C900 5 Speed Gearbox Rebuild - Nutcase Style

[peva]

Originally Posted by spg1

One thing I thought as well, a foundry should be able to pour a cast steel casing and since we already have good castings to take a mold from, it should be possible. Im surprised no one has done this.

You make it sound easy. Trust me it's not. I have some experience in this and it's a lot more involved than you think, and that's why no one has done it.

[S900t8v]

Originally Posted by spg1

This would make sense since with my 89 I can still drive it forward with no problems, but forget going in reverse. Too bad they didn't use two large bearings instead of one. One thing I thought as well, a foundry should be able to pour a cast steel casing and since we already have good castings to take a mold from, it should be possible. Im surprised no one has done this.

The weight of cast steel on the fasteners would be huge?

[S900t8v]

Originally Posted by nutcase

As I understand it, the 89- pinion bearing housing is as strong as the -88 8720732 Chilcast housing. Prior to that there was a sandcast unit (8720239 I think) and prior to that a die cast unit that is failure prone (possibly 8704215). Of those three the chillcast is the desired part. Not sure exactly when it was introduced, but the sandcast one came in some time in 1982 so not long after that as it wasn't used for a while. When older boxes came in for refurb the die cast housing was replaced as a matter of course (if Saab's instructions were followed!).

The larger rear bearing on the 1989- pinions give a longetivity improvement. Some have suggested however that some of the other bearings in the box get the chance to wear more in the mean time causing more damage than if the bearings are changed when the older style pinion bearings start to whine. Not sure on that one though



Not sure where you got that info from? You can mix and match like for like between boxes.

Nutcase I mean you can't mix cluster gears between different revisions. Yes you can use any from same revision 88 and earlier. 89/90. And 91+. You can't mix between these without changing gearset.

[nutcase]

Originally Posted by S900t8v

Nutcase I mean you can't mix cluster gears between different revisions. Yes you can use any from same revision 88 and earlier. 89/90. And 91+. You can't mix between these without changing gearset.

Sorry, misread what you put

[peva]

Nice to see your stuff on eBay Nutcase. Well done and good luck. Paul

[nutcase]

Trying to raise some pennies after spending far too much on tools and bits

[crwchf01]

Originally Posted by nutcase

Trying to raise some pennies after spending far too much on tools and bits

If they are what you need, you can NEVER spend too much on tools and bits, but may bust your available budget

[spg1]

Originally Posted by nutcase

Trying to raise some pennies after spending far too much on tools and bits

Can you give a link to your parts for sale?

[S900t8v]

http://myworld.ebay.com.au/nutcase_1...id=p4340.l2559

[peva]

Originally Posted by S900t8v

http://myworld.ebay.com.au/nutcase_1...id=p4340.l2559

It's actually this; http://www.ebay.com.au/sch/nutcase_1...&_trksid=p3686

[S900t8v]

close enough smarty pants

[nutcase]

Everything is up for roughly what I paid for it, with import tax etc. postage etc. except the cluster shaft which was made for me here

[crwchf01]

Going through the documents I have, the non-moly synchros are compatible with the 2nd-3rd gears. The moly coating was to prevent wear, but I think we kill pinion bearings long before this becomes an issue, at least for us conservative drivers.

[nutcase]

Conservative eh?

That is as I understand it

[crwchf01]

Originally Posted by nutcase

Conservative eh?

That is as I understand it

Don't miss shift and don't try to smoke tires at start is conservative in my book. Accelleration after full engagement and nice twisty roads ARE conservative in my book. Saab never had a really good scatter shield ever developed for truly aggressive drivers. For those who are scratching heads- check National Hot Rod Association rules and regs.

[nutcase]

True

[AJs900Turbo]

Is it possible to install the input shaft after installing the 5th cluster gear?

[nutcase]

No, the hub that the synchro fits over is in the way. Do you have the diff in? If not it's easy to remove the locking plate and then tap the layshaft out enough to free 5th.

[AJs900Turbo]

...good to know as I was planning on putting the diff and everything in minus the input and primaries. Now I know not to do that, thanks.

[nutcase]

Primaries can go on pretty much last of all, still need the side cover for 5th off to allow you to get it into 2 gears at once.