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Join Date: Jul 2001
Location: Orange, Ca USA
Posts: 45
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How to change input seal in a 915?
Hello, guys,
My car has a 1975 915 tranny with leaky output shaft oil seals, and while its out of the car, I'd like to do all the seals as well. The output shaft seals look pretty simple to do, but the input shaft seal is a real mystery to me- its at the bottom of a 3 inch long tube. Does anyone know how to R&R this seal? Please tell me I dont have to crack the case open... Thanks in advance, Jeff Craddock Orange, CA 74 911 coupe
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Jeff Craddock 74 911 Coupe |
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03-19-2002, 07:53 AM
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Join Date: Jul 2001
Location: Springfield, MO
Posts: 1,422
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I believe that the earliest 915's in '72 (introduction) went in from the inside. A real pain. Check your xmission numbers before you go any further.
Good luck, David Duffield |
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03-19-2002, 08:00 AM
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Senior Member
Join Date: Feb 2000
Location: Lacey, WA. USA
Posts: 25,310
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The tube that hides the input shaft seal on my tranny is a "guide tube" that is easily replaceable/removable.
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Man of Carbon Fiber (stronger than steel) Mocha 1978 911SC. "Coco" |
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03-19-2002, 08:31 AM
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Location: Los Alamos, NM, USA
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I think your in the range of 915 models where the seal can come out from the bell housing side but I believe it takes a special tool that's like an apple corer. The tool appears to slip in between the clutch release bearing guide tube and the input shaft and screws/cuts down into the seal to "grab it" so it can be pulled out. Later (I know by 1976) the guide tube was flange mounted to the bell housing so the entire tube could be removed from the bell housing/input shaft and the seal then removed/replaced using pusher tubes/tools. If you do not have a flange mounted guide tube you're either going to have to find the tool or take your transmission apart. Maybe John Walker will comment with a nifty trick to avoid this. I'll look up to the tool number of the "apple corer" seal removal tool this evening if you would like it. Whatever you do, measure the depth of position of the existing input shaft seal so you know how far to drive/push the new one to get a correct re-installation.
 Jim
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03-19-2002, 08:31 AM
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Join Date: Mar 2001
Location: Marysville Wa.
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if you have the removeable guide tube, you don't really need the special tools. just remove the tube and punch out the seal and use a tube of some sort to drive the new one in the same place. there were two early diff housings with a non-removeable tube. the real early ones required the gear clusters and diff to be removed to replace the seal. brilliant engineering. this housing had a thick tube with a deep bevel on the inside of the leading edge. 72-early 73. the next version had a non-removeable, thinner tube where you used the normal tools (shown), to extract it externally. it would be difficult to swap the seal on this one without the tools, but i'm sure there's a way.
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https://www.instagram.com/johnwalker8704 8009 103rd pl ne Marysville Wa 98270 206 637 4071 Last edited by john walker's workshop; 08-25-2007 at 08:02 AM.. |
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03-19-2002, 09:42 AM
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John Walker, Did you make your "apple corer" seal removal tool or buy it? I may need one of those someday. Jim
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03-19-2002, 10:02 AM
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i got it at a porsche dealer that closed (bayside). the driver could be made easily, but Baum sells them both. around '82, (can't remember precisely), there was another guide tube that had the seal sitting deeper than the rest. about another seal's width deeper. baum doesn't sell that one, so i need to make it. important for this reason to measure the original depth of the seal before yanking it.
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https://www.instagram.com/johnwalker8704 8009 103rd pl ne Marysville Wa 98270 206 637 4071 |
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03-19-2002, 11:23 AM
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Location: Los Alamos, NM, USA
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A possible way to improvise the "apple corer" 915 input shaft seal removal tool is to use a pipe nipple if one can obtain one of the correct length and diameter. The sharp tapering threads on the end of the nipple would gradually screw into and grab the seal if they were the right size. One could make a handle by using a pipe T or cross with other pipe nipples at right angles to the cutting nipple for handles. I would attempt to find a brass or copper nipple for the cutting nipple to avoid marring the inside of the guide tube. Now I haven't tried to rig this up; but to attempt this I'd take the new seal and the measurements of the guide tube (inner diameter and depth of seal position) and go visit my local plumbing supply store. Just an idea. Jim
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03-19-2002, 11:33 AM
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Location: Orange, Ca USA
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Guys,
thanks very much to all of you for all the replies on this topic, I would have been lost otherwise. My trans has the collar that isnt removable. I'll try making John's apple corer tool using the pipe nipple as Jim suggested. John, does the apple corer have to be tapped in with a hammer to get it started? Any other ideas for getting this baby out are appreciated ... You guys are great! Jeff Craddock Orange, CA 74 911 Coupe
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Jeff Craddock 74 911 Coupe |
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03-19-2002, 12:30 PM
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Location: Los Alamos, NM, USA
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If you make this tool be sure and deburr the sharp inside edge of the nipple so it doesn't mar the sealing surface on the input shaft.
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03-19-2002, 02:03 PM
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Join Date: Oct 2000
Location: Centennial, CO, USA
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I replaced my seal on my '72 915 tranny last week. I had to remove the circular ring plate to get to the seal. I was hesitant to do it, but once I got in there it was a piece of cake. Make sure you have the big o-ring for that plate. The seal would not come out any other way. By the way, the rest of my tranny components were already out because I was doing a full syncro and dogteeth replacement job. None the tools I tried worked to extract that nefarious seal from the outside. Be careful as the mag case is soft. HTH.
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Bill '72 911T-2.4S MFI Vintage Racer(heart out), '80 911SC Weissach,'95.5 S6 Avant Wunderwagen & 2005 997 C2S new ride. Last edited by zotman72; 03-19-2002 at 02:38 PM.. |
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03-19-2002, 02:35 PM
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I believe Jeff's seal (1975 model 915) has to come out and be installed from the bell housing side due to the way the step on the inside of the guide tube (the seal registers on this step) is counterbored. He either has to take the transmission apart to remove the input shaft or use the "apple corer" tool. I don't think he can get to the seal by taking off the transmission housing (differental housing) side cover, removing the differential unit and the use some type of driver sleeve (with a slot down one side so it can pass over the installed input shaft) with a slide hammer rig - this is the only way I can envision doing it from the inside and it sounds awkward and risky. The guide tubes appear to be cadium plated steel.
Jim
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03-19-2002, 02:53 PM
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Location: Orange, Ca USA
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Jim,
you're right- it wont go any other way. I'm going to try and build the tools and make avail to guys on the list if they have this weird design. Porsche could have made this a lot easier by making the guide tube removeable. Jeff Craddock Orange, CA 74 911 Coupe
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Jeff Craddock 74 911 Coupe |
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03-19-2002, 04:23 PM
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