IMS and RMS with Tiptronic

[ddruker]

I spent an hour or so yesterday removing the old rear main seal and the IMS bearing cover, and cleaning up the gunk that had accumulated on the transmission case. I also spent another hour cleaning all of the parts I had removed - tons of grunge from 20 years on the road.

Other "while I'm in there" jobs I did yesterday:

- I cleaned out and re-greased the axle CV joints
- I removed and replaced both transmission mount capsules (new part is Rein AVT0307P, you need two)
- I evaluated the drivers-side transmission output shaft. It was covered in gunk, but after a thorough cleaning it looks like it was probably not leaking after all.

Notes on the RMS and IMS:

It took several attempts drilling a small hole into the old rear main seal and using a small screw to pull the old seal out - it was stuck in there pretty good.

It probably took 20 minutes to remove the old IMS cover. I went very very slowly levering back and forth on both sides, using pieces of wood to level against to protect the engine block. It was a tedious process.

I did find a small nick on the outside edge of the crankshaft bore which I smoothed with 1000 grit sandpaper.

I also noted that the crankshaft bore is a tiny bit uneven, creating a small raised ridge, where the two halves of the engine case come together. I'm not going to mess with this.

I will do a more thorough cleaning of all mating surfaces with acetone or lacquer thinner once the new parts to finish up the job arrive.

More notes:

It was a bit difficult to get the small pieces of cooling hose off to disconnect the transmission from the cooling system. They were really stuck! I found that lifting the end of the hose and spraying in some silicon lubricant helped a ton. I'm planning to replace these segments when reinstalling - they are standard 18mm ID, 25mm OD radiator hose you can find on the internet and cut to length. Cohline is one good brand.

Mark the transmission to engine bolts when you remove them to make it easier to remember which goes in which hole - I marked them one to seven on their heads with a sharpie.

You will need to replace most of the last step bolts when doing this procedure - they are one time use fasteners.

- 8 flex plate to crankshaft mounting bolts - 99907309101 - these are different shorter bolts for the tip than for a manual transmission
- 4 engine casing bolts - 99938500401
- 3 new IMS cover bolts and and a new IMS cover nut which come with the LN Engineering Kit

You also need to obtain the following specialty chemical items - I bought on Amazon

- Loctite 29031 wicking green threadlock for the new IMS cover nut
- Elring Curil T sealing compound for the IMS bolts

I now have at least 10 labeled zip lock bags of parts I've removed - one bag for each step in the process.

Make sure you have plenty of blue locktite on hand for the re-assembly process.

I also bought a paint pen to mark the final location of the various fasteners.


Knock on wood so far everything is going well.

[Gilles]

Knock on wood so far everything is going well.


[/QUOTE]

You may have to remove the bottom tensioner in order to center the IMS bearing shaft before you can install the IMS cover back again (with it's new o-ring..)

[ddruker]

One question for the brain trust today, and one more bit of learning to share.



First the learning -

My secondary air injection system had failed over the year, and I fixed it last year by putting in new valves, a new vacuum accumulator, and new fancy silicon vacuum tubing. I couldn't easily get to the tubing going to the tiptronic transmission cooler coolant cutoff valve, so I left that portion alone. With the transmission out, I just replaced the section of vacuum tubing going to the transmission today, and checked the valve for operation - and guess what - the valve was broken. It's a cheap plastic part. How it is supposed to work is that the valve is normally open, allowing coolant to flow to the transmission oil cooler. When the ECU decides to close the valve, it activates an electrical switch that applies vacuum to the transmission coolant cutoff valve, which will cause the valve to close. There is a cheap rubber diaphragm at the top of the valve that is leaking on mine - so it doesn't hold a vacuum and it will never close. Easy to diagnose by sucking on the vacuum line. Current Porsche Part number is 92857457304, about $90, the version made by OEM supplier Mechano Bundy is $30 under a slightly older part number 92857457303. So - when you have your transmission out for this procedure, check your coolant cutoff valve by sucking on the vacuum tube. If it leaks air, or if you can't get the actuator arm to move, replace the valve.





Now the question -

It's about where to apply the cam lock when I install the new LNE bearing. I have a 5 chain motor. Most of the directions I have read say to pull the lower green plugs on both cam covers.


As you are looking at the back of the motor, one of the ports to see the cam position is on your left, right in front of you, wide open and easy to access. The other port is in the front of the motor on the passenger side, tucked away behind the edge of the access panel - without a lot of access or room.



My question is - does it matter which of the two lower cams I lock? If it's ok to lock the cam on the back of the motor, that's just so much easier. Do I need to even bother removing the plug from the front cam cover? Or is it important to look at the front cam position to make sure it has not moved following the installation of the new IMS bearing? Or should I be locking the front one because Porsche engineers are just trying to mess with me?

