1982 300SD Alternator Pivot Bolt won't unscrew! - PeachParts Mercedes-Benz Forum

LNGfish · #1 04-03-2009, 08:41 AM

Thanks for reading.

This bolt is the long bolt under the alternator that the alternator swings on. It goes through the large block mount bracket, through alternator base, and then screws into the Bracket again.

Well I tried with a 17mm box wrench and some WD-40 but I could only get it to go about 1 turn CCW. So yesterday I took car to the shop and the fellow put some other Penetration oil on it and some Oxy/Acetylene heat on it. Got it pretty hot ( till it started to smoke). Not super hot, but hot.

He did not have much luck with it either but he got it to turn maybe 3 turns CCW. I had only gotten it 1 turn CCW. So it is getting better.

I'm not sure what to do now?

Anybody ever see this problem?

Any suggestions?

When you turn it CCW after 3 turns CCW now, it just jambs up hard!

The bolt still goes in and out and I can see it at the open end when I turn it fully CW. The bolt turns.

Thanks!

toomany MBZ · #2 04-03-2009, 10:50 AM

Get it as loose as you can, then hit it again with the penetrant of your choice.
Good luck.

LNGfish · #3 04-03-2009, 11:49 AM

No luck, still binding bad! Now I'm seeing if the alternator and the cast aluminum bracket can come out as a Connected Unit. But pass!! on this!! there is one bolt I can't reach that comes in from the front behind the Hormonic Balancer through this this Humongeous alternator base Bracket.

Previouis owner told me the fellows at his shop could not get the bolt out either and they rebuilt the alternator in place, mickey mouse, with new Brushes and Voltage Regulator.

I want to get it so I can get the alternator out in the future to put new bearings in it should it need it.

I may have to drill the bolt end out from the Radiator end and retap the hole but I would need an angle drill which I don't have. This is bugging the you know what out of me.

HELP!

oldsinner111 · #4 04-03-2009, 12:24 PM

Alot of people cut it off.Then you will need a used bracket.Mercedes Source has one.

LNGfish · #5 04-03-2009, 12:26 PM

OMG I got it out! "Bolt from He_ _". Found some metal on the grooves of 1 or two threads on the bolt. I'll chase them out with a thread chaser or a fine file. Fortuneately no damage, Phewwwwwwwwwww!

I have never seen a bolt get stuck like this!

I'm a big believer in Never Seize and this bolt will have plenty when it goes back in so alternator can be removed in future should it need it.

I find it hard to believe the PO and his shop did not fuss with it more rather then rebuild the alternator in place!!!.

Rebuild yeah, without bearings!!!!!!!!!!!!!!

What is this World coming to?

Anyway sometimes it's hard to do a job right!!

LNGfish · #6 04-03-2009, 12:28 PM

I would have had to use a used bracket but I noticed there is one mounting bolt that comes in from the Front and to get to the head you may have to remove the hormonic balancer. Glad I didn't have to cut it off. Maybe I have the bolt angel over me today!!

charmalu · #7 04-03-2009, 02:42 PM

I had the same problem with that bolt, never could get it loose to adjust the belt.

when I pulled my engine it was easy to remove the whole mount with alt. there is a cut out I believe in the balancer, get it to line up and you will have access to that front bolt.

I had the alt and mount sitting sideways for 3hree weeks soaking it with PB Blaster every one raves about. used an impact gun and could get it to turn ok, but would not slide out

.

finally used a smaller diameter bolt and beat the snot out of it and it finally came out. It is steel in an aluminium housing, water/salt etc... get in there and causes the bolt to rust and swell up making it tight.

I replaced the bolt with a new one and slathered it well with Antiseiz compound.

when I got it out the PB Blaster had only penetrated about 1/4 inch

.

Note: You don`t have to pull the engine to remove the alt. I was replacing the engine anyway.

Charlie

toomany MBZ · #8 04-03-2009, 03:05 PM

Glad to hear you got it out. On the SD I bent a ratchet loosening one of those bolts. Finally got it.
If you can find Kroil, a better than (?) PB blaster penetrant, use it.

LNGfish · #9 04-03-2009, 03:49 PM

Now I see what happened. The original Alterntor was removed and this one was slightly different in dimensions, so this caused the mis alignment at the bottom. Grinded off a few spots on the alternator (boss flats), added a washer, and now it slides right in perfectly aligned!

Took along time to get nothing done, but now atleast I know it can be removed it the alternator needs a real rebuild, like with bearings, lol.

LNGfish · #10 04-03-2009, 03:51 PM

Yeah I saw the cut-out in the Balancer. I did not need to get that bolt out since I wrestled the bolt out. That 2 shops and 3 mechanics could not get it lose.

I'm feeling lucky!

Don't pay me by the hour, you'd go BROKE!

tyl604 · #11 04-03-2009, 04:02 PM

too many MBZ - is that a Harbor Freight ratchet?

LNGfish · #12 04-03-2009, 04:30 PM

Wow, that rachet is sure bent! Were you doing the lefty loosey righty tighty thing?

toomany MBZ · #13 04-04-2009, 12:02 AM

Quote:

Originally Posted by tyl604

too many MBZ - is that a Harbor Freight ratchet?

Unknown, there is no name on it, I forget where I got it.
Still works, tho.
Damn near pulled something in my chest too!

LNGfish, yes. Not the first REALLY tight bolt on a Mercedes. (breaker/cheater bar) On the 240 I had, it was necessary to take off the other bracket, bolted to the engine block, to remove the alternator. That was fun!