need some advice bolt or rivet in my cross members?

[red Ranger (Sarah)3.0L]

hello everyone I have a interesting question to ask I am about to undertake a big cross member replacement on my rwd extended cab Ranger, I only need to replace 2 cross members but the only catch is I don't have a welder or a air compressor so I'm wondering if I can just bolt them in and it will be fine. the two cross members I need to put in is the tire carrier one and the fuel tank cross member and I'm just wondering is I can bolt both of them up and just be done with it happy to hear any suggestions.

 

[Curious Hound]

Yes. Bolts are fine.

Here are the rules I live by when doing that. Maybe others will chime in. I do tend to overengineer things like this.
1. Try to keep the holes as close as possible to the actual bolt size. Don't overdrill or wallow them out. If you remove a 1/2" rivet, put back a 1/2" bolt.
2. I normally use grade 8. Grade 5 is probably fine. But no lesser grade of bolt.
3. I usually use fine thread bolts and nuts with flat washers and loctite.
4. Torque to the proper torque for the fastener. For example, a 1/2"-20 grade 5 bolt gets 85 ft-lbs. There are charts available with fastener torque specs, such as;

Tightening Torque Guide

Tightening Torque Guide for Grade 5 & 8 Hex Cap Screws This table is based on IFI 5th Edition Technical Data N-12/N-16, using Equation (1) and a torque coefficient, K=0.20 for non plated steel fasteners and K=0.15 for plated fasteners. These Figures represent an estimate of torque (torque...

www.almabolt.com

 

[rusty ol ranger]

I prefer bolts. Eaiser to remove next time

Ive used them to replace rivets on things like radius arm brackets...crossmember shouldnt be an issue at all

 

[don4331]

The official way from Ford for replacing rivet with bolts, was to ream the holes so a 1 size larger was a snug fit with the 2 pieces clamped together. Noting 1 size larger could be a metric bolt not imperial. (For the split frame sections of '98+, the rivets were 13/32" & 15/32", so 7/16 & 1/2" bolts worked fine) You don't want "play" in the hole.

Rivets will "fill" the slightly mismatch in alignment/hold diameter when they are pounded in place (you're not just upsetting a head, you're also expanding the shaft to fill the hole).

Ford's recommendation when replacing the section of the '98+ frames was grade 8 bolts (Like @Curious Hound, I consider this overkill - the steel in the frame is only 30ksi material). For the few penny's more for the better quality bolts, its worth the piece of mind.

 

[Blmpkn]

3. I usually use fine thread bolts and nuts with flat washers and loctite.

Why not split lock washers or nylock nuts? I've been trying to figure out what I'm gonna do to reattach everything to mine. Your method was the one I thought of first.

 

[19Walt93]

I used 7/16 grade 8 bolts on mine, the key is to have a tight fit between the bolts and the holes. I cut threads in the crossmembers and then nutted the bolts.

 

[Curious Hound]

Why not split lock washers or nylock nuts? I've been trying to figure out what I'm gonna do to reattach everything to mine. Your method was the one I thought of first.

I'm not sure of the effectiveness of split lock washers or start washers. It won't hurt to use them. I sometimes do. But thread locker is better. I have seen a lot of tests showing that the vast majority of lock washers are almost worthless. Do your own research on that.
Nylock nuts or other self-locking nuts are better than plain. I prefer to just use plain nuts and add Loctite. And it only takes a drop of threadlocker. There is no need to drench everything with it. I got that from a Loctite factory rep years ago in a training class.

 

[Curious Hound]

I cut threads in the crossmembers and then nutted the bolts.

Not a horrible idea. But make sure the 2 pieces are firmly clamped together with no gap. If there is a gap and both pieces are threaded, then the threads will tend to maintain that gap.

Although we want the holes and fasteners to be the same size to maintain alignment, the majority of the fastening is done by clamping force. That is why proper torque is important. The torque produces clamping force that increases the friction between the pieces being joined. That friction/clamping force should be 90% or more of what is keeping the pieces aligned in position.

 

[Curious Hound]

More food for thought. I have used Nord-lock washers in industrial settings where I'm not paying the bill. They definitely work. On my Ranger, Loctite is good enough for me.

Yes. This is arguably an advertising video. But you can find independent videos showing the same tests.

Video: Nord-Lock Washers in the Junker Vibration Test

Nord-Lock washers are compared with other locking methods in the Junker vibration test, which is considered to be the most severe vibration test for bolted connections.

www.nord-lock.com

 

[lil_Blue_Ford]

I usually ream it out if needed and run SAE grade 8 through. Whatever the closest fit is. Grade 8 washer under the head and a serrated flange nut anymore.

Technically the closest to a rivet would be a shoulder bolt, but they’re not really readily available in the sizes we would need and it’s probably overkill.

 

[sgtsandman]

Why not split lock washers or nylock nuts? I've been trying to figure out what I'm gonna do to reattach everything to mine. Your method was the one I thought of first.

Nylock nuts are pretty reliable but not always in the grade you want.

Split washers don't always perform the way they are supposed to and the nut or the bolt will spin loose.

There is no doubt that thread locker is going to hold as long as the threads are clean.

 

[lil_Blue_Ford]

Thread locker, serrated lock washers and deformed thread lock nuts typically hold the best. Serrated flange nuts also typically hold well.

 

[Curious Hound]

I usually ream it out if needed and run SAE grade 8 through. Whatever the closest fit is. Grade 8 washer under the head and a serrated flange nut anymore.

Technically the closest to a rivet would be a shoulder bolt, but they’re not really readily available in the sizes we would need and it’s probably overkill.

The shoulder on the shoulder bolt would have to be shorter than the thickness of the 2 pieces being joined. Otherwise, the nut would tighten down on the shoulder before tightening the joint. Shoulder bolts are not normally used for tightening things together. They are most commonly used to provide a fixed gap so 2 pieces can rotate or slide in relation too each other.

The thing with rivets is the shank expands and becomes tight inside the inner diameter of the holes. We can't quite do that with threaded fasteners. In fact, with torque, the threaded fastener often stretches slightly, making it smaller in diameter.

 

[SenorNoob]

Seems like stover nuts would be best if you don't want them to back off. Though Loctite on fine threads might be better.

 

[Blmpkn]

Mmmm.

I'll just use Eric's method I guess.