[Dr Rock]

Car has been feeling a bit rough through the pedals when at speeds above 50mph, also I can feel 'grinding/roughness' when slowing down for junctions/roundabouts etc, but there is no 'whining' in 5th, all gears select fine etc.

So I jacked the '89 up and put it on axle stands, front wheels and brake calipers off. If the brake discs are rotated by hand everything appears smooth. There is the usual slack in the diff as the gears mesh, the brake discs rotate in opposite ways as they should, wheel bearings, CV joints and inner drivers appear to be fine.

Start the engine and then put it into gear and I can hear 'noises' from the front. 'Noises' are not there when not in gear. Sounds like something rotating and occasionally clunking into something else. Definitely there in 5th, 4th and 3rd.

If I skooch under the car and put one end of a big screwdriver against the gearbox and the handle against my ear I can't hear any specific area that the noises are coming from. I can hear different things whirring in different places though.

The right hand brake disc rotates freely and the left hand one barely moves around, as though something is holding it back and then letting it move again, like if brake pads were dragging on the disc (which they aren't 'cos they are off the car..). If I stop the right hand disc moving the left hand one increases in rotational speed (which one would expect), but the right hand disc now bucks a bit in my hands, like something inside the 'box is dragging and then not dragging.

Is this supposed to happen and if not, what could be causing it?

Cheers,

Fraser

 

[Fred]

Hi Fraser,
I think the problem is more likely to be drive shaft or wheel bearing than something inside the box. One way to test would be to repeat the excersize with the drive shafts pulled out. Remove bottom ball joints and slide shafts out of inner driver. (You may need the angle grinder if the ball joint bolts have siezed).
Fred

 

[Dr Rock]

Hello Fred!

All the bolts on everything all come out fine (it is my car after all ) A couple of years ago I replaced the RH inner driver and driveshaft, and I kept the shims that were on the car...

I seriously doubt it is the wheel bearing. (Be nice if it was). The LH one has been replaced and I know what wheel bearings sound like when they go bad.

The LH driver and axle are fine (I had the axle out last weekend, plenty of grease and no ridging on the driver surfaces)

Sometime I'll get round to taking both the driveshafts out and repeat the test, although I have a feeling the result is going to be the same...

Thanks for replying though

 

[Basre]

Sadly it's likely your Pinion Bearing.. These are V common failure items.. and if your car has significant mileages V likely.
Trick is to fix it NOW rather than later as these have known to allow the pinion to shift, locking the Trans into a v expensive mess .. not doing much good for the car and driver either as this invariably happens at speed .

 

[Dr Rock]

Yeah, I thought it might be: I'll monitor how it goes. First of all I have to get the Beetle fixed and on the road to see about selling it, then I can spare the time for the Saab. It would be easier to buy another car, but cheaper to change the gearbox... (Good job I have a spare 'box that I know works fine )

 

[woywitka]

thats really too bad, my pinion bearings may be going south as well. i am starting to a high pitched noise at about 90km/h in 5th. i have never heard about them locking up while travelling forewards, just reverse. hopefully i can get another year out of my tranny, i already need a new turbo and/or possibly headgasket. good luck to you, seems like 2nd hand box is the best bet! how may km's on yours, i was told the pinion bearings are good for 89!

 

[Fred]

I don't see how it can be bearings on the pinion shaft if it's so obviously only affecting the drive to one side. Wheel bearing or driveshaft more likely. It could also be the smaller of the two bearings in the LH inner driver carrier, the bigger inner ones carry the diff so should both go around regardless of which wheel stops turning.
You could also try just changing the inner driver housing for a spare. I'm not sure whether shims should go with inner driver housing or with casing? they set diff bearing preload and crownwheel backlash. Any gearbox experts?

 

[Dr Rock]

I have to say I am a bit sceptical about the pinion bearing hypothesis as there really is no 'whine' in any gear.

I'll get round to taking both driveshafts out at once and see what that does, and I may change the LH inner driver while I'm there, as I have a spare one (when I did the RH driver I got the LH one from the scrapyard first, not thinking about the speedo drive...;oops: ). Given the state of the totally dry and rusty RH one when I got the car it could be the LH driver....

BTW which side are the differential teeth on? I think they are on the RH side... I just want to know so I can check the teeth while the driver is out. From what I have read, the shims go with the gearbox.

FWIW: Car has 165,000 miles on it.

 

[Fred]

Looking at the picture in the book the crown wheel teeth are on the rights, facing inwards. Best way of getting a look at them is to take off rear gearbox cover, which if you haven't got a drain plug (1989?) is also the best way of changing gearbox oil.

 

[Dr Rock]

So that means you would see the teeth if you took the LH inner driver out?

'Box has a drain plug: I don't do daft cover removal to drain the oil

 

[Basre]

Welll.. I don't blame you for being 'Skeptical' given the consequences.
But This is well travelled territory.. and..IF.. it indeed proves to be the Pinion bearing, the problem will worsen with use.. ultimately ending with a siezed differential.
Suggest phoning Eriksson's (Google) for a bit of Diagnosis help.

