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Nutserts/rivnuts suck for attaching driveshaft loop

8K views 34 replies 20 participants last post by  Scott L 
#1 ·
Against my better judgment, I drilled 8 large holes in my 4" frame tubes to attach Forte's driveshaft loop as suggested. I made the rivnut tool and inserted the 8 supplied rivnuts. Half of them wouldn't hold and I had to run out and find a store that sold them, which was no easy effort. Glad I bought a pack of about 20. It took me multiple tries to get the things to hold, and I'm still not done. Had to walk away from the garage. Why didn't I just get self-tapping bolts and drill nice small holes in my frame? Getting a cheap mig welder and welding the loop in would have been a better idea, too, rather than drilling those big holes and messing with the stupid rivnuts. Anyone thinking about a driveshaft loop (seems advisable with the driveshaft spinning mere inches from the driver and passenger) might want to learn from my mistake and frustration and install it with self-tapping bolts or drill and tap your frame for standard bolts. Sorry...had to vent a bit...
 
#2 ·
I've had mixed success with rivnuts. The tool from Harbor Freight is a waste of money. I ended up buying the Marson tool from McMaster Carr- much better.

As far as the driveshaft loop, I bought the generic one from Summit and welded the ends to the frame, cut the loop and drilled for re-attachment with bolts, so it is removable later.



 
#3 ·
I bought the loop from Forte's, but didn't use the rivnuts. I drilled and tapped the 4" tubes for 8 self tapping bolts. Quite a job drilling from underneath, but they drew up tight enough and no messing around with the rivnuts. Jim
 
#4 ·
I appreciate the heads up but I've got to ask what size rivnut tool you were using??? Those are some really big rivnuts, I just got the hoop about two weeks ago and have started to install it. It seems that having the frame up on stands and the hoop seated securely with a wood block held in place with a floor jack is holding it in place just fine for drilling. As for the rivnut, if the jack is holding the hoop in place and you start threading the grade 5 or 8 bolt...that rivnut has nowhere to go but into the frame. I haven't gotten that far yet but it seems to make sense, no? Sorry to hear you had such a hard time, I hope my way works a little bit better but I will definitely try with one before I drill any more holes.
 
#5 ·
Rivnuts?

Rivnuts need a very exact hole size to be effective. Too small and they won't go in, too large and they won't expand enought to fill the hole and grip.

I would worry about water getting into the tubes from those rivnuts not fitting the curve of the 4 inch tube.

Since the drive line hoop has the holes predrilled, why not just put a jack under the hoop to hold it up, and do a rosette weld into the holes and on the edges of the bracket. No holes needed and no way for water to get into the tubes.

Ron
 
#6 ·
I have not had a problem with them yet and I use them on everything I can. I also use red loc-tite between the rivnut and the hole in the steel being very carful not to get any in the threads which is a stud and bearing mount loc-tite. If you drill a hole in the frame and us a self tapping bolt it will eventually fail and start rattling.
Don
 
#7 ·
Shawn,
The rivetnuts can be a bit of a pain as you have found out. I live about an hour from Lancaster in Lineboro, MD 21102. If you need a hand I have a lift and welder so feel free if you can get the frame over here we could take care of it in short time.
Wayne
 
#8 ·
Now that is just way too cool. Wayne, you're a helluva guy. :beerchug:

Regarding the welding, may I suggest you consider welding some shoulder Kepp nuts into your tubes (instead of a hard weld). Smaller prep work and removable. Putting the head of the nut into the frame would be smoother and allow for finger start. (Pic below is shoulder nut, but suggest a crimp nut with shoulder)


Just another thought/approach.

Cheers,

Jim
 
#9 ·
I've got to ask why?

HI: Looking at your pictures it seems the drive shaft loop is only protecting the tunnel if the rear u-joint fails. What if your going 70 and the front joint comes apart? Wouldn't the front of the shaft beat the tunnel up also? I thought the loop was centered on the shaft? Just asking.
 
#13 ·
Iv'e used a lot of riv-nuts. They dont work well when inserted in round tubing, they dont pull up and grab all the way around the riv-nut. They work great on flat, but not on round

steve
 
#14 ·
You guys keep talking about water entering the frame...the manual recommended drilling drain holes to let it out. If you haven't done so, it might not be a bad idea as you've probably already got a lot of rivets which have penetrated the tube and will eventually allow moisture in.
 
#15 ·
I'm not worried about the moisture issue, but I regret using the rivnuts in my frame tubes because they don't work so well in this application. The comment made about their not working well for round tubes is right on. If you're gonna use them be very careful to drill the holes so that the rivnuts will just barely fit and use JB Weld or Loctite. You will still probably have to redo some of them. BTW where do you live in Eastern NC? I was stationed at Cherry Point for almost 6 years.
 
