N62 AC Belt Question
 

Hey all,


I have a 2008 E70 with N62 4.8 engine.

Does anyone know the procedure to install the AC belt?

I want to replace it and the tensioner roller, but do not see how to preload the tensioner. It does not appear to be a stretch belt application... but what do I know.

Can I get some help here, please.

Thanks.

N62 AC Belt Question
 

Does this help? Says N62 http://www.bimmerfest.com/forums/att...5&d=1317104555

Thanks, both of you, but I am not sure if this refers to my X5.

The First set of instructions would make it appear that its a stretch belt.
However, when I look at my belt I have a tensioner roller that you put manual tension on (as in not a hydraulic tensioner or not a spring loaded one.

Here is the link to the V-belt and belt tensioner:
2008 BMW X Series (E53,E70,E71,E83) X5 4.8i Belt Drive Climate Compressor

I have replaced belts on a 3 series e36 and one pulled back a spring loaded tensioner using a Allen key as I recall. E90 info here looks to be saying once again there is a spring loaded tensioner.

They talk of a special tool and a torx in the links prior poster gave. I wonder does one really need that special tool? Anybody here that has actually done this job that can tell us?

There's one bolt holding it to the engine block that needs to be loosened then one bolt from underneath that applies the tension, you can see the threaded end of this one from the top and how it pushes the pulley up.

is special needed?
 

What does the special tool do? Can one do the job without it?

No special tools are required. The ribbed belt is not a stretch belt. The tensioner pulley is mechanical and the tension is adjusted with a single bolt (head facing down). The access to adjust the pulley is abysmal and very frustrating at best. Do some searching and you will find that I removed the adjustment bolt and cut a slot in the threaded end. This allows the use of a screw driver to easily run the bolt up or down. Breaking loose/tightening still done with proper wrench.

Thanks.:thumbup:

Your welcome. I should have clarified that my vehicle has active steering and roll stabilization. If yours does not, access to the adjuster bolt may be significantly better.

As others ssaid, no special tools needed but it is a PITA to get to the tensioner bolt. Definitely try to stretch a new belt on first, IF the tensioner has never been adjusted it will still be in the correct place for a new OEM belt.

I don't believe there is really an "adjustment" You tighten the "adjuster" bolt all the way until the tensioner pulley bracket bottoms out. With this in mind, it may very well be a stretch belt...

I had to adjust mine. There was NO WAY it was going to stretch on. At the time I had the fan assembly out so I had enough room to put a notch into it with a Dremel. If I was to do it again I would find a nut that fit, smear the threads of the nut with JB Weld, thread it on and wait for it to dry. I think this would be even easier to adjust from the top than notched.

No, what I meant was that you fully tighten the "adjustment" bolt that you said you cut a slot into. You don't stretch the belt on, you loosen the "adjustment bolt which moves the pulley so the belt will slip on, then you FULLY tighten the "adjustment" bolt until it bottoms the pulley bracket. you don't worry about belt tension or anything else. Because of this, it leads me to believe that maybe it is a stretch belt that self tensions.

Mine isn't bottomed out though. Wasn't with the old belt and isn't now with the new belt. I pried my old belt off and then attempted to stretch the new one on hoping the tensioner was still in it's original position. Unfortunately it wasn't as apparently at some point the dealer had tightened it. I had to back it out most of the way, slip the new belt on and then tighten it to the correct belt tension.

You might be right. I remember mine as bottomed out and adjuster bolt tight.

What size is that adjustment bolt? I will attempt to reach to it from underneath tomorrow. Looks like a long snake extension might be needed to get to it.

Well I was able to change my ac belt. Wasn't as bad as I thought even though mine also has dynamic suspension, etc. Nothing seems difficult after my failed attempt at the oil cooler gasket a few months back lol.

For some reason the bolt is not at its previous position, despite belt being tighter than before. Probably because it's a new belt.

Thanks Greg for your write up in the other thread. I changed water pump, thermostat, hoses, and also installed bimmerfix stent with the help of it.

I recently changed my alternator and replaced my idlers and belts.

The AC belt on the N62 is a PITA.

Turns out the AC belt adjustment is T40 Torx that you reach from the bottom. The T40 is NOT fun trying to get to with a 3/8" drive T40, I was able to get is, but I had to go back and tighten the belt more.

I purchased this 1/4" drive kit on ebay for $23 that had a T40 1/4" drive rather than a 1/4" drive Torx bit set at T40 in 1/4" is a bit tricky to find. 46pc 1 4" Drive Socket and Bit Set Metric Hex Pozi Star Phillips Slotted | eBay

I then used a very long (12"??) 1/4" wobble extension I had already and the T40 Torx bit to get to the adjustment. MUCH easier than with a 3/8" T40 Torx bit. I could have used this set by its self, but found the long 1/4" drive wobble extension gave me another angle from further back than the shorter extensions did not give me.

Some red Loctite and the proper size nut installed on the other end of the adjustment bolt might be another option so you could get to the adjustment from above might be what some would choose to do. Not sure how long the Loctite would take to cure or what thread size the adjustment bolt is.

hey guys, i'm trying to change my AC belt, but now i'm stuck at this spot.

Do I just loosen the adjustment bolt number 2 from the bottom? How do you even reach it from the bottom? There's hardly any room there.

Do I need to loose bolt number 1 at all?

Thanks

^yes, you'll need to loosen both bolts. And yes, number 2 from underneath the car. Also yes, there is not much room, even after you remove the belly pan. A 6" extension with a swivel end is your best chance. Harbor freight has them.

You need to loosen #1 a few turns, then #2 is used to move the pulley.

