72-79 Bus Engine Removal in 20 Easy Steps

by Richard Atwell
(c) Copyright 2004-2011

badge

So you need to drop you engine and Bentley and the other manuals (heaven help you) just don't give enough hints for the first timer: here's how.

This article started with photos showing the dropping of my 78 fuel injected bus engine. I've since added photos of the steps that are unique to 72-74 dual carb models using photos from a 72 bus. The 72-74 models are largely the same but some differences have not been documented yet such as the air filter, EGR and air injection pump systems on the 73-74 models. I will update the article as I find these buses but this may take a while because these models are smog exempt and many of the parts have already been removed by the POs and their mechanics.

Most of the procedures apply to any Type 4 engine in a 72-79 bus. If you don't see particular parts then you've got carbs. I've tagged the carb specific photos. There might be slight differences, such as the way the heater booster is wired but you'll get the general idea. I took a few photos out of sequence so if you see something in a photo that was already removed earlier, that is the reason.

There are two procedures demonstrated in this article. You can either remove the engine by itself or as a unit with the transmission still bolted to it. If you choose the unit method, you can skip the steps I've made a note of. To remove just the transmission skip to the end of the article.

The late model busses don't have a removable valence (the section of the body just above the bumper) that can you unbolted from the body. If you've ever seen a split window bus "parallelogram" after a bad car accident you'll understand why VW reinforced the 68-79 body design and made engine removal harder. You also have to understand that despite all the talk VW gave about maintaining the bus yourself they probably expected you to go into the dealer for engine removal and they simply used the lift to raise the bus leaving the engine on a jack or dolly.

I believe it's easier to drop the engine and transmission as a unit or tilt the transmissions/engine combo down to help remove the engine. Although it's harder to pull the engine off the transmission, it takes much longer to prepare to drop both by removing various hoses and unbolted parts.

As for installation, putting in the transmission first is again easier to do if you ask me because it's quite hard to line up the input shaft with the clutch. You also have better access to the bolts and you can attach the accordion heater tubes while only balancing the engine. The only bolts that are difficult to reach are the ones that secure the transmission to it's overhead carrier.


Tools:

You are going to need a few tools. Some are mandatory and some will help you get the job done more easily. It's up to you; just don't get caught in the middle of an engine drop without them.

Minimum:
Optional:

Red arrows highlight the written instructions. Grey arrows indicate items for removal that are hidden from the camera. Blue arrows highlight something interesting but not necessary for the removal.

Here we go!


Step 1: Heater booster fan

1.1) We might as well get this out of the way so we have room to work. Undo (2) hose clamps (originals were phillips) holding heater hoses to booster fan shroud. fan hoses top
1.2) Undo the round hose clamp at left-side engine tin. Do you still have the rubber seal at the base of the hose where it meet the engine tin? fan hose left
1.3) Undo oval hose clamp at the right-side engine tin then remove the hoses. Do you still have the oval rubber seal at the base of the hose where it meet the engine tin? fan hose right
1.4) Disconnect the fan's relay in two places then remove (2) 10mm nuts holding the fan to engine compartment roof. fan mount
1.4) 72-74 dual carbs: In addition to the booster fan, there is the vacuum advance cutoff switch that it mounted to the engine compartment ceiling using one of the bolts for the booster fan. Remove the wires that lead to the engine tin and the coil and disconnect the hoses that go to the distributor and the left carb. Also disconnect the large vacuum hoses for the charcoal canister and the oil breather. fan hoses carb

