[Nissan4Life]

Spent the weekend doing some RR on my skid plates. My Schrock works engine plate, and factory gas tank plate had been hanging on by a couple of rattly bolts. I have gripped about this before. THe plates are mount in thread holes. The threaded holes are accomplished by tack welding a nut on the inside of the frame while it is still an open channel, prior to boxing it up. THe small tack welds can not handle the force of impacts when you smash the skid plate on rocks and break. One saving grace is that when they brake in this fashion the plate does not fall off. Instead the bolt and once welded nut suspend the plate and they kick of float. You then need to cut/grind the bolt heads off to remove the skid plates.

For the factory gas tank skid mounts, one broke and has been rattling, the others (save 1) seemed to have rusted and I twisted the head off when I tried to remove. A punch and a hammer is enough to knock out the welded nut. The top gas tank skid mount however would not free itself. I have yet to repair that mount location. I have to periodically remove the gas tank skid and beat out the dents so that it does not rub the plastic tank. Of the four engine skid plate mounts I have had to replace 3.

Enter the Rivet Nut.

I had first used M6 rivnuts as that is about the size of the hole. Bad. M6 is not strong enough. Use M8 and drill out the frame holes to match the OD.

Here is a Rivnut installed in the front cross member. The grind marks are from grinding off the head of the old mangled M6 rivnuts.

They rivnut installation tools. However the cheap ones that look like a pop rivet tool, can only go up to m6 and not stainless steel rivnuts. The big ones are expensive $100. Jsut searched and amazon has one that claims it can do up to m12 for $40

It however is common to make a puller with a bolt, 2 nuts, and 2 washers. It does take a little bit to learn how to install a rivnut with a DIY tool.

Finally the front of the engine skid is not supported where it bolts to the frame. Thus a hard impact will bow the plate in. Here I am in the back yard about to beat out the dent with a 8lb maul.

 

[Frontier510]

Oh man rivnuts! While handy and a ingenious solution to a common problem, I hate these things. Why? Even when squished properly they will eventually spin with the bolt in it. Making removing the bolt next to impossible.

From years of dealing with these, three tips.

1. Use green loctite # 290. The bearing retainer stuff. Around the knurle for the panel. Helps hold it in place and keep it from spinning. Or a epoxy glue called hysol.

2. Use antiseeze or copper slip on what ever you screw into them.

3. Drop the torque value on the bolt. Example. If it’s normally 18 ft/lbs. with a rivnut I us 15 ft/lbs.

Happy rivnutting.

 

[Nissan4Life]

Oh man rivnuts! While handy and a ingenious solution to a common problem, I hate these things. Why? Even when squished properly they will eventually spin with the bolt in it. Making removing the bolt next to impossible.

From years of dealing with these, three tips.

1. Use green loctite # 290. The bearing retainer stuff. Around the knurle for the panel. Helps hold it in place and keep it from spinning. Or a epoxy glue called hysol.

2. Use antiseeze or copper slip on what ever you screw into them.

3. Drop the torque value on the bolt. Example. If it’s normally 18 ft/lbs. with a rivnut I us 15 ft/lbs.

Happy rivnutting.

I am familiar with them spinning. Thus grinding the head off. When spun you can't drill them out like the instructions.
Thanks for the tips. I should have used some epoxy when I set them. I did not. Maybe I can flow some super glue in there. Just bought some anti seize.

Do you have a better solution. The cross member mounts you can through bolt. As can you 2 of the gas tank skids. The front engine and the frame mounted ones you can not through bolt.

 

[The other Sean]

I would get some shouldered nuts, drill the hole large enough and then countersink the hole for the flange on the nut and then weld it in.

 

[Frontier510]

Do you have a better solution. The cross member mounts you can through bolt. As can you 2 of the gas tank skids. The front engine and the frame mounted ones you can not through bolt.

Oh boy... my opinion?

My thought process on this. Man I hate rivnuts. Yes sometimes they are a necessary evil. Seems everything you can through bolt that is in single sheer. So good. Keeping in mind everything in tension just has to hold the skid up in downward tension. And the frame take the upward load from the skid. As the skid take a hit. The skid will push on the frame not the bolt. So... options.

1. Tap the frame and use a larger bolt. The hole in the frame is larger than the bolt. It passes through the frame a uses a nut tack welded to the other side. Downside? You have to open the hole up in the skid for a larger bolt.

