Fitting a 5 speed into your bug

[Bug@5speed(US)]

I have collected enough info for an article that I have done in PPT but its to large probably to host as a pdf.. but will post some of the high lights in this thread.

Slide 1- 5-Speed Conversion: Installing a Porsche Gearbox into your Type I IRS Chassis

Slide 3- Starting Point:
In order to install a 5 speed gearbox you must first begin by locating one.
For this conversion the following gearboxes are acceptable starting points
901 and 902 (5 Speed)
901/911 and 914 gearbox
915
For this guide we will discuss the 901/902/914 family of gearboxes. The 915 will follow the basic procedure

Slide 4- Distinguishing Porsche Gearboxes

This is an example of an early 911 gearbox. (used in the 911 from around 1965to 1968)
These boxes are referred to as 901 boxes.
Identification marks are located on the bottom of the gearbox
The 902 boxes are identical to the 901. It was found in early 912, and has the same internals as the 901 but different ratios

Slide 5- Distinguishing Porsche Gearboxes (Cont)

Early 901 Transmissions
Were made of Aluminum 65 to 68.
These boxes had a Push Type Clutch

Slide 6 Distinguishing Porsche Gearboxes (Cont)
(Picture from another board member)
Late 901 transmissions :
Were made of magnesium 69 to 71
1969 continued to utilize the Push Type Clutch
70 to 71 utilized a Pull Type Clutch

Slide 7 Distinguishing Porsche Gearboxes (Cont)


914 Tail Shift Transmission
Found in 914 Porsches (pre-1973 914/4 and 914/6)

Slide 8 Distinguishing Porsche Gearboxes (Cont)

914 Side Shift Transmission
Late 914 utilized the side-shift configuration.
Look at the similarities in the case to the tail shift.
Nose cone and shift rod and fork internals differ
The 914 Side Shift transmission can still be utilized for the conversion but will require additional work and components

[Bug@5speed(US)]

Slide 9 Bug@5-Speed Kit Components



Bug@5-Speed “Beetle Shifter”
The Shifter can be looked as a short throw shifter, due to the reduction in shifter throw.
The base of the shifter provides additional support for the beetle shift rod as well as a bushing for the beetle rod to ride smoothly on. This support eliminates a lot of the issues that some folks may have due the bending their bug shift rods like a Z or are not having the proper alignment. With the supported shift rod, proper alignment from the shifter to the input shaft on the Gearbox is maintained.
-Shifter has spring gate to prevent accidental shifting into reverse.
Can use with a stock, aftermarket or our shifter ball.

Slide 10 Bug@5-Speed Kit Components



Bug@5-Speed “Porsche Style or aka Square Shifter”
This Shifter is similar to the beetle style but with obvious differences.
Shifter comes with a 911 style base to attach to a Porsche tunnel or modified beetle tunnel
Additionally comes with bent shift rod, leather boot, and machined shift knob.
This shifter can also be looked as a short throw shifter, as the shifter has a throw of less than 60 mm per gear.
The Shifter has spring gate to prevent accidental shifting into reverse.
Can use with a stock, aftermarket or our shifter ball.

Slide 11 Bug@5-Speed Kit Components
Bug@5-Speed Front Traverse



Cast Aluminum, with Hardened Black Mounts
Creates mounting point for Nose Cone.
Attaches to the based of the IRS mounts via special wedge spacers and M12 sized bolt

Slide 12 Bug@5-Speed Kit Components
Bug@5-Speed Nose Cone

Cast Aluminum, and machine finished.
The nose cone allows the transmission to be moved fwd 30 mm thereby giving you more space out back and providing better weight distribution.

Slide 13 Bug@5-Speed Kit Components
Bug@5-Speed Rear Support
901 Style

914 Style


There are two designs due to the shape of the gearbox bell housing shape
901 style is designed to attach to 901 and 915 bell housing which don’t have the flat sections that the 914 ‘s have
914 style is designed to attach to the bell housing via beetle rear transmission mounts

Slide 14 Bug@5-Speed Kit Components
Bug@5-Speed Clutch Cable adapter plate and Cable Extension Connector



Adapter Plate is needed due to the lack of an eyelet to secure Bowden Tube and maintain proper alignment
Cable Extender attaches to the end of the factory clutch cable enabling quick adjustment by turning knurled bit

[Bug@5speed(US)]

Slide 15 Bug@5-Speed Kit Components
Bug@5-Speed also carries Inner Shift Forks for use when converting 914 tail and side shift gearboxes


