UKSaabs

Yes - I think the lack of true route cause on many of these means that money could be spent unnecessarily...

Today's question:
3rd gear circlip/snap ring. The 9-3 has a thrust washer under the circlip to support it (looks like a later mod). Almost certain that the 9k doesnt.

Anyone seen a thrust washer under the circlip? This would suggest that either 3rd gear or the syncro hub would need to be a little different to give it space.

No. 7 on this drawing.

Ok - I just found this very random post directed straight at the 9k

Quote:
"At the same time upgrade your clutch shaft with parts 8747933, 90490955 and 90543241 with the parts being the shaft itself, new hub and a washer under the snap ring."

What is not clear is whether the later 8747933 input shaft is specific to the circlip washer mod or not... Either way, I want the mod to be on my car if poss.

Right - got both 9k and 9-3 boxes almost apart

Here are in the input shafts side by side: You can see that the 9k one has longer splines for the clutch so it would take a leap of faith to even try the 9-3 one on the 9k... Net: You can't use the input shafts from the 9-3.
The 9k one is on the right...



After a battle to get the bearing off the 9-3 input shaft, I got to the bottom of the differences in the 3rd/4th gear hub design.
You can see that the 9-3 one has a washer under the famous cirlip. To get this washer in, Saab have machined the syncro hub down 2mm (the washer is 2mm thick).
But they've also had to machine a slot in the input shaft - Looks like a double thickness circlip groove.

So - lets say you wanted to use the later circlip design you'd need to
1) Drop on the 9-3 syncro hub and brass support washer
2) Machine the input shaft another 2mm down - taking off spline material.

How much better is this design? Not sure, but change costs money and this was done by Saab for a reason.....

THe washer...


9-3 support washer groove machined out of hub:



Anyway - the good news is that the actual 3rd and 4th gears are completely interchangeable so I can get my shorter 3rd gear from the 9-3 fitted if I want to.

Bad news is that the teeth on the 9-3 3rd are smaller than the ones that (were) on the 9k third.... does smaller mean weaker?

Next step : pull out the final drive and compare output shaft and crownwheels...

Rebuild-how hard can it be? Very do-able but to set things up correctly don't you need a specially ground bearing race to set up the diff bearing preload?

2290aer wrote:Rebuild-how hard can it be? Very do-able but to set things up correctly don't you need a specially ground bearing race to set up the diff bearing preload?

Good point -

Diff bearing preload is done by shims in the driveshaft stub housing. You measure bearing depth and axle casting depth then calculate the shims you need.
Output shaft preload: Depth gauge on end play, then add X degrees onto the end nut on 5th gear.
Input shaft preload: Depth gauge : Shim up until end float is 0.1mm (need to double sheck value)

My current view is that as long as everything is correctly seated and the build is 'correct' then the final result is maily dependant on a decent effort on the 3 items above. Time will tell!

Oh - I can also tell you that the 9-3 output shaft is identical to the 9000 one. We knew this already but I want to be sure for my own sanity.

Next step: Compare the crownwheels from the diffs. I need to get them off first.

sorry but finer =weaker

look at the torque ratings of the two gearboxes

also look at the teeth on the quaife gearset ......

I do agree - Just want to be sure that I don't jump to conclusions as there are always little nuggets of information floating about..... What if the 9-3 3rd gear is a much stronger material with much better hardening? This seems not to be the case but you never know.

Onwards!

Crown Wheel analysis:

Both the 9k and 9-3 4.05 crownwheels are the same - I checked the offset with the dial gauge both front and back sides and they match.

In summary:
Lets say you have any old baggy 9k box. You can dump the entire contents of a nice low mileage 9-3 Box (in this case an FM55-503) into it with exception of:

1) Input shaft
2) 3rd/4th gear syncro hub. (Easy mod to the 9k shaft if desired)

This also proves that the 9-3 box is really stronger than the 9k unless the casing is a little better (visually I don't see anything significant enough to help)

The nice part is that where the 9k 4.05s are getting (very) rare, there's a nearly endless supply of 4.05 and 3.82 9-3 and 9-5 boxes from which to grab the perky final drives from...

Note: left hand crown wheel is sitting at an angle! They are the same...

I am following this with interest as one of the jobs I have never tackled is a gearbox re-build. Some how I see playing with gearboxes far more demanding than re-building an engine - don't know why - maybe because I haven't tried it - it is when you start talking of preload that my eyes glaze over. Maybe I should acquire a spare box just to take a look. I hope I don't need it but the box in my '94 GM 900 is just in case................?
Mike

It appears to be like a big pile of Lego that at it's centre are 2 shafts and a stack of selectors. The hardest part so far is getting bearings to move / come apart and that's due to a lack of special tools.
If you can get it rebuilt for a reasonable cost and you are not consuming gearboxes then it will be better value to get someone to do it I reckon. I found it was always vastly cheaper to take the box to the box builder too (and take it out of the car yourself)
I also suspect that the first gearbox rebuild you or I do will not be as good as the 2nd....

One other observation on Crown Wheels/ Pinions:

I note that the 3.61 pinion appears to have the SAME tooth size as the 4.05 pinion. Based on the discussions, the smaller 4.05 pinion should have bigger teeth. Although maybe only 10% bigger.
This suggests that the 4.05 CWP is not as strong as the 3.61. There is no real life evidence to suggest this that I can find.

I think the early GM900 has the 9k style 3rd/4th gear hub and 9k 3rd gear.

Interesting about the crownwheels - sounds like 3.82 would be almost perfect........3.61 is a tad too long and 4.05 sometimes seems a bit on the short side.

