Transmissions for Dummies
- MNAirHead
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Transmissions for Dummies
Brought to you by our friend Daniel
Last edited by MNAirHead on Sun Nov 19, 2006 10:26 am, edited 2 times in total.
- Daniel G
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- Joined: Thu Apr 22, 2004 8:38 pm
This thread is meant to help answer some of the transmission questions that are constantly asked. I am by no means an expert, and I still have a lot to learn but I hope this info will be helpful to someone. As some of you may know, this thread can also be found on TheSamba.com, but I know some people don't frequent it, and I thought it would be helpful to put it here as well. Be sure to thank Everett Barnes for allowing us to use TheSamba gallery to host the pictures.
Also, check out our Transaxle Forum...There's a lot of info there.
Identifying VW Transaxles...
The 091...Aka the 6-rib
Found in '76-'79 Bus. They have a 4.56 R&P ratio, and are considered to be the strongest stock VW transmission.

091-Side Shift
*Note: This is the one that can be converted to nose shift.
Essentially the same as the Bus 091 and can be converted to nose shift.
Found in '80-'83 Vanagons with the T4 engine.

091-Mid Shift
*Note: This one cannot be converted to nose shift.
This may actually be an 094 instead of an 091, but I haven't verified this yet.
Found in '83-up Vanagons with the Wasserboxer engine.

094 Synchro 4x4
*Note: I don't know much about this one, except for the fact that they are pretty rare. However, they have a locking differential that can be made to fit in an 091 or 002 (More on this later).
Found in ??-?? Synchro Vanagons.

The 002...Aka the 3-rib
*Note: The earlier 3-ribs have no mounting ears on top of the bellhousing, axle flange retainers attached by acorn nuts, and a shorter input shaft (for the T1 engine). There's more info the early models provided by a member of TheSamba.com posted below the pic. They have a 5.38 (Also 5.42, but it is pretty rare) R&P ratio.
They are found in '68-'73 Buses

*Note: Even though the 5-rib has a few different components than the 3-rib, it's still classified as a 002.
They are found in '74-'75 Buses, and have a 4.86 R&P ratio.

Vanagon Diesel
No information available at this time.

Bug IRS-Late
*Note: The one on the left is from '75-up, and the one on the right is from '72-'74. As far as I know they are the same except for the case differences.
Found in the '72-up Bug. They have a 3.88 R&P ratio.

Bug IRS-Early
They have a 4.12 R&P ratio.
Found in the '69-'71? Bug.
No picture availble at this time.
AutoStick

Bus/T3/T4 Automatic

Bug Swingaxle

Bus Swingaxle with Reduction Boxes

Berg 5 Speed
*This info was provided by Glenn on TheSamba.com
Located on the side opposire from the fill plug.

Throwout Bearing/Pressure Plate Styles

Early Style

Late Style

Also, check out our Transaxle Forum...There's a lot of info there.
Identifying VW Transaxles...
The 091...Aka the 6-rib
Found in '76-'79 Bus. They have a 4.56 R&P ratio, and are considered to be the strongest stock VW transmission.

091-Side Shift
*Note: This is the one that can be converted to nose shift.
Essentially the same as the Bus 091 and can be converted to nose shift.
Found in '80-'83 Vanagons with the T4 engine.

091-Mid Shift
*Note: This one cannot be converted to nose shift.
This may actually be an 094 instead of an 091, but I haven't verified this yet.
Found in '83-up Vanagons with the Wasserboxer engine.

094 Synchro 4x4
*Note: I don't know much about this one, except for the fact that they are pretty rare. However, they have a locking differential that can be made to fit in an 091 or 002 (More on this later).
Found in ??-?? Synchro Vanagons.

The 002...Aka the 3-rib
*Note: The earlier 3-ribs have no mounting ears on top of the bellhousing, axle flange retainers attached by acorn nuts, and a shorter input shaft (for the T1 engine). There's more info the early models provided by a member of TheSamba.com posted below the pic. They have a 5.38 (Also 5.42, but it is pretty rare) R&P ratio.
They are found in '68-'73 Buses

The 002 5-ribBruce wrote:
The first Bus IRS trans in 68 is called a 113 type Bus trans. Same for those up to 71. This is because all the parts associated with the 4 forward gears and reverse are exactly the same as what are found in a Beetle 113 trans. Exceptions are gear ratios and tooth configuration.
Then in 72, the 002 Bus trans came out. The individual gears were all completely re-designed and are called 002 gears. These were used to the end of 75. Beetle gearboxes with only one side cover also use the exact same 002 Bus type gears.
*Note: Even though the 5-rib has a few different components than the 3-rib, it's still classified as a 002.
They are found in '74-'75 Buses, and have a 4.86 R&P ratio.

