W124 Drag link aka steering rod Easy DIY
I changed out my drag link, aka steering rod or center tie rod, over the weekend and it was a very easy DIY.
My symptoms were a clunk in the right front end when turning the steering wheel past 10 o'clock or 2 o'clock. The noise and frequency increased and then went away to only an occassional clunk. To confirm, I put the car on stands and rocked the front wheels holding them at 9 and 3 o'clock. The right ball joint of the steering rod clearly had excessive movement as compared to the left side.
First thing under the car is to break loose the 19mm nuts holding the rod. No access with sockets and I had nothing larger than a 16mm combo wrench. I was stuck but then tried a 3/4" wrench and it fit. Learn something new everyday, 19mm = .748"! The nuts are not too tight and came off easily. I should have left them on as you will see later. I bought a front end tool kit that has 5 different tools in it. As mentioned here on the forum, the lever type tool works best with the drag link, while the pitman type pullers work best on the right and left tie rods. The lever type tool looks like a giant clothes pin. Take off the steering damper (reinstall with 50nm torque) . I positioned the lever tool and started cranking on the bolt with a long breaker bar. I wanted to be as far away as possible from the ball joint when it broke free. When it breaks free, it's like a gunshot! In hind sight, you should unthread the nut to the end of the ball joint but leave it on, so when it breaks free, the rod is retained by the nut. I did the other side a little differently. I only cranked it up half as much and then got out of the way. Sure enough it broke free while I out from under the car. The new one fit right in. Specs call for 35 nm torque (1 nm = roughly 3/4 ftlb) on these locking nuts but no room to get a torque wrench up there. I just snugged them down. Any easy way to check the torque on these nuts?
Checking the ball joints, both seals were intact, the left joint looked OK with good grease and smooth movement, but looser than the new rod. In the right joint, the grease was no longer grease, and the movement was rough and gritty.
Probably my imagination, but the car's steering is a bit tighter now.