[Tyson Pfenneberger]

Here are some pics and info on my project Jeep. My goal is an all purpose all weather vehicle that preforms like a Mog and allows enough room for family and some gear. The approach is simple and straight forward. I do not wish to reinvent what the Mercedes engineers already know. Therefore the base chassis is mostly stock, just rearranged. This is the donner vehicle, 1973 421 Unimog.

 

[Tyson Pfenneberger]

Donner body, 1987 Jeep YJ

 

[Tyson Pfenneberger]

Chassis stretched to 109" Front and rear steer.

 

[Tyson Pfenneberger]

Rear torque tube also installed up front.

 

[Tyson Pfenneberger]

Rear steer.

 

[Tyson Pfenneberger]

4x2 eight speed trans with the lower gear set removed to create a 4 speed transfer case and be able to retain the torque tubes.

 

[Tyson Pfenneberger]

Internals of 4x2.

 

[Tyson Pfenneberger]

Stock steering box. I might change this for clearance concerns. Overall width is approx 74.5"

 

[Tyson Pfenneberger]

Jeep body getting close to completion.

 

[Tyson Pfenneberger]

Dunlop SPT 9 405 70R 20 tires on 11-20 rims. I may change to Iroks in the future. I will post more as progress is made.

 

[green meanie]

wow!that is sweet.a new frame doesn't get much simpler than that!

 

[Amund]

Between this thread and the zuk on 411s, can you tell me the difference between 411 & 421 axles? Gearing? Are they the same width? Same shafts & portal gears? Did the both come with a cast housing (a la 404) in the early days, if so, approx year? Strength, still better than a 60 i hope

sorry for bugging, but I figured Tyson would be the one to ask. I have watched your 404 for years and I love it.

 

[Sapper]

Looking forward to seeing how this turns out. I think it will be a great project that will keep you happy for a while to come.

Jay

 

[Tyson Pfenneberger]

The frame design is what led me to try a project like this. Straight tip to tip with brackets, buckets and trans mount that made stretching it very simple. Relocating rear tube to front gave me the 109" wheel base. So basically a completely stock drivetrain with a more desirable wheel base and only slightly more caster up front.
As for the differences in axles? The early 411's had the 404 style axles only narrower. Apparently the late model 411's have the same housings as the 421, 406, and 416's. The ratios seem to differ a little, mine are 8.89 to 1. I will have to check on widths and such. I am counting on the strength being far better than a 60. Even if it were equal to a 60, how could anyone pass up the extra clearance. ???
I hope this helps and thanks for the kind comments, Tyson

 

[Sapper]

Portals should be much stronger than a 404 and the pinions are 19 spline I believe maybe even 17? You also will still have a close to 50* turning ability as well as the CV style steering joints. Should be stronger then a 60 by far.

Do they still use the same air locker mechanism as the older versions 406/416?

 

[Tyson Pfenneberger]

Yes, I believe so. Piston collar sealed by o ring and sliding within axle tube, putting pressure on spring to engage locking collar. Sure would be nice to have the definative answers that Jack used to provide so graciously.:beer:

 

[Sapper]

That sounds like they are. I may actually have a spare ring a pinion for a 421 then? I am not sure but the spline count on one of the ones I have is 17 and close to 1.5" dia but I would have to measure to verify.

The portals look similar to some of the early 406's and I am curious if they share the same bolt pattern and stub because if they do you could swap them out to get a little different overall ratio.

I seem to have a mixed bag of parts and I am trying to piece them together. Learning a lot in the process but still missing what I need. (SEE SIG)

Have you had the portals off? Do you know what style gears they use?


Jay

 

[Mieser]

Any updates? Very interesting project!

 

[U1300L]

Wrong!!
421 axles are totaly different than 406 axles! Nothing interchanges, only the center casting interchange with an old F type 406 axle!

The frame design is what led me to try a project like this. Straight tip to tip with brackets, buckets and trans mount that made stretching it very simple. Relocating rear tube to front gave me the 109" wheel base. So basically a completely stock drivetrain with a more desirable wheel base and only slightly more caster up front.
As for the differences in axles? The early 411's had the 404 style axles only narrower. Apparently the late model 411's have the same housings as the 421, 406, and 416's. The ratios seem to differ a little, mine are 8.89 to 1. I will have to check on widths and such. I am counting on the strength being far better than a 60. Even if it were equal to a 60, how could anyone pass up the extra clearance. ???
I hope this helps and thanks for the kind comments, Tyson

 

[jptbay]

Wrong!!
421 axles are totaly different than 406 axles! Nothing interchanges, only the center casting interchange with an old F type 406 axle!

According to my original Mercedes parts and service manuals, for 411/421 mogs with the newer style axles (406/416 type) virtually every part number crosses over to a 406/416 part number. Some exceptions include components related to axle width, as the 411/421 axles are narrower. Ie inner axles, and axle tubes.

JARE (on this board) from Finland runs this style 411 axle in his Formula Offroad competition buggy. I doubt it is possible to find a way to abuse an axle more. His axles are stock other than swapping out his portal gears to newer 406/416 ones, which are wider. These wider gears are a direct swap in. He also swapped in shortened 406/416 inner axles that are stronger (increased diameter). Check out some of the wild video footage he has posted here.

The differential locking mechanism is the same as 406/416 axles. A little known fact is that these lockers can be either pneumatically or hydraulically operated. Some Mogs had no on board air systems. The lockers are actuated by a remote slave cylinder located above the transmission, and use ATF fluid. You can actuate your locker by either method.

J.P.