Vanagon Diesel
No information available at this time.

Bug IRS-Late
*Note: The one on the left is from '75-up, and the one on the right is from '72-'74. As far as I know they are the same except for the case differences.
Found in the '72-up Bug. They have a 3.88 R&P ratio.

Bug IRS-Early
They have a 4.12 R&P ratio.
Found in the '69-'71? Bug.
No picture availble at this time.
AutoStick

Bus/T3/T4 Automatic

Bug Swingaxle

Bus Swingaxle with Reduction Boxes

Berg 5 Speed
*This info was provided by Glenn on TheSamba.com
T1 Tranny ID NumberGlenn wrote:
Berg 5
A Berg 5 is built from a stock Type 1 Swing or IRS tranny. It requires the basic Berg 5 kit, a special shifter and cross member.
You have to completely disassemble the tranny and send YOUR mainshaft and pinion shaft to Berg to be lengthened. You then reassemble the tranny, this is the time to select new gear ratios and put in some heavy duty stuff. The 5th gear site in the nosecone.
Take a look at http://www.glenn-ring.com/resto/resto5.html for more info and pictures.
Located on the side opposire from the fill plug.

Throwout Bearing/Pressure Plate Styles

Early Style

Late Style

Last edited by Daniel G on Thu Jul 06, 2006 1:54 pm, edited 3 times in total.
- Daniel G
- Moderator
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- Joined: Thu Apr 22, 2004 8:38 pm
Lockers and LSD's
The Synchro Differential
The synchro locking differential can be adapted to work in a bus tranny, but it isn't a direct fit...You need to rig up a shifter mechanism and do some other mods to get it to fit. There aren't any off-the-shelf kits for this, so you are pretty much on your own if you decide to do it.


Richmond Lock-Right
I don't know much about this one, but it seems like it would be worth the money.
http://www.richmondgear.com/01pdfs/ptrax.pdf
More Info on the 094 Synchro Drivetrain
The Synchro Vanagons had 4 wheel drive, and used a vicous coupling to engage the front differential. They are pretty rare, but they can be found if you are lucky. If you want to build a 4x4 buggy, it would be possible to build one with the synchro parts, but you may have to spend a long time searching for the parts.
Here is a pic of the transaxle...

And here are some pics of the front differential...


There is also a famous VW rally car that has an 091 that was modified for 4x4, but I can't remember where the site about it was at anymore.
The Synchro Differential
The synchro locking differential can be adapted to work in a bus tranny, but it isn't a direct fit...You need to rig up a shifter mechanism and do some other mods to get it to fit. There aren't any off-the-shelf kits for this, so you are pretty much on your own if you decide to do it.


Richmond Lock-Right
I don't know much about this one, but it seems like it would be worth the money.
http://www.richmondgear.com/01pdfs/ptrax.pdf
More Info on the 094 Synchro Drivetrain
The Synchro Vanagons had 4 wheel drive, and used a vicous coupling to engage the front differential. They are pretty rare, but they can be found if you are lucky. If you want to build a 4x4 buggy, it would be possible to build one with the synchro parts, but you may have to spend a long time searching for the parts.
Here is a pic of the transaxle...

And here are some pics of the front differential...


