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husker boxster · 03-21-2020, 08:57 PM

In order for me to move fwd with the 928, I must remove a plate on the bottom of the bell housing. The plate is held on by 6 bolts, 4 of which are easy to get to. The back 2 however, are not accessible unless the exhaust pipes are dropped from the exhaust manifolds. There are 2 exhaust manifolds that each have a flange with 3 bolts holding the exhaust pipe to the manifold. Of course the 3 nuts are fused onto the bolts AND the flanges, and won't budge when trying to remove them with a wrench.

So the nuts must be cut off. But there's no room for a hack saw. Time for a dremel to grind them off. Other than the nut at the bottom of each flange that can actually be cut off, the top 2 must be ground off. Takes a bit longer, but is doable with the dremel. Spent parts of 5 days working on this. After doing a couple, I figured out a system that worked faster on the remaining nuts. All 6 are ground off.

But I'm not out of the woods yet, as I need to get the flanges separated which will allow me to lower the exhaust pipes. The remaining bolts are still fused in the flanges. The next step? Heat. I bought a new benzene torch, as my old one almost caused an explosion. There are 2 types - a lower temp one using blue bottles of fuel and a hotter version using a yellow bottle. Since I have a few old blue bottles already in the garage, I bought the blue torch. Tried it on the 1st bolt I’d ground the nut off and it wasn't hot enough. I called a mechanic friend and he suggested the yellow torch. So I went back and bought it (I've always needed 2 benzene torches). It did heat the metal to red but it didn't loosen the nuts - that's when I decided to grind them off. Now I'll heat the metal to red hot and hopefully drive the bolts out of the hole. At the very least, I hope I can get the exhaust pipe flange off the bolts, allowing the exhaust pipes to drop down. If that doesn’t work, my mechanic friend has an acetylene torch and he can get them off. But that escalates the project.

So after I got all the nuts off and before I tried yellow heat, I gave 1 of the bolts on the driver’s side a few good whacks with a hammer and punch. It flew out and the vibration knocked a 2nd bolt half way out. The 3rd bolt gave a bit more resistance, but it came out too. I had the driver’s side out. The bottom passenger side bolt still wouldn’t come out (this is the one I tried early on and assumed all were stuck because of this one). Went to the top of the flange and both popped out with some persuasion. I took a small screw driver and carefully drove it between the flanges and they cracked loose. Took the punch and hammer to the last bolt and it popped out. Yay!

But no time to celebrate just yet. There was a pipe running down from the engine bay to the cats and it was joined together by a nut on a threaded flare section. This pipe was keeping the exhaust pipe from dropping down. The bottom, immovable nut was a 22mm and I had a flared wrench for it. But the other nut was big. I measured it at 27mm and went on a journey to find an open end wrench at a parts store, while the nuts soaked in Aerokroil. Took me 3 tries to find one but I was in business. Got home and tried working them loose. No go after several attempts. Decided to try blue heat on it since the line appeared to be a non-steel or iron composite. Gave the big nut a good bit of heat, then tried my wrenches again. It came loose! I loosened the nut and the exhaust dropped down. Finally, some success.

I loosened the 2 previously inaccessible bolts on the plate and removed it. I painted some stripes on the flywheel, one on top and one on the bottom, so I could tell when I’d turned the flywheel 180 deg. Then went on top and made sure the offending cap was clear of the hole. Turned the flywheel and the cap came out. More success.

Decided to do some clean-up on top of the bell housing before putting everything back together. Also took the opportunity to clean one of the twelve ground wires on a 928 that can cause electrical issues. This makes the 10th of 12 that I’ve cleaned. This one is normally buried but only required 1 bolt and wire to be removed to get to it since I already had a bunch of stuff removed for the CPS. Then put the CPS in and got the pig tail routed and connected. Sweet Baby Jesus, the CPS sure looks good back in place.

I’m going to put the fuel lines back on tomorrow and hopefully try starting it again. Then on to measuring the thrust bearing.

