The Transaxle Thread

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SeanRitchie

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The official thread for all transaxle related FAQ's and basic information. There is lots of mis-information floating around on the internet, hopefully this one thread will be able to inform all readers and give the correct information. 

I'll start it off with some basic info on each Weddle Industries produced transaxle. A phone call or e-mail will always be the best way to get the proper and accurate information you need for your specific application. 

This thread is not limited to Weddle units only, but I will not be able to answer any questions on non-Weddle units. Hopefully some of the other reps can jump in and answer questions on their units.

All information posted here is for basic information only. Due to an extremely wide variety of applications in this sport/hobby, there is no way to issue "hard numbers" to any one transaxle. Everyone has different driving styles, every car is built different, and there are lots of variables in how any driver navigates and drives through rough terrain. These variables will drastically affect how long any transaxle can be used between services, and/or fail under extreme use. The faster and harder any vehicle is driven through rough terrain, or abused with improper use will accelerate the wear and tear, and require more frequent servicing with higher cost of services.

Let's get started.

 
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Volkswagen Type 1 Transaxles:

The type 1 has the smallest R&P and differential gears, which typically limit how much power they can handle and how hard they can be driven. A fully built Type 1 can reliably handle around 200 HP at the crank in a lightweight sand rail.

Type 1 transaxles were used in the VW Beetle and were very common to use in early off-road buggy's. This is where it all started.

Early units from 1961-1968 are known as Swing-Axles. These have fixed length axles and axle tubes attached at the trans which have a single pivot at the transaxle housing. These have limited wheel travel due to the max angle allowed at the pivot and fixed length axles. 1968 model years have longest length axles and are the best to use for off-road buggy's for max wheel travel. 

1969 and later units are known as IRS units. These use the common CV joints that are still used today and allow for a lot more wheel travel with longer length axles and double jointed pivots, which allow for more articulation of the suspension pivots. 

Both swing axle and IRS transaxles have the same R&P and 1st-4th gear sets, with some minor variations in early to later internal designs. Any new transaxle built today would incorporate the best of early and later parts to make for a strong gearbox.

Parts for all VW transaxles today are becoming obsolete everyday and cost is rising. The days of a "cheap" VW transaxle are quickly fading as more parts are having to be remanufactured at higher costs and lower volumes.

 
Volkwagen Type 2 (Bus) Transaxles:

The Type 2 (Bus) transaxle is actually spread across many variations and years of production. There are three common variations used in off-road buggy's. All Type 2 transaxles can typically handle around 250 HP at the crank when fully built with aftermarket gears, with no larger than 33" tires in a common sand car application. 

002 transaxles were produced from 1968 to 1975. These are commonly known as 3-rib and 5-rib transaxle due to the number of cross ribs on the top of the main differential housing. The more ribs across the top, the stronger the housings. These use a larger R&P than the Type 1 trans, but use the exact same 1st-4th gears. The larger R&P means stronger gears, and lower overall ratio's which work best for off-road buggy's with larger tires.

091 transaxles were produced from 1976-1983 and are probably the most common to use in off-road buggy's. Commonly referred to as a "6-rib" trans. These use the same size R&P as the 002 models, but have larger differential gears, and wider 1st-4th gears for the most strength. (Note that 1980-1983 model years have the shifter located on the side of the nosecone, rather than directly out the front of the nosecone. These can be converted to front shift with a full teardown and rebuild of earlier shift parts and housings)

094 transaxles were produced from 1984 to 1992, actually labeled as 091/1 from VW and have 091 part numbers in the castings. These are commonly referred to as "Waterboxer" transaxles due to being the first model that used a water-cooled engine the in the Vanagon busses. These are also known as a "side-shift" trans as the shifter is located on the passenger side of the main case and will require a special adapter to connect a shift rod. The biggest advantage to these units is having a strong reverse gear that can actually be used if stuck, where earlier models have a very small, weak reverse gear that can break very easily. 

Oil Capacity: 3.7 Quarts

094/Vanagon transaxle with side shift adapter installed.VW 094 #2.jpg

 
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Mendeola Transaxles (Off-road transaxle line procured by Weddle Industries in 2013):

The Mendeola transaxle was one of the first transaxles produced that could handle V8 power in larger, heavier buggy's in the late 1990's. These were designed off of VW transaxles and use a variety of VW shift mechanism parts, but most notably the small, weak reverse gear. 

The MD2D is the most commonly used model and can typically handle around 400 HP at the crank, with no larger than 35" tall tires. These have a 10" R&P to eliminate the weak link of the VW transaxle, and have wider 2nd/3rd gears to handle the extra power. These typically have a 23-spline "G50" input shaft, but early models have a smaller VW spline input. Weak links will be reverse gear, and mainshaft bearing that will require frequent replacement before failure. 

https://weddleindustries.com/products/MD2D-TRANS/MD2D-TRANS

The MD4E was an "Economy" based transaxle designed to use a Type 1 gearset and front housing, mated with the larger 10" R&P to handle a bit more power and larger tires than the VW trans. These are limited by a smaller input shaft with VW splines and a non-Weddle made 10" 5.14 R&P. These look identical to the MD2D trans from the outside to an untrained eye. 