Step 2: Air cleaner, AFM, decel valve and s-boot

2.1) Remove the vacuum line and charcoal canister hose from the EEC valve on air cleaner. Remove the front of the air cleaner and filter by undoing the (5) clips. Two clips are at the back (shown in gray). Undo the two clamps (originally phillips screws) on s-boot but leave the s-boot in place for the next step. The left portion of the air cleaner and AFM are removed as one unit. air cleaner
2.2) Pull off the major vacuum hoses at the indicated points. Some hoses may have hose clamps because they are sometimes old and the cause of vacuum leaks. Pull the rubber boot out of the aux. air regulator. Undo (2) 10mm bolts holding the decel valve to the firewall and lift the decel valve and hoses off in one piece. You can now remove the s-boot or leave it in place. decel valve
2.1) 72-74 dual carbs: remove the air cleaner to simply access to the rest of the engine. This is a photo of the 72 oil bath air cleaner. To remove, you undo to clips at the side of each carb and then lift and pull up the pizza slices. The right slice has two hoses. The right hose was originally covered in red cloth braid and connected to the control box behind it. The left hose was originally covered in green cloth braid and connects to the rubber boot below the right intake manifold where the brake booster pulls it's vacuum from the engine.

When you are ready to lift out the oil bath undo the bottom clip on the right side and the one of the left towards the rear. The top clips are only for removing the lid. You may have to pull on the carb linkage to get enough clearance for removal.

air cleaner carb

Step 3: Battery

3.1) Disconnect the negative and positive cables.

Now is also a good time to remove the battery. You should check on the condition of your battery trays and this way you'll also have better access to your rear light wiring and your charcoal canister if you have a 78-79 bus. Undo the 13mm bolt securing the battery clamp to the battery (installed incorrectly in this photo btw).

battery
3.2) Remove the hose on the engine tin for the vapor recovery system (it goes to charcoal canister). On some models this hose is on the other side of the engine behind the coil. vapor hose
3.3) Unplug the FI wiring harness from ECU at the connector. There is a little metal tab at the base you have to depress to release it and when you've lifted it about 30 degrees you can unhook the top from the ECU. Lay the harness across the engine. ecu connector

Step 4: Fuel Line Removal

4.1) Fuel lines will be disconnected later so you have to be able to control the flow of fuel. If you are removing the fuel tank anyway consider that even with the engine out it's quite heavy empty and each gallon of gas weighs ~6 lbs. The easiest most manageable connection is the fuel filter inlet. This is a good time to replace the fuel filter anyway especially if your 15k miles are up. If you don't intend to drain the tank have proper clamps that won't damage the fuse hose (vice grips are bad). clamp fuel line
4.1) 72-74 dual carbs: you should have plenty of fuel line to clamp onto. Do not unscrew the tap from the tank unless you are planning to remove it after the tank is out of the bus for a thorough cleaning. In this photo the PO has added an inline filter that was not installed by the factory. clamp fuel line
4.2) Use the hose clamp to regulate fuel flow and collect the gas using a low profile container. You can stop the flow with a golf tee or pencil but I prefer a proper hose clamp that lets me control the flow especially if the tank is half full and my 2 gallon gas container has to fill up several times.

After completing several engine drops you'll be able to keep gas from spilling but always wear rubber dish washing gloves that cover the cuff of your sleeve in case is does run down your arm.

drain tank

Step 5: Voltage Regulator

5.1) Unplug the multi-wire connector on the bottom left of the voltage regulator and disconnect the blue wire at the insulated 2-way tee.

The blue arrow points to a hot start relay I installed. It's a little hard to get the wires through the grommet on the body but it keeps it from getting wet and there is a convenient ground point under the voltage regulator screw.

VR
5.1) 72-74 dual carbs: there are two wires to disconnect on dual carb models. They are color coded to help you reconnect them but if there is any doubt or if the PO has been busy be sure to label them. VR carb

Step 6: Throttle cable

6.1) Undo the 8mm bolt from the barrel nut and release the throttle cable from throttle body. Save the barrel nut and bolt in a safe place and push the cable housing through the rubber grommet. Check to see if you have any slack in your throttle cable first. Lots of folks who can't reach top speed need to adjust their cable so remember to tighten it during engine installation.

