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Topic: Installing a Straight Axle in Your Split Bus (Read 5,857 times)

riffraff
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Installing a Straight Axle in Your Split Bus
« Thread Started on Oct 23, 2006, 1:32pm »

Part One

I built my first straight axle last winter from mail ordered parts and a 72 Standard Beetle transaxle. I searched the web to try to find a good tutorial, but did not find one that I considered comprehensive enough for the novice.
The articles were short on detail and presumed that I had far more experience than I did.
What I have tried to do here is describe, in detail, the procedure from start to finish so that the novice mechanic can tackle (and succeed at) this job. There will undoubtedly be sections that some people can skip over as the detail may be painful, but I figure it is better to include too much information than too little.
This tutorial is based on my memory of building a straight axle rear for my 61 bus, so this should be accurate for 59-63 buses. If your bus is a split case (pre 59), you need to change the front transaxle mount and I think stock e-brake cables are required. If your bus is 64-67, this procedure will work, but I don’t know what e-brake cables work. Also, the brakes from a big nut transaxle will not work on the straight axle.
It is a really good idea to have a Bentley Manual for your year of bus on hand!!!
Best to assemble all the parts and tools you will need for the task ahead of time so there are no nasty surprises when your bus is torn apart and in 169 pieces on the floor at 11:30 on a Sunday night and you realize you have no transaxle gaskets.

Required Parts
Swingaxle transaxle, from a Type 3 or 68 and later Beetle. Either of these transaxles have the long axle, long spline axles that are required for the straight axle kit.
Lengthened axle tubes – These are 61 to 66 Beetle axle tubes that have had 1 5/8 inches added to the length.
Short Bearing Caps – these are the bearing caps used on the 61-66 Beetle axle tubes.
Type 2 tunnel trans nose cone
Type 2 hockey stick (or later Beetle with two dimples)
Modified, notched springplates
Beetle length shock absorbers (I like KYB whites)
Axle seal kit (2)
66-67 e-brake cables (2)
Transaxle gasket set
Swing Axle boots (2) and clamps – (Get the soft ones with lots of pleats, the stiff Brazilian ones are impossible to work with)
90W gear oil (4 litres of GL-4)
Brake fluid

Optional Parts
These parts are not absolutely required, but while you are in there and have everything torn apart, it is a good idea to change these out as well.
Soft brake lines
Outboard hard brake lines
Rear wheel cylinders (German)
Brake shoes
Wheel bearings (S*K*F or F*A*G, not Chinese)
Might as well have the drums turned as well.
Clutch cable
Bowden Tube
Throttle cable
Wheel spacers (see brake section)
Longer lug bolts (see brake section)

Tools
Apart from the regular assortment of wrenches and sockets that I assume everybody that owns an ancient A/C has, there are very few “special” tools required to do this job.
These include
36mm socket for the axle nuts.
27mm socket for the Frame horn bolts)
¾” Breaker bar
Snipe (I find a chain link fence post makes an excellent snipe)
3 jaw puller
Four jack stands
Needle Nose pliers with the tips ground to a smaller outside diameter.
[image]

Preparation
This is pretty important. If you can get a bunch of this little stuff out of the way before you get really serious, it will make the whole operation way smoother.
The very first thing to do is to spray some Liquid Wrench on the grub screw that attaches the hockey stick to the shift coupler. These can corrode into place and can be a real bear to deal with if they are sheared off. Multiple applications of Liquid Wrench coupled with alternating heat and cold (Torch and spray water bottle) will usually break the corrosion bond between grub screw and coupler.
You will want to start on this a week before the transaxle changeout.

[image]

Is the bus going to be converted to 12V while you are at it? If so, you will need to change out all electrical components and hog out the bell housing of the straight axle centre section if it was 6V. You will also have to change the starter bushing. You may also need to change out your flywheel and clutch.
Brakes and Wheels
Next, decide what brakes you are going to use for the straight axle. You can use your existing Type 2 drums with Beetle brakes with some modifications to the drums, 4 lug Beetle brakes or (my personal choice) run early Type 3 brakes. If you decide to run bus or Type 3 brakes, you will need a ½ to ¾” spacer between the drum and wheel to keep the tires from rubbing on the springplates.
[image]

You will also need longer lug bolts to accommodate the spacers. Post 98 Golf/Jetta 14 mm lugs will work and are ½” longer than stock bus lugs.
If you chose to re-use your existing small nut Type 2 drums, you will need to have some machining done to them. 5/8” will have to be romoved from the snout, the inboard outer lip will have to be machined down flush and 1/16” of the inboard end of the outboard lip will have to be machined flush. Refer to this page for specifics.

