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091 trans in 61 bug?
Posted: Wed Aug 23, 2023 6:52 pm
by JettP
Can an 091 transmission be squeezed to fit in a 61 bug with a standard 1600 block, and still utilize the entire engine bay with tins? I would like to use that vs. a standard T1 transmission with my turbo powered engine.
Re: 091 trans in 61 bug?
Posted: Wed Aug 23, 2023 7:12 pm
by Ol'fogasaurus
Look at the off-road forum for examples. I have two builds there (with a lot of pix and discussions) that have the bus into bug conversions. One is my black buggy and the other is my blue buggy. There are also other good builds in there too.
The bus trans conversion has a couple of problems. One is the nose cone sits higher than the stock bug trans that goes into the tunnel as the bus unit comes out on top of the tunnel.
The CVs are larger in dia. both inside and the outside ones. A bus stub axle will be needed also. There will be a conversion for the shifter to sit on top of the tunnel.
Bus is IRS while early VWs are swing axle so if you have an earlier version then changes have to be made.
Lee
Re: 091 trans in 61 bug?
Posted: Wed Aug 23, 2023 8:40 pm
by Ol'fogasaurus
Also the bus axles will be of different length than stock so you will need two of them.
Lee
Re: 091 trans in 61 bug?
Posted: Wed Aug 23, 2023 9:00 pm
by H2OSB
This is a bit out of my field (not really certain what my field is, TBH), so those who know, correct me if I'm incorrect. You can use the stub axles from a Porsche 944 for the larger CVs if the Bus units are difficult to find. I know for certain they're a direct replacement for your typical Bug stub axles. IIRC, Bug CVs are ~90mm, and 944/Bus are 100mm. I know, usually, putting the Porsche name on any part makes it 3x more expensive than the corresponding VW part, but 944s were plentiful and many parts are quite cheap.
Now, the fact your car is a '61 may mean I'm totally incorrect. Did you convert to IRS?
H2OSB
Re: 091 trans in 61 bug?
Posted: Thu Aug 24, 2023 8:03 am
by AdminSteve
Yes this conversion can be done and has been done a lot. You will need to convert the rear suspension to IRS which in my opinion is the hardest part of the conversion but all the other parts are available to do it pretty easily.
AdminSteve
Re: 091 trans in 61 bug?
Posted: Thu Aug 24, 2023 8:43 am
by JettP
Thank you, that absolutely makes my day! I will be doing a lot of research and make it happen!
Re: 091 trans in 61 bug?
Posted: Thu Aug 24, 2023 2:27 pm
by Ol'fogasaurus
It has been so long that I had to look up just when the VW bug converted from swing axle to IRS. 1968 was the last year of the swing axle here in the "states" which mean you probably have a swing axle setup. Not sure about other countries.
There are a couple of ways to do the conversion with just changing the swing axle torsion tube to the later IRS setup. Not easy, a lot of welding but can be done.
The big problem with reusing the swing axle setup is the pivot for the trailing arms
001.JPG
This is one of the pivots and it is built into the trans mount at where the torsion tube is.
DSC04948.JPG
A close up of the pivot (remember there is one for each trailing arm.
009.JPG
This is what it looks like.
There is a kit available that does the job.
Trailing arms
I think are different (been a long time since I played with this stuff) but again, they might not be.
I hope this helps.
Lee
Re: 091 trans in 61 bug?
Posted: Thu Aug 24, 2023 9:20 pm
by Ol'fogasaurus
There is another thing to look into and that is the trans mount lower connection to the pan.
pan and torsion tube support 03 (2).jpg
This is a look at the top of the connection but...
pan and torsion tube support 03 (2).jpg
This is looking at the underside of the pan and the connection to the trans mount. Notice that there is a gap between the pan (you can see the stiffening flange on the underside of the pan in the hooked area of the mount) and the pan; you will find it is not a hard connection.
Lee
Re: 091 trans in 61 bug?
Posted: Sat Aug 26, 2023 8:09 am
by JettP
Thank you, you have given me much to study this weekend! I appreciate you.
Re: 091 trans in 61 bug?
Posted: Sat Aug 26, 2023 11:30 am
by Ol'fogasaurus
https://www.bing.com/search?q=swing+axl ... c1a3ee4a35
This is an example of one of the rear t railing arm pivots available.
Lee
Re: 091 trans in 61 bug?
Posted: Sun Aug 27, 2023 9:16 am
by Ol'fogasaurus
JettP. what are you trying to decide to do with the 61 Bug?
There are so many options you can have from junking it to a complete resto with all kinds of things in-between. Using a bus trans usually gets you into rough use of the Bug, like racing, off-road, the dune, and so on just to name a few things.
There is only 1 thing that I can think of that the bus trans would change and that is a complete resto.
If you haven't done it already put it on a lift or jack stands and give it a top to bottom inspection looking for rust problems, dam(n)age like from wreck or just total confusion on what to do.
DSC00646.JPG
This is going almost as far as one could go but with the bad parts on the Bug this ended up being needed. I modified two engine stands to make the rotisserie, but I didn't account for the roughly 12-degrees of angle needed at the front where the front beam connects to and again, the roughly 12-degrees that the deflection of the trans mounts are designed to handle with the engine and trans both mounted on the trans mount "fingers".
To cover the angles each end could be lifted, and the sloppy part of the rotisserie covered the rotation problem.
Pan halves then the body lift build came next. This was on my "Black Buggy". My blue buggy was different in it's problems.
I hope this helps but it does lead to a long build also.
Lee