The alternator pulley seems to be going a bit noisy on me. I'm assuming there's a bearing somewhere in there. Can I change just that, or should I go for the rebuilt alternator unit?
I looked at a few rebuilt alternators on the web, and they don't seem to come with the pulley attached. Is this normal?
Cheers, Ben
Didn't find your answer? Ask the community — no account required.
F
Fred W
Much more likely to be one of the idler pulleys. These have a history of going that way, alternators do not.
B
Ben
Cheers Fred, I appreciate that.
I actually had the car in for other work and the mechanic showed me the play in the alternator pulley. So back to my original question, is there a way to replace just the bearing in the alt. pulley or the pulley assembly altogether? Or, do I have to get a rebuilt alternator?
I've been pretty handy with fixing my own Saab so far, I can probably do this alone, once I figure out the way to the part that needs changing.
Not to be nasty, but it seems this days that garages really prefer to change entire major parts rather that getting into replacing the usual small malfunctioning part out of the bigger assembly. (sorry for the rant).
F
Fred W
Ah, then you've already done your homework... it'll be a rebuilt alternator then.
B
Ben
Thanks Fred!
Not to beat it over the head, but does anyone have any experience opening an alternator and changing just the bearing?
I use to do it for Renault in Europe, not easy, but very doable. The cost difference (if you don't count your work) was big (i.e. rebuilt alternator = $200US, bearing = $5US).
D
Dave Hinz
Yup, if you're comfortable doing small motor repair, there's really nothing surprising.
Exactly. I've got one apart on the bench right now for my 99Turbo, on the theory that the one I have is fine, just gritty. We'll see how that goes...
B
Ben
Excellent! For my own education, does the Saab alternator have a bronze bushing at the pulley side and a bearing at the other end (towards the electrical connections, diodes, etc.)?
Or the bearing sits right at the pulley, with a bushing at the other end?
Cheers, Ben
D
Dave Hinz
It depends on who made it and during which decade. I haven't had a c900 or newer alt apart (yet) so let us know when you find out ;)
I'd expect there to be a bearing at the pulley end regardless, that's where all the axial load is.
Dave
D
darthpup
How hard can it be to fit a new bearing? Here in Virginia they will rebuild the whole mess for fifty dollars. There is nothing critical here. Actually a good ball bearing would probably do better than a sintered bronze one.
B
Bob
FWIW - If you have not replaced the upper idler pulley in 45K miles or if you do not know when it was done, replace it and the belt. Check the water pump pulley (bearing) for wear while you are in there.
B
Ben
Hi all,
I managed to replace both bearing in my alternator. Here's the specs and the how:
Car: '99 9-3, manual, with A/C Alternator: 130Amp BOSCH
- After removing the alternator off the car, I removed the front pulley nut (24 mm) with an impact wrench.
- Pulled the pulley off the shaft with a 2 arm gear press.
- Removed the black cover off the back of the alternator and the brush holder as a unit (2 screws).
- Removed the 4 bolts that connect the 2 halves of the alternator together.
- Pried off the 2 half's (mine were a bit rusty, took some doing).
- Removed 4 small screws that hold the big bearing in the front (pulley side). Depressed the bearing.
- Used the 2 arm puller to remove (very carefully) the small bearing at the back (you have to remove a plastic cover off the bearing first). THIS is the bearing that was making noise in my alternator.
- Pressed back both bearings.
- Cleaned as much as I could all the parts and assembled back in reverse order.
_ Installed on car, and presto, it seems to be working ok (so far 500km).
TOTAL cost = $10 CAD for the bearing at the local alternator rebuilder. DEALER cost, if I would have had it in with a new alternator = 1,200 (parts) + 300 (labor) = 1,500 DEALER cost, with rebuild alternator = 400 + 300 = 700
Hope this helps, I can send links to reference sites on the web, if needed.
Cheers, Ben
Dave H> >
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required
Report Content
You are reporting this content to the moderators. They will look at it
ASAP.