Exhaust System Removal  Driveshaft Removal  Transmission Removal  Clutch/Flywheel Removal
Transmission Refitting  Driveshaft Installation  Centering Driveline  Exhaust System Installation
Essential Tools  Laws of Physics
Exhaust System Removal
The ease of exhaust pipe removal is strictly a function of the condition (and previous abuse) of the 3 nuts securing the up-pipe to the exhaust manifold.
The entire Exhaust pipe can come out as one assembly. It is amazing heavy. The balance point for the entire exhaust is the rear flange center muffler. Use it as a jack point to prevent the weight of the exhaust from overly stressing the manifold stud bolts.
The 3 exhaust manifold nuts will require a 12" extender, socket (15mm or 17mm), and ½" ratchet to get loose.
Mine were severely rusted so I soaked them with Liquid Wrench several times. No matter how tight the bolts are you do not want to overpower them. Breaking the stud at the exhaust manifold will require removal of the manifold (more rusty frozen bolts) and a difficult stud extraction. I have heard of people taking a propane torch the heat the bolts up. The best idea is from Click and Clack of Car Talk Fame. Their suggestion is starting one or two weeks prior to removal, liberally apply liquid wrench every other day thereby giving fluid time to ooze into the interstices of rust and crud.
(Any further words of wisdom from those wiser than me on this topic ?)
The exhaust pipe is held at 3 other locations. The rear of the transmission, should be very ease to let loose. A rubber strap is secured from the trunk bottom just forward of the gas tank. It is difficult to see the 13 mm bolt and nut which have several large washers. The rear is held by 2 rubber pretzels. A long Phillips screwdriver works handily. Just stick it through the rubber donut and lever off of the muffler tab.
30 minutes Lapsed time (with easy manifold bolts) 30 minutes.
Remove the aluminum heat baffle 10 mm nuts w/ big washers. A deep 10 mm socket helps.
The rear universal at the differential is held with 17 mm locknuts. (aircraft). They require a box end wrench. Set the parking brake, loosen 2 nuts, release brake, turn driveshaft 180 degrees, set brake, loosen the other 2 nuts.
The front is secured to the rear of the tranny with a "Guibo" (Italian for black rubber donut) by 3 19mm nuts and bolts. They are torqued very tight so an18" breaker bar is helpful to loosen them. Again, set the parking brake for each of the 3 bolts. The 3 remaining Guibo bolts can be removed when the drive shaft is taken out of the car.
Release the center bearing nuts. 13mm. The drive shaft requires some bending but comes out easily.
If you are not re doing the driveshaft, just undo the 3 front Guibo bolts and the center bearing. It should fold back enough to give access to everything.
45 Minutes Elapsed Time.
(To date I have really enjoyed working on my Bimmer. Piping, wiring, bolts and nuts all seem to be laid out so that one can get a wrench on them for ease of maintenance. Besides it seems very Germanic to design and engineer a car that way. The transmission removal lays complete waste to any of those heartwarming thoughts.)
There are three primary strategies for extraction:
An excellent idea if you are putting a 3.5 liter engine in along with your drive line. Otherwise this route requires draining the coolant, undoing water hoses, steering pump, a/c pump, gas lines, misc. electrical.
After reviewing 2 and 3 this may seem the best alternative.
The bellhousing has 7 bolts, only one of which you can easily get a socket on. 4 bolts you can barely even get your fingers on. 5 bolts require box wrench removal which takes gobs of time.
There are 4 19mm bolts securing the tranny to the bellhousing. The top left bolt requires specially modified tools to remove. The transmission tunnel severley limits wrench motion to the 2 top bolts. Peter Florance has an excellent E-message complete with pictures for customizing tools to get the top left bolt loose. One the gear case is removed, access to the here to fore inaccessible bellhousing bolts is worlds better. (or is it ?)
(I opted for Option 2 figuring that making the custom tools for Option 3 would take as long as removal of those pesky inaccessible bellhousing bolts.)
There are two 17 mm bolts at the rear of starter. 10:00 0’clock and 12:00 O’clock. Remove the return gas line from the fuel rail for better access. The 12:00 O’clock bolt had to be worked with a 17mm box end 1/8th of turn at a time. Your frustration tolerance levels will be tested during removal. (A $20 SK 3/8 12" flex drive, in combination with the 3/8" universal and 12" extender looked like it could spin the bolt out. It would take two people though.)
The 10:00 O’clock 17mm bolt can be loosened with a box end then spun out with the above indirect ratchet drive set up.