The blue arrow points to the throttle body gasket. It goes hard over time and fails to seal properly resulting in a vacuum leak. Be sure to inspect it.

throttle cable
6.1) 72-74 dual carbs: the throttle cable is attached to the linkage on the left side. Undo it by loosening the 2.5mm grub screw that holds the cable to the cross bar. throttle cable carb
6.2) 72-74 dual carbs: Pull the cable housing from behind the tin so the cable is clear of the tin. Tuck the cable somewhere above the transmission for now. cable housing carb

Step 7: Brake booster hose

7.1) Undo the brake booster hose from the 3-way tee connecting it to the plenum and lay it in the driver's side battery tray. This is another potential source of vacuum leaks. booster hose
7.1) 72-74 dual carbs: if you can't figure out which hose is for the brake booster look for the round valve with the ATE logo. Ignore the fuel filter in the photo (it was a PO addition to protect the smaller filter in the mechanical fuel pump). booster hose
72-74 dual carbs: remove the hose from the metal tube that goes through the engine tin. You'll find this on the passenger side by the alternator and starter wire. hose port

Step 8: Double Relay and Series Resistors

8.1) Unplug the right most connector from the double relay and the series resistors connector. This will release the FI wiring harness from the firewall. The rest of the connections can stay put for the engine drop. double relay

Step 9: Document and remove coil

9.1) I can't stress how important it is to take a photo of the coil wiring or at least write it down. It's very easy to install the engine and not be able to start it afterwards while everyone scratches their heads looking over the wiring. Wiring varies from model to model and the wiring diagram must be followed. You have been warned.

I like to remove the coil for clearance. Take off all the wiring and undo the 10mm bolt securing the clamp to the fan shroud. I've got a Pertronix setup which is why there is no green wire (no condenser) on Terminal 1 and an extra red wire on Terminal 15.

coil
9.1) 72-74 dual carbs: also notice the brown wire that comes out of the harness and ground on the fan shroud.

Again this is Pertronix setup which is why there is no green wire (no condenser) on Terminal 1 and an extra red wire on Terminal 15. The brown wiring for the electric chokes and idle cutoff switches was original brown but I only had brown on had when I made this repair. If any terminal on the cutoffs falls off it will ground with the tin and the engine will shut off as the coil positive becomes grounded. The grey braided strap at the bottom left of the photo is for the a/c compressor if you have it (you can leave it as is). The is probably one wire missing in this photo (PO abuse) that would normally lead to the vacuum advance cutoff switch. See Bentley Engine & Clutch page 73.

coil carb
9.2) Disconnect the wiring from the oil pressure sender (less stress than unplugging it at the 2-way tee) and pull the wires from under the fuel rail. Rest them in the passenger's side battery tray. pressure sender

Step 10: Bumper

10.1) Getting the bumper out of the way will make it easier to deal with the exhaust and help the engine to clear the body later on.

Remove the (4) 17mm bolts holding the bumper to the body.

bumper

Step 11: Exhaust

11.1) Exhausts vary from model to model. I've got an extractor style which has eliminated the cross-over pipe so it's relatively easy to deal with. First remove the EGR filter from the exhaust and at the engine tin if you have one, then unbolt the exhaust system from the heater boxes only.

Now would be a good time to repaint the exhaust again before it rusts. The nuts can be a bear to remove. Use lots of penetrating oil and consider replacing the nuts with stainless steel graded bolts. Anti-seize is also helpful.

exhaust

Step 12: Fan guard and timing scale

12.1) Remove the guard protecting the impeller fan and the timing scale by undoing the (3) 10mm bolts. The guard is especially delicate and often broken.

Skip if you are removing transmission and engine.

timing scale

Step 13: Oil filler

13.1) Remove the top half of the oil filler by enlarging the securing ring. It's slippery and under a lot of tension so use a pair of vice grips (there are specialty pliers for this job but I don't have a pair, boo hoo). After the top part is off, quickly stuff a blue paper towel into the hole so nothing falls into the engine.

Skip if you are removing transmission and engine

oil filler

Step 14: Engine tin

14.1) Time to remove the engine tin so we will be able to pull the engine as far back as possible. Remove (3) of the screws (originally phillips) holding the middle piece of tin in place. Some screws are just hidden under the foam engine seal (if you have no seal you need to get one asap!)

Skip if you are removing transmission and engine

engine tin middle
14.2) Some of the screws also secure the heat shield that is located between the muffler and the engine tin.

