[sicktim]

Has anyone done a clutch replacement on their N20? It looks simple enough, but wonder what other things I should expect to replace while doing this job... such as rear main seal.

Here is what I have planned:

- Sachs Clutch Kit: Pressure Plate, Clutch Disc, PP Bolts, Throw Out Bearing, Fork.
- Pilot Bearing
- Rear Crankshaft Seal (rear main seal)
- Flywheel Bolts

Are there any other exhaust seals that I will need? Not having the TIS anymore makes this challenging.

I'll make a write-up if anyone is interested

[MarcoZandrini]

I wouldn't touch the RMS unless it's leaking or seaping oil. You could buy it so if the seal is leaking when you pull the flywheel you have it. But, make sure you can return it if it's not needed. Go to www.realoem.com and enter the last 7 characters of your car's VIN. Hit enter and bookmark the page. Start browsing for bolts and stuff. Be advised that you may have to replace the nuts holding the exhaust to the exhaust manifold. Stock up on penetrating oil, too.

[marantjo]

I'd be interested in a write-up, or at least a short summary. I'll be keeping my car for a while and may need to do this in the future.

[sicktim]

Originally Posted by MarcoZandrini

I wouldn't touch the RMS unless it's leaking or seaping oil. You could buy it so if the seal is leaking when you pull the flywheel you have it. But, make sure you can return it if it's not needed. Go to www.realoem.com and enter the last 7 characters of your car's VIN. Hit enter and bookmark the page. Start browsing for bolts and stuff. Be advised that you may have to replace the nuts holding the exhaust to the exhaust manifold. Stock up on penetrating oil, too.

I found all the bolts, but nobody carries them. I wonder if they are reusable, non aluminum bolts. I assumed FCP would include it with their clutch kit, but they don't have them at all. I am having trouble finding any write-ups from anyone who has done a clutch job on any N20 engine.

I'll definitely document my work for the community.

[dradernh]

Originally Posted by sicktim

I found all the bolts, but nobody carries them. I wonder if they are reusable, non aluminum bolts.

I suggest trying Bimmerworld. I doubt they carry the bolts, but it's quite possible they can direct you to a supplier.

[sicktim]

Turns out the bolts I received were steel. So they are most-likely reusable. Also, the Sachs kit doesn't come with pressure plate bolts as advertised.

[sicktim]

It's going to be a while until I tackle this project, but when I do I'll certainly document it.

[aerobod]

Originally Posted by sicktim

Turns out the bolts I received were steel. So they are most-likely reusable. Also, the Sachs kit doesn't come with pressure plate bolts as advertised.

BMW uses plenty of steel stretch bolts that aren't reusable. The key differentiator is that if the ISTA calls for an initial torque followed by an angle, then they are stretch bolts and are one-time use.

[sicktim]

Originally Posted by aerobod

BMW uses plenty of steel stretch bolts that aren't reusable. The key differentiator is that if the ISTA calls for an initial torque followed by an angle, then they are stretch bolts and are one-time use.

Nope looks like just torque.

[sicktim]

Due to the Hobby Shop's limited hours, I didn't have time to take pictures. However, I got most of it done today. 2 tools I didn't have and was slightly out of the ordinary were a T60 Torx and an 18mm socket (for the driveshaft) and an 18mm wrench. You will also need an E-torx set.

I attached the transmission removal PDF since it was the most helpful with pictures.

Things purchased:
- Sachs clutch kit (FCP Euro)
- Pressure plate bolts (x8)
- Transmission Fluid (2 quarts - Redline MTL)
- Transmission Dowel Pins (x2)
- Transmission Selector Rod Seal (mine was leaking)

Big picture I was able to do it in this order. The exhaust does not have to come off, but you have to bend your exhaust aluminum shielding to get to it. I'm just going to bend it back once done.

1. Removing Covers and Exhaust shields.
- The rear exhaust shield was unbolted and slid back to get access to the Center Support Bearing (driveshaft) bolts. I think you could just remove the front aluminum foil shield and not unbolt the CSB.
- 8mm and 10mm sockets.
- You may need to remove the rear chassis support and will need a T60 for the rear bolts (#1).
- Replacing Bolts: #1 - 100 Nm + 90 deg


2. Undoing driveshaft from transmission.
- Mark the driveshaft and transmission alignment. I used a tire marker and drew a line on the flanges.
- Remove 3 nuts and bolts with 18mm socket and 18mm wrench. These look like one-time use nuts, but i'm going to reuse mine.

3. Unclipping shifter linkages.
- Surprisingly easy. Some small e-torx bolts in the rear of the shifter link and 3 pins that easily come out.
- Shifter linkage pin held on with a clip and then it slides out. No washers.
- Shifter linkage attach point on transmission. 2 pins. The pins come with their circlips attached to the pin. You just rotate the circlip up off the transmission with a screwdriver and the pin pops out.

- You could probably take the shifter out completely. I elected to let mine hang off the shifter boot. Slightly annoying later, but manageable.

4. Remove attachments (Clutch Slave Cylinder, and 2 electrical connectors, +2)
- Clutch Slave Cylinder. 2 13mm bolts
- Electrical connector on side - easy to reach. Remove wire from wire clip and move out of way.
- Electrical connector on top - Not as easy to reach. I had to drop the transmission slightly and then remove it, but installing it, I did it with the trans in place. I have smaller hands and arms.
- Remove grounding strap
- Remove exhaust support bracket on transmission.