You want this kit as it has the 1/4" drive Torx bit that will get you into the head of #2

46pc 1 4" Drive Socket and Bit Set Metric Hex Pozi Star Phillips Slotted | eBay

You may still need to purchase a set of 1/4" wobble extensions, but you can get these at Advance, AutoZone, Harbor Freight.

I see you mentioned using a T40 from this set, but those two bolts are T45. I tried the T40, it works but alittle loose. T45 was a much better fit. Are you sure the T40 will work?

Also after loosening number 2, how much do I tighten this adjustment bolt? Do I just tighten it as tight as possible? The belt will self tension?

Thanks guys!

I have to assume the T40 comment was for the tensioner bolt and the T45 was for the set bolt. I was a while ago I played with the tensioner.

I never found anything that indicated the belt was a stretch belt, but I recall I found the tensioner fully adjusted. I ran my tensioner in quite a bit, but do not recall bottoming it out.

Go ahead and remove bolt #2 anyway you can or as others have mentioned. Once you have it out, cut a slot in the end (not head) of the bolt. This way, in the future, you can run the bolt in and out with a screwdriver from above and only have to tighten/loosen it from below.

ok, just finished the AC belt. god, that was a royal PITA!!!

I was able to remove the adjustment bolt from the bottom with a few regular 1/4" extensions and a T40 hex bit. The bolt is actually a T45, but there's no way a 3/8" drive socket will fit in that tight space. So I just used the T40 bit and it worked. I bought a set of wobble extensions but end up not needing them.

Removing the adjustment bolt was a little tricky was doable. The hardest part for me was trying to align it just right to bolt it back on. It's not a straight shot as you can see from the picture. The damn pulley was in the way. I think it's almost easier just to loosen the bolt enough to slide the belt ON and then tighten it instead of removing the bolt completely.

Anyways, I did end up removing the bolt and cutting a slot on the end like DavidJ suggested. Now I can loosen it and work from above if I ever end to change the belt again. Hopefully not anytime soon.

Thanks for all your help and tips guys!! :thumbup::thumbup:

Glad you got it done. Normally, you don't need to remove the bolt, just loosen it enough to get the belt off/on like you mentioned. The slot in the end of the bolt will make that task easier.

I took mine to the indy I use. Jobs like this with the right tools take less than an hour. Well worth it IMHO.

AC Belt & Alternator belt install 08 BMW X5 4.8i
 

What a PITA!!!!!! I was fortunate enough to change both my AC and alternator belts on my 08 BMW X5 4.8i (94k), two days ago (Saturday) from the post date. Thanks to all the post/pics from others like gregg3gs and lordshin88 that gave me the courage to attempt this task.

I would like to share some tips from my experience. The serpentine belt (alternator belt) has one adjusting bolt, which is a Torx T60 bit, which is spring loaded-eventually the easiest of the two belts. The AC belt has two adjusting bolts as pic's here on this site has noted and describe them as bolts #1 and #2. Bolt #1 was I believe a Torx T45 and reached from the top of the vehicle, and bolt #2 underneath the vehicle is a Torx T40. This AC bolt #2, underneath the vehicle is the PITA working in very tight space. There was enough room underneath for me move the pulley with a finger tip towards the front of the vehicle using one hand to clear a very small amount of space, and the other hand to ease the extension up towards the bolt head.(Of course bold #1 on the AC should already be loose to get this small amount of movement), I was able I to increase my chances of a clearer pathway to get my 3/8 universal and extension at the bolt the head #2. It was still a "very-very" tight space and it took many exhausting attempts getting enough revolutions on bolt #2 to eventually tighten up the AC belt. I hope this little bit of suggested information helps some one.

glad you got it replaced. It was definitely a PITA. Not hard, but frustrating having to work in such a tight spot.

Thanks. I think I may have to tighten up that finicky AC #2 bolt underneath the vehicle just a bit more, I get a little occasional squeal on start up from that AC belt. SMH

A few things I've learned about the A/C belt and pulley; hope this helps.

Having the right tools (below, not expensive) turns this from a knuckle-busting frustration into a 30-minute job.

* If you're getting a squeal from your belts when you start the engine, don't just assume it's the easier-to-change serpentine belt and tensioner. Don't ask how I know :-)
* An easy test for which belt is squealing: while it's squealing, turn off the A/C with the snowflake climate control button. If the squealing stops, it's your A/C belt.
* Both torx bolts are T45, but a T40 is a lot easier to fit on #2 - especially if you use a 1/4" T40 socket.
* I loosened #1 a half turn with a 1/2" drive T45 socket from above
* I loosened #2 from below enough to slip the belt off the tensioner. Had to loosen it a lot further to get the new belt to fit. Used that 1/4" T40 bit and a 9" 1/4" wobble extension from Harbor Freight. Turn counter clockwise to loosen, just like a ordinary bolt. I threaded the bit and extension through a hole in the large shiny black subframe, just forward of the engine.
* Taking off the A/C belt requires pulling the serpentine belt from the crankshaft pulley; you don't have to take it all the way off all the pulleys. However, if you're going to replace the A/C belt, you might as well replace the serpentine belt, too. The tensioner is a T60 Torx

I’m not sure anyone referenced this yet in this post. Both bolts should be torqued to 22nm. They lock then tighten to 22nm. You don’t have to remove the upside down bolt to Dremel a flathead slit. With the fan removed you have enough room.


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+1 on slotting the AC tensioner bolt!

On my 2007 4.8i with adaptive drive the adjuster head is nearly impossible to access.

The tensioner pulley+bracket is very overpriced from bmw. If anyone needs one let me know, I am selling OEM INA replacement pulleys without thr bracket for half the price.

-Rich

www.newtis.info. throw the last seven of your VIN in and hit submit. "AC belt" in the first search field and the first result will be the procedure you desire. Cool eh?