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S2 Bellhousing and Reference Sensor Removal Questions

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Old 04-09-2019, 10:30 AM
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Zirconocene
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Default S2 Bellhousing and Reference Sensor Removal Questions

This is a little embarrassing to have to ask but I've gotten stuck and I hope someone can help.

Background: replacing the rear main seal, following the write up from Pelican primarily, but with other guides/tips as well (Jay's garage, Clark's, 944Online).

When I went to remove the reference sensor on the car I had trouble removing the hex head bolt that holds down the sensor, so I decided to go to the other end of the wire and disconnected the electrical connection, thinking that would be OK so long as I was really careful with the sensor. The electrical connection crumbled and I have to replace the sensor but I thought that would be enough to keep going.

However! In trying to remove the bellhousing I can get it loose but it's hung up on something on the upper left of the bellhousing (as you face toward the front of the car). As I was inspecting things up there I also noticed that there appears to be a ground wire bolted to the top of the bellhousing, which was not mentioned in any of the write ups that I've read. Is that a normal ground point for the S2? I have to replace it as the sheath is cracked but it was an unexpected bit of work and now that the car is up on a lift access to the top of the engine is a little hairy.

Is the reference sensor what's stopping me from removing the bellhousing (I added a link, below, that says this is the case but I haven't found any corroborating information/posts via Google)? I have removed the clutch fork pin, and that part of the bellhousing separates easily from the engine block so that's not what's going on. Can anyone offer me some tips on removing that bolt on the reference sensor? Here's a link to a picture of what I'm struggling with (FCPEuro site: https://www.fcpeuro.com/products/por...68-80243052615). If you look at the 2nd picture you can see that the bolt sits down between the molded plastic walls. I can't get a socket with walls thin enough to be able to unscrew the bolt. When I take a look at this video (
) it looks like the bolts heads on that engine are really long. On my car, the bolt head just sits down right in the pocket that molded into the sensor. Any tips? I have pondered removing the reference sensor bracket but I'd like to avoid gapping the new sensor if possible. Once I replace the sensor, are there downsides to replacing that hex head bolt with an allen head bolt?

Per this post (http://forums.pelicanparts.com/porsc...-question.html) there is also a sleeve that needs to be removed; is that something that a pick can get out?

Are there any other S2 specific things that need to be removed on the top of the engine before I can access the clutch and flywheel?

That's a lot of questions and any help would be greatly appreciated. I feel like the end is in sight for getting this part of the refurbishment done and I'm eager to keep going. Spring is practically here and I'd like to get my baby on the road.

Thanks.

Last edited by Zirconocene; 04-09-2019 at 04:07 PM. Reason: Added more links and info
Old 04-10-2019, 11:06 AM
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Zirconocene
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Some further information that I have been able to find on Pelican. The example that is shows with the standard bolt is what I have going on (http://forums.pelicanparts.com/porsc...nk-sensor.html).

Somehow, the previous owner was able to get that bolt in between the walls of the sensor; I can't figure out how to get it out.

At this point, I'm getting pretty convinced that I just need to pull the bracket and hope that goes reasonably. With the clutch disassembled it should be relatively straightforward to gap the sensor, correct?

Thanks in advance for any insight.
Old 04-17-2019, 10:18 AM
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Dan Martinic
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Originally Posted by Zirconocene
Some further information that I have been able to find on Pelican. The example that is shows with the standard bolt is what I have going on (http://forums.pelicanparts.com/porsc...nk-sensor.html).

Somehow, the previous owner was able to get that bolt in between the walls of the sensor; I can't figure out how to get it out.

At this point, I'm getting pretty convinced that I just need to pull the bracket and hope that goes reasonably. With the clutch disassembled it should be relatively straightforward to gap the sensor, correct?

Thanks in advance for any insight.
I don't know about your S2, but on my 951 you can't remove the bellhousing without removing the bracket; my bellhousing isn't notched (look up "notched bellhousing") and I have the extra metal shield on the bracket.

Pull the bracket. Then, see if you can get the proper bolts for the sensors

I've got pics of how I get to the bracket bolts if you want. They are.... interesting
Old 04-17-2019, 10:46 AM
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Zirconocene
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Thanks, it hasn't been straightforward. The confusion for me has been twofold: First, most of what I've read is not about the S2, so it's not always clear what has carried over from late 944/Turbo development and what is more related to the 968. Example: my car has the split torque tube which, from what I've read, showed up on the 968 but is present on my car (retrofit? I don't know). The second source of confusion was a reply on the Pelican forum that said you could remove the bellhousing with the sensor still in the bracket so long the wire was disconnected. Having struggled with the thing for a while I can now say that it is totally unclear how that would work on any car that has an un-notched bellhousing (which I won't be doing), regardless of whether or not one's car has the aluminum sleeve or not. Perhaps it would be worthwhile to send Pelican a note about that misleading bit of information.

