930 transmission overhaul

[aseem]

Inspired by what I call Randys Ultimate gearbox thread I decided to open my 930 tramsmission and doing the work my self.

The problem is grinding of gears when shifting up into third under load. I guess the synchros needs to be replaced. I've known for a while that work needs to be done, and after first reading Randys excellent thread last year, and how he with the help of the PP community managed to do his own gear box, I thought that I can do that as well. But as time passed, I chickened out and when I this winter finally had the time to drop the engine, I was planning to send the tranny away.

But, I re-read the thread again, and then again, and now I'm confident that I can do this my self. Hopefully with the help of the PP community members. Right?

I droped the engine last week: Yeah, first engine drop, and my new jack

Now the tranny is off, and the nose cone of:






As yoy can see on the next picture, the nuts are not castle nuts, but have a collar that have been knocked into a recession in the axle. I assume I can just bend it back out, and undo the nut.

Can I use an impact wrench to undo the nuts? Right now the transmission is in gear. I remember from Randys posts, that the box could be put into two gears at once to lock the gears from turning. any ideas what I should do?



The clutch haven't been the best lately, so I was expecting to wind rubber bits from the rubber-disk 930 clutch, but it looks ok. New clutch is on the agenda as well.

Edit: Well, I guess I will have to take of the spring-plate before the condition of the rubber-disk can be determined,



I appreciate any help with this project......

[rob justice]

As you can see on the next picture, the nuts are not castle nuts, but have a collar that have been knocked into a recession in the axle. I assume I can just bend it back out, and undo the nut - use a small chisel and gently knock the locking tab out of the recess but be careful not to damage the shaft.
Once off - and I warn you the larger of the two is extremely tight, throw the nut away, dont reuse.
You need to lock the box, you can select 2 gears allowing this or use a locking tool.
I have a home made locking tool - made using the old clutch friction plate centre. If you need to borrow it, give me a shout and I'll post it over.
Its interesting to see the inside of a 930 box.
Keep posting and don't worry, you'll get plenty of help from this board.

[dyerkes]

Arnljot,

I am glad someone else is starting to rebuild their 930 trans. I am starting to work on my '86 911 Turbo, and I too am planning on rebuilding mine. Although I don't have any experience to provide you in this rebuild, but I will help to try to get answers to any questions that you might have. Keep taking photos and posting your progress.

Thanks,
David
1986 911 Turbo

[9dreizig]

hey guys I'm scavenging for a few parts for my 80 turbo and will be putting the engine that is arriving next week ( thanks Harald) and tranny. After that the plan is to drop my engine and tranny in my 86 turbo and re-build that in around Feb-March.. So any help you need I will try to find some answers for you as well...
T

[aseem]

Rob. Thanks for the advice. OK, so you advice replacing the nuts!

Do you have a picture of how you use the friction plate as a locking tool. I'm going to replace mu clutch anyway, so I can sacrifice the disk.

How do I lock the 930 box in two gears?

[rob justice]

Here's the tool I made up. Slides onto the input shaft and bolts onto the housing.
If you plan to replace the clutch, the tool then is almost free.
Its just the friction plate centre cut out and then welded to a piece of flat bar with a couple of holes drilled to line up with the housing.

[aseem]

Great, thanks.
Cool avatar Rob. I use that for my MSN Messnger profile.

David and Dreizig, I will post pictures along the way. Now that I know others are interested, I feel an obligation to take pictures. Its hard to remember some times, because I get so into the dismantling. Taking pics will force me to stop an think, also they are important documentation when its time to put it all together again.

Anything else I need to do before I undo the intermediate housing? The selector rod can almost be pulled out of the opening, but there is a lever (?) attached to it that is too large for the opening. I guess I can remove the housing first?

[David]

I'm subscribing to the thread. I'm just finishing up my 930 engine rebuild and EFI. I elected to leave the tranny alone for now. I'll come back later for the rebuild and gear change. I'll be curious to see how it goes.

[aseem]

OK, the nuts are off and so is the lever for the reverse gear. Revers gear is not visible as it sits in the nose cone. Ill take a pic later. I didn't manage to lock the tranny in two gears, but with an impact wrench it was no problem. I'm now working the intermediade housing to get it off, but so far its stuck. I'm using a rubber mallet and carefully smacking my way around. No luck so far...... Is there something else I have to do?

I also removed all of the starter ring bolts, and expected the ring an spring plate to come off. But they ar stuck. I did not use a cluch alignment tool when unscrewing the bolts, and something moved. But now its stuck. I have to come back to that...





A peek through the service opening:

[Jesset100]

aseem, I can't offer any suggestions on what to do but would like to know what kind of camera you are using. The pictures are clear and sharp. Good job! Oh, with what you wrote you are Inspiring me to do my trans.

[2garden]

I am just finishing my 930 engine and transmission rebuild project. The bad news is that the transmission cost almost as much in parts as the engine. I needed all four syncro rings, 1st 2nd and 3rd dog teeth hubs, and 1/2 slider. Changing just one element in the chain is a waste of money.

[dyerkes]

2garden,

Can you lend Arnljot any assistance with the issue that he is having. We'd certainly appreciate it if you could post any photos or "lessons learned" during your rebuild.

Thanks,
David

[aseem]

Jesset. My camera is a Nikon Coolpix 5200

[aseem]

Ok, so there is 10 bolts, not 9 :-)

The intermediate case came off nicely. Now, I have a general idea of what to do next, but I'd like to know if there are some issues that I have to be aware of before I procede.

I could really need som advice at this point.



From the other side:



1st and 2nd selector fork and loose gears:



3rd and 4th selector fork and loose gears:




1st and 2nd gear shift rod, with 3rd and 4th right behind:

[aseem]

I'm stuck and need advice!

I've removed three detents, for reverse gear shift rod, 1st & 2nd, and 3rd & 4th.

I unscrewed all the bearing retainer plate nuts, but one. As you can see from the picture, the nuts under 4th loose gear is blocked by the gear and I cant remove them yet. I think I need to lift the hole assembly before unscrewing them.

The problem is that last nut behind the two shifter rods. It's impossible to get at with a spanner. The only way I can see right now, is to remove 1st&2nd shift fork and shift rod.

Any ideas or suggestions? Please.

[dyerkes]

Aseem,

Looks like you continue to make good progress. You might want to email J. Walker, who frequents this website, to see if he can lend assistance. Also, you might want to take a look at this link for additional insight http://www.pelicanparts.com/MotorCity/marcesq3/TrannyRebuild.htm

Hang in there!
David

[aseem]

Yes, I was hoping that John Walker would pitch in.

Thanks for the encouragement. BTW your link isn't working.

[dyerkes]

Try this http://www.pelicanparts.com/MotorCity/marcesq3/TrannyRebuild.htm .

The problem was I ended the sentence with a "." period which was at the end of the link and that was included as the link.

David

[aseem]

Bump

[hobieboy]

I rebuilt mine last year with help from my mechanics... I replaced all synchros as well as re-geared the box but didn't touch the R&P or differential.

The way we did it is: mark the shift fork then unbolt the shift fork from the gears, then both shaft can be lifted up and the gears can then be "disassembled" from the shafts. You'll need the factory tool to separate the dog teeth though and one of the 2 gears (2nd I think) will need some creativity.