http://www.23window.com/irs_drumspecs.asp

This will allow you to use the Beetle guts and backing plate with Type 2 drums.
If you run 4 lug Beetle brakes, you can get a four to five lug adapter that will allow you to run wide five wheels. (Incidentally, the adapter also acts as a spacer).
If you will be using stock wheels, you will need spacers to keep the tires from rubbing on the springplates, if you are planning to run after market wheels, the offset will likely be enough that you will not need spacers, but getting the wheel out of the wheel well will be more of a problem
You will also want to be sure the axle nuts are broke loose on the donor transaxle.
If you’re lucky, the axle nuts have been broken free on the donor transaxle, if you are not so lucky, you have to do this with the transaxle out of the vehicle. The best way to do this is to load the transaxle up into the back of the pickup and take it to a shop and have them buzz them off with a big air ratchet.
If this is not practical, try to wedge the drum from turning with a bar between two partially threaded lug bolts. Now come onto your six foot snipe and proceed to bend the bar and the lug bolts.
Now load the whole thing into the back of the pickup and take it to a shop and have then buzz off the nuts with a big air ratchet!

OK, you have done all the up front work, chosen your brakes, assembled all required parts, tools, beverages and slave labour and coaxed the grub screw out of the coupler.

Removal of Transaxle from Bus
Regardless of which brakes you plan to use, be sure to bust loose the 36mm axle nuts BEFORE you do anything else and while the bus is still on the ground. The torque spec on these is ~220 ft lbs of torque, and when they have not been off for decades, it can take north of a thousand ft lbs of torque to break them free. I have found a 36 mm socket with a ¾” drive breaker bar and a six foot chain link fence post snipe will break free the most stubborn axle nuts. Fit a short extension between the socket and the breaker bar and set a jackstand to the proper height under the extension. You can now hang off the end of your six foot snipe and be in no danger of the socket flexing off the nut. It is also a good idea to break the frame horn bolts free as well now (don’t remove them, just start them).
Time now to jack the bus up so the rear wheels are airborne and put jackstands under the torsion tube. I like to jack up the front and put jack stands under the front beam as well to keep the bus stable and level.
If you are going to use your Type 2 drums, pull them off and send them out to the machine shop. Remove the rear shocks completely from the bus.
Now, next step is to remove the engine from the bus. I am assuming that everybody taking on the lowering of their bus already knows how to pull and install their engine. It is a good idea to disconnect the battery at this point as well as there will be exposed terminals at the starter motor when you pull the transaxle.
Next thing to do will be to remove the transaxle from the bus. I recommend buying a new nosecone and hockey stick for the straight axle so that you can leave the bus transaxle intact. Not only will it be sealed from the elements, but it will be ready if and when you (or a future owner) decide to put the bus back to stock height. Always a good idea to prepare for that eventual outcome.
If you insist on using the nosecone and hockey stick from your bus transaxle, drain the oil from it before you pull it from the bus. That is accomplished by removing the 17mm Allen key drain plug on the bottom of the transaxle and the drain plugs on each RGB.
Removing the transaxle is relatively straight forward, but a couple of pointers may be in order if you have not previously attempted this miracle. First thing to do will be to undo the brake lines from the wheel cylinders and disconnect and remove the e-brake cables. Bolt the e-brake retainer clips back onto the backing plate so you don’t lose them. Undo the clutch cable and pull it free of the pivot arm. Undo all the wiring from the starter motor. Now undo the four bolts on each side that hold the RGB’s to the springplates. It is a good idea to affix a large clamp to hold the springplates to the RGB’s while removing (or installing) them so as not to strip the threads in the RGB’s.
Let the RGB’s hang free of the springplates. (the shift coupler is already apart, right?) Now, undo the bolts that hold the nose cone to the front transaxle mount and unbolt the ground cable if applicable.
Next, slide a floor jack underneath the transaxle and take a bit of weight on it. Undo the frame horn bolts, slide the transaxle back a couple inches and it should be free of the bus. Take it over to a corner of the garage where you will not trip over it and take the starter motor off of it if you are going to re-use it. Remove the Bowden tube as well and inspect it and decide if you are going to re-use it or replace it.