I ended up removing the sensor bracket completely and will have to regap the sensor. Everything will be open so I hope that helps to keep things straighforward. My bracket was held in by hex head bolts and I don't know if that helped or not but it wasn't difficult to get out (this is in contrast to the stories I have read about improvising tools to get back in there). However! It also looks like the set bolt was not tightened all the way. When I removed both bolts they were the same length, which is not what I see on diagrams so it's not clear to me if it would even be possible to tighten it down completely. I bought some socket/allen head bolts of different lengths and hope that helps to keep things more secure, as the sensor head was a little chewed up; I hope I'm not making trouble for myself but at this point, it'll just be another little bump in the road.

For what it's worth, once I had the whole sensor and bracket assembly out, I was able to use a crescent wrench to remove the sensor from the bracket; this will also be replaced by a socket head bolt. I don't know that I would have ever been able to get that done with the bracket still attached to the block.

If nothing else, I hope that this helps someone else down the road; this forum has been a treasure trove of help and information.

Fun times. I'm now struggling with the pilot bearing but am convinced that there is light at the end of the tunnel, so to speak.

Cheers
Old 04-17-2019, 11:04 AM
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Dan Martinic
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Sounds like it's going well! Put some anti-seize on those bolts

PS.. harbour frieght used to sell a 'mini' slidehammer set that pulled my pilot bearing out nice and easy. Seems they no longer have it?

It's hard to find a tool with small enough jaws for our little PBs
Old 04-17-2019, 02:32 PM
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For pilot bearing removal have you tried using the grease method?

Old 04-17-2019, 02:39 PM
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Re pilot bearing removal with grease: Not yet. I bought a slide hammer for the job but it's too long

I've also tried making it a puller type but that's going poorly. I don't know if it's the design (only 2 jaws) but the fingers keep pulling out when I start trying to pull out the bearing. I've considered the grease method that you posted, as well as the bolt and allen key, but I'll see first if a tool I can borrow from an auto parts store works. If not, on to the messy stuff because the other things I've seen, like making a slide hammer with a bolt and a closed end wrench moved that bearing all of 0%.
Old 05-02-2019, 02:02 PM
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My slide hammer just barely fit, so was able to complete the removal. It was a pain as the puller is much less effective if you are not directly in line.

Were I to do this again, I'd swap out the 'slide' length of the puller with some shorter all thread and washer/nuts. You can cut it to a length that fits and still use the bearing grabber end as designed. Hope this makes sense.
Old 05-02-2019, 02:35 PM
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Default The end of my saga with this

First off, thanks to everyone that chimed in to help out.

Here's what ended up going down: I removed the whole sensor bracket and it turned out to be the right thing to do, as once I had everything out and in hand it became clear that there was never going to be a way to remove the aluminum sleeve that the sensor sits in. So long as that sleeve stayed in, I was never going to be able to remove the bellhousing. I could move the sleeve up and down just a little bit but even with multiple applications of Kroil I could never slide the thing out all the way. There was 0% chance I would have been able to get that out with the bracket attached to the engine block. Ultimately, I banged the sleeve out using a nut that was threaded onto a bolt. The nut (I don't remember what size, apologies, but it was an SAE size and it fit so that the points of the hex just overlapped with the bottom of the aluminum sleeve) didn't gouge the sides of the sensor bracket but even if it had it wouldn't have really mattered, since I decided to go ahead and lap the inside (I used these, 17mm for the bracket ID, first time ever and it was really effective and fast, with a 400 grit paste: https://www.mcmaster.com/catalog/125/2743). There was gouging on the inside of the aluminum sensor sleeve, as well, so I lapped that (as above, but with a 15mm) then went ahead and polished the outside of the sleeve with some fine grit sandpaper while I had everything near the drill press. Overkill? Probably, but I hope that everything stays assembled for a long time and so long as I had everything available and could clean things up, why not?

I gapped the sensor to 0.75mm (not the recommended 0.8, because the old sensor had been mangled a bit and was not flat on the bottom), still within the recommended specs.

As for the pilot bearing, I ended up taking a flyer and buying a Harbor Freight tool: https://www.harborfreight.com/3-jaw-...ller-4876.html, $20 with no coupons. The OD of the jaws when fully closed is 3/4", much larger than what the pilot bearing will accept but a little bit of time with some files, keeping the jaws as symmetric as possible, and having filed the back of the jaws, as well, to provide a bit more grabbing area, and the bearing came out. I went back to look at my improvised puller, which had a 1/4" aluminum bridge that I'd made and saw that the bridge had bent (!) during my previous attempts. So, good on HF, their tool didn't suck and it was not too much work to get it to do what I wanted it to do.

I'm back in assembly mode and just figured out that some jackhole replaced one of the bellhousing bolts with the wrong thread pitch at some point in the past and sourcing an M12x1.5x50mm bolt locally has been all the fun you can imagine. Needless to say, it's back to McMaster.

Cheers



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