How to loosen the Bottom Alternator Bolt?
 

I need to remove the main serpentine alternator belt on my 2006 Scion xA and I was trying to loosen the bottom bolt on the alternator. After several hours of failed attempts,
I finally gave up with the bolt head corners starting to look rounded. I was wondering if there is some kind of special tool or trick to getting this bolt loose.

The first thing I tried was a simple 14mm socket. This doesn't work because of the close proximity of the water pump pulley.to the bolt head. I can get it on there, but as soon as I start
turning the wrench, it hits the water pump pulley and forces the socket off the bolt head. So an ideal socket would be about 1.5" long so that the base of the socket wrench doesn't hit
the pulley. Unfortunately, there is only about 1/2" clearance after that for the wrench itself.

I'm thinking that maybe there is a special tool they sell, or perhaps the engine mounts need to be loosened and engine jacked up so that the bolt will have more clearance. There is also an airbag sensor in the way that might provide a small amount of extra room if removed.

As far as special tools, I'm thinking about getting a set of offset box end wrenches that might get back in there. Other than that, maybe weld a 14mm socket to a piece of flat 1/4" steel.

I got stuck on the bottom bolt, but now I'm wondering if just loosening the top bolt would be good enough.

Any ideas on how to get this bolt loose?

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I had to take off the intake manifold to get it completely off :(

So how did you get the bottom bolt on the alternator? I don't need to take it completely off, just loosen it enough to get the new belts on.

I'm wondering if anyone has tried one of those offset box end wrenches.

Well I got to the bolt with a adjustable gear wrench by getting to it from the bottom/back side like where the manifold is. If you just have to loosen it id try a mallet lol. there is a bolt hole in the bracket you can turn a bolt into to give you a place to lever on

By "adjustable gear wrench" do you mean something like this:
https://cimg4.ibsrv.net/gimg/www.sci...504bdc9756.jpg


I was also looking at serpentine belt removal tools. They look like they might get in there and do the job. The only problem is that none of them work with a 14mm socket.

https://www.harborfreight.com/search...removal%20tool


https://cimg1.ibsrv.net/gimg/www.sci...a8beedee31.jpg

Ah a crows foot adapter. Have you ground down a wrench to fit between the pulley and the case I would try that if you haven't... I'm finally comprehending your situation, the water pump pulley is blocking that bolt.

you, could, take those three bolts off the water pump pully and then tap the pulley off and that would work to get the belt off. its not pressed on or anything

The water pump pulley is under tension from the main belt. It might come off, but wouldn't go back on very easily.

I'm going to get that serpentine tool. its basically a flat socket wrench with long handle. It doesn't come with a 14mm socket, but I will get a new set of those as well. I want 6 point sockets because the only thing I have around here is 12 point. The 6 point is less likely to round over the bolt head. The 12 point socket has already done that..

With a small enough socket, it should be able to get onto the bolt.

I had to look at mine just to remember what's going in that area of the engine bay. It's a pretty tight fit! I did notice you can get a way better angle on it from looking up.
You'll just have to remove the passenger side cover. Also I'm pretty sure the bolt, on mine at least is 13mm. If your 14 is too big try the 13.

https://cimg0.ibsrv.net/gimg/www.sci...b8a7c84ee4.jpg

I bought the serpentine belt tool at Harbor Freight and it definitely makes getting to the bolt a lot easier. Its not the perfect solution because there is no ratchet mechanism so the bolt can't be removed completely with it. In my case, the bolt corners are so rounded over now, that even the 6 point socket couldn't get it. I used an extractor socket on it and it finally broke free, but the size of the tool prevents turning it any further..

I have been using a 14mm socket and it seemed to fit good and tight, but I'll try the 13 and see if that works any better.

Now I have to replace the bottom bolt with a Grade 8. The fact that it rounded over so easy says it was probably made from pot metal or equivalent.

ANY idea what size and length it is?

