clutch bellhousing removal

JanBrewer · 09-15-2008, 12:06 AM

err... I am sure this is a new one to most people... I cannot get the clutch bellhousing to clear the drive shaft. No matter what I do, I cannot get it off the vehicle. The TT has been turned over and pulled back all the way so the bell housing on the TT touches the frame where the TA attach point is. It cannot go any farther back at all. Yet the clutch bell housing just cannot get past the drive shaft. I just spent three hours cursing and maneuvering the thing in all directions. Any help would be appreciated.

2Tight · 09-15-2008, 08:18 AM

Is this on an 83/84? I remember that there was a sweet spot where the TT can be rotated to gain another 1-1/2". Another easy option is you can always go in through the starter hole and unbolt the pressure plate; then the whole tamale will drop almost straight down without having to clear the BH.

70SWT · 09-15-2008, 08:54 AM

Regardless of the year, it should come out if the tranny is dropped. There is massive room to slide back the torque tube.

Any chance the drive shaft has slid through the bearings a bit inside the TT? Had this happen before due to...

...you may need to place a jack under the front of the engine to level it out a bit. It will often tip forward once the drivetrain ass'y is unfastened, locking the tip of the driveshaft into the pilot bearing.

JanBrewer · 09-15-2008, 09:16 AM

It's a 1986 NA. I guess the shaft may have slid forward.

I supported the engine with a jack the whole time, and the TTcame out without any issues at all. However, after rotating it and pulling back all the way to the crossmember, there is absolutely NOT enough clearance for the bellhousing cover to come off, no matter where it is rotated/jiggled. It always comes agonisingly close....

The TT came back around 8 inches I guess. I have tried lifting and lowering the engine to various heights during the procedure, but no way to clear the shaft was found. I am clueless as to why it should be like this. I thought that the shaft sliding inside its bearings was really hard to do...

SolReaver · 09-15-2008, 10:01 AM

I had similar problems. it took hours to get the thing off. First check that the sensors and/or sensor block is out so that the housing isn't catching on them. Then check to see what angle the engine is. I had to jack the engine on the front to get it to lean back and have the bell housing clear.

Taz's Master · 09-15-2008, 10:53 AM

I had the same problem with my '86. I couldn't remember what I did (I even searched old posts, because I know I discussed it), but I know it did come out. On reassembly it had to come out again, and it was much easier. I believe that using a jack to alter the angle of the engine is indeed what worked for me. So many things about the clutch job are like this, so many things that should be straight forward and easy turn out to be very difficult.

JanBrewer · 09-15-2008, 11:07 PM

thanks dudes!

Let me be sure I am absolutely clear on this. I can jack the front of the engine; not the oil pan on the back of the engine?

Will there be any damage to the engine mounts if I overjack the front or something like that? I think jacking the front could indeed work: it would enable the square frame on the bellhousing that the TT bolts into to clear the shaft nub first before I take the BH off the flywheel.

I will try it when I next get to work on it. This darn job is so frustarting when you have only bits of time here and there to do it.

SolReaver · 10:52 PM

Yes. You jack the front of the engine and tilt it back. It is prety much the only way to get the space to work with. It is possible to over tilt the engine and over strain the mounts, but you would really have to work at it. A few inches should do.

I jacked from the front where the alt and PS tensioneres were and used a wood block so as to not damage anything. If you jack the back of the engine, it will of course tilt forward. When I tried to get the bell housing back on, it would not install unless the engine was tilted.

Careful of the firewall insulation. It itches like mad. So wear gloves and long sleeves.

Replace all the bolts, the RMSeal, and the pilot bearing while you are there. The shift fork bearings and shift lever rod will likely be toast. If you don't have the parts yet, order em now. To remove the pilot bearing easily, see my post Pinion bearing removal tool. Oh hec, here is the text:

I discovered a really great way to remove a pinion bearing on the 2.5 litre engines. I am pretty sure that it will work on almost all of the 944 and 924's out there. Hec, It will probably work on any bearing that has a recess behind it. But please check and use some common sence.

Background: Clarks suggests 2 methods of removing the pinion bearing while doing a clutch. Niether one worked for me. So, I came up with this way, and it works like a charm.

Get yourself a 3/8" "Drop in anchor"(used for fastening to concrete) and a 3 1/2" or 4" bolt (or longer) with threads down it's entire length. Both of these items are readily available in any hardware store worth mentioning. The standard thread for a 3/8 th anchor is 16 threads per inch FYI, but check the anchor against the bolt itself to be sure.

Grease the bolt liberally and insert it into the anchor. Grasp the smooth end of the anchor firmly in a Vice grip locking wrench, (no mechanic should be without one) insert the anchor into the pinion bearing to be removed, hold the vice grip steady, and turn the bolt. The bolt will mushroom the portion of the anchor on the other side of the bearing. Continue to turn untill the bolt contacts the far wall of the crankshaft recess. Once it connects, Continue turning and the bolt threading past the anchor will push the pinion right out.

The tool is unfortunately a one time use, but the bolt and the anchor will run you between two and three dollars. I considered it money well spent as it saved me a lot of time and aggivation. This method doesn't use heat, so it doesn't destroy the seal and it is sooo much faster than either method I had read about.

You are free to use and disribute this tech-tidbit. If this works for you (and it will) you owe me (Solreaver) a beer , or you can send me money for a beer!, If niether of these works for you, you can drink a beer in my honor. If you are on the wagon, you can get a friend to do it.

I also suggest that you get 2 o rings that fit tightly on the release fork shaft and stick them on the fork below were the shaft slides into the bearings. This keeps the bearing grease in the bearings longer and may save the shaft should you need to do the clutch again in 80 to 100 K.

unsigned · 09-18-2008, 10:59 AM

I had the same issue. No matter what I did, I couldn't get it to clear. One evening I accomplished nothing but a lot of cursing under the car.

I think SolReaver is on the right track, being a novice with new motor mounts, I chose to loosen them before jacking.

JanBrewer · 09-18-2008, 02:04 PM

Wow. I don't know what to say. You are the man Sol!! I will drink muchas cervezas in your honour.

But I haven't gotten under the beast again yet since the last post... I have a two year old, work two jobs and go to full time school... there really was no room for a 944 in my life but oh well, I'm hooked already.

Will update on the bellhousing and the pilot bearing once I get to it. How do I tell if the fork shaft is toast? That was the one part I had not yet ordered.

So, anyone have a clue how long my new pilot bearing is likely to last with a torque tube whose drive shaft is a teeny bit out of round... like 0.75 mm out...

SolReaver · 10-20-2008, 09:05 PM

Well just getting back to the world of the living myself.... try setting aside some "quality Porsche time" The job is a biggie so don't get discouraged. However, you might want to get it done before you forget where everything goes.

how long the pilot bearing will last with a slight imbalance...well....ya might want to think about finding a junkyard and getting a propeller shaft when the opportunity presents itself. Note that they are heavy and non-fun to remove. Once you have completed the job, if there is de minimus vibration you could always ignore it and hope it goes away (that is a joke)

your fork shaft will prob be toast, you can tell by looking at it. It should be a smooth shaft with no nicks or indentations where the bearing seat. As the factory installed porsche oem grit, the bearings and shaft will be junk.