Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 05-21-2004, 12:47 AM
Registered User
 
Join Date: May 2004
Location: Yamhill County, Oregon
Posts: 5
need help!!! 78 300d ... pulley will not stay on!

I have a 1978 300D...

long story short...

Driving to work and I lost PS and all the lights came on, I drove home... found a bolt in the driveway... opened hood to see the balancer&pulley nolonger attached to the engine....

i put it back on and put all the belts back... but it will not stay tight...

after just a couple of minutes the lights some on and the pulley is loose, nearly fallen off. I cannot seem to make it stay on.... WTF!!!!!

thanks

Reply With Quote
  #2  
Old 05-21-2004, 01:48 PM
MrCjames's Avatar
California Dreaming
 
Join Date: Jun 2003
Location: SF Bay Area
Posts: 599
Ouch, you may need to put a fork in the engine as the crankshaft snot sounds damaged. I assume you are referring to the “Crankshaft Balancer?” If so you might be able to do some things but I do not believe you will have any long term solution without changing the crank as well, the items that are currently broken.
Reply With Quote
  #3  
Old 05-21-2004, 04:50 PM
bjcsc's Avatar
Registered User
 
Join Date: Nov 2002
Location: Charleston, SC
Posts: 672
the items that are currently broken what? What pulley are you referring to? Can you post or email a pic?
__________________
1982 Mercedes-Benz 300CD
1982 Mercedes-Benz 240D - stick
Reply With Quote
  #4  
Old 05-22-2004, 03:09 AM
Registered User
 
Join Date: Jan 2001
Location: oregon
Posts: 2,013
If you are talking about the front crank pully and harmonic balancer bolt I would try a new bolt (probably a dealer part) and blue locktite and make sure that you are toqureing it to the right specs my 86 SE specs are 250 lps "thats tight".................

William Rogers........
Reply With Quote
  #5  
Old 05-22-2004, 04:23 AM
Registered User
 
Join Date: May 2004
Location: Yamhill County, Oregon
Posts: 5
I will try to make it that tight and see, well Ill check my book and see what the exact torque is for mine.


The bolt threads looks okay, what signs should I look for to tell if the bolt needs to be replaced? (besides it falling out )

And just for fun, what could have caused it to come off in the first place? I have had many cars, and some were not in the best shape... but this is a first for me.

Thanks!!!

~Brian
Reply With Quote
  #6  
Old 05-22-2004, 04:34 AM
Registered User
 
Join Date: May 2004
Location: Yamhill County, Oregon
Posts: 5
HOLY CRAP!!!!!


My torque wrench only goes up to 150 ft-lbs ?????

well Ill give it a shot anyhow!
Reply With Quote
  #7  
Old 05-22-2004, 08:49 AM
LarryBible
Guest
 
Posts: n/a
You need to confirm that you are talking about the heavy balancer that is held on with a 27MM head size bolt. If so, are you getting the pins in place? There are two pins about 1/4" dia. that pin the balancer in position. They are tricky to get properly in place.

Is this the pulley on the crankshaft or another pulley? Please be more specific.

Good luck,
Reply With Quote
  #8  
Old 05-23-2004, 01:47 AM
Registered User
 
Join Date: May 2004
Location: Yamhill County, Oregon
Posts: 5
The pulley is the one connected to the balancer. Then onto the crankshaft.

The balancer and pulley came off as one piece and went back on as such. I am assuming that everything is lined up because everything is lined up properly ( ie. the belts) and I can turn the crank by turning the pulley.

So I went back out tonight to try it again with the torque wrench... but I dont think I am doing it properly... I continue to block it and tighten... but once I get to a certain point it will not tighten.

While the balance is blocked from moving and I am tightening the bolt, the crank is turning the motor, they pulleys, etc., arent moving... but the crank is....


How can I stop it from turning the motor so that I can fully tighten it? Thanks

~Brian
Reply With Quote
  #9  
Old 05-23-2004, 02:20 AM
Registered User
 
Join Date: Jan 2001
Location: oregon
Posts: 2,013
You have to use a flywheel or starter ring lock.You can buy them from aftermarket MB tool sites online or improvise one . I used a very large screw driver and a pair of needle nose vice grips using one of the two holes in the front bottom of the bellhousing that is ment for the MB locking tool.........

William Rogers..........
Reply With Quote
  #10  
Old 05-23-2004, 05:21 AM
Registered User
 
Join Date: May 2004
Location: Yamhill County, Oregon
Posts: 5
so there are access holes near the bellhousing that I can insert a screwdriver to block the flywheel?

How do I access these holes, need I remove a cover or some kind of inspection plate? and do they face to the front, rear, driver or passenger side of the car?

THanks much, I cannot wait until I can drive her again!!!!


~Brian
Reply With Quote
  #11  
Old 05-23-2004, 10:49 AM
LarryBible
Guest
 
Posts: n/a
Yes there is an inspection plate on the lower front of the transmission housing. The plate is sheet metal, is vertical and is held in place with a few small fasteners.

You have another problem, however, if you are blocking the balancer and turning the crankshaft, you do not have any pins in place. There are two metal dowel pins that key the balancer in place on the crankshaft. These keys are what prevent the balancer from turning on the crankshaft, the bolt just holds it firm rearward so that the pins are held in place.

Pull the balancer and look at the relationship between it and the crankshaft and I think you'll see what I mean.

It could be that the notches in the crankshaft and balancer are damaged so that you can't really tell what's going on.

If you will search harmonic balancer in the diesel discussion forum, you will find much information about this.

Good luck,
Reply With Quote
  #12  
Old 05-23-2004, 03:30 PM
Moderator
 
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
And its worse than that....

When examined closely one will see that there are two dowels keying the balancer. You will note engine timing marks on the balancer, there is only ONE right position and MB would in no way allow you to do it wrong, thus the two doewls are not 180deg apart. You have to know where the motor is and whether you are on the right stroke to chose between the two positions as it isn't obvious until close observation on assembly.

That was the good part, I can tell you that there is about one chance of solving the problem without a crank repair. That would be to start with a new balancer or atleast a used one that hasn't failed. This one has failed!

A proper fitting balancer will have to be pulled onto the crank with a puller. It will have to be done carefully as the two halfs of the dowel hole must align perfectly and once a few millimeters on the thing doesn't turn relative to the crank by hand. A long heavy punch and hammer can tap out a slight misalignment as the balancer approaches proper depth. Once in position the dowels should driven into the two aligned holes with a hammer and the large bolt properly torqued.

You stand little chance of a long term repair if you can turn or install the balancer by hand. It must be snug to down right tight. We have fixed ones with too little interference by drilling two new dowels at 90 deg to the pair already there. Using a bearing/stud mount type locktite might be a last resort, used on the crank to balancer fit, not the bolt.
__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
Reply With Quote
  #13  
Old 05-24-2004, 02:24 PM
MrCjames's Avatar
California Dreaming
 
Join Date: Jun 2003
Location: SF Bay Area
Posts: 599
Steve paints the picture pretty clear about the challenges you face if you choose to work with what you have. His suggestion about drilling new holes would serve well for a better repair that may work for an undetermined amount of time.

The color of loctite you would be looking for is Green.

Good luck


Last edited by MrCjames; 05-24-2004 at 03:01 PM.
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 10:36 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2023, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page