 

[Jezzadee]

Welll.. I don't blame you for being 'Skeptical' given the consequences.
But This is well travelled territory.. and..IF.. it indeed proves to be the Pinion bearing, the problem will worsen with use.. ultimately ending with a siezed differential.

We all know of the pinion bearing weakness in these cars, but everyone who seems to have experienced pinion bearing failure has reported a distinctive whining noise. Are there other symptoms that specifically point to pinion bearing failure?

I have to say it sounds a lot like a driveshaft type issue to me - worn on one side could cause an irregular 'rotating' noise, especially when pulling away from stationary.

Incidentally, do you mean Jorgen Eriksson? It's just that there are rather a lot of Erikssons listed in Google when searching for Saab gearbox.

 

[Fred]

Never done it, but I guess all you'll see through the LH inner driver hole is the rollers and cage of the taper roller bearing that supports that side of the diff.
I have taken the rear cover off (because I don't have the luxury of a drain plug), you have a great view of all the diff and could see how much end float is on the pinion bearings.

 

[cdaly]

Quick thread hijack here. ;oops:

My autobox has a pretty disinct whine at speed. It really only shows up around 60 and higher. When I got the car 2 years ago, I went to change the diff oil and discovered there was none in there! Filled it up with some heavy stuff and the whine is much reduced but still to be heard at speed. Now, given that it's an autobox, is it likely to fail catastrophically like the manuals? I'm inclined to think that, given that it's an N/A, auto, 'vert that it won't get the hacking that the manual LPT gets (well, actually, I know it doesn't get the hacking...) and so will impose less strain on the pinion bearing... Or am I going to be pulling engines again?

 

[Dr Rock]

What can I do with g/box now I'm here?

This is an update on the "Inner Driver with Parkinsons" thread:

Right now the '89 is up on the axle stands and the LH axle and inner driver are out, the oil is drained and the diff cover is off. I can't see anything damaged or chipped or broken. The LH driver seems fine, both in the cups and bearing wise.

Never having been here before I want to know what not to do. Can I rotate the RH axle by hand to rotate the differential or is something going to fall over? Can I start the engine and engage a gear or should I put the LH inner driver back in before doing that? (I'm thinking that would be a good thing to do..)

What can I measure whilst I can see into the diff? Pinion bearings? Any kind of backlash etc?

I am guessing the pinion bearings are the roller bearings around a helical gear shaft that comes out of the gearbox and engages with the differential?

Any help ASAP would help, as I would like to get the car back on the road this weekend

Cheers,

Fraser

 

[jefspg]

I would put the inner driver back in and then start the car up and put it in 1st or reverse gear and let the gearbox spin a little to try and narrow down the noise.

There is probably a little bit of oil left in it. I definitly would not rev the thing up or rev it too fast though!

If you don't hear the noise then maybe it is a wheel bearing.

 

[Fred]

As Jefspg says, Don't run engine without the inner driver holder in place, as the diff side bearing outer race isn't in place.
Yes ,you can see one of the pinion bearings.

Check:
Pinion:
That the pinion doesn't wobble about at all.
That there's no end float on the pinion.
Precis of bits of manual 'the gearbox output shaft bearings should be preloaded so that torque necessary to rotate pinion is 1 foot pound' This is without the diff in place, but the point is there should be no play in the bearings.

The backlash (ie slack) between crownwheel an pinion should be set to a number marked on the edge of the crownwheel, normally it says -17 which is 0.17mm or 7 thou. This is adjusted by moving shims from one side driver to the other, so that crownwheel is moved in relation to pinion. If it looks tight and tidy with no sloppy backlash, I'd leave the shim packs exactly as they are!

Did you try running engine with both driveshafts out?

Looking at the inside face of the left hand driver assembly you should see the working surface of the diff bearing outer race, the taper rollers in their cage will still be attached to the diff. This surface should be very smooth no pits or dents.

I'll try and find a picture!

 

[Fred]

This picture may help.
Item 8 is the outer race of the taper roller bearing that supports the diff. If either wheel is turning these bearings both turn.
Bearing Item 5 supports outer end of item 1, these bearings are probably the only thing 'inside' the gearbox thats stops turning when you hold one wheel still.

Try removing the speedo drive from the LH bearing housing (remove clip and lift out)

 

[Dr Rock]

Well both driveshafts are out and the nice and clean LH inner driver is back in. Started the engine and selected gears and I couldn't honestly detect any noise or vibration/roughness Which is nice. I can hear the clacking of the diff gears a little bit but I think I'll leave that (Don't want to make things worse).

I think the RH wheel bearing is a bit rough though :roll: so I am now off to Leic Eurocarparts to get a new bearing and I'll get it fitted on Monday... I'll do the CV gaiters as well while they are out.

Hopefully that will sort all this out

Tune in next week for another thrilling episode in the life on an old Saab...:cheesy:

 

[Dr Rock]

What could hammer a front wheel bearing?

Swapped the LHS inner driver and axle this morning on the '89 and it is much better now. Not quite there, but much better.

The replaced inner driver seemed fine: no ridging on the drive surfaces, bearings nice and smooth. I noticed the LH wheel bearing had been hammered on the inside by the CV joint: what could have caused this?

Anyone any ideas?

Cheers,

Fraser