3

Didn't see this asked from searching but I've always been in debates with whether Loctite should be used on suspension components. To be clear, I'm talking about components that do not utilize a cotter pin.

I do look up torque specs on all aftermarket suspension installs and re-torque after 500 miles and I add a white line from the bolt and nut with a whiteout pen for reference. So is adding blue Loctite to suspension an added benefit, headache if an issue occurs or overkill?

4

Since there is a need to re-torque the fastener, it doesn't make sense to use Loctite. This is true for two reasons (after the Loctite has set):

  • With the Loctite holding the fastener in place, it will give you a false torque reading. The fastener interface (bolt to nut) will not want to move due to the locking action of the Loctite, so it will appear there will be much more torque present than there is in actuality.
  • When you do break the fastener free to re-torque it, you have actually broken the Loctite and have ruined the bond which it had at the fastener interface, thus making the Loctite useless.

Bottom line, if you must re-torque (which with suspension bolts, not a bad idea), it doesn't make sense to use Loctite, clean and simple.

  • Loctite doesn't work immediately. It forms an acrylate polymer that is catalyzed by an anaerobic and activated metal environment. As such, application before torquing to spec is completely reasonable and used in automotive builds. Your torque reading might be marginally off but within the allowable range. Your torque wrench is likely to have a greater error spread. – Hari Ganti Feb 23 '17 at 21:50
  • Also, you clean the Loctite off the threads when installing a new bolt. In theory, you never reuse a fastener, and you clean the mating threads before fastening. The Loctite simply prevents vibration from backing a fastener out. – Hari Ganti Feb 23 '17 at 21:51
  • Some OEMs advise the use of thread locker on various bolts in service manuals. It's normally to prevent loosening from areas that are subject to excessive vibration. This is a valid use of thread locker. I would question the need to re-torque things, I've not seen this advised anywhere, but I have seen thread locker being advised. Specifically, the removable and reusable types act almost like PTFE tape in countering loosening from vibration. I would only apply it if the service manual recommends it or it is already applied when removing something. Correct torque application is still paramount. – DizzyFool Feb 24 '17 at 9:27
  • @DizzyFool - Salient points. Thanks for the add! – Pᴀᴜʟsᴛᴇʀ2 Feb 24 '17 at 13:16
0

most cars you will never undo that nut again, personal choice, me I use grease and a torque wrench, so the poor buger who gets the car will think of me and smile.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.