Suspension bolt/nut question

How do you lock your nuts?

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Bobalos

Bobalos

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What do you guys prefer to keep the nuts from backing out on your suspension bolts?  Im talking about A-Arms, Trailing arms, Tie Rods, etc, not the rear view mirror & glove box door.

Nylocks

Loc-Tite

Double Nut/Jamb Nuts

Prevailing TQ (Stover) / 2 Way lock (dimple in middle of Nut)

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Id be really interested in hearing from folks like @J Alper @L.R.S. @Hondo @MGMFRP & all of the other folks that take apart & put together off road cars all of the time & what seems to work the best. 

 
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@Bobalos Whenever I've used the ones you picture they don't unthread well and sometimes to the point of having to cut them off.  Is it something I do wrong?  That's why I use Nylock and mark them with a paint pen so I can see at a glance if they've loosened. 

 
I use these. I also only use proper shank length bolts and fine thread on all of those critical bolts. When torqued properly, I have fewer issues with a nut/bolt set-up. I will also torque mark certain nuts (spindle uprights) and safety wire blind bolts (no nuts) like the steering rack. The fine thread is supposed to help hold torque and resist vibration. The nuts I get from McMaster-Carr are advertised as lock nuts for heavy vibration resistance. Just one guys opinion.

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As mentioned above proper shank length for sure. This is an absolute must on trailing arm bolts. The threads eat the tabs away. 

We use fine thread with new nylock nuts at proper torque for size. 

 
I use grade 8 bolts and nylocks for all suspension hardware and a drop or Red Locktite.  I use Blue Locktite for any bolt going into aluminum.  We used stover nuts and f911 12 point fine thread bolts for all suspension hardware when I was racing Class 1.  All hardware on the race cars and prerunners were fine thread.  I learned that you cannot use an impact or any sort of power tool on a stover nut.  I've cut a lot of stover nuts off bolts because they would gall up and be impossible to remove.  Not sure why the impact caused this but when I used hand tools I had very few problems with the stover nuts.

I work on all brands of off-road cars and I'm always surprised to see builders not using the proper grip length for suspension hardware.  Not naming anyone in particular.  As @Hondo said the threads will cut into the tab and it will oval the hole.  I've fixed plenty over the years.  

Toward the end of my racing career we had switched to using RPI hardware from @9rocky.  We could custom order the proper grip length which would save me countless hours in the shop cutting each suspension bolt to the exact length we needed.  I use RPI hardware on my personal car and have swapped out several clients bolts to RPI.  It's expensive but well worth it.

 
Unlike the daylight savings poll I put up the other day, this is pretty telling. 

thanks for the input folks.

Bob

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L.R.S. said:
I use grade 8 bolts and nylocks for all suspension hardware and a drop or Red Locktite.  I use Blue Locktite for any bolt going into aluminum.  We used stover nuts and f911 12 point fine thread bolts for all suspension hardware when I was racing Class 1.  All hardware on the race cars and prerunners were fine thread.  I learned that you cannot use an impact or any sort of power tool on a stover nut.  I've cut a lot of stover nuts off bolts because they would gall up and be impossible to remove.  Not sure why the impact caused this but when I used hand tools I had very few problems with the stover nuts.

I work on all brands of off-road cars and I'm always surprised to see builders not using the proper grip length for suspension hardware.  Not naming anyone in particular.  As @Hondo said the threads will cut into the tab and it will oval the hole.  I've fixed plenty over the years.  

Toward the end of my racing career we had switched to using RPI hardware from @9rocky.  We could custom order the proper grip length which would save me countless hours in the shop cutting each suspension bolt to the exact length we needed.  I use RPI hardware on my personal car and have swapped out several clients bolts to RPI.  It's expensive but well worth it.
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Thank you for the kind words Jeff. The slotted nut posted previously is what we recommend. It is sometimes called a split lock. We stock those for our dealers. I am not a fan of Stovers. We sell mostly to race builders such as Mason, TSCO, Brenthel, Jimco, Alumicraft, etc. They have all been using the split loks for years with good success. I like never seize on the shanks, and a drop of Loctite on the bolt. Use a map gas torch to slightly heat the nut before removal. This will loosen the Loctite, and give the bolt a better chance of not being damaged.

 
How does that split lock nut work?  Are those tabs folded in slightly  to bite on the bolt?

 
Bobalos said:
How does that split lock nut work?  Are those tabs folded in slightly  to bite on the bolt?
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Yes. They have to pass 15 cycle prevailing torque tests to pass acceptance tests. They are a MS21045 series. They give a little without being completely deformed like a Stover. Hence the Stovers' tendency to damage the bolt upon removal. My advice to race prep people is to put a sharpie mark on the nut each time they are removed and re installed. I recommend 3 cycles, some guys go 5. The nuts are fairly inexpensive in relation to the bolt. Throw away the cheaper nut and protect the expensive bolt. Expense is relative though. We have run our hardware on our cars for up to 2 years.

 
@9rocky got me in touch with one of his preferred resellers and already have the new bolts on order. Glad I am swapping them out our versus running what is currently on the car. 

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Depends on the application.  Nylocks when there is a nut.  Double nuts for items that aren't tightened to the fastener's torque spec (clutch slave, link pins, beam through rods).  Loctite for blind holes depending on application (red for larger fasteners in a location I can heat up to melt the red).  Castle nuts with cotter pins for steering and stub axles.  

 
@Rockwood, I agree with your post a general rule guide just about everywhere on a buggy.  There is certainly no one size fits all solution. 

thanks

Bob

 
I am on the same page as @L.R.S. and @Rockwood    Although I will not use stovers on anything I have to service because they weaken the threads by distorting them if used over.  I never use a Nylock twice and never use the bolt again if its had a stover.  If it needs to be better than a Nylock I use a Castle with Cotter. 

If the hole is blind and into steel I will use a proper amount (read that small) amount of Red Loctite (blue if into aluminum) and almost always will safety wire the head.  You would not believe how many suspension and especially steering bolts I find either loose or worsr WAY over torqued and stretched - they will break that way - 

I torque EVERY bolt on the car with exception on interior and small brackets etc.  It takes many 1 minute longer to Torque them and 1/2 the time is setting the wrench.

I never use Grade 8 on Suspension it has to be Grade 9 or better - that means US made DB 12pt, F911 or specialized MC or NAS bolts where applicable

I also try to whenever possible "size the shank - bolt grip - correctly" and have no threads cutting brackets, but its more important to just keep things tight. Loose threads are like a saw, tight and properly Torqued other than suspension is not going to be a problem 99% of the time.  I keep an assortment of different thickness AN washers (mostly .030 .060 .090 .120 around to get the bolt grip correct

I also tend to size up bolts sometimes, such as floor boards using grade 8 3/8 bolts  vs lots of people using using 1/4 or 5/16  and using grade 9  - far less expensive and far stronger. 

I will not use Chrome (hydrogen embrittlement) or Stainless (too soft) bolts on suspension - with the exception of ARP stainless in smaller sizes - they are grade 8, but then you must use anti seize, they still gall.  I see lots of cars with Stainless suspension bolts from "name brand" builders - and I replace lots to those bolts that are Bent

I see lots of steering racks with broken Grade 8 bolts or bent Grade 8 bolt because they were loose, also If I find a bent bolt, I replace all the other bolts around it holding the same piece because I know that are beyond their stress and will eventually fail

I have lots of used nuts and bolts I give away  ...

Yeah I know I am paranoid ...

 
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I got it all fixed up.  She's loaded and ready to roll out in the morning.  

Seriously,  thanks for the input folks. 

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