Oil Capacity: 4.5 Quarts to fill plug (4 Quarts OK)

 
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Mendeola/Weddle S4/S5 and S4D/S5D (procured by Weddle Ind. in 2013)

These units were the next level up from a 2D transaxle for many years. These utilized a racing style "sequential shift" design that eliminated the H-pattern shift system in the VW and MD transaxles. The sequential shift works on a ratchet mechanism where one push/pull of the shift lever is one upshift or downshift, the same way any motorcycle gearbox is operated. These are also "Dog engagement" gears by design, which allow for extremely fast shifts, and can also be shifted without the clutch with proper shift techniques.  

These have large gears that can handle lots of power, as well as a full size reverse gear that is such stronger than the weak VW and MD reverse gears.

The S4/S5 units have a 10" R&P and can handle upwards of 700 HP at the crank, with no larger than 35" tires. The R&P becomes the weak link under higher power and harder driving. These are available standard with VW bell housings, or a Chevy V8/LS bell housing that will use a larger 10.4" and 11" clutch's for much better drivability. 

https://weddleindustries.com/products/S4-TRANS/S4-TRANS

The S4D/S5D units are identical in function and use the same gears the S4/S5, but with a larger 11.5" R&P to handle more power and bigger tires. These can handle upwards of 1000 HP at the crank in most applications. 

https://weddleindustries.com/products/S4D-TRANS/S4D-TRANS

Weddle Industries procured the rights to produce these units in 2013. Many improvements and design changes have been incorporated into these since then. The new "Gen 3" shift mechanism released in 2020 allows for faster, crisper shifts, as well as allows for "no-lift-shift" capabilities with proper ECU's and tuning. External paddle shift systems can also be added with the use of a proper ECU and tuning.

Oil Capacities:

S4/5: 5 Quarts

S4D/S5D: 6.75 Quarts

 
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Weddle HV transaxles:

Weddle started the lineup with the HV-1 in 2009. These incorporated a 10" R&P set mated with the VW 094 gearset and full size reverse gear. These were directed to compete with the MD2D and offer the strong reverse gear, and fix some of the other weak points in housings and design. These were the first H-pattern economy level trans to offer a full size, direct fit Chevy bell housing that allowed the use of a 10.4" and 11" clutch assembly, which offers better drivability and a lighter clutch pedal over the smaller 8" and 9" clutch's required for use on the VW and MD transaxles. These are limited by the 094 gearset, and can typically only handle about 400 HP and 35" max diameter tires. 

https://weddleindustries.com/products/HV1-TRANS/HV1-TRANS

The Weddle HV-24 and HV-25 transaxle line is arguably the best lineup of H-pattern synchronized, 10" R&P transaxles on the market. These incorporate all of the features available on more modern gearbox designs, and fix many of the inherent weak links in the VW, MD, and even the S4/5 units. These have 27mm (1-1/16") wide gears to handle more power than the MD and HV-1. Mainshaft bearing is a large dual tapered roller bearing to handle thrust rather than the ball bearings in other units that are not designed to handle end thrust, which wear out quickly and fail with use. Mid-plate bearing support between 2nd and 3rd gear to eliminate shaft deflection under hard loads. And a mechanical internal oil pump and oil circulation system that pumps and distributes oil to every upper bearing and gear in the trans, which means there will never be a dry bearing or gear when accelerating hard up hills.

The Weddle HV-24 and HV-25 can handle upwards of 600 HP at the crank and 35" tall tires. The limiting factors will be the 10" R&P and smaller MD sized diff gears compared to the larger gears in the S4/S5 units. These are best suited for moderate powered V8 buggy's where anyone can drive them as the H-pattern synchronized gearbox works like any production manual trans.

https://weddleindustries.com/products/HV24-TRANS/HV24-TRANS

https://weddleindustries.com/products/HV25-TRANS/HV25-TRANS

Oil Capacities:

HV-1: 5 Quarts

HV-24: 6 Quarts

HV-25: 6.5 Quarts

 
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Albins AGB transaxles:

Weddle is the North American distributorship and service center for Albins transaxles and parts. These were first introduced in the early 2000's as a gearbox for high powered Class 1 Baja race buggy's. These were originally designed off of the Porsche G50 transaxle which was proven to handle good amounts of power in road cars, but the Albins version was fitted with a much larger 11.5" R&P to handle the larger tires and power, as well as the roughest terrain in Baja.

These have now been redesigned and improved to the point where there is no longer any Porsche parts left. Albins designed a sequential shift mechanism and gear design which has proven to be one of the strongest transaxles to date. These are capable of handling 1000+ HP in the highest level sand cars built today, and are only now starting to show some limitations when being pushed by 2000 HP engines.

https://weddleindustries.com/products/AGB-SS5-TRANS/AGB-SS5-TRANS

Oil Capacity: 7.5 Quarts

 
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Sean, this is awesome info and my question is probably a pretty big ask. 

