Pelican Technical Article: Transmission Removal Wayne R. Dempsey
Time: 3 hrs
Tab: $0
Talent:
Tools:
Torx socket set, jack + jackstands, Triple-square removal tool
Applicable Models:
986 Boxster (1997-04) 987 Boxster (2005-08)
Parts Required:
-
Hot Tip:
Have a buddy help you when you're ready to drop the unit
Performance Gain:
Ability to access engine
Complementary Modification:
Clutch replacement, replace transmission mounts
This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your Porsche Boxster. The book contains 312 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 950+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Boxster owner's collection. The book is currently available and in stock now. See The Official Book Website for more details.
Check out some other sample projects from the book:
One really nice feature of working on the Boxster is that you can drop the transmission out of the car without dropping the entire engine. This allows the potential for you to complete many different projects that would have taken a lot more time and had been a lot more difficult to perform. As a result of this design, a clutch job on the Boxster is a fairly straightforward task and is not too terribly daunting. The first step of course, is to remove the transmission from the car. Follow the list of steps below:
Disconnect the hydraulic line bracket from the transmission if there is one. Suspend the slave cylinder from the chassis so that it won't hang from the hydraulic fluid line.
Disconnect the shifter cables (see Figure 3). Very early cars have a slightly different cable setup that is attached with multiple cotter pins that need to be removed.
Install a jack stand below the engine (see Photo 5 and 6)
Support the weight of the transmission using the floor jack (see Figure 6)
Disconnect, remove, and label each bolt that holds the engine and transmission together using Photo 4 as a guide. It's very important that you make sure you don't mix up the hardware and where it goes: use a plastic storage bag for each bolt and label it with the letter corresponding to Figure 4. When I first removed the transmission, I mistakenly mixed up all the hardware and it took nearly two hours of looking at the Porsche factory diagrams to figure out what bolt went where.
Using a buddy, slide the transmission back and lower to the ground.
The transmission weighs more than 100 lbs, so make sure that you are prepared when you pull it out and lower it. I recommend placing the transmission on a rolling furniture cart so that you can easily move it around and work on it.
Installation is pretty much the reverse of disassembly. See Project 45 for the proper installation of the slave cylinder. When attaching the transmission to the engine, tighten all of the M12 bolts down to 63 ft-lbs (85 Nm) and all of the M10 fasteners down to 33 ft-lbs (45 Nm).
The procedure is a bit more complicated for removal of the automatic transmission. You need to order some special tools in order to secure the torque converter when separating the transmission from the engine. You also need to disconnect the vacuum lines, the shift selector mechanism, and the coolant lines prior to removal. Due to space limitations here, I am not able to go over all of the details, but fortunately, most automatic transmissions do not need to be removed very often. The Bentley manual has a detailed section on the automatic transmission removal process.
Figure 1
Remove the right side heat shield from the support bracket. Do not forget to reinstall this when you put the transmission back into the car, as it protects the shifter cables and mechanism from the extreme heat of the exhaust system.
With the muffler removed from the car, remove the aluminum reinforcement bar from underneath the car (attached with bolts indicated by green arrows). Detach the muffler support bracket from the end of the transmission (orange arrow).
This photo shows the process of disconnecting the shifter cables. Using two screwdrivers placed on either side of the ball, pull up and snap each shifter cable end (green arrow) off of its ball mount (yellow arrows). Detach the shifter cable sheath from its bracket by removing the small spring clips and prying them out of their bracket (inset photo, upper left). Inspect the inside of the cables carefully, as you may find that they are cracked and need replacement (right arrow). Unfortunately, at this time, you cannot replace just the bushing in this cable, but only the cable itself. I am currently working on having repair kits made for these cables however: check the website link at the beginning of this project for details.