« Last Edit: Oct 24, 2006, 7:27pm by riffraff »

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Re: Installing a Straight Axle in Your Split Bus
« Reply #1 on Oct 23, 2006, 1:38pm »

Part Two

Preparing the Straight Axle
The first thing to do is to drain the oil from the transaxle. It is skanky stuff, and the more of it you can keep off of yourself, the better!
Undo the axle nuts and pull the drums off of the axle. Undo the four bolts that hold the bearing caps and backing plates to the axle tubes. Pull off the bearing caps., don’t lose the spacer!
Now you have the ignominious task of pulling the axle bearing off of the axle. Sometimes they come easy, sometimes they come tough, but once this is done, the worst is behind you. What I have always done is to turn the 36mm castellated nut on inside out on the axle until it is fully engaged, but no threads are showing. Then I give it some love taps with a 3 pound hand sledge. That will generally push the axle in enough that, when retracted, I can get the puller on the back of the bearing. If there still is not enough room to get the puller jaws on the back, you can undo the six bolts that hold the axle tube to the centre section and pull it out as far as it will go. Block the gap between the tube and the centre section and tap the axle in a little further. Repeat this hillbilly procedure until the puller will fully engage the bearing.
Once you have the puller on the back of the bearing, pull the bearing free of the axle. Sometimes these are a real prick to get off! Now, undo the six bolts that hold the axle tube to the centre section (if you have not already done so). The axle tubes will slide off the axles. Remove the plastic daisies and clean them up for re-use.
[image]

If you have a feeler gauge handy, check the clearance between the paddle and fulcrum plate. It should be no more than 0.02 “. Take your custom ground set of large needle nose pliers and release the large snap ring that holds the retaining washer at the inside end of the axles inside the centre section.

[image]

Slide out the snap ring and retaining washer along the axle. You can now pull the axles out of the centre section and check the paddles and fulcrum plates for wear and scarring. If the axles or fulcrum plates look a little discoloured at the thrust end of the paddles, you can swap the fulcrum plates and axles from one side of the centre section to the other. That allows you to change the trailing end on one side to the thrust end on the other side.

These fulcrum plates and paddle end of the axle is off the passenger side as you can tell from the wear marks

[image]

If the paddles and fulcrum plates look good now and the clearance was within spec’s, put the axles back in using a white lithium grease to hold the fulcrum plates inside the side gears while you slip the axles back into them. This can be a little tricky as the tolerances are tight, so don’t feel special if you don’t get them in on the first try! It is generally easier to fit the axle and fulcrum plates into the side gear with the side gear out of the trans. Then the whole operation can be slid back in.
Now, clean up the face of the new axle tubes that mate with the centre section and that face on the centre section real good because there is a little trial and error fitting of gaskets going to take place.
Re-fit the cleaned up plastic daisies on the centre section. Open up your set of transaxle gaskets and select two gaskets that go between the axle tubes and the centre section. Seat both of these gaskets dry on the same side of the centre section of the trans. You can now slide the lengthened axle tube over the axle and bolt it securely to the centre section. Now you have to do the “drop” test.
With the trans braced and sitting level, lift the outboard end of the axle as high as it will go, now let it go. If you have the correct number of gaskets between the axle tube and the centre section, the axle and tube will slowly drop. If there are too few gaskets, the assembly will not drop at all and if there are too many, it will freefall. Adjust the number of gaskets between the centre section and axle tube to get the “slow drop”. Once this is accomplished for both sides, replace the backing plates and slide the new bearings over the axles. Fit the seal kit over the bearing and slide the new, short, bearing caps into place. Tighten down the four bolts that hold the bearing caps and backing plates in place on the axle tubes.
Now for the nose cone. There are 7 bolts that hold the nosecone in place . Undo these 7 nuts and the nosecone will slide over the hockey stick. Remove the hockey stick as well. Before replacing the hockey stick, be absolutely sure that the transmission is in neutral. You can check this by ensuring that the gaps in the “forks” that the hockey stick engages are all lined up vertically so that the hockey stick can engage any of the three without having to move fore and aft (this will make sense when you see the forks!). Fit the new hockey stick in the gaps, grease the shaft and slide the Type 2 nosecone over top of it. Snug down the five nuts. Manually run through the gears to be sure that everything is together properly. It is easier now that when you go to take a test drive and can’t find any gears! Bolt the correct voltage starter motor onto the bell housing complete with the proper sized starter bushing.
Bolt on brake components and install the axle boots so that the seam is at a 45 degree angle to the horizontal. Slide the brake drums on to be sure they clear the backing plates and shoes and do up the 36mm nut hand tight. You will need to take the drums off again to install the e-brake cables, but having the drums on will keep grease and crap from getting on the brake shoes as you install the transaxle.