Skip if you are removing transmission and engine

engine tin sneaky
14.3) These screws are accessible from the underside of the tin.

Skip if you are removing transmission and engine

engine tin under
14.4) Remove the (3) phillips screws on the left-side engine tin.

Skip if you are removing transmission and engine

engine tin left
14.5) Remove the (3) phillips screws on the right-side engine tin.

Skip if you are removing transmission and engine

engine tin right
14.6) By removing the underside screws last you can catch the heat shield before it falls to the ground.

Skip if you are removing transmission and engine

Photo missing...
14.7) I like to pull the engine seal out part way at this points. It's only a little harder to do before you remove the engine tin screws. The engine seal parts at the back by the impeller fan which I think makes it easier for installation and removal. That's the way the factory did it. engine seal
14.8) All of the tinware pieces are ready to be removed. Start with the middle, then the left or right. It can be tricky to lift the right piece over the oil filler tube sometimes. Do you still have the rubber seal in the hole or is it missing?

Skip if you are removing transmission and engine

engine tin screws

Step 15: Starter

15.1) Disconnect the starter wires. The alternator and battery cables are the largest wires. Using a 13mm socket, disconnect the large nut at terminal 30 where all of the wires with ring terminals are connected. Retighten the nut afterwards so we don't lose it. Pull the two spaded connectors from the terminal 50. One red/black wire goes to the ignition switch and the other red/white wire goes to the double relay to power the pump for fuel injected engines like mine.

Observe the way the wiring is laid out (take a photo) and put it back the same way when you reinstall the engine. VW was very thorough to prevent wire jackets from rubbing against sharp metal of the body such as the flapper boxes. If you let a large current carrying wire like the alternator cable rub against a flapper box, it will cut through the insulation, the electrical system will short and there will be a serious fire.

starter wiring
15.2) Close-up of the starter wiring partially removed. It's hard to mix up the wires because of the ring terminals but on terminal 30 you should have (1) large red wire for the alternator, (1) large black wire for the battery, (1) red wire for the heater booster fan and (1) thick red/white stripped wire for the fuse box. The large cables are usually wrapped in a beige sheath.

The red/white wire triggers the fuel pump via the double relay. In this photo you can see that I've got a hot start relay installed and the blue arrow points to one of the relay's wires. Normally the black/red wire which is connected to the blue wire of the relay connects to terminal 50 where I have the black wire from the relay. An large red wire on terminal 30 powers the double relay. All the red wires can be confusing but again remember all the ring terminals connect to 30.

starter closeup
15.2) 72-74 dual carbs: the configuration is a little different. Terminal 30 should have (1) large red wire for the alternator, (1) large black wire for the battery, (1) thick red/white wire for the fuse box, and (1) red wire for the heater booster fan relay. Terminal 50 should have a (1) red/black wire that goes to the ignition switch and (1) red wire that goes to the computer diagnostic plug. You can't confuse the wiring on Terminal 50 because it's simply two male connectors. The black wire (blue arrow) was added by the PO. starter wiring carb
15.3) Two bolts hold the starter to the bell housing. Use a 15mm socket to remove the nut on the bottom of the starter. stater
15.4) The next part is really tricky. The upper bolt that holds the starter in place has a special D-shaped head. To remove it, you need to use a 17mm wrench and remove the nut securing the top right corner of the bell housing. When the nut is off you can push the bolt out part way and remove it from the other side. stater removal
15.5) You can see from the bolt holes that the starter can only be installed one way. The oil you see is from a flywheel seal leak (the reason I'm dropping the engine, again boo hoo). starter out

Step 16: Heater Cables

16.1) Before the engine can come out the heater cables connected to the heater flapper boxes must be disconnected. One method involves using an 8mm socket to undo the bolt holding the cable to the barrel nut on each side. The cables will no doubt be rusty and it's hard to get your hands up into this place so be patient.

The problem with this technique is that upon reinstallation it's difficult to align the heat control boxes with accordion tubes. The install is further complicated by the fact that the asbestos cuffs get easily damaged. I would recommend instead disconnecting the flapper box from the connecting tube below. The bolts are often rusty so use penetrating fluid and be careful not to strip the screws.

