ARRGGG! Can't Reconnect Tranny & Engine!

88911coupe · 03-24-2009, 05:22 PM

I'm at my wits end...can't seem to get the tranny to connect up the last 1/4" to 3/8"th with the engine! FYI this is a G50 for an '88 Carrera.
I don't want to force it for fear of breaking something. Has anyone run into this and if so what was the problem? The only thing I replaced was the starter gear which is on correctly and the pilot bearing which appears to be exactly like the old one. I've rigged up a contraption to allow some "tilting" of the tranny so I can move it around a bit. The "ears" for the shaft aren't in the way and there does not seem to be anything externally that's stopping it. I know the output shaft is at least partially engaged so that can't be it...it's just the last 1/4" or so.
For those that have done this before does it go fairly easily the last bit or does it take some gentle persuasion?
TIA!

Gogar · 03-24-2009, 05:51 PM

Is the ring gear installed backwards? That's my post-whore shot in the dark, and I don't know if it would even matter.

88911coupe · 03-24-2009, 06:26 PM

I'm 99.9% sure it's installed correctly. Per the diagrams I've seen the side that has the very slightly raised lip needs to be the side that the bolt heads snug up against and the side of the ring gear with the "bevel" goes against the pressure plate which is the way I have it done. It's matching the diagram from the Porsche Tech Tip. I've taken it apart several times and I can't see any rubbing on the inside or any obvious signs of interference.
Thanks for the suggestion...

equality72521 · 03-24-2009, 06:27 PM

Not sure how the G50 works but on mine if you don't have the clutch arm for the throw out bearing in the right place you won't get them together.

Tom '74 911 · 03-24-2009, 06:35 PM

I've been there w/my 2.7 and 915 - don't know if it's any different than a g50? Double check that your clutch is aligned correctly (easy to verify w/plastic guide tool) and that the clutch throw out lever/arm is aligned too (easy to verify w/flashlight looking through hole in trans.). I had a friend turn the motor over slowly at the fan pulley as I pushed them together. It helped the splines in the clutch and trans. input shaft line up correctly. I fought this too, until I tried the above, which did the trick for me.

Best of luck!

Tom

88911coupe · 03-24-2009, 06:43 PM

Thanks, I've got the clutch aligned and I can tell the input shaft is mating up with the hole in the clutch plate at least partially since I can see the optimoly has been disturbed. I've gotten pretty good at telling when the splnes line up and it makes the final move towards being buttoned up but something is stopping it just before it is complete. I can see the two "ears" for the clutch release shaft are lined up fine so that does not appear to be the issue. This is really the last tiny bit where it just comes to a stop. I've used the alignment tool and "realigned" the clutch a couple of times but I'm pretty sure how that's not my problem since I don't seem to have any problem getting the input shaft through the clutch.
Thanks again for the suggestions.

equality72521 · 03-24-2009, 06:45 PM

Are both out of the car?

Tom '74 911 · 03-24-2009, 07:01 PM

Is it possible that the new pilot bearing isn't allowing the trans. input shaft all the way in? I don't know? That's frustrating!

Tigerrat · Tigerrat's Garage

Once you get it close enough to put the nuts on it should snug up pretty easily. Maybe time for some pics. Someone may spot something.

88911coupe · 03-24-2009, 07:46 PM

Yes, both are out since I just finished up a rebuild. I think I may have it solved. My earlier estimate of the gap was too large, it was more like 1/8th" and I noticed that is "about" the thickness of the overlapping sections of the tranny case and the part of the engine where it snugs up against the case. I used the nuts to snug it up the last bit and it seemed to work, although I realized the nuts put a lot of force on the case. I did not have to turn the nuts particularly hard so it did seem that the tranny was closing up the gap without a huge amount of resistance. I may pull it apart again tomorrow morning just to make sure I have not done anything to the pilot bearing.
edit...Looks like Tiggerat and I posted at about the same instant...

Tigerrat · Tigerrat's Garage

Sounds good. You may have thought of this but the first thing I did after sliding the engine back under the car was hook up the slave cylinder and made sure the clutch felt right and I got disengagement. No problem but it made me feel better before putting everything back together.

88911coupe · 03-24-2009, 08:38 PM

good suggestion, in fact I was thinking of some way to manipulate the release lever even before I get it back in the car.

ZOA NOM · ZOA NOM's Garage

They should mate up without much resistance. I balance my tranny on one of those shop stools with the lever under the seat, and bounce it slightly to mate them up. I have had trouble when the teeth of the output shaft weren't lined up just right. Don't force it, just back it out and start again. Sometimes the throwout fork can slip slightly to the side and prevent mating.