Slide 16 Bug@5-Speed Kit Components
Bug@5-Speed also carries Modified 901 and 914 TOB Forks for use when converting 901, 914 tail and side shift gearboxes
Modified forks are bent to provide better geometry
These can be purchased on an exchange basis
Lever is newly galvanized after the modification/adjustment*and equipped with a new guiding socket at the back.*




Slide 17 Bug@5-Speed Kit Components
Bug@5-Speed Gearbox Output Flanges



Come in two sized:
Stock Beetle diameter (78mm)
944/T2 diameter (86mm)
Machined and Hardened
Note: early 901 flanges have larger opening and must be specified

[Bug@5speed(US)]

Slide 19- Getting Started (Partial Disassembly)


Drain oil via two plugs on the side of the gearbox (17mm Hex Drive)
Lower plug is magnetized to capture filings
It is a good idea to inspect this plug to have an initial idea of condition of internals

Slide 20 Getting Started (Partial Disassembly)




Removing Flanges
Utilizing 1 inch square stock special tool is made to prevent flange from spinning
Bolt on flanges are size 19mm and are referred to as diff expansion bolts

Slide 21 Getting Started (Partial Disassembly)


The differential side cover/plate is secured by 13mm sized nuts
Removing of the side cover is necessary in order to flip the differential
This is necessary on the 914 gearboxes due to the 914 boxes being set up for mid engine configuration
Failing to due this will yield one fwd gear and 5 reverse gears

Slide 22 Getting Started (Partial Disassembly)


Side Cover removed exposing a poorly maintained gearbox
This is not what you want to find
With cover removed it becomes evident that in order to remove the diff, the pinion shaft and main shaft will have to be removed

Slide 23 Getting Started (Partial Disassembly)




Few more items that need to be removed to enable the intermediate plate, and gear stack to be pulled away from the case to access diff
Unbolt 2 13mm nuts to removed side cover plate; freeing inner shift rod
Removed reverse gear switch and pin

[Bug@5speed(US)]

Slide 24 Getting Started (Partial Disassembly)



With the intermediate plate and gear stack out of the way you can now pull the differential from the box
Now reinstall with differential Ring Gear facing the opposite way
Reinstall all items in reverse

Slide 25 Getting Started (Partial Disassembly)




Nosecone is secured to intermediate plate via 13mm nuts.
Once nuts are removed utilize a rubber mallet to remove nosecone
Take caution when removing the nosecone, as the reverse gear assembly may fall out/off

Slide 26 Getting Started (Partial Disassembly)



With cover removed now is a good time to transfer reverse gear shaft onto your new nosecone
Example shown of early 901 nose cone
Utilize a small punch and remove small pin
Remove reverse shaft and relocate onto Bugat5speed Nosecone
Reinsert small pin to secure/lock reverse gear shaft


Slide 27 Getting Started (Partial Disassembly)

Reverse Gear shaft shown on the old nose cone


Reverse Gear shaft and locking pin

[Bug@5speed(US)]

Slide 28 Getting Started (Partial Disassembly)


With Nose Cone removed, now is a good time to remove the speedometer drive gear
Two approaches
(1) Use a hacksaw and cut (Not best approach)
or
(2) Remove Expansion bolt (held in place with (80-87ft/lbs) and decouple drive gear (Better approach)


Slide 29 Getting Started (Partial Disassembly)



The Expansion bolt is size 32mm, and will require that you lock the gearbox down in order to utilize an impact drill to remove.
There are many methods to locking the gearbox, one such method is to utilize an old clutch disk, using some one inch stock and a few bolts (See side picture)

Slide 30 Getting Started (Partial Disassembly)



Once expansion bolt is removed from, you will notice that the speedometer drive gear is secured via a small pin
To separate remove lock pin

Slide 31 Getting Started (Partial Disassembly)



The Bug@5-Speed Nose Cone and Front Traverse are shown on the right.
With the reverse gear shaft installed and locked in, you can attach nose cone to the intermediate plate and gearbox.
Be sure to replace the factory gasket or utilize a liquid gasket to create a good tight seal
Secure to gearbox with the self-locking nuts and washer
Torque 13mm nuts to 18 ft/lbs (Per Porsche Manual

[GS guy]

Excellent write-up Alex! Keep it up!

Jeff

[Bug@5speed(US)]

Thanks..

I will have the rest of the pics and notes up shortly..

Little under the weather these past few days.. passing a cold/flu between son and wife..

