C900 gearbox girdle

A place for long term threads surrounding a specific project or SAAB build for motorsports or restoration
User avatar
Geoff
Team Turbo Troll Crew
Posts: 3840
Joined: Fri Oct 20, 2006 3:31 pm
Nickname: Geoff
Number of Saabs currently owned: 6
Location: Nude Humpshire

Re: C900 gearbox girdle

Postby Geoff » Tue Dec 27, 2016 7:56 am

Nice mockups! This is one of those projects that bounce around my head from time to time. The base geometries, many bolt holes, lack of published dimensions, adjustability needed at the diff carrier, and ability to fit around other parts of the car add up to an interesting challenge.

John's comment about dowel pins got me thinking about using shoulder bolts. Shoulder bolts have tight tolerances on the shoulder (similar to pins) so they could be used the way pins could be - to take the load between components - plus they would be easily removable. If you could get really precise measurements off your gear case you could potentially use shoulder bolts at some, or all, of the factory bolt locations. But as Dennis pointed out, due to manufacturing variances it might not fit a different case.
The kind of dirty that doesn't wash off :eyebrows:

User avatar
squaab99t
Posts: 1121
Joined: Wed Mar 28, 2007 5:43 pm
Number of Saabs currently owned: 4
Location: Shoreline Wa

Re: C900 gearbox girdle

Postby squaab99t » Sat Dec 31, 2016 1:39 am

Thanks Gary for sharing the pixs. I have never seen a failure like that before.
Looks like it ran low or without lubricants. SWAG

DeLorean
Posts: 1195
Joined: Sat Mar 31, 2007 9:54 pm
Number of Saabs currently owned: 9
Location: Pennsylvania, Forever!
Contact:

Re: C900 gearbox girdle

Postby DeLorean » Sat Dec 31, 2016 11:45 pm

It most likely did not run low on lubricant. The car does have a trans cooler, but it feeds and returns into the main case. I am rolling it around in my head now and am kind of wondering. My initial thought was that, well maybe, we had tightened those 3 bolts down to friction tight, but they were not tight against the soldered bolts in the direction of force? Perhaps the housing shifted at full torque and created an impact failure that blew the whole housing apart. I know it sounds kind if far fetched. But in Racing we have broken things where numerous Saab tech's have said "Huu, never seen that one before..." Any possibility we are starving the primary drive of lube?
Less brake more gas!

User avatar
Jon1
Posts: 272
Joined: Sat Mar 01, 2008 5:09 pm
Number of Saabs currently owned: 30
Location: Fort Edward, NY
Contact:

Re: C900 gearbox girdle

Postby Jon1 » Fri Mar 24, 2017 6:35 am

Dennis, any updates?
Jon
jon1
with many classic 900 turbos

User avatar
squaab99t
Posts: 1121
Joined: Wed Mar 28, 2007 5:43 pm
Number of Saabs currently owned: 4
Location: Shoreline Wa

Re: C900 gearbox girdle

Postby squaab99t » Sat Mar 25, 2017 8:00 pm

Jon1 wrote:Dennis, any updates?

Just new plates with the hole dia tightened up. I need to cad the paper dolls I made with the paper mock-up and send those to the laser cutter.
Day job and other family projects kinda puts a damper on the Saab projects.

User avatar
Jon1
Posts: 272
Joined: Sat Mar 01, 2008 5:09 pm
Number of Saabs currently owned: 30
Location: Fort Edward, NY
Contact:

Re: C900 gearbox girdle

Postby Jon1 » Sun Jan 14, 2018 6:20 pm

Found some more photos Image Image
Jon

jon1

with many classic 900 turbos

User avatar
squaab99t
Posts: 1121
Joined: Wed Mar 28, 2007 5:43 pm
Number of Saabs currently owned: 4
Location: Shoreline Wa

Re: C900 gearbox girdle

Postby squaab99t » Tue Jan 16, 2018 11:41 pm

Thanks Jon. Interesting add on double plate. I’m thinking it puts those bolts on the diff cover in bending and you can’t really up the diameter more than the 8mm. May need to study it some more to help understand the design intent.
The side plate with fins makes it look like a Moto Guzzi cylinder head.


Return to “Projects and Build Threads”

Who is online

Users browsing this forum: No registered users and 1 guest