1250V is home, now the work begins! - Page 2 - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
post #11 of 15 (permalink) Old 05-23-2019, 01:40 PM
Lifetime Premium Member
 
Date registered: Jun 2016
Vehicle: U-1300, 3 ea 406, 3 ea 404, Haflinger, 2 ea LMTV.
Location: Greenback, TN
Posts: 72
Mentioned: 0 Post(s)
Quoted: 17 Post(s)
Lifetime Premium Member
I made that exhaust brake mistake when the overdrive went to neutral during a shift, on a steep hill and curve on the Blue Ridge Parkway. That will wake you up when the music stops and the steering wheel goes dead.
tennmog is offline  
Sponsored Links
Advertisement
 
post #12 of 15 (permalink) Old 05-23-2019, 01:52 PM
BenzWorld Elite
 
TRUKTOR's Avatar
 
Date registered: May 2006
Vehicle: U1450L DOKA
Location: BOZEMAN, MONTANA
Posts: 9,414
Mentioned: 3 Post(s)
Quoted: 151 Post(s)
The overdrive finding neutral is an attention getter.

Going from compression braking to freewheeling, just when you were downshifting for more braking, is a drill for sure. It does not happen very often, fortunately, but you get pretty quick at stabbing the clutch in hope of finding something.
TRUKTOR is offline  
post #13 of 15 (permalink) Old 05-23-2019, 07:46 PM
BenzWorld Senior Member
 
logonwheeler's Avatar
 
Date registered: Dec 2014
Vehicle: 1986 U1300L Expedition Camper
Location: Colorado Springs, CO
Posts: 413
Mentioned: 0 Post(s)
Quoted: 65 Post(s)
Any idea why the OD inadvertently goes into neutral? I have had our Claas do the same and wondering if anyone has discovered the root cause.
logonwheeler is offline  
Sponsored Links
Advertisement
 
post #14 of 15 (permalink) Old 05-23-2019, 09:10 PM
BenzWorld Elite
 
ACAD_Cowboy's Avatar
 
Date registered: Oct 2009
Vehicle: 2015 Rubicon Unlimited (Let the shame be upon me!)
Location: Long Island, NY
Posts: 3,709
Mentioned: 0 Post(s)
Quoted: 168 Post(s)
Send a message via AIM to ACAD_Cowboy

That seems to sum it up, it just happens.

-= Francis =-

These, in the day when heaven was falling, The hour when earth's foundations fled, Followed their mercenary calling, And took their wages, and are dead.

Their shoulders held the sky suspended; They stood, and earth's foundations stay; What God abandoned, these defended, And saved the sum of things for pay.

A.E. Housman
ACAD_Cowboy is online now  
post #15 of 15 (permalink) Old 05-24-2019, 07:29 AM
BenzWorld Elite
 
TRUKTOR's Avatar
 
Date registered: May 2006
Vehicle: U1450L DOKA
Location: BOZEMAN, MONTANA
Posts: 9,414
Mentioned: 3 Post(s)
Quoted: 151 Post(s)
In my case, I have attributed it to two things :

1. 'Lazy Leg' clutch work. This is just not pushing the clutch pedal far enough to fully actuate the button on the solenoid. Since the clutch will work and allow for shifting without actually being floored, when driving along for the course of a day, I think that I sometimes push the clutch pedal far enough to tap the button, which is enough to find neutral, but not enough to complete the shift.

In my experience, I only find neutral when shifting while also shifting the Claas OD, either up or down. During regular shifting, which does not involve a range change on the OD, it always works as normal.

The reason that I think that the 'Lazy Leg' is the culprit is because I can always avoid the issue if I concentrate on flooring the clutch and making good contact. The clutch pedal is fairly stiff, so I think it is normal to tend to short stroke it, which can lead to an incomplete OD shift, which leaves you in neutral.

I never have the problem if I think about the clutch action - therefore : Pilot Error.

This is the main cause, in my case.

2. On my truck (yellow box / arrow), I don't have the little pad welded to the clutch arm which is specifically added to insure that the arm hits the button. My Green truck had the pad, my new truck does not. It is on the list....

I found neutral on the OD with the green truck, so the pad won't overcome Lazy Leg, but it does make sure the clutch arm hits the button on a full stroke.

I have found that without the pad, I can push the clutch in a way that the arm flexes, and the slim target of the button, combined with the narrow edge of the clutch arm, allows for a glancing blow, which works the same as the lazy Leg - enough contact to hit the button, but not enough to complete the shift. If I don't push the clutch at an angle, it does not flex, and does not miss the button dead center, and all is good.

So, the obvious answer for this problem is to add the pad.

Both of my Class OD's were installed by Hellgeth, but the installation on the green truck was years after the installation on the current truck. In the Hellgeth Instruction sheet, they show the installation of the pad as part of the deal. I think that experience showed them that the clutch arm was just too slim to be a reliable actuator, so they modified their approach, and added the little pad.

Scott at EI mentioned a mechanical problem related to this, which involved crud in a valve body or something , which is externally mounted on the Claas unit, and easy to address. His input is included in a thread on this here somewhere.

I have not had any problem with that part of the system.

Oh, the wad of wires hanging out from behind the black panel are normally all stowed and zip-tied securely in place. I was working on the Voltmeters, and that panel was in and out a few times that day. I would not drive around with it
as it appears in the photo, with the three stainless screws backed out, etc.
Attached Thumbnails
Click image for larger version

Name:	CLAAS BUTTON.jpg
Views:	13
Size:	56.4 KB
ID:	2515280   Click image for larger version

Name:	Screen shot 2013-04-04 at 3.31.07 PM.png
Views:	15
Size:	529.5 KB
ID:	2515282   Click image for larger version

Name:	Screen Shot 2019-05-24 at 8.29.01 AM.jpg
Views:	13
Size:	49.9 KB
ID:	2515288  

Last edited by TRUKTOR; 05-24-2019 at 09:38 PM.
TRUKTOR is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > Mercedes-Benz Vans/Trucks/SUV/Others > Unimog

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may 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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 

Title goes here

close
video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome