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 ShopForum > Technical Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 03-31-2001, 07:58 PM
John34609
Guest
 
Posts: n/a
I just bought a 1984 300D turbodiesel. I work on it every weekend and absolutely love it. Nothing major, just rust repair, dash repair, some steering components needing replacement, hoses, etc. All DIY stuff.

However, I read an earlier post about adjustment on power steering gear on a W123 styled MB. It said to loosen the 17mm nut and then counter clockwise on the threaded allen head fitting inside the 17mm bolt. Well, my fitting was I think 18mm and I had to resort to a 3/4 open end as I didn't have one that would fit. I loosened it and then took the allen head fitting and loosened it counter clockwise. Then tightened back up on the bolt. The result was tighter steering but my question is this: Now the bolt and allen head threaded shaft all turn when the steering wheel is turning (with engine running). Is that normal? I cannot remember if that is supposed to be that way or not. The steering is nice and tight now though!!

Question 2: In an earlier post, someone told me that I should NEVER turn my rotors. My rotors are definitely out of true and I wanted to have them turned to take the shimmy out of braking from highway speeds... the thing likes to shake to pieces if I'm running 70 mph and then have to hit the brakes. ON american cars, I turn them when they get a warp to them.. why would these be any different?

Question 3: My turbo diesel in my 300D runs great. However the idle is a little slow. How do I adjust the idle? It is a 1984 model.... which I think calls for 750 RPM at idle but I think it is closer to 650 at idle. It needs just a little bit of throttle when first started in the morning to prevent the sputters until warmed up. So the question remains, how to adjust the idle???

Please help me!

Thank you!!
Reply With Quote
  #2  
Old 03-31-2001, 09:20 PM
Moderator
 
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
Item 1) The adjustment for the P/S gear box is supposed to be done off the car where the effort to turn can be measured. With experience many have done it on the car. I fix a car a month that has been aligned by several shops with no solution, by readjusting the pitman bearing load. I have done hundreds but never saw one where the bolt turned with the steering. In most cases if the 19mm jam nut isn't tightened securely the bolt will leak. I presume you are too far out.

2) The rotors on MBs seldom have more than 1.2mm of wear tolerance. That is .048in. If they are new then there might be enough there to turn. If they have 30k miles they are half way through that tolerance already. They are designed to be disgarded. And they are so cheap that its probably easy to spend more paying to have one turned than to buy new (at least if you are doing your own work). The standard turning roughness also makes poor brakes.

3) Down the back side of the pump is a 14mm jam nut on a long screw. Loosen the jam nut and tighten (clockwise) the screw.
__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
Reply With Quote
  #3  
Old 04-01-2001, 12:21 PM
John34609
Guest
 
Posts: n/a
Thank you for the sage advise and direction. I will just get new rotors and bearings... you are right, it is really not that expensive to get new front rotors. As for the stearing, I have just about an inch of play in the stearing wheel... maybe a little less, but play nonetheless. It drives me nuts because it is all over the road... the stearing is smooth when you do it, it's just that play that you have to compensate for... how can I adjust it in the car? i.e. without having to remove it from the car?

As for the idle adjustment, is this something ok to do with the car running so you can have someone sit in the car and tell you when you get to approx. 750 RPM? I guess I could just do it by ear, but I want it as low as possible but still idle enough to stay above sputter range.. 650 is just too slow an idle (which is about where it looks to be by eyeballing the tach).

Thank you for your help!

Reply With Quote
  #4  
Old 04-01-2001, 12:51 PM
Moderator
 
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
Play in the steering is aggrevated tremendously if the steering is stiff. By this I mean that if the alignment is right the car should tend to follow the road, the steering is just for direction. IF the steering gear is keeping the wheels from following the road (stiff - this is hard to feel) then one is constantly chasing the road.

The numerous cars I mentioned fixing all had these syptoms which sound just like yours. The play that is adjustable at the top of the pitman shaft is the play between the reciprocating ball carrier and the pitman internal lever. This is a ball and socket. When you adjust the allen counterclockwise one is pulling the socket up to the ball. Once they are together further adjustment causes the box to have enough stiffness that it can keep the wheels slightly turned or anywhere in between. In this state the car seems to wander. The remaining play at this point is in the worm-ball-carrier and can't be removed (assuming no other play in tierods etc.).

I would try readjusting the box till you are sure there is no interference. I do this by reaching down with my right hand and grab the steering coupling right at the input to the gearbox. With your left hand screw the adjustment clockwise till your right hand can feel the the changes your left hand makes (slightly twist the coupling with the right hand back and forth as the adjusment is made).

When I make an adjustment on the car I always feel the play in this method and stop before the play is all gone to avoid the tight situation. This is due to the fact that the stiff box can not be felt except through the idnetification of symptoms, as in your case.
__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
Reply With Quote
  #5  
Old 04-01-2001, 01:02 PM
John34609
Guest
 
Posts: n/a
Thanks again... any tip regarding the idle situation? You told me how but I just wanted to clarify it could be done with the engine running so you can hear it improve, feel it, etc.

Thank you!!
Reply With Quote
  #6  
Old 04-01-2001, 01:06 PM
Moderator
 
Join Date: Mar 2000
Location: Gainesville FL
Posts: 6,844
Yes, do it with it running. I hesitate to recommend the use of the cars tach for adjustment purposes. I doubt that it is accurate to within 200rpm. Be sure not to get it too fast as most rythmic idle surges are due to too high idle speed.
__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician
Reply With Quote
  #7  
Old 04-01-2001, 01:12 PM
John34609
Guest
 
Posts: n/a
Thank you for the quick reply Steve. I only need to raise it just a little bit... right now it is just a whisker too low and it causes a large amount of vibration at idle.. I could also have bad motor mounts as the ones on it are very crackly looking on the rubber part. However, when I use my foot to slowly raise the rpm's, the vibration goes away with just a little more idle speed.

Have a great day!
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
We often overlook Fuel Pump damage--Low Sulfur Fuels and bad fuel (85 300D) Carrameow Diesel Discussion 16 11-15-2007 06:43 AM
Opinions on purchasing a 1987 300D swogee Diesel Discussion 12 05-03-2005 11:27 AM
1976 W115 300D motor into 1979 W123 300D sebtowne114 Diesel Discussion 5 04-14-2005 08:26 AM
auto tranmission problem in 1981 300d o2pilot Diesel Discussion 2 06-15-2004 12:19 PM
300D turbo slushbox vs 300D n/a 4 speed The Warden Diesel Discussion 5 05-28-2004 01:40 AM



All times are GMT -4. The time now is 04:53 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page