03-21-2020, 08:57 PM	#38
husker boxster Registered User Join Date: Sep 2006 Location: Omaha Posts: 2,912	In order for me to move fwd with the 928, I must remove a plate on the bottom of the bell housing. The plate is held on by 6 bolts, 4 of which are easy to get to. The back 2 however, are not accessible unless the exhaust pipes are dropped from the exhaust manifolds. There are 2 exhaust manifolds that each have a flange with 3 bolts holding the exhaust pipe to the manifold. Of course the 3 nuts are fused onto the bolts AND the flanges, and won't budge when trying to remove them with a wrench. So the nuts must be cut off. But there's no room for a hack saw. Time for a dremel to grind them off. Other than the nut at the bottom of each flange that can actually be cut off, the top 2 must be ground off. Takes a bit longer, but is doable with the dremel. Spent parts of 5 days working on this. After doing a couple, I figured out a system that worked faster on the remaining nuts. All 6 are ground off. But I'm not out of the woods yet, as I need to get the flanges separated which will allow me to lower the exhaust pipes. The remaining bolts are still fused in the flanges. The next step? Heat. I bought a new benzene torch, as my old one almost caused an explosion. There are 2 types - a lower temp one using blue bottles of fuel and a hotter version using a yellow bottle. Since I have a few old blue bottles already in the garage, I bought the blue torch. Tried it on the 1st bolt I’d ground the nut off and it wasn't hot enough. I called a mechanic friend and he suggested the yellow torch. So I went back and bought it (I've always needed 2 benzene torches). It did heat the metal to red but it didn't loosen the nuts - that's when I decided to grind them off. Now I'll heat the metal to red hot and hopefully drive the bolts out of the hole. At the very least, I hope I can get the exhaust pipe flange off the bolts, allowing the exhaust pipes to drop down. If that doesn’t work, my mechanic friend has an acetylene torch and he can get them off. But that escalates the project. So after I got all the nuts off and before I tried yellow heat, I gave 1 of the bolts on the driver’s side a few good whacks with a hammer and punch. It flew out and the vibration knocked a 2nd bolt half way out. The 3rd bolt gave a bit more resistance, but it came out too. I had the driver’s side out. The bottom passenger side bolt still wouldn’t come out (this is the one I tried early on and assumed all were stuck because of this one). Went to the top of the flange and both popped out with some persuasion. I took a small screw driver and carefully drove it between the flanges and they cracked loose. Took the punch and hammer to the last bolt and it popped out. Yay! But no time to celebrate just yet. There was a pipe running down from the engine bay to the cats and it was joined together by a nut on a threaded flare section. This pipe was keeping the exhaust pipe from dropping down. The bottom, immovable nut was a 22mm and I had a flared wrench for it. But the other nut was big. I measured it at 27mm and went on a journey to find an open end wrench at a parts store, while the nuts soaked in Aerokroil. Took me 3 tries to find one but I was in business. Got home and tried working them loose. No go after several attempts. Decided to try blue heat on it since the line appeared to be a non-steel or iron composite. Gave the big nut a good bit of heat, then tried my wrenches again. It came loose! I loosened the nut and the exhaust dropped down. Finally, some success. I loosened the 2 previously inaccessible bolts on the plate and removed it. I painted some stripes on the flywheel, one on top and one on the bottom, so I could tell when I’d turned the flywheel 180 deg. Then went on top and made sure the offending cap was clear of the hole. Turned the flywheel and the cap came out. More success. Decided to do some clean-up on top of the bell housing before putting everything back together. Also took the opportunity to clean one of the twelve ground wires on a 928 that can cause electrical issues. This makes the 10th of 12 that I’ve cleaned. This one is normally buried but only required 1 bolt and wire to be removed to get to it since I already had a bunch of stuff removed for the CPS. Then put the CPS in and got the pig tail routed and connected. Sweet Baby Jesus, the CPS sure looks good back in place. I’m going to put the fuel lines back on tomorrow and hopefully try starting it again. Then on to measuring the thrust bearing. __________________ GPRPCA Chief Driving Instructor 2008 Boxster S Limited Edition #005 2008 Cayman S Sport - Signal Green 1989 928 S4 5 spd - black Last edited by husker boxster; 03-21-2020 at 09:03 PM.