2. Use a insert. Like a time sert. Keen sert and so on. The frame is thick enough to get 3-4 threads of the sert. Frame is still taking the load, from a hit to the skid, in a tension application. You are still taping the frame, but you still can use the original size hardware. No modification to the skids.

3. And this is the route I'd go. A top hat threaded bung. Everywhere. You'd take your 6 mm bolt for example . Drill the frame to 1/2 inch. Take some 3/4 round stock. About 1/2", 3/4" long. Turn it down to 1/2" except the last 1/8 of length. So it has a flange on it. Tap the center hole to your thread pitch probably 6x1.0. Shove it up in the frame and weld the flange to the frame. It would be completely bomb proof. Downside is you have to have access to a lathe and welder. Or a machine shop can make them for you for a nominal fee.

Questions if I wasn't clear ask. Good luck. If you have a welder or access to one and no machinest let me know I could make the bungs for you. Ill apologize for my spelling now.

 

[whistler]

That is what I did on my front skid although it has since been changed.
Yes, I need a lathe.
May I ask what make of lathe you have?

 

[Nissan4Life]

Wonder if I can tack a weld on the rivnut.

 

[ef9]

With riv nuts, I would at least use a stainless screw to prevent the screw from rusting and binding in there. But most rivnuts are steel, you can find aluminum, which doesnt corrode as fast as steel.


Sent from my iPhone using Tapatalk

 

[Frontier510]

@whistler. Ah.. the fabricator, machinists, racer on the forum chimes in. Thank you. I've always respected your work. I have no idea the make of the lathe's at work. Never looked. I have access to two at work. When you need to make something. You have a go. They are big though. Will have to check it out when I get home.

@Nissan4Life. If your looking at tack welding in rivnuts. That tells me a lot. I'll just make you bungs. Give me an address. Done. Problem over. Say 12? What thread?

@ef9. Most rivnuts I've seen are aluminum. Though I believe he said he used stainless. Witch could be welded to the frame. But why.

 

[whistler]

I was looking for a lathe when I got sick. Really wanted a Monarch tool room lathe but they are ridiculosy expensive.
I am able to some lathe work on my mill.
I can turn diameters somewhat by using a rotary table, boring heads(left handed boring bars). If the material is small enough to fit in a collet.I sometimes put a lathe turning tool in a vice and use the z feed on the quill to turn the diameters.
I sometimes trig everything out in 3-5 degree increments to cut out diameters. Pita until I get my DRO installed.
Thanks for the offer. Very kind of you but if I need lathe work I can't handle, I have friends with lathes.

Wonder if I can tack a weld on the rivnut.

I have but not where high torque is necessary. Just to keep it from spinning.

 

[Nissan4Life]

@whistler.
@Nissan4Life. If your looking at tack welding in rivnuts. That tells me a lot. I'll just make you bungs. Give me an address. Done. Problem over. Say 12? What thread?

Frontier510. As usually that is VERY generous of you. However at this time that is not necessary. I just spent the weekend fixing the mounts and installing the rivnuts. I am not going to replace those unit they fail. Another evening anti seizing the bolt an possibly gluing the rivnuts and I am done.

Thank you again for your offer. Your EZ down retainer plates are still rocking.

Cheers

 

[Nissan4Life]

OK back to it. I have been prepping my truck for the biggest annual 4 wheelin event on my personal calendar: the 15th (?) Annual Fall 4 wheeling trip.

I had all of my skid plates pulled off to work on various things. Now they are all painted and ready to go back in. The rivnuts worked perfectly. None of them spun. I used Stainless Steel nuts and greased the bolts well. Going to clean up the rivnuts and give them a glue.

While I am there, I have a new Shrock works Gas tank Skid to install. The installation instructions are attached. Surprised that it only uses 3 of the 4 factory mounting points. However one of my points are dead. The top most factory nut on the cross member near the rear diff had the bolt sheared off in it. The last couple of times I dropped my gas tank skid to pound out the dent so it is not rubbing the tank, I skipped this busted mounting point and just went with 3. Now I am going to have to address it. For the other broken points, I was able to knock them in with a punch and a BIG F Hammer, this location is up in there in a way that you can't really get a full hammer swing. A drill is a little tight too.

Tonight I plan on working on this. We'll see what I come up with.