AWD SAAB using Subaru driveline.

[Jordan]

I agree with TrailingThrottle too, another variable though I think is the shock loading difference between tarmac and gravel. You definitely can't bang in gears no matter what surface you're on and nobody likes to cringe when their car hits full boost. For right now I think the stock trans will do just fine for what I need it for, but for two reasons I'd consider a competition gearbox with dog engagement (meaning bigger gears).

1. Strength
2. Better gear ratios

If I had a hi-po car I would seriously start saving up for a competition box. 900s in the next few years are going to get harder to find, and the pain of swapping them gets old fast.

[allessence]

For starters, I don't slam gears, pull hole shots, or make the tires spin on purpose.

I've seen many 25-30 gear boxes that have failed in regular Turbo/non turbo cars and have seen them go with many different failure modes depending on year of manufacture.

The biggest problem as pointed out is supplies are going to start running short and this means pricing is going to go up.

I'd call myself a smooth driver that really tries to treat the car/transmission with the utmost respect since I have rebuilt so many not including all the ones for myself in the last 20years. So, I fully agree with a racing gear box simply because it would be one last concern that is on my mind. As would switching to something more robust.

So, who is into buying a HP box? Could there be enough interest to get the ball rolling?

Also, I believe the last 2 failures involving the tin/syncro spring wouldn't have happened had I replaced those components to begin with. But again most boxes I have rebuit are the 88 and earlier boxes.

Also, in regards to oils. The Royal purple 10W-30 oil is working much better than the MAXgear 75w-90. I believe the notchiness is do to residual maxgear left in the trans during the change. I will do 2 more oil changes over the next 3k-6k and will keep things posted. Maybe I'll post a trans oil post.

[Ram85SPG]

I'm following this thread with interest since I recently started hearing the dreaded pinion whine in my '85 SPG. I'm hoping to keep it going for a little while longer while I save up for a moderately "strengthened" gearbox from Scanwest, which seems to be the best option in the states. Not to hijack the thread, but any experiences with these?

I have some modest performance upgrades (implemented and planned), but I definitely want to spend on the transmission first if it is warranted. I think there is definitely interest in a high HP box, haven't we all seen countless threads in the forums about folks trying to improve the stock gear box? The main question I guess is how exactly would one get the ball rolling?

[airsweden]

The main question I guess is how exactly would one get the ball rolling?

Money makes balls roll! At least thats what Geoff tells me.

[Ram85SPG]

from what i gather, something like $3K seems to be the price point that people are willing to pony up for a "strengthened" gear box. the question is, what exactly would this buy you, and in what quantities? i think scanwest charges around $3K for a gearbox with the works (shot peened/cryo'd gears, new 3rd gear i think, newer case, diff cover, bigger pinion, etc etc). i think luke mentioned in another thread that having bigger gears cut would be in the range of $3500. i'm no transmission expert, but i seems like bigger gears would be much stronger, with some street driveability sacrificed? how hard is it to drive without synchros?

[Jordan]

I think what we are talking about is not a "strengthened gearbox" , which may help bandaid many of the weak points of the trans, but what Trailingthrottle is saying, what Jennifer and others have proven is that in the end, no matter what pinion bearing you have, no matter what your gears are treated with or what case you use, the gears themselves are being pushed too close to their failure limits, and nothing is going to fix that besides bigger stronger gears. That said, it's not a cheap part to replace even in decent sized quantities. According to Luke just a replacement sychroless gearset is looking to be around 3500.. and then that would have to be reinstalled. It is still in its very early stages, but I hope something will come of it.

As for drivability of a dog box, I have no personal experience, but TrailingThrottle commented on it in the "I blew my trans thread". Basically what I have heard is that it makes upshifts easier and faster but downshifts require more precise rev matching, etc. Since the gears are still helical (at least at this point), there should be no increase in noise.

[Geoff]

I think that $3500ish figure is for a gearset with straight cut gears. The helical gears would require special tooling for each gear that would be many thousands each. (?)

Money makes balls roll! At least thats what Geoff tells me.

Whatever it takes to get a nice tight box!

[Ram85SPG]

I just looked at the Speedparts gearset (helical gears), and it's 38.5 SEK. At the current conversion rate, that's, get ready, $6000+. Sweet jesus those must be some strong gears! I can't translate the page, so I don't know the specs. Anyone know about these?

[Crazyswede]

the dollar has been losing value. A few years ago that same gearset was about $4000 USD.

[Geoff]

I just looked at the Speedparts gearset (helical gears), and it's 38.5 SEK. At the current conversion rate, that's, get ready, $6000+. Sweet jesus those must be some strong gears! I can't translate the page, so I don't know the specs. Anyone know about these?