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I tried the 13mm socket and it was too small. I had to use the bolt extractors since the head was all rounded over.
Toyota lists the bolt as Part Number 9010510075 but doesn't say what thread size it isor length.

I'm guessing that they put Locktite on the threads when they assembled it which would explain why it was so hard to break free.

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Careful on simply jumping to a Grade 8 fastener. The OEM fasteners - assuming that is actually what was in there - are not made out of pot metal and they are not thread locked into place. Is it possible somebody before you replaced the OEM fastener with a cheap hardware store one? Grade 8 fasteners have their place, but you should not need one in this application.

I am the original owner and this is the first time I've had to work on it beyond oil changes. The bolt rolled the corners over very easily.

The whole thing that started this was the A/C compressor. The outer coupling from the pulley to the shaft broke off one day and I found the parts in the plastic belly pan under the engine. I bought new ones, but it noticed the belt was all cracked up. I decided its time to change them.

I'm not sure of the bolt size but im glad you got it out. I'm guessing they just get all corroded cause mine, the bolt, is messed up too

@mrrcom &n4mwd, For the top bolt of the Alternator I use penetrating oil. That help. For the bottom bolt, I was at the mechanic. He use an electric drill. What was impossible for me, for the mechanic took 7 seconds. Then I lubricate with lots of car grease the bottom bolt and the top bolt of the Alternator. To prevent the rust I paint with silver car caliper paint the top bolt of the Alternator. This was done after we tensioned the belt. Each time I see rust on bolts I keep spraying them with paint. I see that in New York the maintenance guys keep painting the G.Washington Bridge all the time. They finish one side then next day start the other side. Tesla cars are made from aluminum? Looks like never rust. Maintenance free!

https://cimg9.ibsrv.net/gimg/www.sci...8993c6e10e.jpg
I keep spraying with silver color paint every other month to prevent rusting. Please do not laugh! Thank you.

I can't even see any silver paint lol before I zoomed in I thought it was going to look like i painted it haha I think next time I have to mess with the Alternator ill just get rid of the stock bracket and put in a turn buckle and just keep the bottom bolt only snug. It would be cool to somehow get a spring loaded tensioner on the belt but I guess it's not a huge issue.

Simply painting over rust will not stop it. You need to remove the rust, then re-finish the surface. When they repaint bridges, they media blast the surface first to remove old paint and corrosion. Then they prime and paint the clean surface. All painting over rust will do is give you a warm, fuzzy feeling.

As for aluminum not rusting, that's not technically correct either. Aluminum oxides (another name for rust on steel), just not quite as quickly as steel. Just look at aluminum car wheels after a few years in the salt. There is virtually nothing that's truly maintenance free. Even "maintenance free" car batteries need the connections periodically cleaned.

SUCCESS!

I finally get the belts changed. So far no squeals. I also got the new faceplate adapter screwed onto the compressor.

In summary, because the bottom bolt's corners were rolled, I had to use a bolt extractor socket and a serpentine belt tool to break it loose. Later on, I used a think 3/8" drive ratchet wrench that had its handle duct taped inside of a 2 foot long piece of 5/8" ID chromoly steel tubing I had. Its a tight fit, but possible to get it over the bolt. Once loosened, the top bolt was loosened so the alternator could swing up and the belt came off.

I would only touch that lower bolt with a six point socket - never a 12 point.

The PS belt and A/C compressor require access from underneath which means all the plastic belly pan needs to come out. There are two of them.

That brings up another QUESTION. Where do I get replacement plastic rivet plugs to fasten the plastic back under the wheel well? Several of mine broke coming out.

Try these folks: Assorted Clips & Fasteners for Toyota & Lexus Cars - Small Hardware (clipsandfasteners.com)

You'll also find that your local auto parts store has a decent selection.

Those rivets are an odd size - not usually available in auto stores - 7mm I think is the size you are looking for. The inch sizes are not a good fit

Heres the page for the toyota parts house for the under cover. a bunch of mine broke too

https://parts.toyota.com/a/Scion_200...5410-5102.html