Trying to fit a later 901 gearbox to a 1965 car.....help!

sdimbylow · Post by **sdimbylow** » Fri Dec 12, 2008 8:21 pm

Hi all,

Is there someone out there who can offer some advice on my current head scratcher.
I had an older smooth case gearbox in my 1965 bodied 912 but wanted to replace it due to a noisy diff.
I got hold of a newer 901 box (with more ribbing on the case) but otherwise looks the same. My plan was to swap the drive flanges over and fit it in. Job done.
However, The newer flanges dont fit into the earlier gearbox as the bearing seats are fractionally smaller and the splines slightly different.
Here are some photos:

My question is: Can I get a drive shaft that will fit my existing wheel hub and also the larger gearbox drive flange. It has 6 bolts and is 110mm diameter? Shown here in these photos: (the green wire is just to hold it off the driveway!

Alternatively I could get a spacer machined up to link the current drive shaft to the new gearbox?

Has anyone done this before?

Any help would be most appreciated.

Steve

Alan @ CanfordClassics · Fri Dec 12, 2008 9:34 pm

Hi,

Is the same car in question that someone called me about? If so call again as we have an idea.

Thanks

Alan

davidppp · Post by **davidppp** » Fri Dec 12, 2008 9:57 pm

Hello there.

Its not simple I'm afraid, and there are really no options..

I have looked at these options myself and seen some amazing bodges ..all failed ..

The only sensible thing is to get the box rebuilt with a new diff...or swop for a know good box..

Kind regards
David

sdimbylow · Post by **sdimbylow** » Fri Dec 12, 2008 10:05 pm

Hi David,

Thanks for the reply. Do you think a spacer is a bad idea? I am a Design Engineer and can arrange for a Stainless Steel spacer to be machined to connect my current axles with the newer gearbox drive flanges.
Also, do you have a good contact to look at a gearbox re-build? I am in the West country.

Cheers

Steve

jpinhorn · Post by **jpinhorn** » Sat Dec 13, 2008 1:19 am

I had the same problem fitting a 71 gearbox to my 65 car.
We made up some spacers from duralumin they work a treat.
We often have to make the same sort of thing to fit hewland gearboxes in various racing cars.
Make sure you get your self some good quality cap head bolts and green lock tight to fit the spacers to the output flanges and you shouldn’t have any problems.
Pm me if you want my number to discuss.

John

Alan @ CanfordClassics · Sat Dec 13, 2008 8:00 am

There is another more simple option. That I hope to investigate soon

Alan

Alan @ CanfordClassics · Sun Dec 14, 2008 10:48 am

Sorry my idea did not work out. It was based around using type1 VW IRS shafts and type 2 CV joints.

Thanks

Alan

sdimbylow · Post by **sdimbylow** » Mon Dec 15, 2008 10:15 pm

Thanks for trying Alan. Sorry I didn't call back on Saturday I had baby issues! Have now discovered that the clutch fork from my older g-box won't fit to the newer box. Perhaps this isn't meant to be. I will try the spacers and also try to source another smooth case if possible. I am also considering stripping the old gearbox to see what the problem was. Wish me luck!

Alan @ CanfordClassics · Mon Dec 15, 2008 10:32 pm

Hi,

Yes, there are also a few different types of forks. With regards to the CV joint issue there may be another option. Chatting with Mike Bainbridge today it might be worth investigating the 914 gearbox stub axle/joint flange. These are the early small CV joint style yet may have the correct inner fitting for your box. Worth asking?

Thanks

Alan

PS. If you need another early ally box I have a used one plus a fully rebuilt one ready to go.

Gary71 · Post by **Gary71** » Tue Dec 16, 2008 7:57 am

How about using the old outer CV and a new inner CV that fits the box?

Assuming it's not a straight fit onto the existing driveshaft splines (because that would be too easy

) you can get a driveshaft specialist to weld half your exisiting outer shaft to a suitable inner shaft carrying the correct size CV.

I have used http://www.davemacprops.com/ for various jobs of this type when fitting bizzare drivetrains to unsuitable cars in a past life

Sounds wrong, but can be done correctly and relatively inexpensively.

sdimbylow · Post by **sdimbylow** » Sat Jan 10, 2009 10:58 am

Hi All,

Many thanks for your comments, I thought I would give an update on the gearbox issue.

I think it was Homer Simpson who said that 'If something's hard to do, then it's not worth doing.' So I have managed to get hold of a good smooth case early gearbox from Max at Revival cars. I fitted the gearbox, along with a new Dansk exhaust and refurbished tinware etc and the car is transformed with no diff noise and smooth shifts through all the gears. So, apart from the generator packing up, all is well. Doh!

I believe that it is possible to make the newer gearbox fit but I am much happier with keeping to the correct box. I will consider refurbishing my original box to swap over at a later date, or selling it as a going concern to re-coup some costs.

I will add photos to the projects page to show some of the work that we have done over the winter.

Thanks again,

Steve