[ddruker]

I received the IMS and RMS parts and tools from LN Engineering last night. Today I installed both the new IMS bearing and the new rear main seal. There are no instructions included with the LN Engineering kit - so I downloaded the instructions for the dual bearing replacement from their website, and I figured out the RMS installation from posts here.



I installed the cam lock on the left side lower cam on the back of the motor - I had to rotate the engine one more time after my first attempt to get the cam notches lining up properly. One extra spin got everything to line up correctly at TDC.



I really just had one wrinkle - it was cold in my garage this morning - probably 45 degrees - when I installed the new bearing, which was about 5 degrees after sitting in my freezer overnight. The new bearing didn't just fall into the hole - I am guessing the temperature differential wasn't enough for this - so I had to tap it in using the provided installation tool.



Here's the wrinkle - when I tapped the new bearing in, the IMS shaft moved around a bit - it wanted to sit in the upper right of its hole, not in the center of the opening.



To fix, I removed the third chain tensioner, which is just below the air conditioning compressor which is in turn behind the drivers seat. This gave me enough play that I could ease the shaft back into the center and get the new IMS cover to seal.



I had to run to home depot and get a short 32mm socket to get to the third chain tensioner - it's pretty tight to get to it. I couldn't easily get a wrench in the opening, and my existing 32mm socket is a tall one.



After this everything went smoothly. The RMS installation tool is pretty self explanatory - clean the crank and the bore with lacquer thinner or acetone, mount the new seal with it's blue plastic holder on the lower section of the pressing tool, then bolt the lower section to the crank face, and then install the top pusher section on top - then turning the set screw pulls the upper section in, eventually pushing the new seal into it's opening. Crank until the tool bottoms out, and the top of the seal ends up 13mm below the crankshaft face.



The rest of the process for buttoning up the engine is clearly explained in the LN Engineering instructions and went without drama.



I also replaced all four of the rear engine casing bolts with new encapsulated bolts as called for in the service manual.


Last step before calling it a day was to remount the flex plate. Remember to get all new bolts for this one, use q-tip to get some blue locktite into the mounting holes, and follow the two step torque instructions in the service manual.



Once my 3 foot chunk of 18mm id x 25mm od coolant tubing for the transmission oil cooler arrives, I can cut out four pieces to replace the existing short connector sections of rubber hose on the tip, and then I can move on to reinstalling the transmission. Once that's done, getting back on the road is all downhill.

[ddruker]

Oh and one more bit of information - I was pleased to notice on my invoice that LN Engineering does not currently charge sales tax for out of state orders made on their website. That works out to about a 10% discount for those of us in the people's republic of California... In addition to no cost specialized tool loaning, plus new cam covers and timing chain tensioner seals included at no extra charge, I'm a happy client.



My only complaint is that LN only wants to honor their product warranty if you get their products installed by a shop. I'm pretty sure I'm more careful and do a better job than many shops do...

[ddruker]

I just returned from Spring break, and yesterday I started putting the Boxster back together. With one exception, it's been a very smooth process.

He is the one wrinkle I hit that I will try to attack today.

When you remove the transmission, you lock the engine and the transmission in place using steel posts. There are three holes in the crankshaft pulley separated by 120 degrees you use to do this, plus a single hole in the top of the torque converter housing.

When you replace the IMS bearing, you remove the locking pin from the crankshaft pulley, rotate the crankshaft to TDC and then re-lock the engine at TDC using the teardrop shaped hole in the crankshaft pulley instead of one of the three symmetrical 120 degree holes.

This of course puts the crankshaft in a different position than it was in when you locked it in place with the three holes you used to remove the transmission, so the bolt holes in the flex plate are no longer aligned with the bolt holes in the torque converter.

There isn't an explicit instruction in the service manual to return the engine to the correct "3 hole" installation position once you are done replacing the IMS bearing.

I had actually thought about this, but I had assumed that since this wasn't specified in the manual, once I re-attached the transmission, I would be able to rotate the engine independently from the transmission, to get the flex plate back into the installation position and the holes perfectly lined up, since the flex plate would not be bolted onto the torque converter. WRONG! The friction fit between the torque converter and the flex plate is really strong. With the torque converter locked, the crankshaft won't budge, even with a lot of pressure on the crank pulley bolt.

This morning, I will remove enough components to be able to re-separate the transmission from the motor by an eight of an inch or so, which should allow me to get the engine back into the re-installation position and get the flex plate to torque converter bolt holes lined up again.

Question to those who have done this before - when you locked the crankshaft in place using the 120 degree holes, were the bolt holes in the torque converter and flex plate perfectly lined up for you when you reattached your transmission? It seems to me there is a little bit of wiggle room in the setup - how did you get the bolt holes to line up if they were not perfect?