

Thanks for the tip… The vin# sticker on the tranny looks almost new. So with that I was able to use RealOem and identify my tranny as a E30 325E build date 04/87. After searching Pelican I see that in fact my model year uses the large guibo.

So, at this point my options are; change the output flange to the more standard spacing or find a driveshaft from an appropriate donor.

So the search is on…Anyone have a broken tranny laying around that I can get the output flange from???

#11

There are definitely two different output shafts/guibos/driveshafts. I thought it had to do with late model versus early model. Just make sure all your stuff matches. When I was looking for a used tranny I made sure I got one with the output flange that matched my driveshaft/guibo.

#12

Change the output flange to the smaller/more universal size. Bolt-up and go.

IIRC, good luck getting the retaining nut off of the output shaft.

RP

#13

Whewww… The trans flange is off and I’ve sourced the correct one…

What a bitch to get that nut broken free. After attaching the trans to the engine (for greater stability) and a good dose of heat I was able to literaly jump on my breaker bar. After about three attempts it finally let go…

Thanks to all that responded!

PS - I found a good source for the proper thin wall socket needed to reach the output shaft nut.

Advanced Auto Parts - Gearwrench 30mm thin wall socket - part# 80826. For $11.29 you’ll be set.

and, I can attest to it’s strength!!!