Changing Ends: Looking Closer At Different Rod End Offerings

Not too long ago we were getting ready to install our long travel kit on Project Storm Trooper, as with any project the direction has changed. No, we aren’t ditching the independent front suspension we are making it stronger with some added additions.

The clearance on our old upper control arms would not allow us to mount our Bilstein 8125 series coilover and our newly added 70mm M9200 bypass. To allow both shocks to fit we needed to redo our upper control arm and make it wider.

We were looking for more strength in our suspension and FK Rod Ends RSMX series was the right fit. The extra material around the ball gave us the strength we needed.

To make sure that we would be covered in any added stress the extra width may put on the rod ends, we decided to do things a little different this time around. With the help of FK Rod Ends, we narrowed down our rod end choice to give us some added strength without having to get a ton of new parts.

Previously we had a JMX12T, a 3/4-inch rod end, on our upper control arms. It served its purpose, but with the truck seeing more dirt and abuse in its future we decided to look at something with a little more meat on the bones. The RSMX12T was our new choice.

The JMX12T rod end on the left with the RSMX12T on the right shows the difference in the thread size while maintaining the same bore size.

“The main difference is in the sizing between our RSMX and JMX,” Brian McAllister from FK Rod Ends explained. “On all JMX series, both the thread and the bore size is the same size. This means that a 5/8-inch unit has both 5/8-inch thread and a 5/8-inch bore as an example. The RSMX series features a heavy-duty shank, which means that the thread will be larger than the bore.”

“This means that a 5/8-inch unit would have a 5/8-inch thread, but a 1/2-inch bore,” McAllister continued. “This also increases the strength rating some due to the additional material around the ball.”

The RSMX10T on the left and the JMX12T on the right show the difference with a different bore size but the same thread size.

The part that we liked the most about the RSMX series was the added material around the ball. The RSMX12T was a 7/8-inch thread with a 3/4-inch bore, this bore size was the same as the JMX12T we were previously using. This allowed us to keep the same misalignment spacers and bolt size.

With our rod end selection done, all we had to do was change the size of the weld bung used in the arms. After spending some time in CAD and a test piece cut, we were able to get the new control arms installed on the truck.

Knowing about the RSMX series, we looked at other rod ends we could replace where extra strength would be good. The next rod end component we looked at was on our tie rods.

Once the front suspension is put back together and the engine is running we will be able to put the rod ends to the test.

We opted to go with the RSMX10T to replace the JMX12T we had there. In this case, we did not worry about keeping the same bore size, but decided to go with a smaller bore. This would give us more material in our steering and only required us to change the misalignment spacers on the rod end that attached to the spindle.

Once our engine swap gets finished up we could get into the dirt and see how everything really handles the abuse. For more information on FK Rod Ends and its products, be sure to visit their website.

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About the author

Steven Olsewski

Steven Olsewski grew up with a true passion for anything with a motor. He loves his wife and kids, and during the year can be found enjoying quality time together. They are a huge part of his life and their passion for God.
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