This photo of the engine with the transmission removed shows location and type of the fasteners that attach the transmission. The location and orientation of the hardware can be very confusing and it's not well documented in the Porsche factory diagrams, so I've provided a legend with part numbers for all Boxsters 1997-08 here: M10x40mm triplesquare (999-073-118-09) B- M12x1.5x100mm (999-072-010-09) C- M12x1.5x100mm (999-072-010-09) with 15x28x3.5 washer (N-905-028-02) D/G- M12x1.5x70mm (999-072-008-09) E/F- M12x1.5x90mm (999-072-009-09) H- M10 hex nut (900-377-011-09) attached to M10x30mm stud in transmission case (999-218-088-09)
This photo shows the bottom of the transmission as we are pulling it away from the engine. The engine weight is supported by a jack stand (white arrow). Place the jack stand on the boss of the engine case where the green arrow is pointing. As you pull away the transmission from the engine, you will see a small gap begin to appear (yellow arrow). This indicates that you are proceeding correctly, and the transmission is beginning to come out.
Although you can do it yourself, I recommend having a transmission-drop buddy around to help you. Using your jack, carefully line up the bottom of the jack with the bottom of the transmission as shown. If you position it just right, you will be able to balance the transmission perfectly on the jack. Don't put your arms, legs, or face underneath the transmission as you are pulling it out: once the mainshaft disconnects from the center of the clutch it will become really wobbly on your jack. Lower it to the floor carefully and pull it out from under the car.
Comments: On a 987 how far does the transmission need to separate from the engine to drop down. Do you need to remove the muffler completely if you remove the the mounting plate at the back of the trans that supports the muffler? It seems that the 987 has more clearance than the 986 between the trans and the muffler.
May 24, 2012
Jerry
Comments: Replaced the original clutch and IMS bearing on my '97 Boxster with 105K miles. I have the transmission on a cradle and high lift jack but can't align to engine. Any trick to getting the two mated?
January 11, 2012
tim
Comments: Would love the same article for a 996 Tranny Removal??? Is there one in existance...6 speed manual
December 29, 2011
Followup from the Pelican Staff: We've got one coming soon... - Wayne at Pelican Parts
WhipE350
Comments: 59coupe - yup I'll be headed to Northern Tools tomorrow to get a 10mm Triple Square. I remember now having seen it in the past but totally forgot.
December 22, 2011
59coupe
Comments: Wayne, maybe you should put 10mm triple square socket at the top of the tech article. This has become a showstopper for me. To all those preparing to do this, do not proceed without it. hopefully you will see these comments before you start
December 18, 2011
Followup from the Pelican Staff: Okay, thanks. I added that to the list of required tools. - Wayne at Pelican Parts
Wayne at Pelican Parts
Comments: Requested: Instructions for dropping the automatic transmission.
Comments: Can this be done with the car on a ramp? I understood from a supposed former Porsche tech that removing the diagonal aluminum braces somehow unsupports the wheel carriers, and heinous damage would result if the car's weight was still on the tires.
I'd rather not have to work under jackstands. Any help appreciated.
September 2, 2011
Followup from the Pelican Staff: You can place the weight of the car down on the supports without the cross-brace installed, but you will need to have the car re-aligned later on. We did this continuously when pushing our project car around the shop during the engine swap. As for a ramp, I'm not sure that's safer than jack stands - if you feel odd about the stands, then put the car up on the ramps, then jack it up and leave the ramps in place, so that if the jack stands fail, the car simply rests back on the ramps. - Wayne at Pelican Parts
Aaron
Comments: Is this for a tiptronic tranny? Thank you so much for the article!
December 1, 2010
Followup from the Pelican Staff: This shows the procedure for the manual transmission. The Tip is a little trickier, requiring some special procedures and a few tools from Porsche. - Wayne at Pelican Parts
Brian
Comments: Thanks for the great article. One little criticism of your list of tools, which was nearly a showstopper for me, was the 10 mm triple square bolt A in the picture. I eventually wrestled it out with a small vice grip and 6 point torx. Where do you get a tool that will do this more easily?
New clutch is great!
June 21, 2010
Followup from the Pelican Staff: Hmm, I thought we had these in the catalog, but I couldn't find them either. I will have my staff track them down and add them to the catalog. - Wayne at Pelican Parts
Check out some other sample projects from the book:
