88> brakes in a 99

[99Super]

What's the story with 88> front hubs on the 99? Do I just re-use the 99 axles, some other axle combination or is there machining involved.

John

[Jordan]

Well normally, if you use the 99 axle with the 900 outer that works fine on pre-88, but the axles for a pre vs. post 88 900 axle are a few mm longer, so I'm not sure what that would do to the length in the inner driver cup. Might be ok, but there is only one way to find out :)

[DrewP]

I had to cut one of my halfshafts about 1/2" so that it wouldn't bottom in the inner CV joint with suspension travel. I believe I used all 900 parts tho, 900 hubs and uprights, halfshafts, inner and outer CV's and a 5-speed.

I cut it down on a lathe so it was easy to put in another snap ring groove to retain the tripod joint. I believe I slid the tripod as far onto the splines as it would go, and that's where the new snapring groove went, then cut off as much from the end as I could.

[Chouan]

I have a set of fronts 99 inner to 88 outer and an 4x108 900 rear axel. All of this was run successfully on a 99. I changed my mind and will not be using this setup on my project so its all for sale :-)

[Crazyswede]

It seems to me that fitting 900 axles in a 99 is as easy as turning one end down the necessary amount and then just grinding/cutting a new slot for the cir-clip

[99Super]

Yeah, I don't need to use the 900 axles. I've set the tranny up to run the early companion flange so the real question is,
does using to 99 axles eliminate the machining need, or maybe the simpler question is, "is the axle length the same on pre and post-88 900's?"
If it is, I'll just swap in my 99 axles and be done w/ it.

When I took Frank for a drive the other day, I discovered that the 87 brakes have gone from fair/marginal to marginal/unacceptable.
The car is that much faster on T5.

John

[Jordan]

It's in the bentley manual, they are different lengths but I can't remember exact number, 6mm? Swedesport and I just went through this with his notchback.

[99Super]

Thanks! I'll check that when I get home.

[Crazyswede]

I think the length issue only comes into play with the passenger side axle. Years ago when I put a set of 900 axles in my 99 I was able to get the drivers side in without issue and it worked fine. The passenger side went in but would bind on tight turns. I was able to run it the entire time I had the car but it would have benefited from being shortened.

[SwedeSport]

There were a few different lengths... and yes the difference is 6 mm.

I believe the changeover happened when they went from solid to vented brakes.

If you use the longer one in the early hub/rotor setup I believe that the tripods could bottom out in the inner driver. And if you use the short ones, in the later spindles, they get closer to the outer edge and risk falling out and put an incredible load on the driver cups.

[hutch]

Sorry to hijack the 99 discussion, but what about an '85 axle in a '90 hub?

I've swapped hubs on my 85 notch to '90 hubs for the 4x108 wheels and didn't notice any any huge issues. I had thought about swapping in the '90 axles to match the hubs but they have the ABS ring on them and I didn't feel like knocking those off if I didn't have to swap the axles. I haven't driven it since so maybe I'm just not noticing the problem but should I switch to '90 axles as well or is it just a problem if going the other way ('90 axles into 85-86 hubs)?

[99Super]

Hutch,
As long as you use the axles supplied w/ the hub, there is no issue swapping hubs on any 900. I put 89 hubs/rotors w/ 9000 calipers in my now ex 86 SPG. They work great! However, as the Bently states, the 88> axles are 6mm longer. Did you use the early axlers because of the tripod bearing?

My problem is that the 900 is a bit wider than a 99. Does anyone know exactly how much?
I'm starting to think the pre-88 axles my work with minimal mods.
88>too long, 99 too short, 900>87 OK? I'll probably pull some axles apart this weekend and measure them if I get the time.
I really need to get the 76 hatch to the scrap yard asap.

John

[hutch]

Yeah I didn't use the 90 axles because I didn't believe they fit into the earlier (pre-86 I think?) transmissions, at least without swapping more parts. I had thoughts of swapping in a later engine/tranny down the road so I figured I'd swap in the 90 axles then. I can certainly still thread the big axle nut onto the axles with the 85 axles in the 90 hubs so I never assumed there would be a problem. But like I said I still haven't driven it and from what Crazyswede wrote maybe I'll run into issues when I do unless thats just for 99's?

Not sure if this is exactly what you're looking for, but maybe check out these sites on 99 vs. 900:

99
http://saabmuseum.com/en/technical-spec ... fications/
Dimensions:
Wheelbase 247.65cm/97.5″
Front Track 139.7cm/55″
Rear Track 140.35cm/55.25″

900
http://saabmuseum.com/en/technical-spec ... fications/
Dimensions:
Wheelbase 252.5cm/99.4″
Front Track 142cm/55.9″
Rear Track 143cm/56.3″