5. Bellhousing bolts - I did this after removing the transmission support. I regretted that.
- There are 8 bolts. 2 short and 6 long bolts (I had one long bolt that was slightly shorter than the rest, but I think they are supposed to all be the same). Mine were steel and I was able to reuse them.
- Top 2 - Needed a 3/8" swivel socket and an E-torx socket (they are all the same size). I used extensions roughly the length of the transmission and did it that way.
- 6 long bolts - Used the same technique but probably don't need the extensions for all of them.


6. Transmission support bracket.
-Remove some exhaust torx bolts. These were pretty well rusted and took some persuading to get out. Use some penetrating fluid and work the bolt back and forth to loosen it up. This seems like it would easily strip the head out so be careful with this.

7. Remove transmission.
- It wasn't too heavy, but I still had a transmission lift to drop it onto. Needed 2 pry bars to slip the transmission off of the 2 dowel pins. I had spare dowel pins in case I messed them up. They were cheap.

8. Replace clutch release bearing and fork
- A clip holds the release fork onto the pin on the transmission side.
- Clean the guide tube off and do not grease it.
- Clean the bronze pin off and regrease it.
- Replace clip onto the bronze pin and slide the fork back in place.

9. Remove pressure plate.
- Internal hex head bolts (x8)
- There are 3 dowel pins that will hold the pressure plate on. I had to pry the PP off.
- Clean flywheel off. Mine had plenty of hot spots, but I don't think you can simply resurface this flywheel. I elected to keep the old one.
- Inspect pilot bearing. I have heard it is a bear to remove, so I elected to not touch mine.

- While I did get a new Rear Main Seal, mine wasn't leaking so I decided not to replace it.

Installation is essentially the reverse of removal.

10. Pressure plate
- Install clutch with "getriebeseite" (gearbox side) facing gearbox. Use alignment tool in kit.
- Align pressure plate to dowel pins (there are 3).
- Install the 8 bolts - 15 Nm then 90 degrees. Work in crosswise pattern.
- You will either need the flywheel lock or have a second person wedge a tool between the block and the ring teeth to hold them in place.
- Remove alignment tool.

- Self-adjusting clutch part. Here is where I came to a bit of confusion. I followed what the instructions said in the Sachs kit. There is an 8mm nut on the edge of the pressure plate that came partially screwed on (but completely loose - see red arrow in picture below).



The instructions said to bolt the PP to the flywheel and then tighten this nut to 8 Nm. The BMW TIS didn't call for this at all and i'll have to look at the old PP to see if it has this nut. I don't think the original parts had this. I think it has to do with the fact that you aren't using the 2 BMW special tools to reset the pressure plate adjustment. In the BMW service section it calls for using a special tool to reset the Self Adjusting Clutch and then another tool to lock it into place while bolting to the Flywheel. When I go back in tomorrow, i'll look at the old PP and see if it has this nut.

- My transmission was leaking at the gear selector rod. Using a pick, I was able to pry this old one off (not easily) and install the new one with a socket large enough to fit over the selector rod. BMW calls for a special tool which looked to be about $60 from FCP Euro. Just YouTube it.

11. Transmission.
- Clean the input shaft splines and regrease using the grease from the kit.
- Install rubber/metal dust cover and plug. Don't forget this, it was a pain to do after the fact. However it is possible, but took us nearly an hour of fiddling.
- Check alignment pins on block for damage.


- I had to get the transmission close and then use the 2 bolts that bolt through the alignment pins to pull the transmission onto the block. Be careful with this. If something is binding, you risk causing serious damage to your transmission or engine block. I did a small portion on each side at a time, pausing to make sure it is actually moving.
- Tighten to 56 Nm (steel bolts only - aluminum are different). Good luck utilizing a torque wrench. I had to use a calibrated hand.

12. Attachments (electrical connectors x2, slave cylinder, +2)
- Slave Cylinder Bolts - 19 Nm
- Grounding strap
- Exhaust support bracket.

13. Driveshaft
- 55 Nm + 90 degrees
- Keep alignment same as removal
- If you removed Center Support Bearing - 19 Nm

14. Gear selector
- Clean and regrease the pins. Check for worn bushings and replace as required.
- Rubber Boot (the one under the leather boot) - Before you get the boot onto the body, make sure the boot is properly connected to the shifter (inner part). Then from below, get as much back onto the body. Next from inside the cabin, using a screwdriver or pick tool slide the rest of the rubber boot onto the transmission tunnel. Using some silicone spray or silicone grease can greatly help with this.

15. Covers and extra bits.


I wish I could have taken some pictures, but I hope this gives and overview for someone interested in tackling this themselves. I had access to a lift, but I think if I had jacked the car up high enough I could have done it without one. The hardest part was putting the transmission back on.

With 3 dudes (mostly fumbling over each other), we were able to get through everything up to getting the transmission back on in 5 hrs. Tomorrow should be easier and quicker.

[sicktim]

I did more research this morning into the different Self Adjusting Clutches (SAC) available. Sachs and LUK have different mechanisms, but do the same thing.

LUK (standard on our cars): Has 3 visible springs and some sort of plate that holds the mechanism during installation. Or you can use the 2 BMW special tools to do it.


Sachs: No visible springs. Has either a nut or rivet that holds on the SAC mechanism. Mine had a nut on the SAC - so to speak.


Here are the instructions for XTend clutches. I also attached them in PDF form if anyone is looking.

[sicktim]

Clutch is in and works great! No more slippage.

[mecodoug2]

Thanks for posting. With only 55K miles on mine I hope it will be another 6 years plus, but as you mentioned there are not a lot of DIYs out there for F22 clutches. I wonder if a B58 clutch will be any harder to do.