2 or 4 speed crawler gears on the 404. - Mercedes-Benz Forum
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 15 (permalink) Old 12-29-2011, 10:02 AM Thread Starter
BenzWorld Elite
 
dxmedia's Avatar
 
Date registered: Mar 2009
Vehicle: 1981 u1300L, 1998 s280
Location: Scotland
Posts: 2,113
Mentioned: 0 Post(s)
Quoted: 18 Post(s)
(Thread Starter)
2 or 4 speed crawler gears on the 404.

I've done the searches and done some reading and still have a few questions.

I've been offered a set of both 2 and 4 speed crawlers gears, new old stock. Not much in them price wise and both within budget (actually 2 sets of the 4 but I'm gassing with a guy to share the shipping and go together to get a couple of sets - It's great living this side of the pond )

Anyway the questions.

Non of the sets come with gaskets. I understand that the gaskets are needed to set the backlash in the gears. Can universal gasket material be used? Does anyone have the depth of the factory gasket material so I can get similar?

Strength, I've heard that the 2 speed set is stronger. I've also read that the strength difference it not between the 2 speed and the 4 speed, but rather the strength of the castings. The later castings having the stronger design. I recall seeing a photo many moons ago where a set of crawler gears only had 1/2 a collar over one part and a question on if this was machined or factory, I seem to recall that this was the weak point? Can anyone recall or have anything to add? The sets I've been offered, both 2 and 4 speed have the 'full' castings.

8 speed conversion. This one is bending my head a little so please bare with me.

I'm planning on doing the 8 speed conversion. Not the one with the 2nd lever (I have a PTO which is not straight forward to work in), but the 'other' way which involves removing a section in the shift plate and it opens up the ability to select 3 and 4 whilst in low range, but the shift pattern is backwards - there are a few guys on difflock.com who have performed this mod. It means that the shift pattern is :-

3 1 5 7
- gate -
4 2 6 8

My knowledge of gearboxes isn't great, so please excuse my ignorance regarding this.

With the 8 speed mod using the second lever, from what I recall there's an alteration made to the reverse lock out which allows 4 speeds in reverse. The issue with crawler gears though is that they cannot be engaged whilst the gearbox is in reverse or 2 gears end up selected at the same time - and bang

Does anyone know if doing the 8 speed mod by cutting away the shift plate has the same effect? As in, it is possible to end up in the situation where reverse gear and low box could be engaged at the same time?

and one last question (was that a phew from the back?)

With the 8 speed mod and crawlers. From what I understand it that the gearbox is a 4 speed box, once the gate is passed in an un-modified box a second gearset is moved in to play which is a lower final output ratio.
With a 2 speed crawler set, another lower ratio is added to the final output, it's called a 2 speed since gears 1 and 2 on the main transmission give 2 different ratios on the final output, whilst in fact the 2 speed crawler is infact just a single lower final output. The 4 speed, is this 2 more lower output ratios (I understand that the final output on the 4 isn't lower than the 2 but it's got an intermediate ratio as well)?

So, with a 4 speed crawler set on an 8 speed conversion, does this make a 404 into a 20 speed?

4 gears in Low Low Low
4 gears in Low Low
4 gears in Factory Low
4 gears in High
4 gears in Reverse

and a 2 speed, is this 16 speed?
4 gears in Low Low Low
4 gears in Factory Low
4 gears in High
4 gears in Reverse?

many thanks in advance if anyone can clarify this for me

Chris.
dxmedia is offline  
Sponsored Links
Advertisement
 
post #2 of 15 (permalink) Old 12-29-2011, 10:32 AM
BenzWorld Junior Member
 
Date registered: Dec 2011
Vehicle: 1963 Unimog 404
Location: County Durham, UK.
Posts: 16
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Hello fellow 'Moggers.
I'm the bloke Chris is gassing to about these so I'll be very keen to hear any feedback. Mine is primarily an off-road toy. So I would also ask how easy is the four speed to operate compared to the two when out playing?

Regards,
Rob.
Rob0tman is offline  
post #3 of 15 (permalink) Old 12-29-2011, 10:34 AM
Moderator
 
techMOGogy's Avatar
 
Date registered: Sep 2008
Vehicle: 72 Haflinger: 75 Pinzgauer 2.7i, 94 & 96 350GDT
Location: Ontario, Canada
Posts: 1,659
Mentioned: 0 Post(s)
Quoted: 42 Post(s)
Lifetime Premium Member
Garage
- I can post some info regarding the strength "ears/collars" issue - see below
- Can help next Tues when I am back at work with thickness of gasket as I have one at the office I can measure.
- As for the 8 speed and crawlers - that is hurting my head already so I will leave to someone else to comment but I am thinking after the 8 speed conversion + crawlers your would be at 10 and 12 speed.

Some basic info (from one of my old posts):
Regarding crawler gears: originally, the Unimog 404 was offered with auxiliary crawler gears for snow blowers and other applications. These were available in both 2 and 4 extra gears supplementing the existing 1st and 2nd. For example, with the 2 speed crawler, 1st and 2nd are first gone through in the crawler "in" position, then in the "out" position, which are the standard ratios. With the 4 speed crawler, you get to shift the 1st and 2nd gate again, all before going into standard 3rd gear. The addition of a 2-speed crawler gear gives you an 8-speed Unimog 404. The addition of a 4-speed crawler gear gives you a 10-speed Unimog 404.