Anyone compared a set of 9000 longblock internals to the shortblock stuff? The longblock boxes are now just a tad scarce

Right: Starting to gather more bits: The Bearings are the hardest part and thanks to Mark D and Stuart for this:

You can also source SKF parts but the Timken numbers were easier to get.

BEARINGS:
4 input / output shaft plus pair of Diff bearings: £128 inc. vat Source: Bearing King

1) Output shaft bearing top 32008 TIMKEN

2) Input shaft clutch side 44649/44610 TIMKEN

3) Input shaft top bearing (edited to fix previous error):
30206/27 TIMKEN This is made from: XFA30206M & Y30206M
This seems a little harder to get so also consider 90490868 saab part which gets you a box with the same as above.

4) Output shaft pinion end NP806712/NP326808 TIMKEN

5) Diff Bearings 32010X TIMKEN

SAAB Direct Parts
New Crush sleeve 55352125
Output shaft nut 12755195
End gasket 90541166 (pricey- 15+vat but my current one is gash)
3rd Needle bearing 8719163
4th Needle bearing 90490857
3rd gear circlip 90511109
4th gear circlip 90511077
5th gear circlip 90511085



Total Saab Parts: £60


Onwards.....

Have you replaced any of the bearings with new items Phil ?? if so where did you get them and do you think its cheaper to source them from somewhere other than a main dealer ??

BEARINGS:
4 input / output shaft plus pair of Diff bearings: £128 inc. vat Source: Bearing King

Output shaft bearing top 32008 TIMKEN
input shaft clutch side 44649/44610 TIMKEN
Input shaft top bearing 30206 TIMKEN
ouput shaft pinion end NP806712/NP326808 TIMKEN
Diff Bearings 32010X TIMKEN

So - The total of 6 bearings including 2 diff bearings would be about £180 from saab as far as I can see.
I messed up assuming the diff bearings would be cheaper not via Saab as the current spec 12788353 bearings are only £12 each inc. Vat... VS. £20 each inc. Vat for the Timkens...

The other 4 bearings are plenty more expensive from Saab though (nearly double the price).

Net: Get the 4 input and output shaft bearings from Bearing King but compare diff bearing prices carefully.

Ensure the Saab diff bearings are a good make before purchasing though.....

32010 Budget Brand
d: 50 inside
D: 80 outside
B: 20 width
£8.41
ex. VAT

32010 Timken
d: 50 inside
D: 80 outside
B: 20 width
£16.83
ex. VAT

32010 X/Q SKF
d: 50 inside
D: 80 outside
B: 20 width
£19.08
ex. VAT

The bearings on my diff were Timken P900 series and are rated as heavy duty over standard bearings....hard to come by though.



http://www.timken.com/en-us/products/be ... /P900.aspx

Thanks Mark - I'll need to check what the 'Saab' ones were last time.

And note that I pasted up the wrong price for the Timken set: It was £116 inc. Vat and delivery for all 6 bearings. (Not £128 as earlier).

So the 3rd gear needle bearing part I had was wrong. It's not 8719163.

It's 8731150 and this has been superceded by 90490856 as used in the GM900 and 9-3

Just for a clarification on Quaife LSDs for the 9k;

There are 2 types: '94/'95 and '96 onwards (same as 9-3)

The earlier one as an offset on the diff. This is because the crownwheel has an offset on it. Even though the crownwheel tooth position appears to be in exactly the same position - it looks as if the output shaft and pinion should also match.

So - if you are picking boxes for your donor, you need to be careful and check you have the right one.

On everthing I can find: The early style offset is found where the box serial number does NOT begin with 'M'.The later style non-offset is found where serial number does begin with 'M'
This saves you taking a box apart to find this out.... like I have just done

Ok - Thanks to Robert I now get the serial numbers. So for folks trying to Quaifes to 9ks or GM900/9-3. (an issue if you have a box but the year of the car is in doubt)

EARLY Quaife with the OFFSET CROWN: QDH4J (9k) QDH2J (GM900)
All boxes with up to --N55112 serial number - up to late 1995. This excludes Mxxxxx which is after N

LATE QUAIFE with straight CROWN: QDH6J (9k) QDH5J (GM900/9-3)
All GM900/9k boxes N55112-- onwards - late 1995 on. This includes Mxxxxx
All 9-3 boxes as they coame in 1998

9k Special:
There appears to be a very late 9k input shaft that has the 3rd gear circlip support washer mod in place.
This would be Serials M65653 and onwards. (again where N is before M so excluded).
I would guess that this is the input shaft that Mark D has in his pics - nice little tweak that was carried over to the 9-3.


So - in the search for final drives and parts with the serial numbers above:
9k gearset: 3.38, 1.76, 1.12, 0.89, 0.70 Chunky longer 3rd, short 5th
9-3 gearset: 3.38, 1.12, 1.18, 0.89, 0.66 Shorter finer 3rd, longer 5th


FM51-101 : 4.45 : 9k Offset crown: 4.45: 9k gearset. Edit: Looks like the base 2.0i model did run to 1998... This means it should be available with late crownwheel although that's a rare car to find.
FM53-501, 503: 4.45 : GM900 or 9-3 : 9-3 gearset. (surprised at this on the GM900)
FM54-003 : 4.05 : 9k gearset: 9k only.
FM55-503, 507 : 4.05 : 9-3 gearset: GM900 and 9-3
FM57-503,507: 3.82 : 9-3 gearset: GM900 and 9-3
FM57-101: 3.61 : 9k gearset: 9k only

As you may have noticed the FM5x number is an exact match for the total final drive in 5th gear. That way you know what gearset is in the box based on the final drive and FM number. Saab just juggle the 0.66 and 0.70 fifth to get the full spread above.