Alternator belts keep squealing. 1984 300D Turbodiesel - Page 2 - PeachParts Mercedes-Benz Forum

lietuviai · #16 10-09-2010, 11:41 PM

Quote:

Originally Posted by Diesel911

Anoter Wild thought
When the Alternator is charging it is harder to turn. So if there was some sort of extreme Electrical load on the Alternator that would make it even more difficult to turn.

I have also been asuming there is no Oil on the Belts.

I've run with heavy loads and with little load on the alternator with the same squealing issues. I've even used a larger higher amp alternator from a 420 SEL with the same issues.
Yes, the belts have been clean.

JiveTurkey · #17 10-09-2010, 11:42 PM

Thank you everyone for the replies on the location of adjustment bolts and mounting bolts. You made my day tomorrow a LOT easier.

Lietuviai: I know this sounds stupid, (because I'm tossing a probably lame idea here) but have you tried using any "belt conditioner?" I had a friend with a diesel Merc a while back with similar (but not identical) problems and the belt conditioner at least kept the belts from chiiiiiiiiirrrrrrrrpSQUEEEEEEEEEELing all the time.

layback40 · #18 10-09-2010, 11:44 PM

Good idea jive, dry lube often gets rid of noise.

Brian Carlton · #19 10-09-2010, 11:47 PM

Over the last two days, I spend four hours fixing the same exact problem on the SD.

When I put the SD back in service about one year ago, it got a set of new belts. However, due to the miserable design on the '84, a 1000 mm belt cannot be installed without removing the fan and the pulley. The alternator cannot pivot in its bracket because the bracket hits the water outlet from the head that is directly above it.

So, I decide to procure some 1005 mm belts in the valiant attempt to avoid removal of the fan and the pulley. No dice.......the 5mm didn't mean squat and the pulley had to come off anyway.

Got it all done last year and, over the course of several months, the belts would loosen and I'd retighten them. This happened three times until I finally got to the end of the travel in the bracket. Well, the summer arrived and the SD went back in the garage...........the SDL has perfect a/c and I had far too much work in the business to address the SD.

Now, this fall........back to the SD.

After removing the fan and the two belts, I compared them to the newly procured stock Continental 1000 mm belts. The only difference should have been the additional 5mm........both belts were of the same model.

However, the width of the stock belt was measured at .440".........the width of the 1005mm belt was measured at .380". Also, the section height of the stock belt was a bit taller than the section height of the 1005mm belt. The 1005mm belts were clearly of thinner construction and appeared to be a completely different model of belt.

So, the SD is finally back together and I am really hoping that the stock Continental 1000 mm belts will last more than 5K miles.........because it's a miserable job to replace them.

I concur with the need to utilize only the 10mm stock Continental belts.........anything else probably won't do the job.

lietuviai · #20 10-09-2010, 11:49 PM

I've probably tried belt dressings before but they're just baid-aid fixes. They only hide the problem which still needs to be addressed after they wear off.

Diesel911 · #21 10-09-2010, 11:50 PM

Quote:

Originally Posted by JiveTurkey

Don't mean to hijack the OP's thread but...
I want to replace the alternator belts (I have a conti matched set), the AC belt, and keep my current power steering belt as it's fine with almost no wear. I'm familiar with how to loosen the AC belts mounting points and how to use it's tensioner. With the alternator what size are the bolts holding it in position and (rough idea) where are they?
Main question. With the power steering belt- How/where do I loosen the pump? And Where in the tensioner?

Again, don't mean to do a threadjack but my question is somewhat related as I have the same squeeling / mismatched / worn out alternator belts. I'll let you know how the matched pair of continental belts are when I get them on OP. I got them from Phil when he was still selling parts

I can not describe it easily but if you look you will see them.
There is if I remember correct; 3 Bolts with nuts that hold the Power Steering down.
Loosen those.
If you look straight on at the Power Steering Pump from the Pulley end at about the 2 O'clock position is a separate Bolt that adjust the Tension; the Bolt does not face the front but you can see it if you stand about where the Glow Plug Ralay is and peek under the Hoses.
On mine it is under on of the Hoses or Tubings.

lietuviai · #22 10-09-2010, 11:57 PM

Brian, I've even tried using a wider width belt. I went to a parts supplier and had them match up a wider set to the OEM Conti's hoping for a solution. It only probably lasted the same 5K as yours did.
I see you share the same misery with the OM617 belt design. I'm probably going to end up parking my 300D if I don't find a satisfactory solution soon.

lietuviai · #23 10-10-2010, 12:03 AM

Quote:

Originally Posted by Diesel911

I cannt describe it easily but if you look you will see them.
There is if I remember correct; 3 Bolts with nuts that hold the Power Steering down.
Loosen those.
If you look straight on at the Power Steering Pump from the Pulley end at about the 2 O'clock position is a separate Bolt that adjust the Tension; the Bolt does not face the front but you can see it if you stand about where the Glow Plug Ralay is and peek under the Hoses.
On mine it is under on of the Hoses or Tubings.

