84 300SD broken plastic adjustment nut on bowden cable
 

Is there a source for this part or do I change the entire assembly?

With a different brand I've slotted a steel nut so it would slide over the cable strand.

That sounds like something I'd do for a temporary fix. The transmission is shifting early. It's going to 4th gear before it gets to 30 mph.

How would one use a slotted nut to repair this problem?

It'd be tough to fix it with a slotted nut. I've seen several broken ones. I THINK I have one... I'll look tomorrow.

I ended up replacing. The part was ~$60. There are 2 different cables with the difference being in the transmission end. They are not interchangeable. The break came around the 84/85 model year. You need the VIN to get the correct part unless you get lucky.

By the o-ring and perhaps an extra because it is inexpensive. None of the rings in my o-ring kit worked and the local McParts stores didn't have anything that fit either.

Junkman, there's a Benz junkyard in Six Mile, SC that I shall visit next week. I'll check on the seats for you. PP wants 101 for the cable.

Vstech, PM me on the part. We need to get together on this front end work also.

I'd have to see a pic of your system. The type I've fixed had a threaded casing end, 2 nuts installed then the center strand has a formed end. This formed end won't allow the nuts to be removed. The bracket hole has a slot in it to pass the center strand then the casing is slid through the hole and nuts tightened.

A slotted steel nut will still be stronger than a plastic nut. Throttle valve cables don't see much tension unless you bottom them out before you throttle pedal does. The trans cable shouldn't be a throttle stop.

A couple of other get it going until I can get parts fixes would be hose clamps or a block of wood drilled , cut in half, two bolts that would capture the cable against the bracket.

I have a similar problem as the op described. On mine the white plastic adjustment nut disintegrated from spending too much time uncovered out in the sun (was formerly a parts car motor). I am not familiar with how the bowden cable disconnects at the tranny side - how does it come out? I'm a little hesitant to dive in there and muck it up since it is still performing its job okay (for now at least).

Here's the link I found when looking into changing the cable. It looks like one of those things that's really tough the first time you attempt to remove it then becomes simple after you kinda get the hang of it.

http://www.peachparts.com/shopforum/diesel-discussion/291245-85-300cd-t-old-auto-trans-bowden-cable-vs-new-one.html


The white threaded shaft broke at the nut on the cable. I twisted it enough to get the shifting to a reasonable level. From my understand this is the last step in getting the shifting smooth. Since I haven't replaced the vacuum pump I'll wait to fine tune the shift points.

Clemson, thanks for that link - it was just what I was looking for on Bowden cable replacement.

You could make a hardwood nut. Cut a small piece of hardwood in two. Clamp the pieces together. Drill and thread it. Pretty easy in brass as well.

Fasten the two pieces together on the cable. Many ways to make them stay together. Even a small adjustable fuel hose clamp would do.

Anyone have a pic of what the OP is wanting to fix?

Go to minute 2.00 and pause the vid. See the white adjusting nut at the end of the small rubber boot on top of the valve cover.

https://www.youtube.com/watch?v=lHoxWI1PzGU