Post by riffraff on Oct 23, 2006 13:32:56 GMT -5
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.