You are correct about the location of the PS tensioning bolt. You provided a better description of it's location.
Beware, the tensioner is threaded into a POS plastic part that is easily stripped because of the age of the part now. Mine has stripped a second time and it is a real PITA to replace. You practically need to remove the pump to change it. I just used a large pry bar to tension the PS belt after it stripped again.

DeliveryValve · #24 10-10-2010, 02:57 AM

Quote:

Originally Posted by vstech

if the crank pulley checks out ok, go to an IMPORT supply house, or call fastlane/allparts express and order 10MM x 1000mm MATCHED pair belts.
..

lietuviai's 1984 300D would be using 10x1037 belts if he has the factory pulley, no way a 10x1000 belt would get on. If it was an '83-85 300SD, then he'll be using 10x1000 belts like Brian's.

.

charmalu · #25 10-10-2010, 08:55 AM

Quote:

Originally Posted by lietuviai

I've heard of crank pulleys being loose before but I didn't think to even go there. When I have a chance, I'll see if that's the case.
Just want to add, the power steering pump has never had a belt issue nor the A/C pump back when it still worked.
Any serpentine conversions out there for the OM617?

Here is a serpentine 617 set up. scroll down to post# 62

http://www.superturbodiesel.com/std/new-project-skunkwerks-em9d-t-858-2.html

Charlie

Beastie · #26 10-10-2010, 10:16 AM

When I got my 85 300SD a few months ago I has the same problem. A shop had installed a belt that was for all Diesels that year. It was not ! Get the correct belt and order it using the engine # At least for my car there was a change about mid yer and when I ordered the first belt ignored the side note referencing the engine #. Same problem. Got the right belt and all is well.
May not be your issue but try the easiest item first.

lietuviai · #27 10-10-2010, 11:20 AM

That serpentine belt set up looks sweet. Too bad that's more work to install than probably trying to solve my issue.
I think I had 10X1035's or 10X1025's on my car when I used the stock size. I don't remember anymore. I was only able to go a few hundred miles with those before they squealed. Once they squealed, they wouldn't go but a few days without squealing again. I then used a 11X1015 set which seemed to work fine, compared to the stock size. I was able to go a few thousand miles before they squealed. But after they started squealing, they would only go a few hundred miles before needing repeated adjustment.
My car has an '84 engine in it so I used what was supposedly stock for it. My car originally had a Cali version 84 but the engine I found was a fed model. I doubt that would make any difference. Truth be told, the engine didn't have an alternator when I got it. Maybe I wouldn't have had any issues if I had the original alternator. I guess I'll never know.

Beastie · #28 10-10-2010, 11:51 AM

Check for the correct belt. Use the engine number on the block in case it has been swapped out. Avoid any place that sells you a belt listed "fit's all"

qwerty · #29 10-10-2010, 11:56 AM

Quote:

Originally Posted by Beastie

Avoid any place that sells you a belt listed "fit's all"

That shouldn't be hard to do!!!

lietuviai · #30 10-10-2010, 12:36 PM

Quote:

Originally Posted by Beastie

Check for the correct belt. Use the engine number on the block in case it has been swapped out. Avoid any place that sells you a belt listed "fit's all"

I quit using belts that were designated for my car. I originally went by the Technical Data Book printed by Mercedes Benz that I have for my car. It shows 9.5X1035's for my car. Those specified belts never lasted long which is why I had a set matched up that would just barely fit over the pulleys when I installed them. I barely needed to turn the tension bolt to take out the slack. OTH, the stock belts were "easy" to install but I would end up maxing out the tension bolt after only a few adjustments to eliminate the squealing.
Gathering my thoughts here, I think this monster is just eating belts. Although the pulleys appear good and appear to line up correctly, (I checked the alignment with a laser) I feel I may just end up buying all new pulleys (crank, water pump, etc.) and try another new alternator.