Bolts Keep Stripping - Advice Please

[KMGHMG]

Hey Guys,

I'm installing towing "base plates" on the front of my LC so I can tow it behind my RV. These attach with three bolts to the front of the frame on either side - where one would attach an after-market bumper. The Grade 8 bolts that come with the base plates keep stripping once I get about 50 pounds of torque on them. The instructions call for about 100 lbs of torque. The bolts causing the trouble are the two on each side that thread directly into the frame. It's happened in three of those four positions.

Have any of you had similar problems when installing front bumpers? Any suggestions on what to do?

As always, thanks!

Matt

 

[AimCOtaco]

Grade 8 would be an SAE thread. All the frame inserts on your cruiser are metric, a 'similar' rating would be 10.9 for a metric bolt. Are you using metric hardware?

 

[KMGHMG]

My bad. The bolts that came with the base plates are 14MM x 1.50 x 40MM according to the installation instructions. No idea how that fits with what should actually be there.

 

[bigredmachine]

is it possible to through bolt it and use a nut or is it se tup to use the weld nuts in the frame

 

[KMGHMG]

Well, the front bolt goes all the way through and has a nut on the top side. The other two are supposed to use the nuts welded to the frame. I didn't have this trouble installing the same set of plates on my 1999 LC - same hardware from what I can tell.

 

[bigredmachine]

try cleaning up the weld nuts in the frame with a tap or thread chaser. or it could be that its really crappy hardware and new bolts would be in order

 

[KMGHMG]

Great suggestion. Thanks. I'm thinking I could also go up a grade in the bolts.

 

[bigredmachine]

ya and maybe a little loc tite red

 

[Skidoo]

Sometimes counterfeit bolts can sneak into the market, so new bolts sounds like a good idea.

 

[hoser]

Try installing the bolts w/o the tow baseplate first. Sometimes, the captive nuts are off-center and you could be stripping your bolts on the baseplate. In that case, you need to either enlarge the baseplate holes... or try and center the captive nuts (which could cause them to unfasten from the frame).

 

[KMGHMG]

Here's the result... I finally had a machine shop look at it. They had to tap the frame holes/nuts to fit a 9/16th standard bolt. Took a long time, but it worked well. Nothing else seemed to work.