I found this translation on another forum:

Gearbox Saab 900 79-93
Gearing kit is manufactured to be able to be used with the stock "endgear?"(9:35/9:33).
Gearing kit is close-ratio and is manuvered with ease (type dogring).
The gearbox is sold only "put together"

Included in the Gearbox
Gear-kit, new bearings, new primary(29/32),2 steelfingers, strengthen "gear-mover?", rebuilt "gear-fork?" 3:rd-4:th gear, "numb cylinder?" to pinjon bearing, new strenghtend lid to the differential,
Casing & bearing to top primary gear , Streanghtend inner drive joints, Bearing width extended from 20mm to 40mm in the gearbox casing.
Mounting and "schimsning" of gears.
The gears are calculated after torque and a specific RPM after a rallycrosscar as follows:
Gears should handle aprox::
1:st 450nm (331ft-lb)
2:nd 495nm (365ft-lb)
3:rd 540nm (398ft-lb)
4:th Will last until the Primary chains brakes
Max 400hk (400hp)

Streanghning of Gearboxcasing can also be done.
Different types of primary gears can be manufactured.
Strenghend "cluch axis" can be manufactured.

Translated from:
http://www.speedparts.se/prod/sp_vxl_900_79-93.shtml



So they make a custom primary instead of doing a custom R&P (it does the same thing). And can have other custom primaries made.

[Jordan]

It sounded to me like the gearset is different to use the stock R&P but they can make custom primaries... hard to tell though.

$4000 dollars for a completely rebuilt trans will all the above mentioned parts would be a pretty fair price IMO.. compare that to the Ericsson rebuild , using only stock parts for like 2500-3000 last time I heard. Too bad the dollar sucks ass. That and shipping.

[Geoff]

Some more info on the Speedparts gearset

Here are some calculated speeds for gearboxes at 6K rpm using the large 205/55/16 tires that Speedparts used for their calculations

Gear.....Stock 45612.......My Quick Ratio Gearbox......Speedparts Gearset*
1.................29mph................25mph...............................46mph
2.................50mph................43mph...............................63mph
3.................76mph................66mph...............................81mph
4.................105mph..............92mph.............................101mph
5.................132mph............115mph

*using special 29/32 primary drive

Note how my 2nd = Speedparts 1st, my 3rd = Speedparts 2nd.

In reality I use smaller tires so my speeds are slightly lower.
I'm using a GM45612 box from an '89 with a 0.97 primary gear ratio (31:30)
1st is too quick but I use it to get up the car rolling. 2nd gear is perfect for rallyx especially because I can take my car up towards 8000rpm and hit mid 50mph range. 3rd is pretty good in relation to 2nd. 4th is a little too far away from 3rd. When you get up to that speed range in a rally car you want to have a little more choice. 5th isn't too bad in relation to 4th. Looks like Speedparts has a decent set. Probably the same as the S&R gearset with 6:31 R&P

What could also be good might be something like this:

Gear.....Speed
1...........40mph
2...........60mph
3...........75mph
4...........95mph

Or maybe even quicker between gears with a lower top speed.

It would be nice if we could put these parts into a 5spd box and have a longer 5th gear for transits.

From what Groo has told me is that the S&R gearset is really long which is why you need the R&P. He said that 1st would go to about 100mph without it. Jorgen told me that the quicker ratio R&P will put less stress on the box, so maybe that's why SAAB built the works boxes that way. I think the S&R gearset with the R&P might be a similar ratio to the Speedparts setup...

Of course the above info is for rally cars. For a street car the Speedparts gearset with one of the stock primary drives might work well.

edit: I messed up a calculation and had the speeds wrong for the quick ratio box I use. I also added the speeds for a stock 45612 box.

[Geoff]

It sounded to me like the gearset is different to use the stock R&P but they can make custom primaries... hard to tell though.

$4000 dollars for a completely rebuilt trans will all the above mentioned parts would be a pretty fair price IMO.. compare that to the Ericsson rebuild , using only stock parts for like 2500-3000 last time I heard. Too bad the dollar sucks ass. That and shipping.

Yeah, it comes with a custom primary set 29/32. They can also make other ratios. The website lists speeds in kph with "special" 205/55/16 rally tires using numerous primary sets.

If I had $4000 when the cost was $4000 I would have bought one. I was pretty tempted to just put it on a credit card and pay it off over time but I didn't do it. I should have!

[Jordan]

the 32 cog gear (I think it is number 8?) is custom?.. its just european if I'm not mistaken. Or I could be mistaken

edit: Yup I'm mistaken

[Geoff]

I think the 32 you're thinking of is the gear on the other end of the chains. A #7 is 32-25 (.78), I forget what the other gear on a #8 is. The Speedparts primary is 29-32 (1.10)
The gears don't flip top to bottom, unfortunately