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Discussion Starter · #1 ·
After being away from saabs for a few years, I'm back! Got myself a 99 9-3 with a weird transmission (5 speed).

It makes a nasty rattling noise while sitting @ idle, which gets worse with the A/C on, or pulling away from a stop (under load).

However, I've noticed that while sitting in neutral @ a stop, the noise goes away when I step on the clutch.

Initially I was thinking throwout bearing problem, but I've got a receipt from the PO that shows a clutch job ~10k miles ago (which I would hope includes a TOB).

Some research shows that it might be more likely that it's the input shaft bearing inside the tranny. I guess that noise might be the input shaft flopping around, and when I depress the clutch, the TOB centers & supports the input shaft (as the shaft bearing is supposed to do).

Does this sound like a reasonable diagnosis? Anyone ever replaced this bearing? Or am I better off finding a "new" junkyard tranny?

Thanks in advance
 

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As I recall the input shaft bearing is transmission EXTERNAL, that is to say, during the clutch job, it can be easily accessed... This is an unusual feature, but a good one, IMO.
 

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Discussion Starter · #3 ·
cool! that's great news. also great news that the bearing is only ~$6 at rockauto (although I gotta make sure it's the right one first...)

would it be #1 on the attached diagram?

In the following tranny rebuild instructions, they don't remove the input shaft bearing until the case is split open... is that necessary?

http://www.thesaabsite.com/9000/9000transrepair.htm

I'd appreciate any advice from someone who's done this before
 

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How nasty is the noise? Can you hear it sitting in the driver's seat? Do you have to be next to a building to hear it?

Reason I ask is that I've had such a noise for about 100K miles (since 50K) ... advice I originally got was that it was the throwout bearing, so I take it easy on it by not standing on the bearing at stop lights. It's hung in there all this time with no issues.

If it's worse than that, maybe you should repair it. There have been a couple issues with bad pressure plate fingers causing noises like the one you mention.

Either way, I'd have a throwout bearing ready to go in if you are pulling the tranny, no matter what was done before. No sense doing all that labor and then finding out it wasn't the input shaft bearing.
 

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Discussion Starter · #5 ·
It's pretty nasty. Easily heard from the driver's seat with the window down. When next to a building it's even more apparent.

Does your noise go away when stepping on the clutch?

It seems that if the TOB were bad, then it would ONLY make the noise when stepping on the clutch (when the TOB is loaded). But I suppose it could happen either way. Maybe the TOB has some slop & rattles against the pressure plate when the clutch is disengaged, but the slop is taken up when stepping on the clutch?

Also, I verified with the shop that did the clutch job that the TOB WAS replaced when they did the clutch (~10k miles ago). I would hope the TOB would last longer than that, which is why I'm thinking input shaft...
 

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You know, I don't trust too many shops and what's the chance that they reinstalled a known worn out transmission when they did the clutch job? The only way to tell is to take a photo of the tag on the transmission before taking it to the shop. I'm not saying that that's what happened, but if anyone has someone change the clutch, make sure to take a photo of the transmission tag before taking it to the shop, then compare it before you leave... Ron
 

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Mine does go away when you step in the clutch, which is why I am thinking it's the bearing just kind of loose in it's holder or something. But, since it is disengaged, it could be something else. Mine is more of a "what's that?" than an annoyance full time.

I wouldn't be surprised if yours was the pressure plate with a loose finger. I wouldn't think a bad input bearing would cause a rattle, but you will have to get in there I guess.
 

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Discussion Starter · #8 ·
I've met the owner of the shop, and had him charge the AC system after I replaced the compressor. He seems to be a pretty honest & straightforward guy. Also, the previous owner was a personal friend of his, so I doubt that he did a [email protected] job on the clutch. I just got off the phone with him and he said they definitely replaced the throwout bearing.

He seems to remember some slop on the input shaft & in the differential section of the tranny.

So i suppose I should start looking for a backup box if/when this one goes...

thanks for the advice fellas!
 

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One of the Saab techs that hangs out on the web has an "always replace the input shaft bearing" policy when he does a clutch. This might be why.
 

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It could be the clutch disk it's self. I know that some guys have had promblems with dodgy disks that rattle. Mainly performance disks tho.
 

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Are you certain it's the trans? Maybe get it up on a lift somewhere and get under the car while it's running to be 100% certain. More than likely it's the trans or something associated is rattling.
 

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My 9-3 has done this pretty much since I replaced the clutch 2 years ago (stage 3 clutch disk with Viggen PP) and I attributed it to the disk, because I did replace the bearings, seals, and changed the oil in the trans... I guess I've just grown used to it which may be a bad thing.

My reasoning for attributing it to the disk is because it is a puck type disk rather than a solid ring disk. I could be completely off in my theory, but if I redid my clutch I would definitely go solid disk, because I am having one bugger of a time teaching my wife to drive my 9-3 :confused:
 
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