Would it be possible to get some overall dimensions and maybe even info on different mounting points when looking to swap from one transaxle to another?

For example, if I was looking to move up from a 2D to a S4 or HV, how much larger is the S4 or the HV than a 2D. Do they have the same mounting points in relation to the axle location? This would help understand what chassis changes would I need to consider. Any of this info would be helpful for those of us who can't see all these different transaxles up close. Thanks!

 
I would like to hear your thoughts on the pbs s4 as well. Strengths/ weakness, and what possible upgrades they would benefit from. 

 
I've done this swap on my car, went from a 2D to a PBS. I chose the PBS because all you have to do is flip the bracket at the rear of the trans. (mid engine) Engine side is the same bracket. To go to the Mendi I would had to raise the engine about a inch and redo both brackets. That would of involved news motor mounts, radiator tube and redoing the exhaust. The 2d I was refreshing everyother trip and the PBS has been flawless for 4 or 5 seasons now.

 
Sean@Weddle said:
Albins AGB transaxles:

Weddle is the North American distributorship and service center for Albins transaxles and parts. These were first introduced in the early 2000's as a gearbox for high powered Class 1 Baja race buggy's. These were originally designed off of the Porsche G50 transaxle which was proven to handle good amounts of power in road cars, but the Albins version was fitted with a much larger 11.5" R&P to handle the larger tires and power, as well as the roughest terrain in Baja.

These have now been redesigned and improved to the point where there is no longer any Porsche parts left. Albins designed a sequential shift mechanism and gear design which has proven to be one of the strongest transaxles to date. These are capable of handling 1000+ HP in the highest level sand cars built today, and are only now starting to show some limitations when being pushed by 2000 HP engines.

https://weddleindustries.com/products/AGB-SS5-TRANS/AGB-SS5-TRANS
Click to expand...
What's the actual wait time if I ordered a new Albins today? 

 
You know what would be amazing? If you modified each of those posts and added the oil change amount assuming no external oil pump system: 

2d and Ebox 4 qt

S4/5 5qt 

S4/5D 6qt 

 
DZRTRUN said:
You know what would be amazing? If you modified each of those posts and added the oil change amount assuming no external oil pump system: 

2d and Ebox 4 qt

S4/5 5qt 

S4/5D 6qt 
Click to expand...
With the car on flat ground I fill them slowly till it comes out of the fill hole. For pump/cooler cars I hot wire the pump to prime the system then check the level at the fill hole.

2ds get a little over 4 qts, S4/5 5 qts, Albins 6 1/2 to 7 qts. These amounts can vary a little. My Albins with a pump, no cooler, gets 8 qts.

20210716_145643.jpg

 
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kgwmu said:
Sean, this is awesome info and my question is probably a pretty big ask. 

Would it be possible to get some overall dimensions and maybe even info on different mounting points when looking to swap from one transaxle to another?

For example, if I was looking to move up from a 2D to a S4 or HV, how much larger is the S4 or the HV than a 2D. Do they have the same mounting points in relation to the axle location? This would help understand what chassis changes would I need to consider. Any of this info would be helpful for those of us who can't see all these different transaxles up close. Thanks!
Click to expand...
Best to e-mail me for updated drawings. Can't load them here as they are PDF.

Looney Duner said:
I would like to hear your thoughts on the pbs s4 as well. Strengths/ weakness, and what possible upgrades they would benefit from. 
Click to expand...


PICKUPYOURTRASH said:
Sean@Weddle X2... Yes Please
Click to expand...
PBS was basically a copy of the Mendi S4/S5 with a few alterations to the shift system and housings, but they were still never 100% reliable with shifting and still have housings that crack/break. Most notable issues are bad shifting or "ghost" shifts, where the shift lever is pulled/pushed to upshift/downshift to the next gear, but the shift mechanism inside does not shift into the next gear (common problem with pre-Weddle Mendeola sequentials as well). 

PBS is now defunct as of early 2020. Any specific PBS parts that are broken will not be able to be purchased new. Can use most of the internals to install into new Weddle housings for around $7000.

Agricon said:
I've done this swap on my car, went from a 2D to a PBS. I chose the PBS because all you have to do is flip the bracket at the rear of the trans. (mid engine) Engine side is the same bracket. To go to the Mendi I would had to raise the engine about a inch and redo both brackets. That would of involved news motor mounts, radiator tube and redoing the exhaust. The 2d I was refreshing everyother trip and the PBS has been flawless for 4 or 5 seasons now.
Click to expand...
Notable difference is that the bottom of the PBS trans will hang down about 1" lower if you choose not to raise the engine. 

Wallnutz said:
What's the actual wait time if I ordered a new Albins today? 
Click to expand...
Always best to call or e-mail me direct for timelines.

 
Question, I have an 091 bus in my car, I notice that one of the side flanges that holds the cv has a lot of up and down play.  what causes this? does it need a new case? 

Thanks, awesome thread!!!

 
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