Removing Alternator : 300TD
 

Hi!
I've read threads about removing the alternator from my W123 (1982 300TD), but now, on the job, it's confounding.

My understanding:

From the photo, http://www.peachparts.com/shopforum/...6&d=1296524298

Nut #1 has to be loosened (but not removed) to allow belt tension to relax. Bolts #2 & #3 then have to be backed out far enough for the alternator to fall out. The NUT on the fan side of bolt #3 is welded to the adjustment bracket, so all three of these fasteners are loosened from the side in this image (that is, the back of the alternator).

***

My problem: Bolt #3 doesn't turn. I can get a 17mm combo wrench on it, but if it's not turning, should I go get a cheater bar? That's all I can think of. I just want to make sure I need to get that one off.

Then, I can forsee lots of problems backing those two bolts out, particularly given how little space there is. I've heard many folks use ratcheting wrenches on these bolts: is that a straight ratcheting wrench, a stubby, or a flex-ratcheting wrench?

Am I not removing enough? I've taken off the air filter housing and the EGR heat shield, but it's still so crammed in there.

Thanks,
Marshall

It's a PITA at best.

From what I remember... someone will correct me if I am wrong.
That bracket needs to come out with the alternator. On my car, and other members, I had to bend something(Adjustment bolt I think) to get the alt out of the car.

I am pretty sure your going to have to get that bolt loose. It is certainly not as straight forward as it looks.

It's been a while but I think I removed 1 and 2. I may be wrong. 2 I definitely removed from below. I think I broke it free with a socket but may have used a gear wrench to get it out. It tends to not want to come out in my experience.

Loosen the belt tensioner to relieve belt tenion, then Remove the 17 mm bolts/ nuts on the regulator side of the alternator. I used a 1/2" drive ratchet with a 18" pipe for extra leverage. The tensioner bracket stays on the alternator and come out the bottom as an assembly.

Here's a thread with some pics.

http://www.peachparts.com/shopforum/showthread.php?t=285723

get a can of AereoKROIL or PB Blaster, and soak the opposite side of the bolts with it heavily.
also soak the 13mm adjuster nut before attempting to loosen it and when You do start loosening it, go very slowly back and forth. or you will break it. you've been warned.

your (OP) description is correct. loosen nut, remove 2 and 3 completely. 1/2" ratchet at a minimum is needed sometimes to loosen a stubborn bolt.

There is another bracket bolted to the engine block, I had to take off to get the darn thing out.

I had to bend the tensioner threaded rod to get it to clear the bracket. Then, to get it back in, I filed a bit of it off so I could fit it back into the bracket. I ended up taking out the fan and shroud to have better access and visibility.

Ok. 1/2 inch drive 17mm socket (maybe with a long breaker) to get that loose. Once it's loose, how do I back the bolt it out, since there's not enough room to keep using the socket wrench.

Go to post 24 in the link funola sent, that will will show what a "welded nut" and plain nut/bolt combo look like. The hole vs. non-hole is not a guarantee.

I've got an '83 300CD with a hole/non-welded nut.

Get some goggles and try working from below.

Pic of alternator mounted, but out of car in #9 here: http://www.peachparts.com/shopforum/showthread.php?t=281707&highlight=alternator

I believe it is possible to remove the alternator without removing #3, but you do have to remove #1 if you're going to try that. And #3 has to at least be loose enough to move the bracket. #2 has to come out regardless. Others may disagree this is possible.

Other pics of odd bolt wear that may jam you up here:

http://www.peachparts.com/shopforum/showthread.php?t=285473&highlight=alternator

I'm virtually certain I took out 1 and 2. 1 has to come off anyway to move the bracket to a new alternator doesn't it?

Every time I do one of these alternators, I have to relearn how to do it, I do it so seldom.

Once all three bolts are loosened, the 13mm adjuster nut can be backed all the way off. (have to do this to remove the belts.) then in theory it can be lifted and the #1 bolt can be removed from the front.

Then bolt #2 can be removed from the rear and the alternator can be lowered and removed from the bottom.

That #2 bolt can be a PITA, as it can be so rusted and corroded, that it won`t slide out. Had that problem back in 07 when I was replacing the engine. luckly I had the eng out, and could just remove the mounting bracket that bolts to the engine.
I could turn the bolt, but it would not come out, even after soaking it in PB Blaster for 2 wks. finally had to beat it out with a smaller diameter bolt.

I would recommend slathering the bolts with Anti-Seiz compound. that #2 bolt catches all the road splash/salt etc.... and really gets seized in.