Of course asbestos is another hazard. I would recommend replacing the cuffs with 2 cuffs from the left side of an 80-83 Vanagon. They are made from silicone and will seal better.

heater cables

Step 17: Fuel lines

17.1) We're ready to disconnect the fuel lines. Everything on the engine can be left in tact. Using a screwdriver, undo the clamp (originally phillips) and disconnect the fuel line that goes from the fuel pump to the 3/4 fuel rail from under the bus. fuel rail
17.1) 72-74 dual carbs: the fuel lines from the mechanical fuel pump must be disconnected. You can disconnect it at the pump or above. If you disconnect it from the pump, disconnect the larger hose on the straight tube. The bent tube connects to the smaller hose that leads to the carbs and goes through the tin. The hose (blue arrow) is a breather line that goes through a grommet in the deflection plates. Both can be left connected. fuel rail carb
17.2) Repeat the same operation as above to the backside of the fuel pressure regulator on the opposite side of the bus.

If you did not drain the fuel tank you must also use a clamp to cut off the fuel flow from the tank.

fuel PR

Step 18: Deflection plates

18.1) Before the engine is dropped the air deflection plates should be removed to gain access to the push rod tubes if you don't have an engine stand and will be storing the engine on the floor. If you don't need to access the push rod tubes your plates may need cleaning badly. deflection plates
18.2) There are 8 screws (originally phillips) to remove in total. plates removed

Step 19: Engine and Transmission bolts

19.1) We are almost ready to separate the engine from the transmission. Before we go any further we need to support the engine. A motorcycle/ATV jack works best but you can use any floor jack and balance the engine on a piece of plywood. See the photos at the end of the article for exact positioning. engine support
19.2) We already removed one bolt from the starter and there are three more bolts. Use a 17mm wrench to remove the first of (3) nuts starting with the top left corner of the bell housing on the engine side.

Skip if you are removing transmission and engine

bell housing left
19.3) The bolt on the other side can be difficult to feel because a few bolts are in that area. Pull it through.

Skip if you are removing transmission and engine

bell housing back
19.4) The last two nuts secure the long studs on the bottom. Use a 17mm socket to remove the (2) nuts.

Skip if you are removing transmission and engine

bell housing bottom

Step 20: Engine Separation

20.1) We're almost ready to support the engine solely on our jack. If you have mud flaps secured to the engine carrier clips with the original style 2-piece brackets, undo the L-bracket on each side. mudflaps
20.2) Using a socket and wrench remove the (4) 13mm nuts and bolts holding the engine carrier clips to the frame. If you have to bang out the bolts with a mallet you have not supported the engine correctly. Fix this situation first.

72-74 dual carbs: (6) nuts hold the clips to the body.

engine carrier clips
20.3) The engine can now be separated from the transmission. This is the hardest part. You have to keep the engine level so you can pull the pressure plate out of the input shaft of the transmission. The input shaft cannot bear the weight of the engine either. Sometimes due to lack of lubrication during installation, the input shaft can stick. Finally the oil filler tube gets in the way during removal so you have to play some tricks with the height of the bus and the engine.

Goto to transmission removal steps and return here afterward.

engine removal
20.4) I'm still not a master at this step but eventually I manage to wiggle the engine back enough to clear the input shaft. The key is to start with a level surface, have the jack level and give the engine carrier clips a few whacks with a mallet.

Skip if you are removing transmission and engine

engine separation
20.5) Using two jacks, raise the body slowly and evenly. Do not use the jacking points (the emergency jack doesn't push from underneath so don't do it either otherwise they will crush). See Bentley for appropriate jacking instructions. jack body
20.6) Once the body has cleared the top of the engine you can roll the engine back. cleared body
20.7) With the engine clear you can lower the body back down and no one in the neighborhood will be the wiser for it. Hee hee. task completed
20.8) Cart your heavy treasure off to the garage knowing you're less than half way done before you can drive again. It's a bus life.