There are two 13mm long bolts at the rear of the cylinder block. 12:30 O’clock and 2:30 O’clock. They are a spacious ½" clear of the firewall. (I could barely get two fingers on them.) Again, mind numbing 1/8 turns with a 13mm box wrench. A 13 mm box ratchet would not fit. For another 1" of clearance you can undo the transmission mount and jack the rear of the tranny up, effectively tilting the engine forward. It can only go an inch or two until the distributor hits the radiator.
You could try the new Sears Professional Box wrenches or Snap On. The thinner box section and sweeter facets might facilitate these awkward removals.
Remove the clutch slave cylinder. Two 13 mm nuts. The top nut requires a 12" extension and 3/8" drive universal for removal. There is 17mm bolt at 8 O’clock on the block that secures the clutch hydraulic line. It requires a box end for removal. Swing the entire assembly out of the way.
There are two 15 mm long bolts (9:00 O’clock and 4:30 O’clock) that require a combination of sockets and box ends to loosen.
There is 13 mm bolt at 3:30 O’clock that requires removal by socket. (The easy one !)
At the lower front of the bellhousing there is a sheetmetal ¼ moon shaped piece with three 10 mm bolts. The sheetmetal is purposely formed to collect grease and crud thick enough to hide the little 10 mm bolt heads. Further enhancing the removal experience, the steering center arm conceals and obscures access to the bolts. A trip to the 25 cent car wash could reduce the "crud in your face" component of this operation.
Remove the speedometer cable by loosening the 13 mm bolt. It should slide right out.
Remove the reverse gear electric lines above the clutch slave cylinder location.
Remove the 13 mm bolt holding the rear rubber bumper to the gear shift "poop deck."
Remove the sliding clip holding the gear shift vertical rod to the horizontal rod from the rear of tranny.
(I had a hard time separating the horizontal rod from the gear lever.)
The transmission balance point is just forward of the transmission cross brace. The Sears 3 ton jack was very handy at this point of the removal.
Use screwdrivers to wedge the bellhousing apart from the engine. It should come apart evenly without too much force. If not check that all of the bolts (especially the ones you cannot see) have been removed. Use the jack to roll the tranny rearward and to lower it.
It is now time to celebrate with a brew of your choice !!
6 Hours Elapsed Time
Clutch and Flywheel Removal:
The clutch is secured with six - 6 mm Allen head bolts. Undo them evenly. To keep the flywheel assembly from turning use a coal chisel at the 5:30 O’clock position between the bellhousing and the starter ring. There is a small depression there to wedge the chisel against. (The Haynes manual recommends a screwdriver at the starter pinion area.)
Rats ! To my disappointment some Fharfiggnuggeneering has crept into my esteemed Bimmer.
As with my VW GTI, one of the Allen heads stripped with a minimum of torque. (I drilled out the stripped allen head with my Black and Decker titanium drill set with little pre drills on each bit. It zinged in deep enough that I could use some vise grips to twist the head off. I used a smaller drill to drill into the thread portion. With a phillips head I was able to reverse the threaded portion out.)
The flywheel is held with eight 17 mm bolts at 77 ft/lbs in Locktite. This is where the 18" breaker bar comes in handy. The flywheel slides right off. I was surprised at how light it was.
2 1/2 Hours Elapsed Time (Stripped allen head removal factor)
Pilot Bearing Removal:
This was my waterloo. (As was the 13th Hole at the Dunes Club in Myrtle Beach)
There are 3 extraction techniques available:
I opted for 1. The SK Tool comes as a dent (or lock) bump-puller with two hinged ears that slide into the hole and have tabs that grab the back of the bearing. Imagine Wile-E-Coyote ears from Roadrunner fame.
Great concept … but it did not work. Take a screw to wedge the ear legs in tight against the side walls of the pilot hole. An ear broke off. The rental shop gave me screw type extractor with new ears. After careful fitting of the screw wedge between ears the front cover of the bearing came out. Reapplication of the procedure successfully pulled out rest of the bearing in pieces.
4 Hours Elapsed time (Due to irretractable frozen up Pilot Bearing.)
Rear Seal Removal:
It slid right out. (Probably not a good thing)
Flywheel and Clutch:
I took the flywheel to be resurfaced. $25 at Tassi in Daly City. They did a great job. They took off 20/1000 to get it back to flat. The clutch facing looked like a 33 rpm record left in the sun.
Sachs sells a super clutch kit that includes a new Pilot Bearing and a plastic spline tool. $190 at German Auto Supply in Berkely. Also bought a new rear seal. Mine was leaking like a bad dog. Strongly recommended.
I bought 6 new 6mm Allen Head bolts. Tassi recommends German Tools for Allen Heads. German Tools? Built to TUV standards ! Recycled German Panzer hardened steel! $9.34 for a 6mm socket. It works like a charm.
As an aside, I painted the flywheel area near the timing ball bearings white to make it easier to spot the timing.