#17 ·
If you're gonna use them be very careful to drill the holes so that the rivnuts will just barely fit and use JB Weld or Loctite. You will still probably have to redo some of them. BTW where do you live in Eastern NC? I was stationed at Cherry Point for almost 6 years.
That sounds like an easy enough approach, I'll probably let the JB Weld sit before I start torquing them in.

As for NC-I am right around that general area. :001_smile: It's grown quite a bit in the past few years but I'm getting settled in quickly before I take off again. I'm actually 'in the field' right now...isn't technology great?
 
#16 ·
If you are going to use rivet nuts, make sure they ones with ribs.



Also make sure you use exactly the right size drill bit as dictated by the manufacture for the rivet nuts you select.

http://www.fastenal.com/catalog_pages/2010/3-281.pdf

It also helps to use a good quality tool for the job.



A last couple of notes: Make sure you have the correct grip range and you can use Loctite Red to help make sure they don't come loose.
 
#19 ·
I drilled and tapped my frame for the bolts.
It is probably less work then fiddling around with the Riv-nuts, etc., when all is said and done..
 
#20 ·
Rivnuts

This topic could not have come at a better time for me, sorry for your trouble Shawn but thanks for venting. I was getting ready to start securing my brake lines this week using rivenuts rather than rivets so they could be removed if necessary. Im wondering if using the rivnuts to mount the clips in the 4" tubing is a mistake based on the comments in this thread. Do you guys have any suggestions whether this is a good/bad idea? One other question that I have not been able to find an answer to is what is the thickness of the 4" frame? Shawn please keep in mind that by posting your frustrations that you have had with the rivnuts may very well keep some of us from going down the same path. Trust me, your post probably just saved me alot of frustrations myself. Thanks for venting!

Todd
 
#23 ·
I was getting ready to start securing my brake lines this week using rivenuts rather than rivets so they could be removed if necessary. Todd
Todd, just rivet the line clamps on..you'll never need to pull them. If in the worst case scenario, and you had to, simply drill out the rivets.
JMHO..:)
 
#22 ·
Hi Shawn,
The driveshaft loop I have built can be welded in place or use the riv-nuts. When I've installed the riv-nut I use a 3" long bolt, nut and flat washer to install the riv-nut. Once I located the postion of the riv-nut with a transfer punch or center punch, I drill one at a time the frame and install the riv-nut. Installing requires drilling (as I recall) a .525" hole. I insert the 3" bolt with the nut and washer closest the riv-nut. I then insert the riv-nut and while holding the 3" bolt ant riv-nut in place, I then thighten the nut which crushes the riv-nut in place. I then put the loop with 1 bolt and mark another hole and repeat the process.
You can call me anytime and I'll walk you through this process.
 
#24 ·
Mike hits a really important point; drill one hole at a time and fit it appropriately. If you don't you will quickly see just how much it shifted when you were putting the rivnuts in, and on the frame, you can't take that back.
 
#25 ·
FYI---The 4" frame tube is .120 wall thickness. Jim
 
#28 ·
For hanging brake lines and the small diameter you would use, rivnuts probably would be fine. I riveted my brake and fuel line clips and would have no problem drilling them out in the unlikely event that it becomes necessary down the road.
 
#29 ·
I quit! At least for the weekend...now since it's pouring and I had to roll the body buck back into the garage and over my roller. Had 2 more rivnuts fail and need to leave it alone. What a waste of time this weekend. Do yourselves a favor and weld your driveshaft loops in place. Weld, don't drill!
 
#31 ·
I saw someone suggest welding inside of the mounting holes as apposed to drilling and bolting. My frame is powdercoated silver. I was wondering is there would be enough heat transfer to burn the powerdercoating. Would welding just the bolt openings be strong enough for the attachment of the safety hoop. I know I should have purchased the frame bare but here I am.
 
#32 ·
I would seriously doubt it. LuisO came and helped me when we retrofitted my IRS cage, we ground down the appropriate areas and there was little to no burned powdercoat to notice. It is a black frame of course but keep in mind you'll also have an area where the frame is also covered by the hoop as a small buffer. If that's the route you go, I don't think you've got anything to worry about.
 
#33 ·
Update: rivnuts in and welded one side toda

Got the last of the pesky rivnuts in yesterday. After some practice with my new el cheapo $90 welder from Harbor Freight and some Lincoln flux core wire, I welded one side of the loop to the 4" frame tube. Ran out of time or both sides would be done. Had fun using a welder for the first time since high school metal shop! Had to go over it a couple times as this isn't exactly a Miller Matic, but after some grinding on my ugly welds, I'm happy with it, and the loop is going nowhere. Peace of mind is a good thing.
 
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