Here's the info from the Unimog repair manual on the 2-speed crawler gear ratios:
ratio max speed 1st gear (standard) 1 : 14.931 7.13 km/h
2nd gear (standard) 1 : 8.232 13.28 km/h
1st gear (w/ crawler) 1 : 46.01 2.88 km/h
2nd gear (w/ crawler) 1 : 25.343 4.30 km/h

Don't have the exact ratios on the 4-speed crawler gears. Basically, the 4-speed gears do not give you any lower gears than the 2-speed set, but it is a "finer" ratio.
Also see my old post here with pics of what the 'stonger' set looks like

--------
Tech

Last edited by techMOGogy; 12-29-2011 at 10:43 AM.
techMOGogy is offline  
Sponsored Links
Advertisement
 
post #4 of 15 (permalink) Old 12-29-2011, 10:39 AM
Moderator
 
techMOGogy's Avatar
 
Date registered: Sep 2008
Vehicle: 72 Haflinger: 75 Pinzgauer 2.7i, 94 & 96 350GDT
Location: Ontario, Canada
Posts: 1,659
Mentioned: 0 Post(s)
Quoted: 42 Post(s)
Lifetime Premium Member
Garage
Quote:
Originally Posted by Rob0tman View Post
Hello fellow 'Moggers.
I'm the bloke Chris is gassing to about these so I'll be very keen to hear any feedback. Mine is primarily an off-road toy. So I would also ask how easy is the four speed to operate compared to the two when out playing?

Regards,
Rob.
1. Welcome to the forum!
2. See here for an interesting mod that lets you work your crawlers like they "should" work when offroading (forward to reverse with 1 lever while in crawlers which can be a life saver dep on what you've gotten yourself into while wheeling).

--------
Tech

Last edited by techMOGogy; 12-29-2011 at 10:45 AM.
techMOGogy is offline  
post #5 of 15 (permalink) Old 12-29-2011, 10:45 AM Thread Starter
BenzWorld Elite
 
dxmedia's Avatar
 
Date registered: Mar 2009
Vehicle: 1981 u1300L, 1998 s280
Location: Scotland
Posts: 2,113
Mentioned: 0 Post(s)
Quoted: 18 Post(s)
(Thread Starter)
Thank you, it appears that the sets being offered have the thinner shafts, can anyone confirm from this picture?

(the 4 speed one)
Attached Thumbnails
Click image for larger version

Name:	4speed.jpg
Views:	784
Size:	36.3 KB
ID:	417657  
dxmedia is offline  
post #6 of 15 (permalink) Old 12-29-2011, 10:50 AM
BenzWorld Member
 
Date registered: Feb 2011
Location: Herndon, VA, USA
Posts: 219
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
This discussion also turned into much to do with gears and was very helpful to me. Good read if you haven't found it already.
kevin h is offline  
post #7 of 15 (permalink) Old 12-29-2011, 10:55 AM
BenzWorld Junior Member
 
Date registered: Dec 2011
Vehicle: 1963 Unimog 404
Location: County Durham, UK.
Posts: 16
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Thanks for the welcome.

I signed up on the back of Chris posting this, very glad I did and also it's a good thing I'm not back to work for a while as it looks like I'll be doing a massive amount of reading.
Rob0tman is offline  
post #8 of 15 (permalink) Old 12-29-2011, 10:59 AM
Moderator
 
techMOGogy's Avatar
 
Date registered: Sep 2008
Vehicle: 72 Haflinger: 75 Pinzgauer 2.7i, 94 & 96 350GDT
Location: Ontario, Canada
Posts: 1,659
Mentioned: 0 Post(s)
Quoted: 42 Post(s)
Lifetime Premium Member
Garage
Quote:
Originally Posted by kevin h View Post
This discussion also turned into much to do with gears and was very helpful to me. Good read if you haven't found it already.
That thread seems to be for the square and round cab mogs vs the 404.

--------
Tech
techMOGogy is offline  
post #9 of 15 (permalink) Old 12-29-2011, 11:14 AM Thread Starter
BenzWorld Elite
 
dxmedia's Avatar
 
Date registered: Mar 2009
Vehicle: 1981 u1300L, 1998 s280
Location: Scotland
Posts: 2,113
Mentioned: 0 Post(s)
Quoted: 18 Post(s)
(Thread Starter)
It does briefly touch the 404 box, just getting to the end of the thread now. Not really the details though, I don't think I've read anywhere about an 8 speed conversion and a 4 speed crawler set up.
dxmedia is offline  
post #10 of 15 (permalink) Old 12-29-2011, 03:16 PM
Moderator
 
techMOGogy's Avatar
 
Date registered: Sep 2008
Vehicle: 72 Haflinger: 75 Pinzgauer 2.7i, 94 & 96 350GDT
Location: Ontario, Canada
Posts: 1,659
Mentioned: 0 Post(s)
Quoted: 42 Post(s)
Lifetime Premium Member
Garage
Do you have a better photo?

--------
Tech
techMOGogy 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



Similar Threads
Topic Author Forum Replies Last Post
Crawler Gears Anyone! kimosawboy Unimog 2 03-25-2010 06:19 PM
404 Crawler gears and Pto set up kimosawboy Unimog 1 10-11-2009 04:08 AM
Crawler Gears lakes4us Unimog 5 08-18-2007 10:50 AM
404 crawler gears ovrez Unimog 0 09-05-2005 03:10 AM
404 crawler gears ovrez For Sale/Wanted/Trade/Giveaway 0 09-05-2005 03:08 AM

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