M-100 Message Board
M-100 Message Board
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
Password:
Save Password
Forgot your Password?

 All Forums
 M-100 Message Forum
 6.9
 Center uni joint
 New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

aussie 6.9

14 Posts

Posted - 03/11/2018 :  21:58:46  Show Profile  Reply with Quote
Could somebody give me advice on how to replace the center uni joint on a 6.9 please . Regards Mark

T.J. Woods

Australia
282 Posts

Posted - 03/12/2018 :  01:31:41  Show Profile  Reply with Quote
The best option would be to take it to a tailshaft specialist as the joint is staked in. Iíve heard of people having it modified to accept circlips with a bit of machine work,

Tim

1976 450SEL 6.9 #1432
1979 450SEL 6.9 #5866
1969 300SEL 6.3 #1394
Go to Top of Page

aussie 6.9

14 Posts

Posted - 04/05/2018 :  22:40:44  Show Profile  Reply with Quote
Thanks for that . Since you replied I have had driveline shop replace the uni but they have had two attempts at balancing the shaft and it still thumps at low speed under acceleration. Ok at high speed . They say they can't balance it at low speed . Any suggestions? The work has been done in Dubbo NSWr
Go to Top of Page

mgmg69

USA
6 Posts

Posted - 04/05/2018 :  23:57:32  Show Profile  Reply with Quote
Driveline troubles like this always are a drag.

Since you say you are getting "thumping" at slow speed when accelerate, I would say that the balancing of the driveshaft is not the issue. Sounds like you have either (1) a bad center support bearing or (2) bad u joint(s). You can visually inspect the center support rubber but of the bearing is bad it can bind. U joints should also be able to be felt when driveshaft is out if you try and articulate the u joint.

Balancing issues usually cause vibration at speed not thumping.

Hope this helps

450sel 6.9 Restore in Progress
Go to Top of Page

Aaron H

USA
487 Posts

Posted - 04/10/2018 :  12:37:08  Show Profile  Reply with Quote
Don't rule out a bad output shaft bearing in the transmission, either. When these wear out you'll get this low speed thump. As MGMG69 stated, low speed vibrations are not due to an out of balance. They're due to what all he mentioned. Center support bushing/bearing, universal joints, AND can also be due to bad flex discs. When the front flex disc is renewed, the rear one must always be renewed with it, as well. Be cautious about buying aftermarket flex discs. They often cause high speed vibrations.
Go to Top of Page

benzman70

USA
205 Posts

Posted - 04/10/2018 :  13:27:34  Show Profile  Reply with Quote
aussie, I had one that had defective rear subframe mounting bushings that let the rear diff pinion angle change under acceleration, causing the rear flex disc to wobble producing a thumping feeling.Replaced the subframe bushings and rear diff to body mount and problem went away.
Go to Top of Page

aussie 6.9

14 Posts

Posted - 04/19/2018 :  07:06:17  Show Profile  Reply with Quote
It seems that the driveline shop have damaged the shaft fitting the new uni. I have decided to order a new complete shaft which are available at reasonable cost. Will keep foum posted.
Go to Top of Page

aussie 6.9

14 Posts

Posted - 06/13/2018 :  06:22:31  Show Profile  Reply with Quote
New Dorman shaft has arrived. Yet to fit it.
Go to Top of Page

aussie 6.9

14 Posts

Posted - 08/16/2018 :  06:52:59  Show Profile  Reply with Quote
New shaft fitted and all is well.
Go to Top of Page

Ron B

Australia
11633 Posts

Posted - 08/28/2018 :  23:40:23  Show Profile  Visit Ron B's Homepage  Reply with Quote
Was your car delivered in Dubbo ? I used to live west of Dubbo . (Condobolin and Cobar) .There was one in Condobolin, Blue mettalic from memory owned by an old family who owned a supermarket there and the other was in Cobar ,owned by the local Doctor.
Go to Top of Page

aussie 6.9

14 Posts

Posted - 09/08/2018 :  07:38:36  Show Profile  Reply with Quote
Hi Ron. My car came from Sydney and I am the second owner. I have had it for 20 years and try to keep it in good mechanical condition. Dr Brady has passed on but I think his car is still in Cobar. Chamens own the store in Condoblin but i don't know of that car. There is a very nice one owner sub 100k car in Dubbo . My car and these others are all looked after by Coadys automotive inDubbo, My car is on full rego and in regular use. I also have a 6.9 parts car , a 450sl and a w220 s430 for everyday use. Regards Mark.
Go to Top of Page

Ron B

Australia
11633 Posts

Posted - 09/12/2018 :  06:47:31  Show Profile  Visit Ron B's Homepage  Reply with Quote
I would have imagined Dr Brady to have passed by now as he was pretty old when I knew him almost 30 years ago . It wasn't John Chamens Supermarket but the other one (yes Condo once had two Supermarkets...) The Chamens were big on US cars and his father had once owned a early Oldsmobile Rocket 88 .I can't for the life of me remember the family's name but the car was Blue Gray mettalic and a real gem as it was hardly ever driven. Life is getting grim out there these days as one more Drought hits. I think we may have spoken some years ago actually.
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
M-100 Message Board © 2002-2015 International M-100 Group, Inc. Go To Top Of Page
This page was generated in 0.22 seconds. Powered By: Snitz Forums 2000 Version 3.4.06