How many times can you torque bolts on a hitch?

I’m guessing 25k towing miles and towing 23-25k I have never torqued my bolts other than original assembly. Honestly have not thought about it. But with quality fasteners and a quality torque wrench it’s not a big deal.

I have “not” routinely torqued mine....as in never! Discovered in November, that I should have. No harm....just a few loose bolts, and one with no nut. I’ll monitor mor3 closely in the future! memtb

I think bolts should be replaced only if the bolts have been tighten beyond the specified torque. If tightened beyond the setting, bolts can be stretched and fatigued. As long as they are not tightened beyond the specified settings they should be fine. On new assembly or construction of anything mechanical, re-torquing after break-in is a good idea, especially critical components.

MFL wrote:

Cummins12V98 wrote:
map guy, skinnyme said his 16k has 10.8 bolts, what standard thread bolt would that compare to?

google says 10.9 about equal to grade 8

Jerry

So grade 5 equivalent?

B&W uses Grade 8 bolts with locking washers, NO flat washers. They have 4 bolts each side compared to 2 each side on the CURT. I do believe the bolt diameter is a bit larger with the CURT???

Looking at the hitch owners manual - you are stuck using metric hardware due to the construction of the hitch. Stay with a class 10.9 bolt. Do not lower the bolt class to 8.8.

I am not a fan of a bolt with a lock washer/flat washer stack such as how Curt has called out on the leg to main body connection. From experience -this combination won't stay torqued properly due to the movement forces in play during operation.

I would consider going to flange head bolts, eliminate the washers and use high strength thread locker to avoid the periodic re-torque of the bolts. This would depend on whether or not I could get a flange bolt with proper threaded/unthreaded dimensions that mimic the original bolt. The use of washers does reduce the potential to gall the finish but will require the periodic re-torque due to the potential for movement with a minor loosening of the bolt torque.

Using high strength thread locker will require heat to break the bond of the thread locker for disassembly or re-torque.

Hopefully the OP has a large enough torque wrench for the required torque. Proper torque values go a long way towards having an assembly stay assembled properly.

Cummins12V98 wrote:
map guy, skinnyme said his 16k has 10.8 bolts, what standard thread bolt would that compare to?

google says 10.9 about equal to grade 8

Jerry

map guy, skinnyme said his 16k has 10.8 bolts, what standard thread bolt would that compare to?

I have a Curt A-16 hitch. Bought it about a year ago. The bolts in question on my hitch are marked 10.8.

Cummins12V98 wrote:

mapguy wrote:
Technically you can't buy a Grade 8 bolt in a metric size. I suggest you look for Class 8.8 minimum but think you would be better served with a Class 10.9 bolt. You probably will have to go to a real hardware store or a bolt supplier.

Belmetric is a quality online
business that has a wide range of metric bolts

So what grade would you compare the CURT bolt to?

Can't tell what the marking is on the bolt head in picture. IF 8.8 -this is a class 8.8 bolt. Class 10.9 would be marked "10.9".

Curly2001 wrote:
Gotta let the professional bolt guys compare and recommend replacements. These thread in a cast A arm that pins into the rails.
Curly

Take a bolt to a commercial bolt/hardware supplier and get a better grade.