If that #1 bolt gets screwed up on the adjustment part, here is a fix a guy did a while back that is helpful.

http://www.peachparts.com/shopforum/showthread.php?t=188559

Charlie

Hm. I still can't get bolt #3 loose. I got my 1/2" drive, 17mm socket on it, but there's barely room to get it on without running into stuff in the way:http://i1090.photobucket.com/albums/...ernatorfun.jpg I've liberally (too liberally, perhaps!) sprayed liquid wrench on the bolts. RED: the problem "#3 bolt." Using the socket wrench gets in trouble with fitting (?) with the blue arrow. Using an open-end straight wrench runs into the EGR clamp (yellow arrow). I can't get that bracket off because the nut on the back is spinning, and even if I could, I don't think it would help. I have a ratcheting wrench, but there's not enough room around that #3 bolt head to get in on.

Any other ideas? Can the alternator be removed without getting #3 loose? It's not obvious to me that #2 can be removed the way it's welded to the adjustment rod which goes through a captive bracket . . .

#1 has to come out because the new alternator needs to attach to that bracket. As I mentioned earlier, I'm virtually certain I did not remove #3 when I did it. My thought is to back the threaded section out of the adjustment nut and then remove the bolt, but again I don't remember exactly how I did it.

from below the car, that bolt can be reached with both a socket on a ratchet, and with an box end wrench.
once it's broken loose, it'll need to be undone with a box end. I like the ones with exaggerated angles on the handle. _/- kinda...

to remove the alt from the bracket in the car, almost requires bending up the bracket.
removing #3 and #2 lets you drop the alt with the bracket still attached. then removal of #1 is easy and no bending is needed...

I wish I could remember exactly how I did it but I'm virtually certain I left that bracket on the car when I swapped out the alternator on my 116, and I didn't bend anything.

#3 bolt threads into a welded nut on mine. If the nut on yours is spinning, you need to put an open end wrench on it. If ratchet will not fit #3 bolt head, use a box end wrench with a long pipe for leverage. Sounds like your in deep doodle. Vstech has ran into that and can give you more advice. What ever you do, do not round off #3 bolt head or nut.

yeah, it can be done, but it's a pain.
much simpler to take it all down at the same time.
the 116 has a bit more room to work in than the 123 too...

steve, the #3 bolt should be threading into a bracket... I think #2 nut is welded on most brackets, but I've run into plenty that were loose... annoying... I love my mig!

Welded nut on the bracket is what I meant. This is from memory so could be wrong.

Got it out!
 

I got the alternator removed today. It CAN be done without loosening the #3 bolt. It wasn't pretty, though. What I didn't understand was how the #1 bolt came out. With the nut off the adjuster, the alternator shoves all the way back down the track and the adjuster bolt comes free of its bracket. With the #2 bolt removed from the bottom, the alternator can slide even though #3 isn't loose. Maybe because of the #3 not being loose, I couldn't get the alternator moved in the last 1/2" of the slot, so I had to resort to bending the adjustment bracket to free the threaded adjustment rod which is attached to the #1 bolt. Then the #1 can be backed out and the alternator falls out.

I got lucky putting it back in, which in this scenario (with the mounting bracket still attached to the engine) the hard part is getting the bushing sleeve that the #1 bolt passes through to line up when re-installed. I put it on a retracting magnet and slowly pushed it in while gently manipulating the #1 bolt.

I admit that bending the mounting bracket is bad form, but it may be the only way to do it if the bracket is held immobile by a stuck #3 bolt as in my case.

Thanks to everybody for all your help!

I have had to re & re mine twice now over the years. 84 300D.
I removed the alternator with the adjusting bracket attached.
Once on the bench I remove the bracket and install it back into the car.
The alternator will go back in easier without the bracket attached.
I install the bottom bolt then swing it up under the adjusting bracket and slip the bolt in place from the front.

Here's a picture of the bits:-

http://www.peachparts.com/shopforum/...8&d=1298541006

From this thread:-

http://www.peachparts.com/shopforum/showthread.php?t=294656

Too late to help now, but I would have sprayed or tried to wick penetrant onto the FRONT of the nut/bracket for #3 near the threaded end not near the bolt head end at the REAR of the bracket. The pic shows liberal use but on the head end, not the thread end.

If that didn't work but you were able to get it out, I'd have recommended taking advantage of the exposed underside/back of the nut and tried to free it up with more penetrating oil.

see post #5. I recommended he soak the opposite end from the picture...

I soaked both sides of that bolt. Repeatedly.

I will admit now my big mistake: when I removed Bolt #1 and took out the alternator, I had my grand opportunity to have room to turn that #3 bolt and loosen it, because the #1 bolt was out of the way. But I was too excited that I got the alternator out, and forgot to do this! :rolleyes:

Hi
I have an 85 300CD and am stuck on the number 2 bolt. I have tried PB Blaster various sockets and box wrenches and it is not budging. I've rounded my nut finally. Is there a change it is a left handed bolt? I have even mounted a wrench on the nut and place a jack under the free end to force it. It goes up about 2 inches and then nothing, HELPPPPP
Thanks
Zen

Definitely not a LH bolt. Usually, if corrosion has taken over, application of heat makes the difference. Don't focus the heat in too small of an area, especially on aluminum, or you may have more serious problems.