Well... I am on my 5th Alternator at under 60,000 miles.

Last January, I purchased an O'Reilley's Remanufactured Alternator to replace my second factory OEM Valeo unit when the decoupler died. The O'Reilley's has a Lifetime warranty, and I noticed that the case was cracking after 8 months (see photo). So, I had to replace it as well. I swapped it out yesterday, but the replacement unit was DOA; therefore, today they gave me another one under warranty to try.

Yesterday the swap went fine and I torqued the Alternator retaining bolts to 37-ft-lbs as usual - no problem. But since the alternator was bad yesterday, I had to put the cracked one back in for 24 hours - again, no problems.

Today, however, when I installed the new replacement (which appears to be working fine so far), I was unable to torque down the upper Alternator retaining bolt. Apparently either the bolt or the bracket is stripped (my guess would be the bracket?). Since the lower alternator bolt torqued down fine, I just need to fix the top bolt. What they suggested at O'Reilleys was to just buy a longer bolt for the top where the threads show out the back and put a nut on the back. So, my questions are:

(1) Does this sound like a good plan?
(2) Do you know the "specs" on the upper alternator bracket bolt so that I can order a slightly longer one?

Thanks!

 

The number on that bolt shows dimensions as:

10mm x 1.5 x 95mm

HTH

 

Thanks!

 

I've had mine off before and I can't remember how much room you have but a Helicoil is a common repair for stripped out threaded holes.

http://www.helicoil.in/pdf/HeliCoil%20Catalogue.pdf

HTH

Steve

 

The question here is why so many alternators!!????

 

If the bracket threads are toast, I would remove and take to a machine shop and have Heli-coil inserted, or replace the bracket outright. I'm sure Marc at Vettenuts has some good used ones on hand if needed.

If needed: GM 12578068 New is in $60 - 70 range.

YMMV

 

Original Alternator - bad regulator - replaced under warranty
2nd Alternator - clutch smoked last January
3rd Alternator - switched to O'Reilley ReMan - best output of the 3, but developed a crack as shown in the photo (was still working though)
4th Alternator - O'Reilley warranty replacement DOA (Clutch appeared to be the problem)
5th Alternator - another O'Reilley warranty replacement - so far, so good the past 24 hours.

 

Might just buy a new one, but not sure why the original stripped out so easy? I guess about 5 cycles is all they are good for?

Does it hurt to add anti-sieze compound?

 

37ft-lbs is a lot of torque for a M10 bolt threaded into aluminum. I'm not surprised you stripped out the threads.

 

10x1.5 Helicoil.

Frank

 

Is that not what the book calls for? I have (3) Torque references and all say 37-ft-lbs?

 

Well, crap. Just went out to start the car today and I am getting the "Charging System Fault" on the DIC - so I guess this is the wrong alternator this time. It shows to be the correct one for an Automatic 2001 in the system, so not sure what to do from here. This is the first time I have seen that message on any of the alternators.

 

Not at all. Just try not to overdo it. FWIW, I used it when replacing my waterpump, not only for anti-galling purposes, but I had a small amount of surface rust on all six bolts as well, so after cleaning them, I smeared a thin coat all over the smooth, unthreaded, shank portion of the bolts, in addition to the threads of course. Steel bolts into aluminum threads.

With few exceptions, anytime I have to replace fasteners, I always try to use OEM if I can, even if I have to pay a little more. Most of the time they are far superior to AP/hardware store fasteners.

HTH

 

That is the factory service manual torque call-out. Also, looking at many torque spec references for bolts, that is in the range for a M10 bolt, depending on the grade. But if the bracket threads stripped out, then they are the "weak link" on this fastener. Swapping out alternators so often has probably takes some toll on the bracket threads. Also, make sure your torque wrench is calibrated.

http://www.cncexpo.com/MetricBoltTorque.aspx

http://www.swtc.edu/ag_power/diesel_...e%20values.pdf

http://www.fastenal.com/content/feds...0Fasteners.pdf

http://www.imperialsupplies.com/pdf/...rqueCharts.pdf

 

All I'm saying is that I believe 37 ft-lbs is a lot for that application and I'm not surprised a M10 bolt installed 5 or 6 times into an aluminum threaded bracket using that torque has pulled the threads out of the bracket.

 

I see a lot of you recommending a heli-coil for the stripped threads on the OP's bracket. There is nothing "wrong" about using heli-coils for applications such as this; millions have been used for many years and have worked well.
There is another product that I personally believe is a better option for many applications. That product is a Time-sert. During ten years in an automotive machine shop in San Francisco, we used many time serts. We used them when there was enough room for them, and for applications were felt we needed the extra strength of a product like this. I have even used them to repair head bolt holes in engine blocks.
Google time sert and see what you think. More money and a little more time than a heli-coil, but worth it in my opinion.
Perfect product for repairing threads in a hard-to-find (expensive) part.
George

 

http://www.timesert.com/index.html

http://www.timesert.com/html/mtrcsert.html

 

John:
IF, and I say IF, you go with the bracket replacement route, I would strongly recommend replacing your PS pump pulley with the all metal LS2/3 style pulley. It is a "cross-bar" 4-spoke design that allows access to the PS pump bolts without having to remove the pulley in the future. It is plug-n-play, i.e. remove old one-piece unit, and press on the new one.
GM part # 12568997 It's cheap ($20 or under) and the difference in diameter is so small, you even get to reuse your old serp belt.

 

Are you saying that if I replace the bracket, I have to remove the PS Pump pulley to gain access?

 

As I understand it yes, or at least have some kind of special wrench/tools like a crows-foot for example to get at the PS pump bolts themselves located behind the pulley.

Found this pic from another members thread from a few years back:



Some AP stores have loaner tools for pulling and installing the pulley, but I have read nemerous threads here over the years where guys have broken/damaged their old solid plastic OEM pulley.

HTH