Use a piece of hardwood to tap the rear seal into place. Coat the surfaces with oil to facilitate the installation. I made sure that the crank wiper portion was nicely seated on the crank and that the seal was evenly set in the hole. (By feel)
Use some plywood to tap the new pilot bearing into position.
Use red Locktite on the threads of the 8 - 17mm flywheel bolts. Hand turn them in. Then ratchet them in snug. Using a Sharpie pen, number the heads in an even tightening sequence. Torque the bolts in several torque increments ending with 77 ft/lbs. (The Haynes Manual had a misprint calling for 8 ft/lbs.)
Insert the plastic alignment spline into the pilot hole. Slide the clutch disc into position with the thick center part facing you. The pressure plate slides right onto the flywheel locating pins. Tighten the Allen head bolts in a cross pattern sequence. . The manual calls for 17 Ft/lbs of torque. . Check the sliding fit of the centering spline several times before final tightening.
German Auto said to be careful. The flywheel threads are easy to strip. Another reason for new bolts.
Before you forget !!, install the new throw-out bearing in the transmission bellhousing.
Here is where the Sears 3 ton jack really paid for itself. Positioning the tranny for reattachment is like docking the Lunar Lander. It is a real exercise in 3 dimensional navigation while you are on your back with a limited view. (At least the new tranny is all spanky clean and nice to handle.)
The balance point is the bottom of the gear case just forward of the cross member. I lined up the jack to roll toward the front of the car. With the bell housing about 3" rearward from the flywheel, jack the whole tranny up to its final height making sure it is level and centered on the clutch/pilot hole.. Make sure you shove the gearshift thru the drive tunnel hole. While wiggling the output flange, roll the tranny forward praying that the splined input shaft slides into the clutch splines and pilot bearing hole. (I got lucky the first time.)
The bellhousing snuggled up about 1" from the engine block and was nice and even all around. However it was rotated out of alignment. It took levering with a couple of phillips head screw drivers to get the holes to line up enough so that I could get the 9:00 O’clock 17 mm bolt started in the threads. By ratcheting that bolt slowly, the tranny sucked up tight to the engine block. Now comes the re-installation of the bolts from hell. (Maybe Option 3 is better) The two 13 mm bolts at the end of the cylinder block were impossible to get started with the limited finger room. The two 17mm bolts at the starter were a challenge. If you have a willing partner it might be possible to get the flexible/universal/extender ratchets on most of the bolts which would save tons of time spinning them in. You can use the jack to tilt the engine forward which affords a little more room at the top of the bell housing.
(Only one of the special wrenches I bought at Sears worked. The (Bob Villa autographed) Craftsman speed open end was a marginal improvement. The extra short open ends and ratcheting boxes were of no use.)
( I was able to get all of the bolts in except one 13mm at 2:30 O’clock. Hopefully it will not prove fatal, at least until I slip that 3.5 liter in there.)
Next secure the 13 mm nuts holding the transmission cross member. Now hook up the reverse light signal wires at the top left of the tranny. (They are hard to get at after the clutch slave goes in.). Reposition the clutch hydraulic lines and the 17mm bolt (keep loose) at the block. Next install the clutch slave cylinder with two 13 mm nuts. Reinstall the speedometer cable with the 13 mm securing bolt.
Reattach the shift lever and shift linkage with the sliding lock tab. I had to use channel lock pliers to squeeze the linkage bar thru the gear lever hole. Needle nose pliers helped with installing the sliding tab.
There is a rubber centering mount with a 13 mm nut and bolt at the rear of the gear lever "poop deck".
The Haynes manual says to install new aircraft style locknuts which I chose to ignore. I always use graphite anti seize goop on threads to facilitate future work.
Install the 3 Guibo bolts and the new Guibo to the drive shaft.
Slide the driveshaft in rearward to the differential flange. Use a Phillips head screwdriver to align the holes before you slip the bolts in. Use a box wrench to tighten 2 nuts at a time. I tried to simulate the torque reading by feel since my torque wrench would not fit into the tight space.
The guibo requires a little jockeying to get into position. There is a pilot that has to be centered. I had to push the shaft upward in a funny feeling motion and loosely set the two 13mm nuts holding the center bearing. The 3 remaining guibo bolts install easily. Using the handbrake you can torque most of the bolts in a criss cross sequence.
Remove the guibo restraining strap. (I levered the skinny section apart with a screwdriver.) My guibo assembly did not have a heat shield.
Centering the driveline:
Beats me !!
It seemed to want to position itself so I bolted the center bearing bolts in that position. Lying upside down on a creeper eyeballing the driveline for straightness is only speculative at best. It does not make any weird noises or vibrations so I guess it is OK.
1:30 Hours Elapsed Time.