There is also a famous VW rally car that has an 091 that was modified for 4x4, but I can't remember where the site about it was at anymore.
Last edited by Daniel G on Thu Jul 06, 2006 1:44 pm, edited 2 times in total.
- Daniel G
- Moderator
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- Joined: Thu Apr 22, 2004 8:38 pm
Transmission Links. To be added as I find them
Articles and Resources On the Internet
Henryhoehandle's Site
*I highly recommend that you read his site. I personally learned a lot from it. He is a very knowledgeable guy.
http://www.geocities.com/lets_rock_1998/transtalk.html
'71 Bus 002 Refresh
http://www.type2.com/rvanness/transmis.htm
091 Refresh
http://www.ratwell.com/technical/091Transmission.html
901 Porsche Rebuild
http://home.san.rr.com/pb914/rebuild/
Bowden Tube
http://www.thebugshop.org/bsfqbwdn.htm
Part Suppliers
http://www.longenterprises.com/
http://www.2weddle.com
http://www.ranchoperformance.com/
Articles and Resources On the Internet
Henryhoehandle's Site
*I highly recommend that you read his site. I personally learned a lot from it. He is a very knowledgeable guy.
http://www.geocities.com/lets_rock_1998/transtalk.html
'71 Bus 002 Refresh
http://www.type2.com/rvanness/transmis.htm
091 Refresh
http://www.ratwell.com/technical/091Transmission.html
901 Porsche Rebuild
http://home.san.rr.com/pb914/rebuild/
Bowden Tube
http://www.thebugshop.org/bsfqbwdn.htm
Part Suppliers
http://www.longenterprises.com/
http://www.2weddle.com
http://www.ranchoperformance.com/
- Daniel G
- Moderator
- Posts: 646
- Joined: Thu Apr 22, 2004 8:38 pm
Converting to an IRS Bus Transaxle
Why Convert?
There are a couple good reasons...
1. Strength. They are a lot tougher (stock and built) than even a beefed T1 is for offroading.
2. Gearing. The bus transaxle has gear ratios that are much better for offroading than T1's do.
Mounting Styles
10-Degree Mount
This mounting kit tilts the engine and transaxle up 10 degrees for better ground clearance, and also allows you to run the shift rod in the same location as the T1 transaxle. It requires clearancing the frame horns as well as drilling holes into the bellhousing.




Below is the original style made by Barrett Enterprises. Here is a thread specifically about it...
http://www.thesamba.com/vw/forum/viewto ... busintobug

Here's another thread about it with more info about the newer style...
http://www.thesamba.com/vw/forum/viewtopic.php?t=119707
Solid/Strap Mount
This is the most common mounting kit used. It's cheap, simple to install, but IMO it's not the best way to do it. However, there's nothing wrong with it, and it works fine on plenty of buggies and bajas. This mount does not put the shift rod in the tunnel, so you must make provisions for this. You can either raise the shifter of get an adapter made to put the shift rod back down in the tunnel. Also, sometimes the bellhousing strap will have to be tweaked to fit around the starter boss. You'll see what I'm talking about if you use this kit.

There is also a piece in the kit that bolts to the transaxle mount studs on the torsion housing and to the nose cone of the tranny, but I can't find any pics of it right now.
Bellhousing Mount
There are several different bellhousing mounts available. I know Kartek carries several different styles, and it would even be possible to fabricate your own pretty easily. You must have a roll cage to use this mount. This isn't an issue in a rail, but you will run into problems if you try to use this mount on a baja without a full rollcage in the rear.




Mid-Mount
There are two different types of mid-mounts, and they are available for both stock frame horns and tubular frame horns, You must add tabs to the frame horns to bolt this mount to if you use it.
The first style bolts in between the intermediate housing and the main case of the transaxle. You must get the transaxle housing machined to be able to use this mount.
Tubular Frame Horns...

Stock Frame Horns...

The second style slips over the intermediate housing and attaches to the transaxle case studs. You may have to install longer studs in your case to use this mount, but you should discuss this with the vendor you buy it from, since I don't have that information at this time.
Tubular Frame Horns...

Stock Frame Horns...

Misc Mounts
These are some various other mounts I found pics of. I don't really have any info on them, but they may give you ideas for some mounts you can make yourself...



When you convert to a bus transaxle, you must also change a few other things, such as your axles, CV's,stubs, and possibly the trailing arms. I will cover this briefly in another post, but since that is really a suspension issue, I won't go into much detail.
Why Convert?
There are a couple good reasons...
1. Strength. They are a lot tougher (stock and built) than even a beefed T1 is for offroading.
2. Gearing. The bus transaxle has gear ratios that are much better for offroading than T1's do.
Mounting Styles
10-Degree Mount
This mounting kit tilts the engine and transaxle up 10 degrees for better ground clearance, and also allows you to run the shift rod in the same location as the T1 transaxle. It requires clearancing the frame horns as well as drilling holes into the bellhousing.