If you strip down your engine check out my Vacuum and Fuel Hose article for getting the induction system back together.

1/2 done

Transmission Removal:

T.1) Remove the wing nuts from the clutch cable. Do not let the cable turn while you turn the nut. The original cable used to have a slot in the end for a screwdriver to prevent this. clutch cable
T.2) Remove the clamp that secures the Bowden tube to the transmission by undoing the (2) 13mm bolts. bowden support
T.3) Pull the two leads for the backup light switch. The orientation of the leads doesn't matter. backup switch
T.3) 72-74 dual carbs: the backup light switch is on the passenger side. Pull both leads. backup switch carb
T.3) 72-74 dual carbs: pull the two leads from the vacuum advance cutoff switch at the front of the transmission (nose cone). See Bentley Engine & Clutch page 73 for a description of this unit. It's installed on all 72-74 models except for the 74 with the M/T. cuttof switch carb
T.4) Use a 13mm socket to remove the bolt holding the transmission ground strap on. Look for it above the backup light switch. ground strap
T.4) 72-74 dual carbs: the ground strap is located in a slightly different location than the FI bus. ground strap carb
T.5) Undo the 6 bolts that hold each CV joint on. Do not attempt removal without the proper tool: some bolts are allen head, some are triple square. Clean the heads of the bolts or risk stripping them (screaming afterwards won't help them come out but it feels good). Repeat on the other side. CV joint
T.6) Bag each CV joint to prevent contamination of the grease and support each axle using rope. axles
T.7) Use a 10mm socket to disconnect the rear shift rod from the transmission shift lever. If you have a screw with safety wire attached then the head maybe 8mm. shift rod screw
T.8) Support the transmission to prepare for the drop. I like to use an ATV jack but you can use any floor jack. support trans
T.9) With the transmission supports, Use a 15mm socket to move to (2) bolts on the transmission carrier. The nuts are welded to the support so you don't need a 17mm box wrench.

When you reinstall these bolts, install the one over the starter first. The second bolt is always harder to thread and if you do the starter one last you won't be able to see what you are doing because it's obscured requiring you to hug the transmission as you blindly fiddle with the bolt.

trans bolts
T.10) Undo the (2) 17mm bolts securing the transmission limiting stop (rectangular block).

Don't clean this item: leave the dirt as is so you can use it as a guide for remounting it in exactly the same spot.

nose cone bolts
T.11) You are now ready for removal. Grab the shift rod and pull it off the shift lever or hold in it place while the transmission is pulled back. Depending on your jack or dolly you might not clear the rear valence. Since the transmission weights so little, just lower it onto something to clear the rear valence rather than jack up the bus. shift rod
T.12) A scene from "Dr. StrangeBus: or How I Learned to Stop Worrying about the Leak and Drop the Engine". Eat your heart out Slim Pickens.

That's it. See my 091 Transmission Refresh article for what to do while the transmission is out.
Slim Pickens eat your heart out

Jack Support Tips:

To support the engine only you need a 8"x18"x1" piece of wood to lay on the motorcycle jack. Position the wood so that it supported the case about 2" behind the engine support bar and under the tabs that protrude near of the engine case.

support plank 1 support plank 2 support plank 3

Notes:

  • Many thanks to Jason Thorpe for helping with this lengthy engine pull in order to help document it for this article.
  • We had perfect California weather, all the tools on hand and a flat parking space to do the work. Except for the rusty heater box cables it went like a charm thanks to the motorcycle/ATV jack: a $59 HF holiday special. Don't leave the VW garage without it. The red jack is from Handy Industries (NLA). It's very nice but cost my neighbor $250.
  • Sears has started to sell an Aluminum motorcycle jack for $150. It weighs half as much as a steel jack and seems worthwhile. Search craftsman.com for 50191.

History:

02/07/04 - Created
03/06/04 - Added transmission information
11/20/04 - Added 72-74 differences
03/01/05 - Added Engine support pictures
06/03/09 - Moved up battery disconnect
09/06/11 - Fixed broken photos, added translate button, updated footer