But appreciated the comments
Alex

[Bug@5speed(US)]

Slide 60- Type I IRS Chassis Prep



A center punch and hammer are utilized to mark the location for drilling.
Starting with a smaller (approximately 6mm or ¼” bit) make the necessary pilot hole
Note: Remember to use cutting oil, and eye protection

Slide 61- Type I IRS Chassis Prep



Final hole will be made with a M12.5 or M13 Drill bit. The Front traverse will be attached to the IRS mounts using a M12 Bolt (19mm), two washers, and the supplied metal wedges.

Slide 62- Type I IRS Chassis Prep



The wedges are provided to create a level surface for the mount to go onto.
4 wedges are included in the kit.

Slide 63- Type I IRS Chassis Prep



You will notice the location of the second wedge on the back side of the IRS mount.
Using M12 hardware, secure the bolt with a lock not and some thread lock

Slide 64- Type I IRS Chassis Prep



Picture of what the under side of the chassis should look like.
With gearbox partially secured and all the trimming, cutting repositioning and clearance now complete, it is a perfect time to check everything once more.

Slide 65



The Knurled Extension bit is utilized due to the stock cable being to short.
Make sure you attach the extension with some grease to ensure smooth operation and adjustment

[Bug@5speed(US)]

Slide 66- Type I IRS Chassis Prep



You will notice with the gearbox installed that the clutch cable tube that exits the rear of the transmission tunnel is not properly aligned to mate with the new adapter plate
Maintaining this exit angel will cause the tube to interfere with the gearbox, Bowden tube and the clutch cable.
This will need to adjusted/modified.

Slide 67- Type I IRS Chassis Prep

The clutch guide tube is held in place with a strong weld from the factory
Utilizing a metal drill or Dremmel along with a steady hand, break the weld and tube free. A sharp chisel will a great help, too.
Using a suitable-sized punch, metal rod or piece of steel bar, you then carefully bend the tube, thereby realigning the exit angle of the cable. A new spot will be needed to retain the tube at this new angle
Note: Care must be taken to not damage the tube when removing the factory welds, as any dents or kinks may cause clutch cable interference
A trial assembly of the re-routed Bowden Tube (flexible clutch cable conduit) from the back of the chassis is checked on last time. Need to ensure a smooth curve with no tight angles is necessary

[Bug@5speed(US)]

Slide 68- Bug@5-Speed Shifter Install

Our Shifter Guide goes into more detail, but here are some pics of a partial install. More to come, as some details may not be clear.
Such things as modification to Bug and 911 Shifter Rods, Porsche coupler, where to locate your shift rod, and any modications required.
Following slides are just to high light some of the install.

Slide 69- Bug@5-Speed Shifter Install





Installing of the shifter onto tunnel is relatively simple
(1) Remove old beetle shifter
(2) Make template of the base of the Bug@5-Speed Shifter, and trace this onto tunnel
(3) Using a cut off wheel or similar type tool cut the necessary 50 x 78 mm for the new shift lever into the tunnel
(4) Finish off by grinding edges to crate smooth finish

Slide 70- Bug@5-Speed Shifter Install





Next, you will need to tap 4 holes onto the tunnel to install the supplied (4) hex bolts
Lastly Install shifter as shown in pictures onto the tunnel and secure utilizing the (4) hex bolts
Following instruction in shifter guide for adjustment and alternatives modifying the beetle tunnel shifter rod

Slide 71- Bug@5-Speed Shifter Install




Here you see the difference between the factory stock beetle shift rod, and the 911 shift rod option.
Lower picture shows where the Porsche coupling would slide into the 911 shift rod.

[Bug@5speed(US)]

I am happy to report, that I should be getting my chassis back from Metricautohaus very soon.

I will update thread with more pics once I have her in my hands..

Stay tuned
Alex

[buggyboyshane]

Originally Posted by Bug@5speed(US)

I am happy to report, that I should be getting my chassis back from Metricautohaus very soon.

I will update thread with more pics once I have her in my hands..

Stay tuned
Alex

goddamit alex!! how did i miss this thread!!! wish id seen it ages ago!!

i have my engine in starting etc etc but cant get the clutch cable to move much as its hitting side of gearbox casing. i have bent the throw out arm slightly with oxy acetylene.... but there doesnt seem to be the right movement of the arm in the case.... it doesnt seem to move right?

could you throw up a picture of the way the arm should be installed in the case? and the bits for it?

is it easily bent or a bugger??

cheers oh great gearbox one!

[Bug@5speed(US)]

buggyboyshane


Just got back from a trip, give me a day or so, and will update you..

Also PM your email address.
Alex

[jmd]

hey guys, can you show some images that outline your "Early 901" rear support part? In looking at your install images you show the part, but not how it mounts to the trans. that might help me make a decision about purchasing or fabricating... Also can you PM me the cost for this part?

thanks.