AC Belt change with rusty crank bolts

Magnesiumnitrate · #1 02-08-2019, 06:57 PM

The bolt heads on the harmonic balancer for my e70 30i (n52) are super rusty. I’m afraid I’ll snap a bolt head off if I try and use one to instal the ac stretch belt. (It’s the 4 bolt pattern, not a single central bolt)

I have some large kobalt clamps and I may try and clamp one around the balancer for more leverage but otherwise I’m at a loss.

Any thoughts on how I can turn the crank by hand or install the stretch belt without turning the crank?

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ard · #2 02-08-2019, 08:24 PM

Funny no rust here and I too am in 'USA'.

Have your applied wd40, let it soak a few days, and tried it? Bolt heads may be very different from the threads (which may be more protected)

Order new bolts now, not later....

Magnesiumnitrate · #3 02-08-2019, 08:45 PM

Welp my clamp idea did not work. The balancer is just too slick, clamps slide right off.

Quote:

Originally Posted by ard

Funny no rust here and I too am in 'USA'.

Have your applied wd40, let it soak a few days, and tried it? Bolt heads may be very different from the threads (which may be more protected)

Order new bolts now, not later....

Mine spent the beginning of its life near the ocean. I’m guessing the humid air did it.

I’m not sure I was clear enough though. I’m not trying to remove the harmonic balancer, just leverage those bolts to turn the crank and pull the AC belt on/off the car.

rpoitras · #4 02-08-2019, 09:00 PM

Are you sure there is no central nut there? I have a 2010 X5 3.0 and just did my belts two weeks ago and I used the nut in the middle. It was around 26mm, I think, maybe a bit bigger? I did mine from on top and couldn't see so I took a picture with my phone and sure enough there was a nut there.

As an aside, I bought that Lisle/whatever brand stretch belt installer/remover and it was completely useless for this job. The a/c pulley has a large lip which blocks the tool from resting on the pulley and no way to use it on the main pulley. The new a/c belt was obviously quite a bit tighter but I actually got it on just by initially holding it on the a/c pulley with my left hand, carefully so I wouldn't get pinched, while my right hand was turning the main pulley with a 1/2" ratchet. I was able to walk it on the pulley and get it lined up correctly. I spent more time trying with that tool than it took just to do it by hand. Note, also, I have 4 zone climate and it makes a difference with the belts or something so maybe yours is different if you don't have that option.

Good luck!

Edit: Just attached the photo that I took in case you have the same setup.

Magnesiumnitrate · #5 02-08-2019, 09:23 PM

Well I’ll be damned. I do have a large central nut. I had read that our n52 came
With a Motorsport style 4x4 pattern. Didn’t even consider taking a picture.

Now that I’ve seen yours though, I’m a bit concerned with mine. They look far more corroded than yours.

Safe to start torquing on that or should I just order the stupid expensive oem tool?

ard · #6 02-09-2019, 01:37 PM

Holy picture sizing batman!

rpoitras · #7 02-09-2019, 08:19 PM

That nut should be more than enough and definitely no need for any additional tool. It really didn't take that much power to turn the engine. I turned it clockwise which is normal rotation for the engine, but I don't know that it matters any way.

So, just a quick run-down on how I get the a/c belt on. I did this with the fan removed to give me access. From on top I put the belt around the main pulley then on the a/c pulley I wrapped it around the bottom going towards the top as far as I could. Then, while holding that belt tight against the a/c pulley I would slowly rotate the engine cw. The belt slipped a couple of times but without me realizing it kinda just popped on at one point. Once it's a on a bit you just need to keep rotating the engine while guiding the belt on the pulley a bit more. It took no longer than a few minutes before it was totally seated.

Magnesiumnitrate · #8 02-10-2019, 07:58 AM

Dope man, thanks for the tips. I’ve got it all disassembled (I just cut the OG belt) and did the oil filter housing gasket and oil cooler gasket yesterday afternoon. Degreased the engine where there was oil everywhere and today I’m going to clean the pulleys individually before putting everything back together.

I’ll try your method and if it seems sketchy I have an Indy that can slap it on for me cheaper than the OE tool.

pshovest · #9 02-10-2019, 09:32 AM

Make your own tool.

https://xoutpost.com/bmw-sav-forums/...my-2008-a.html

Magnesiumnitrate · #10 02-10-2019, 04:26 PM

Quote:

Originally Posted by rpoitras

That nut should be more than enough and definitely no need for any additional tool. It really didn't take that much power to turn the engine. I turned it clockwise which is normal rotation for the engine, but I don't know that it matters any way.

So, just a quick run-down on how I get the a/c belt on. I did this with the fan removed to give me access. From on top I put the belt around the main pulley then on the a/c pulley I wrapped it around the bottom going towards the top as far as I could. Then, while holding that belt tight against the a/c pulley I would slowly rotate the engine cw. The belt slipped a couple of times but without me realizing it kinda just popped on at one point. Once it's a on a bit you just need to keep rotating the engine while guiding the belt on the pulley a bit more. It took no longer than a few minutes before it was totally seated.

Just one more question. Have you had the serpentine belt off? My tensioner was actually pretty easy to unload and I’m wondering if either the previous owner replaced it with a lighter one or mine is worn out. Every video online shows the tech struggling to unload the tension.

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