Porsche or VW flanges, 901 trans HELP!
 

Hello everyone!

I have a question about the flanges on my Porsche 901 1969 transmission, they measure 4,3 inch, the problem is that they are hitting the framehorns. Could I replace these flanges with a VW beetle's? Are the diam. smaller on VW's? Or should I just notch down the framhorn a 1cm or so?

PLEASE HELP fast!!

Here is a picture:

http://www.meanbugs.com/tabort/flag.jpg
4,3inch diam. hits the frame

Hi Martin,

Yes you can replace them by 90mm flanges.

My 914 gearbox in my split bus with 90mm flanges (almost the same setup):

http://home.planet.nl/~schur505/A2M/215.jpg


Luuk

90mm is that VW typ1 IRS diam? They are bolt on the 901 trannys? Thanks!

90mm can be VW type 1 or Porsche 914/915.
Porsche however has only 4 bolts, bug has 6.
I used 914 flanges, but I did modify them to 6 bolts.

http://home.planet.nl/~schur505/A2M/193.jpg

I have a pair of type1 CV sized output flanges to fit a 901 (coarse splines) I will sell if you need them :)

They are drilled for 6 holes:

http://www.veewrx.com/VWRX-engine-ge...tputshafts.jpg

Sounds good! How big diam. are they? Because thats the problem here, I need more space to my framehorns. Or what could I use to the flanges I have? I want to keep it as simple as possible. Thanks for all answers, great forum!!

I think type 1 IRS flanges will fit the 901. Can anybody confirm?

Yes, they fit.
Those from trevorbrady are 90mm. VW type 1 never had 110mm. ;)

http://www.veewrx.com/VWRX-engine-ge...5-outputs2.jpg

901 (type1 sized CV) flange on left, 915 (930 sized CV) on right

as skywalker says, 90mm outside diameter

Thanks guys!!! :) So then I just have to find flanges from an IRS type1 Bug then, Same splines as the 901? Thanks alot!!

Anyone here who are OR have used these types of flanges in 901 tranny in a type1 chassi? Im afraid that the driveshafts will be too long. What do you think? Hmm

Martin, I tested those 901 flanges in my 915 transmission in my VW chassis using stock VW type1 IRS trailing arms, stock VW type1 drive shafts and stock VW type1 CVs. Everything mated up nicely.

I have since upgraded to the 930 sized flanges which I had redrilled to suit the stock 944/VW type2 CVs, stock 944 turbo driveshafts with early 944 turbo aluminium trailing arms.

I tried to keep everything to standard off-the-shelf parts where possible but I couldn't find a pair of output flanges to fit the 915 transmission that used the 944/type2 CV bolt pattern so I had to have them modified instead.#

just found this pic of the above setup:

http://www.veewrx.com/VWRX-engine-ge...4gearbox11.jpg
(note driveshafts are angled because the transmission was moved forward a bit)

Great info, thanks again Trev! Check your PM inbox ;)

Ok, so I am working with a 69' 901 with 108MM output flanges and 87 944 alu trailing arms. I am wondering if anyone else is using this setup and if so what is the final solution (hopefully someone up and running can chime in) for the cv's and axle's? I am looking for fact not speculation... thank you for any insights.

Trevor,
are you able to post some images of your modified flanges?

I now have 930 size output shafts (redrilled to 944/VW Type4/VW bus size CV bolt pattern), 944 CV joints, early turbo aluminium trailing arms, 944 turbo drive shafts and it all works nicely.

these are the 930 output shafts: the 930 CVs use 4 bolts and two dowels, the arrows point tot he 944 CV PCD holes drilled and tapped

http://www.veewrx.com/VWRX-engine-ge...edflange04.jpg

http://www.veewrx.com/VWRX-engine-ge...edflange01.jpg

http://www.veewrx.com/VWRX-engine-gearbox/4-7-05-09.jpg

the full low-down is here:

http://www.veewrx.com/VWRX-engine-ge...ne-gearbox.htm

Trevor,
Thanks for the post. I am working with the 901, so I am not sure the total difference between mine application and yours but it seems that your 'redrilling' might be something that I can look at. Originally the gent that built my trans thought he might have the output shafts to get the connection to the 944 cv's but later discovered that he did not. so the two questions I have are 1. Are the output shafts difficult to remove/change? 2. Is there a 901 application of this mod that someone has done succesfully?

thanks again for sharing your experiences.

there's a single bolt in the centre of them (17mm/19mm, I can't remember) and they just "plug out". Installation is the reverse of removal, as they Haynes manual says. :lmao:

trevor,
that got me right where I needed to go, thank you.
As you mentioned the Haynes is there any chance you
have one and if so does it tell you the torque specs for
when I put these back on?

thanks for all the help.

sorry, no torque specs :(

just dropped off my 901 flanges to the machinist with my 944 axle as reference.. we will see how it all goes. thanks for all the insights.

so I have been told by my machinist that there is no way that he can drill these 901 output flanges, that the material is too hard?! How is this getting done? Trevor, any insights on this as you've had your's drilled? So now I am back to square one. Getting the 901 output flanges to mate up with the 944 turbo cv's? I am starting to hit a wall here, as this is the only thing keeping me from bolting this all together?

Anyone?

I find it difficult to comprehend that the material is too hard? the only problem that I can source is the fact that the 901 appears to have a 4 bolt/2 dowel arrangement - see http://www.aircooled.net/gnrlsite/re...he5spdconv.htm that gives a good build up of the installation.

Clive

I'ts easy breezy, press out the dowels, drill and tap for M8 keensert (I think it's M12x1.25 IIRC) and put in the keensert. It's not hard material and a standard HS drill does the trick.

Good luck..
Lanner

Jmd,

Info sent, sorry for the delay..
VR
Alex

solution found.
 

Gents.
I have figured out a simple solution to my problem.
- Ditch the large late 901 output flanges (4 hole 2 pin)
- Source early small diameter 901 output flanges (6 holes)
- the only difference's between these is a slight length difference and a diameter difference at the primary shaft, meaning that this has to be turned and re-polished to remove a minor amount of material. then it plugs right in, matches with the 944 stuff end to end, and will allow the use of 944 axles...
More info coming once I get it all dialed up.

Side shots:
http://farm4.static.flickr.com/3445/...646649f102.jpg
http://farm3.static.flickr.com/2512/...615d2d5e6e.jpg

Flikr Shots:
my Flikr Album

thanks to everyone for helping provide information. I plan to fully document this process to hopefully help those after me save a bit of time and money...

thanks for the Info Jmd
can't wait to See your write up, and when I'm ready to go with 944 arms and set my 901 up I know where to come read about it.

thanks again

Chris.

final solutions
 

Guys,
I just wanted to follow up to this post with some installed images incase anyone else is interested.

Starting here and moving forward in the images shows the two output flanges compared and then some measurements to help others trying to solve similar problems.

http://www.flickr.com/photos/3931035...7619575747670/

Again the solution was to source a pair of earlier smaller diameter course spline output shafts and have the base shank turned down by a mil. they fit like a glove. and allow plug-n-play for 944T axles.

Hope the pictures and such help.
Let me know if you have any additional questions.
Also thanks again to everyone for helping me resolve this issue and being supportive.