Rod ends for SBU shifters

I pulled some parts out.

• The threads on the Rods are M8 -1.25
• The sockets are Right Hand and Left Hand threads on opposite ends of the rods.
• The jam nut on the Rod takes a 13mm Wrench

-The flats on the socket ends take a 12mm Wrench
-The ball is ~ 12.90mm diameter
- The ball fixture is pressed into the shift lever arm.
-The diameter of the shaft on the ball fixture is ~ 10mm .

I’ll be interested to see what MEREX sends to you.

One of mine shows cracks in the plastic…a prelude to failure.

One of the socket bodies is not round - it looks like a hammer blow, rather than abrasion.

One of the shafts is arrow straight, one has slight doglegs in it and a few wear marks, where it was rubbing against something.
It is straight enough.

The plastic inserts look like they overlap the metal body on both the open and closed sides. It may be that they were heated and soft when installed in the housing. This might explain why the inserts are not available by themselves.
Assuming that is true, or whether that is a provisional UNIMOG truth. They might have been available in the past, or never.

I'm liking what I see on the McMaster-Carr link.

The ones with the Neoprene seals don't have a Load cap. rating, and they pivot 35°.
The ones with the Rubber seals have a rating, and pivot to 34°.

I think the thing to do would be to push out or drill out the ball stud from the factory lever arms, drill them out and weld in a regular M8-1.25 nut. Clearance is somewhat tight, so I don't think a coupling nut is a good choice. A jam nut on the threaded male stud, and you should be good. Instead of a jam nut, a thin spring type lock washer and thread locker would be less bulky. Then trim the male stud of excess length as necessary.

I think either one would work, as the rating should be sufficient for a hand operated lever, one that probably isn't used every day. The Neoprene Seal equipped pieces are plated steel, so I think they may be stronger, whether they are rated to not. The Original MB pieces look to be zinc, and they do not look to be built for high strength, so I think the McMaster-Carr ball joint linkages would be an upgrade. Price-wise, the Rubber Seal versions are about twice as much, so maybe they are the way to go, thinking you are paying more to get more ?

One consideration would be clearance - but I think the best way to pin that down is to buy a couple and fiddle around with them. They look like they would fit, but I still have to measure the threaded depth on the OEM pieces, and so on.

Maybe today I can play around with my OEM pieces and try to come up with a number for what their pivot range is.

The OEM piece is close :

Shank Thread Lg. = 20mm (McM-C = 14mm)
Shank Center Lg. = 30.3 mm (McM-C = 28.5mm)

The OEM rods have about 25mm of threads on each end for adjustment.

So, between the two rod ends, with the McMaster-Carr pieces, you'd lose less than 1/2" in adjustability. The McMaster-Carr piece will bottom out less than 1/4" sooner than the OEM piece. I think that will work fine. With the slightly shorter Shank Center measurement ( 28.5mm to 30.3mm), the McM-C end will want to extend further (screw out) than the OEM piece, so bottoming out should not be an issue.

Just messing around with the pieces, I came up with this range of motion for the MB parts. It may be off a little, but just based on the angle at which interference takes place, I think it is a reasonable guess.
It is essentially the same as the McMaster-Carr pieces.

In use, I think only a fraction of the range will be used, because the shifting action is a fairly short fore and aft throw. In any event, it appears that the McM-C pieces will cope with the alignment requirements as well as the factory pieces.
Time will tell.

More or less.

More fiddling, in order to check the previous results.

Matched a grommet to the OD of the ball.
Dummied up a ‘stem’ for the ball.
Inserted the grommet ‘Ball’ into the socket fitting, and
swung the arc.
Results about the same as the previous method.

I agree - the load rating required in this application is probably very low. I was more curious about the range of motion, and the bulkiness of the McM-C parts, but they seem to be OK size-wise.

The Mercedes-Benz pieces just press fit together, but it isn't something you can do with your fingers. It would take a vise. That is why I didn't put mine together - I didn't want to lube them up and assemble them, only to have to possibly take them apart. Plus, the one ball has a ratty, pitted finish from rust (I think), and one of my inserts has cracked. The MB inserts have little to no 'give' and are quite rigid. It may be that they lose some of their resilience over time. Then the cracks appear, then they exit into the snow, or mud, or sand, or rocks.

I'm curious to see what MEREX sends - If they are the original pieces, or are they what A. Vos supplied to krietpiel ?

They are obviously up to the task, but I'm leaning towards the McM-C stuff, at least I intend to put an order in and then proceed to fiddle with those pieces, depending on the MEREX package.

The shift rods.

Both 10mm in diameter.
Two lengths -
A. 469mm (18 - 1/2 “)
B. 431mm ( 17 - 11/16”)

A little more information on the rods for these assemblies. I think that the two lengths that I mentioned above might literally only be part of the story.

Neil told me some years ago that the long rods were no longer available from the MB parts department, so the choice was either used pieces, or used and new pieces (but only the 'Short rods') pieced together with coupling nuts to achieve the length of the 'Long Rods'.

This seemed like a problem that could easily be solved with a competent machine shop. The conversation was a while ago, and I do not know if MB has stepped up and made a run of the Long Rods or not.

I'd want the one-piece Long Rod over the composite pieces - two less threads per rod to rattle apart. Also, no chance of the coupling nuts interfering with the other rod / coupling nut assembly.

In these photos, you can see two short sections of rod, attached to a shift plate (or console), that Roberto was working on. Two short lengths with one coupling nut attached. In this case, I think there are two PTO levers and one Lever for the Working Gears, but the short rod sections with the coupling nut would be the same, I think.

In the photo of the transmission assembly on the pallet, with the Working and Crawler gears attached, the two
one-piece rods look to be longer than the two measurements I posted above (18-1/2" and 17-11/16"). They also look like they might be a little larger than 10mm in diameter. It might be an illusion - The two rods on the milk crate look like they might be a close match to mine. It is hard to tell from looking at photos - a measuring tape would settle it in seconds. Their diameter looks about the same in relation to the rod ends, so maybe they are 10mm, but it would be good to know for sure.

So, if you (Ragnian) have the one piece Long Rods on your rig, could you please post up the overall lengths, the diameter, and the length of the threads ? (Once you pull things apart). I think I'd rather get them made as opposed to piecing them together. Unless I already have the Long Rods and just don't know it.

Thanks.

The only possible issue I see with going with the larger diameter tube would be clearance. In some photos, the two rods look pretty close to each other, in others, not so much.

One of my rods has wear marks on it in a number of spots. Nothing major, but that could have come about when the two levers were in different positions - Working gears only, and Crawler Gears engaged 'on top of the Working Gears'. Or, both disengaged, and also the possibility that the rod with the marks was installed end-for-end at some point. The marks look to be in spots that would indicate that the two rods were rubbing against each other.

There are a lot of possibilities , however. The one rod could have been in a PTO linkage instead, and there are at least two different versions of the lever part of the equation. The photo of the pieces on the milk crate show two matching lever assemblies. Merex shipped me one of each, and I'm going to try and match them both to the Milk Crate type.
Also, I'd say it is pretty unlikely that my two lever and rod assemblies came from the same donor truck.

I'll see what MEREX sends to Ragnian and go from there. I think I'll probably go with the McM-C rod ends and weld nuts to the drilled-out lever arms, but I'll see.

Good information.
I checked on shipping to Bozeman, Montana,
and it didn’t compute.
It is good to see that the original pieces are available.

Images from the linked site.