Below is the original style made by Barrett Enterprises. Here is a thread specifically about it...
http://www.thesamba.com/vw/forum/viewto ... busintobug

Here's another thread about it with more info about the newer style...
http://www.thesamba.com/vw/forum/viewtopic.php?t=119707
Solid/Strap Mount
This is the most common mounting kit used. It's cheap, simple to install, but IMO it's not the best way to do it. However, there's nothing wrong with it, and it works fine on plenty of buggies and bajas. This mount does not put the shift rod in the tunnel, so you must make provisions for this. You can either raise the shifter of get an adapter made to put the shift rod back down in the tunnel. Also, sometimes the bellhousing strap will have to be tweaked to fit around the starter boss. You'll see what I'm talking about if you use this kit.

There is also a piece in the kit that bolts to the transaxle mount studs on the torsion housing and to the nose cone of the tranny, but I can't find any pics of it right now.
Bellhousing Mount
There are several different bellhousing mounts available. I know Kartek carries several different styles, and it would even be possible to fabricate your own pretty easily. You must have a roll cage to use this mount. This isn't an issue in a rail, but you will run into problems if you try to use this mount on a baja without a full rollcage in the rear.




Mid-Mount
There are two different types of mid-mounts, and they are available for both stock frame horns and tubular frame horns, You must add tabs to the frame horns to bolt this mount to if you use it.
The first style bolts in between the intermediate housing and the main case of the transaxle. You must get the transaxle housing machined to be able to use this mount.
Tubular Frame Horns...

Stock Frame Horns...

The second style slips over the intermediate housing and attaches to the transaxle case studs. You may have to install longer studs in your case to use this mount, but you should discuss this with the vendor you buy it from, since I don't have that information at this time.
Tubular Frame Horns...

Stock Frame Horns...

Misc Mounts
These are some various other mounts I found pics of. I don't really have any info on them, but they may give you ideas for some mounts you can make yourself...



When you convert to a bus transaxle, you must also change a few other things, such as your axles, CV's,stubs, and possibly the trailing arms. I will cover this briefly in another post, but since that is really a suspension issue, I won't go into much detail.
- Leatherneck
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- Joined: Sat Jul 01, 2006 6:47 pm
- Daniel G
- Moderator
- Posts: 646
- Joined: Thu Apr 22, 2004 8:38 pm
Porsche 901 Conversion
I don't know much about it myself, but I thought I would provide a link on how to use one in a VW. It really doesn't have any usefulness off road, but could be useful for a street or race car.
http://www.aircooled.net/gnrlsite/resou ... pdconv.htm
Daniel
I don't know much about it myself, but I thought I would provide a link on how to use one in a VW. It really doesn't have any usefulness off road, but could be useful for a street or race car.
http://www.aircooled.net/gnrlsite/resou ... pdconv.htm
Daniel
- Leatherneck
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- Joined: Sat Jul 01, 2006 6:47 pm
When figuring out your gears this will help figure out your speed at Whatever RPM.
http://www.et-studios.com/motorsports/gears/gears.html
http://www.et-studios.com/motorsports/gears/gears.html
- Leatherneck
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- Joined: Sat Jul 01, 2006 6:47 pm
- mightymanx
- Posts: 705
- Joined: Mon Feb 09, 2004 10:29 am
I case you guys didn't know....
There is a way to put a bus box in a bug WITHOUT a 10-degree mount, rasing the shifter or using one of those crap adaptors.
It is a intermedate housing that lets you use the bug nose cone on the bus box.
It is very popular in the drag racing comunity. where it has proven it self to be bulletproof.
http://www.thesamba.com/vw/classifieds/ ... ?id=140691
It might seem spendy but how much do you have wraped up in the 10-degree mount fab work etc..

There is a way to put a bus box in a bug WITHOUT a 10-degree mount, rasing the shifter or using one of those crap adaptors.

It is a intermedate housing that lets you use the bug nose cone on the bus box.

It is very popular in the drag racing comunity. where it has proven it self to be bulletproof.
http://www.thesamba.com/vw/classifieds/ ... ?id=140691
It might seem spendy but how much do you have wraped up in the 10-degree mount fab work etc..
- Leatherneck
- Moderator
- Posts: 17104
- Joined: Sat Jul 01, 2006 6:47 pm
Hope that this has not been posted yet but great site.
http://www.geocities.com/Baja/Dunes/9702/transtalk.html
http://www.geocities.com/Baja/Dunes/9702/transtalk.html
- turboblue
- Posts: 3969
- Joined: Fri Feb 07, 2003 12:01 am
That's the transmission forum moderators website.Leatherneck wrote:Hope that this has not been posted yet but great site.
http://www.geocities.com/Baja/Dunes/9702/transtalk.html
It's all good though............
