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JoeSR · 05-23-2022, 07:29 AM

The controls on this site will not let me add to my original thread. It is too old, just like me. So, here is a link to the thread and my reply...

https://www.irv2.com/forums/f22/tie-...ue-529513.html

I am the OP. Stuff got in the way and I never did replace the bad tie rod end dust boot until this weekend when I noticed that the right boot was completely missing.

Since I will be leaving soon on a trip, I wanted to find a boot locally. Napa universal boot 650-1178 would fit the shaft but it is too long. So, I trimmed off ~7/16”. I should have trimmed of at least another 1/8”.

That brings me back to the castle nut and what initial torque should I use? The Workhorse spec of 300 ft-lbs seems excessive.

I decided to measure the break away torque, but first made some witness marks on the nut and mating surface. I applied CCW torque in 25 ft-lb increments up to 100 ft-lbs. The castle nut did not move. My next torque wrench capable of measuring torque in the CCW direction started at 200 ft-lbs. The castle nut broke free well under 200 ft-lbs. Great! So, either the spec is wrong or the factory did not read the spec.

In the CW direction I could measure the torque in small steps. At 75 ft-lbs a slot in the castle nut lined up with a hole in the tie rod shaft, but the witness marks did not line up. At 125 ft-lbs the next castle nut slot lined up with the tie rod shaft hole and the witness marks were lined up.

So, there we have it. Based on a sample of one. Tighten the castle nut to 75 ft-lbs. Then tighten the castle nut further until the next slot is aligned with the cotter key hole. The resulting torque will be between 75 and 125 ft-lbs.

I hope that helps the next guy.

n2zon · 05-23-2022, 04:34 PM

Why did you find the factory spec excessive? And, are you a MechE?

OldWEB · 05-23-2022, 04:42 PM

You are able to add more words of wisdom to the old post by checking the box that you understand the thread is old. Worked for me.

JoeSR · 05-24-2022, 07:10 AM

n2zon,

In 55+ years of keeping my vehicles on the road, I have found more than one error in a factory shop manual. 300 ft-lbs far exceeded any other torque that I had applied to a tie rod end. That is why I raised the question.

I don't know why it matters, but I was a EE not a ME.

OldWEB,

On the first attempt to reply to my old post I had not seen the box that you mentioned. After that attempt failed, I did see the box. Checked it, but that second attempt failed as well. Trying a third time and expecting a different result would have been a mark of insanity.

Orrin · 05-24-2022, 07:18 AM

You also could ask a shop that works on trucks. They would likely have the correct spec. Also check with the maker of your front axel.

OldTimer · 05-26-2022, 07:28 AM

JoeSr... Thanks for coming back to update your post. Really appreciate you sharing the detail and your experience.

Adaycj · 05-26-2022, 08:35 AM

I often generate a sanity check by finding the threaded diameter (nominal, nearest actual size), and thread pitch. In the case of a specality part you'd need to guess at the grade, but it isn't grade 2 in the case of a tie rod.
Then look it up in a bolt torque/tightening chart. If it is close, tighten away. If it is off by a lot, figure out what is wrong.

I've never in my life tightened a tie rod to knuckle end to 300 lb/ft. I never had a job as a heavy equipment tech, but I'd double guess that number too.

n2zon · 05-26-2022, 03:29 PM

Quote:

Originally Posted by JoeSR

n2zon,

In 55+ years of keeping my vehicles on the road, I have found more than one error in a factory shop manual. 300 ft-lbs far exceeded any other torque that I had applied to a tie rod end. That is why I raised the question.

I don't know why it matters, but I was a EE not a ME.

In my 50 or so years of keeping my own on the road, with occasional stints turning wrenches for money, I've seen more than a few errors in service manuals as well. If I recall correctly (always a dangerous assumption) the tie rod ends on the ZF IFS on our chassis were torqued to something like 134-175 ft lbs. So I'd question that specification too.

However, with all due respect, I must *also* question the methodology you used to determine what torque to use for that fastener. I would recommend that unless it's been signed off by an ME or AE with a PE number that people call the company or a dealer to ask what the correct torque might be rather than using that technique.