[n54supremacy]

I removed my alternator by loosening the intake manifold and cannot seem to get the new alternator back into the car. I tried to remove the OFH because that supposedly made it way easier but the very last OFH bolt completely stripped and is seized. I tried everything I could including cutting a flathead slot into the OFH bolt but cannot seem to get it off. I think i will go back to trying to just muscle the alternator in. Any tips?

[e91Owner]

I'd say try a bolt extractor, but honestly I've had better luck with just regular vice grips. Just make sure the teeth are still sharp or you'll end up stripping it worse.

[Serf27]

The AC compressor bracket closes a little when the alternator is removed, making it very difficult to side back in.

What I do and what I recommend is to taper the bottom on the alternator where it slides into the groove.
A small taper at the bottom will let it slide down a bit then small taps with a rubber mallet on top to put it in place.

As for the bolt, if you can get the grinder in there, cut the head of the bolt off and pull the OFH out then remove the bolt with the OFH out of the car.

[e91Owner]

Originally Posted by Serf27

As for the bolt, if you can get the grinder in there, cut the head of the bolt off and pull the OFH out then remove the bolt with the OFH out of the car.

Thought that might work too, but the small bolt isn't a lag like the longer ones.

[Serf27]

Originally Posted by e91Owner

Thought that might work too, but the small bolt isn't a lag like the longer ones.

I don’t follow.

The only thing holding the OFH is the head of the bolt.
It only passes through the head and screws into the OFH.
Cutting it off, he can slide the OFH off with the cut off screw still screwed in.

[e91Owner]

Originally Posted by Serf27

I don't follow.

The only thing holding the OFH is the head of the bolt.
It only passes through the head and screws into the OFH.
Cutting it off, he can slide the OFH off with the cut off screw still screwed in.

Looking at the bolt, unlike the other OFH bolts, it is treaded all the way to the head… it's not a lag bolt. That was making me thing it was biting on both sides, but now that I think about it, I think you're right, it's only threaded on the OFH for that one.

Having cut those inserts off with an oscillating tool by the corner of the valve cover, you just have to be very careful. It'll cut through the bolt super fast, but everything around it even faster.

[Serf27]

Yea, that bolt just passes through the head and is only threaded on the OFH.

A grinder would work to cut the head off.
Another option would be to drill a hole in the bolt from the side to weaken it.
Then with a chisel on the head, hit it and that should pop the head off.
I’d try the grinder first.

[Dave92N54]

I'm more impressed that you removed the plastic head flange without it breaking

[n54supremacy]

Originally Posted by Serf27

Yea, that bolt just passes through the head and is only threaded on the OFH.

A grinder would work to cut the head off.
Another option would be to drill a hole in the bolt from the side to weaken it.
Then with a chisel on the head, hit it and that should pop the head off.
I’d try the grinder first.

As this bolt is stripped, I have the replacement bolts here and this particular one IS threaded and biting the head and oil filter so if it were removed then it would still hold the OFH to the head.

[Serf27]

No it’s not.

The bolt pulls the OFH to meet the head.

[charlie_m]

Originally Posted by n54supremacy

As this bolt is stripped, I have the replacement bolts here and this particular one IS threaded and biting the head and oil filter so if it were removed then it would still hold the OFH to the head.

A little clarification here: the bolt may indeed be fully-threaded, but the hole in the head that it passes through is a *clearance* hole. Only the end threads of the bolt engage the threaded hole in the OFH.

So remove the now-goobered-up Torx head from that bolt and the OFH should come off. With the OFH now on the bench and that bolt no longer under tension, the remaining part of the bolt should come out easily. If you have an oscillating tool and a fine tooth blade, that should work to get most of that bolt head taken off.

[noah.s]

Not positive if it'll work on the N54, but on my N55 I was able to avoid removing the OFH by loosening the AC compressor bracket. This allowed for enough wiggle room to get the alternator out. It's still a bitch as those bolts are kinda hard to get to but saved me from removing the OFH.

You may be able to find some more info. about this online somewhere, I can't remember where I found it.

[rt7085]

Use a bolt extractor socket. Do not use a power tool. Use a socket wrench carefully. This is an aluminum bolt. It will snap when abused too much. Never reuse ANY aluminum bolt. Always new even after being used and torqued to spec once (because they stretch-yield).

[e91Owner]

Originally Posted by rt7085

Use a bolt extractor socket. Do not use a power tool. Use a socket wrench carefully. This is an aluminum bolt. It will snap when abused too much. Never reuse ANY aluminum bolt. Always new even after being used and torqued to spec once (because they stretch-yield).

They're steel and given the size of the head, it would have to be a really small bolt extractor at a pretty odd angle.

[n54supremacy]

Originally Posted by Serf27

The AC compressor bracket closes a little when the alternator is removed, making it very difficult to side back in.

What I do and what I recommend is to taper the bottom on the alternator where it slides into the groove.
A small taper at the bottom will let it slide down a bit then small taps with a rubber mallet on top to put it in place.

As for the bolt, if you can get the grinder in there, cut the head of the bolt off and pull the OFH out then remove the bolt with the OFH out of the car.

This solved my issue, I ended up leaving the bolt in because I need the car to run and the OFH gasket has been replaced recently so i dont believe it will fail. To get the alternator in i took about 3 mm of material off the side of the bolt holes that touch the ac compressor bracket, then I tapered the material about 3 more millimeters down from the center of the bolt hole. I removed the upper coolant hose and smeared all the alternator bolt holes and mounting points with motor oil and a few taps with a rubber mallet slid it in ( I did have the intake manifold pulled about 3 inches off the head and lifted it up). After this I replaced all the parts and mounted the belt according to the TECHINICAL DRAWING. Loud knocking noise from alternator bearing is gone but still have strange rumbe present possibly related to cylinder 6 misfire?

[Serf27]

[RayLivingston]

I had to do a roadside alternator replacement on a 335i. The bottom flange of the new alternator was about 0.5mm too thick to fit into the slot. I just used a file, and calipers, to carefully file it down to the same dimension was the old one, so it was a nice, snug fit back into the slot. Only took a few minutes. Never touched the OFH or compressor, and just loosened the intake and pulled it back about an inch. All quite easy.

[n54supremacy]

Originally Posted by RayLivingston

I had to do a roadside alternator replacement on a 335i. The bottom flange of the new alternator was about 0.5mm too thick to fit into the slot. I just used a file, and calipers, to carefully file it down to the same dimension was the old one, so it was a nice, snug fit back into the slot. Only took a few minutes. Never touched the OFH or compressor, and just loosened the intake and pulled it back about an inch. All quite easy.

essentialy what I did but took off a lot more material and took a lot more time to do it