Springplates
Now it is time to change out your spring plates. The spring plates are held on to the bus by means of a spline on the inboard end and bushings in the torsion housing caps on the outboard end.. Undo the four bolts on the cap that holds the torsion bars in place. Pull the cap off, it should come easily, even if it has never been off. Pull out the outboard bushing, it should come easy. Now you see how the springplate is slid over the splines on the torsion bar. Using a white marker, (WhiteOut works good) mark a line across the torsion bar and the springplate. This will be a reference line that shows how the spring plate and torsion bar were originally oriented. Carefully pull the springplate off of the torsion bar without pulling the torsion bar out of its inner splines. The torsion bar can be pulled out of the inner splines about 1 inch without disengaging the inner splines, but limit it to ¾” or so for the time being. If, by chance, you happen to pull the torsion bar out of its inner splines, don’t panic, it is not a big deal, just better for now if you don’t.
The number of splines on the outboard end of the torsion bar is 48 and the inboard end has 44. This allows for almost infinite adjustment of the ride height.
With the springplate off the torsion bar, gently pull the torsion bar out of the housing until it clears the inner splines. Now rotate it 1 spline clockwise and slide it back in. Slide the notched springplates on the outboard splines 2 splines counter clockwise from where the stock springplate was. You want the springplate to be pretty much horizontal. This is a good starting point for an initial ride height setting. Slide the outer bushing over the torsion bar and bolt the cap back on.

Installation
Your straight axle is ready for installation. This is best done with a buddy and a beer. There is no trick to it, just wiggle it in until the front trans mount engages the nosecone and the frame horn bolts are aligned and do up these bolts hand tight. Now, bolt the springplates to the axle tubes. No sense in torquing them on there too tight as you will probably need to adjust the ride height after it is back together and you will have to free the axle tubes from the springplates to do that.
Hook up the shift coupler and the starter motor wiring and snug the front transaxle mount nuts first, then the frame horn bolts. Be sure there is a good 1” bend in the Bowden tube.
This is a good time to check again that you can get four forward gears and one reverse with the shifter.

Park Brake Cable Install
This is pretty straightforward. If your bus is 59 to 63, you need 64-67 park brake cables. Rumor is you can use stock cables for pre 59. You will need sheath extenders for the park brake cables. I made mine out of ½” copper pipe and spray bombed them black. Cut the pipe 1 9/16” long. Fit them between the sheath and where the sheath enters the body tube.
The return spring will be too long, so it will have to be cut down to 38 coils. It should all go together now. Thread the cables to the front of the bus and use liberal doses of wheel bearing grease, but do not hook them up to the park brake lever yet.

Final Bolt Ups
Put the wheels on the back of the bus. You may find on buses with a inny fender lip that you either have to jack down the springplate to get the wheel into the wheel well, or drop the axle down off the springplate. Driving a slammed bus does have it’s drawbacks! If you are running Bus or Type 3 brakes, you will need a ½ to ¾” spacer between the drums and the wheels to keep the tires from rubbing on the springplates and longer lugbolts.
Hook up the clutch cable and put the shorter shocks on.
Put the engine back in. Even if you have not changed to 12V, be sure you have the correct flywheel, clutch and release bearing for the year of transaxle you have installed. Take the bus down off of the jackstands and roll it back and forth to level out the rear end.

Leveling the Rear
The best way to level the rear is by using a sliding protractor (VW tool 058). The next best way is trial and error. You want the wheels to be pretty much straight up and down (Zero camber) with the engine installed and a full tank of fuel. Look at the wheels from the rear. If they look like this \ / (positive camber), then the springplates are set too high. If they look like this / \ (negative camber), the springplates are set too low. In order to change the level the bus rides at, move the springplates up or down by using a combination of both inner and outer splines and clockwise and counter-clockwise rotation of the torsion bars to create the desired ride height. Remember, whatever you do to one side, do to the other side so the bus sits level side to side.
Once you have the ride height set where you want it, move the axle fore and aft in the elongated springplate holes so that the alignment of the rear wheels looks like it has a very slight toe in. Snug the bolts down. You should now torque the axle nuts to 220 ft lbs and engage the cotter pins. Now, take the bus for a test drive. Once back from the test drive, check all your bolts to be sure that everything has been properly tightened and torqued.
I assume that you have installed dropped spindles on the front as well. Once the bus is back together and driving, it would be a good idea to take the bus for a four wheel alignment so that you can get all the wear out of your tires that you expect.

Ultimately, this is the result you are looking for:

[image]

« Last Edit: Oct 24, 2006, 7:48pm by riffraff »

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commercialair
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Re: Installing a Straight Axle in Your Split Bus
« Reply #2 on Oct 23, 2006, 8:17pm »

Finally!!!!

Thanks Keith, I'm sure there are alot of people that can use this.
It's great to have this as a reference.

All your contributions to the virtual garage are appreciated.

I'll tackle swing lever pin and bushing replacement in the very near future.

BTW, Karma for you!!!!!

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dpeters81westy
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Re: Installing a Straight Axle in Your Split Bus
« Reply #3 on Oct 24, 2006, 12:24am »

Chris... If you need a Photographer for your "how to..."
I'll snap pictures for you...
and maybe buy the coffee...

anything to help all the NUTS out there.

- DP

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