Engine/gearbox separation advise

bjmullan · Post by **bjmullan** » Sun Oct 21, 2007 10:01 pm

During our engine swap today we ran into a problem when it came to splitting that engine and gearbox. We initial thought that we had a 1969 setup which meant that the gearbox would just pull off but it soon became clear that this wasn’t going to happen. Further investigation revealed that we had a 1970 setup and the Haynes manual described using 3 M6x 12mm socket head screws with appropriate spacers to release the bearing tension before removing the forks. First question is where can I get such screws and spacers and secondly why do I have to rotate the bearing by 90 degrees before the removing the forks?

Any help/advise would be welcomed

johnM · Post by **johnM** » Sun Oct 21, 2007 10:11 pm

Brenden if your gearbox is a 911 gearbox rather than a 901 it should be just a case of getting a screwdriver in to turn the clutch release bearing around 90Deg if you fiddle with the clutch lever you should be feel/hear the bearing click out of the fork.

Regards

58A - 71E · Post by **58A - 71E** » Sun Oct 21, 2007 11:11 pm

Personally I have found on my 911/01 that applying pressure by hand to the lever takes enough pressure off to allow you to rotate the throw out bearing with your finger through the access holes without having to use a screwdriver, the gearbox will then virtually fall off so watch your toes

As for the Haynes manual...

Barry · Post by **Barry** » Mon Oct 22, 2007 9:39 am

Ditto: wot dem sed

.

At Silverstone I spent many a happy hour trying to reverse the above process on Phil's (Early911) 2.2, which had spun the release bearing from the fork

.

Get a torch in at the hole near the top: you can see the bearing in there is hooked up on the release fork, and it should become clear how to unhook it without the aid of the Haynes spacers

.

BTW, keep the gearbox loosely bolted up to the engine until you've unhooked the bearing, otherwise the engine falling away from the box sometimes keeps the tension on the bearing, making it harder to release.

bjmullan · Post by **bjmullan** » Thu Oct 25, 2007 10:42 pm

Hi guys I hope to look at this either tomorrow or over the weekend and to be honest I'm not 100% sure on how to rotate the bearing through 90deg? Is it on it's axis of rotation or some other axis. Anyone got a picture of what it looks like separated might help.

johnM · Post by **johnM** » Fri Oct 26, 2007 1:19 am

Brendan

The release bearing has the input shaft to the gearbox running through the centre of it. The clutch release fork is clipped into the release bearing; the bearing has 2 ears opposite each other these ears locate onto the clutch release fork. What you are doing is rotating the release bearing through 90 deg so that the 2 ears disengage from the end of the clutch release fork.

Hope that helps

Regards

bjmullan · Post by **bjmullan** » Fri Oct 26, 2007 7:52 am

John your a star, now I understand

58A - 71E · Post by **58A - 71E** » Fri Oct 26, 2007 9:22 am

Brendan, hopefully this will help -

Take the pressure off number 2 so that you can rotate number 8 90degrees, should come straight off

bjmullan · Post by **bjmullan** » Fri Oct 26, 2007 11:44 am

What a simple job once you know what you are doing. Thanks guys

bjmullan · Post by **bjmullan** » Sun Oct 28, 2007 10:34 am

Our confusion was that when we looked at the release bearing on Mike's 2.4 engine it didn't make any sense to rotate it at all! The next question is what do I do next? From looking at the assembly I believe that both cars are fitted with the larger 225mm flywheel so is it just a case of swapping the clutch assembly or is there more to it?

Picture of my release bearing clearly showing the tabs for the fork to slide off from.

The clutch release fork and transmission.

And the release bearing from Mike's 2.4T engine.

Nick Moss · Post by **Nick Moss** » Sun Oct 28, 2007 1:25 pm

The 2.4 uses a different cluth release system, which makes it much easier to separate the gearbpx. You should be able to fit the earlier clutch and pressure plate to the later flywheel.

johnM · Post by **johnM** » Mon Oct 29, 2007 12:10 pm

Hi Brendan

you can swap just the clutch release bearing or swap the whole clutch/ pressure plate, your pressure plate is aluminium and better than Mikes cast one. So I would swap the aluminium one over, you will need a clutch alignment tool or you can make your own with a bit of bar turned down to the right size, no need to have splines on it.

Kind Regards