Installing the Heat Shield :
Re-installation is purely a function of cleanliness. There are six 10 mm nuts with large washers. Make sure that the driveline does not rub against the shield.
Re-installing the Exhaust System:
Since my 3 manifold bolts were rusty, crusty and boogered, I sweetened the threads up with a 10 mm x 1.50 pitch thread die. ($3.90 at Sears and worth every penny) Install a new exhaust gasket. German Auto Supply sold me copper nuts which are softer than steel bolts and do not rust. Before installing the copper nuts, coat the threads with anti seize compound. I also used three washers to keep the nuts on the nicest part of the threads left.
Jack the exhaust pipe up to take any load off the studs. Attach the transmission mount (loosely) and the rear rubber strap near the fuel pump. Now tackle the 3 studs at the exhaust manifold. Turn the engine on to make sure the gasket is seated 360 degrees. Mine was not.
Reattach the rear rubber pretzels using a Phillips screw driver or equivalent. Reattach the mount at the fuel pum. Tighten the hanger at the transmission.
Sears 3 ton Jack
The roll around style that looks like an alligator. It makes quick work of jacking up the old Bimmer and is essential IMHO for removing and installing the transmission. In addition the jack is helpful in removing and installing the exhaust system. Sears has them for $90.00 made in China. The lowering mode is not so great but the ease of effort in getting the car in the air really streamlines the way to under car activities.
After 20 years of messing around on cars I finally caved in and bought a creeper. Boy what a quantum leap in physical efficiency. The savings in time and physical exertion are tremendous. I have listed this under essential because the savings in muscle exertion allowed me to focus on the other more difficult tasks like wrestling that heavy pig of a transmission out of its greasy nest.
12" Ratchet extender (3/8" drive)
You will need it to get at several of the challenging nut and bolt locations.
Universal Drive (3/8" drive)
You will need this to get at some of the more obnoxious bolt locations.
Box metric wrenches 10mm, 13mm, 15mm, 17mm, 19mm
Are required at the bellhousing and at the rear drive shaft nuts. Open ends will not fit due to space constraints. More importantly, box wrenches have multiple positions on the bolt compared to only 2 positions for open end wrenches.
Sockets and ratchet 10mm, 13mm, 15mm, 17mm, 19mm.
All of the nuts and bolts fall into these sizes.
6mm Allen Head socket
Socket is preferred due to removal torque required. An allen wrench might work with a pair of vise grips.
IMHO a torque wrench is essential.. If you intuitively know what 77 ft lbs feels like lying on a creeper in a reverse half nelson posture, or if recurring nightmares of frisbee flywheels sailing by your feet do not haunt you, then I guess a torque wrench is not essential. Do not be cheap like me. Get the one with the click system.
Pilot Bearing Remover
The SK pilot bearing removing tool (Avail. at big city rental shops or possibly clutch and transmission shops)
(Alternates include Black Cats or
the heavy wheel bearing grease and wood dowel technique.)
Dummy driveshaft for clutch plate alignment.
(Comes with the Sachs Super Set Clutch Kit) Otherwise you might be able to borrow one from your friendly BMW mechanic.
Nice and Helpful Tools
SK 3/8" flexible drive system 12"
Maybe just maybe, with a little help from your friend, you can get a socket on those friggen upper bell housing bolts ! You could save 1 ½ to 2 hours.
18"long ½" drive breaker bar
Excellent for breaking loose bolts whilst in previously mentioned reverse half nelson position on creeper.
10mm x 1.5 pitch thread die
To clean up those rusted and abused exhaust studs.
Sears Professional, Snap On (or better) thin line box wrenches
Would make turning those pesky bellhousing bolts easier.
The Peter Florance customized tranny removal wrench and socket system.
The benefits include less weight at one time and potentially easier access to those pesky bellhousing bolts. Probably way faster going back together since you do not have to marry the bellhousing and the drive spine at the same time in three dimensional space. See Peter’s Bulletin on Custom tranny tools.
Vermont Bolt extraction system
For stripped Fharfiggnugen hardwaren. Titanium drills also recommended.
Dream Tools !
German TUV quality hand tools
-made of recycled Panzer case hardened steel.
For breaking bolts loose.
Electric ratchet system
For spinning nuts back into place.
Full hydraulic Bimmer jackenen upperdeinclouden
-with remote control. Forget the creeper! Save $90.00 on the Sears 3 ton jack.
Modified Laws of Physics and Other Phenomenon while under the car.
This means that in reality the 90lb transmission weighs close to 300 lbs while you are trying to re-center the drive splines.
This also means the exhaust system weighs in at 250 lbs. (Which must be how BMW prices it’s replacement exhaust systems. $4.00 /lb times 250 lb = $1,000 !)
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