need some advice bolt or rivet in my cross members?

[19Walt93]

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.

I only thread the receiving piece of metal and file the insert side just enough to allow the bolt to slide in.

 

[Eddo Rogue]

Not sure if this helps, but I grinded the rivets off the radius arm brackets and used bolts. 7/16" fit through the rivet holes perfectly. Haven't noticed a problem or difference from the rivets. The new radius arm bushings eliminated the clunk though. They feel nice.

I used bolts for easier installation of bushings, and I plan to swap in extended arms one day.

 

[red Ranger (Sarah)3.0L]

This is very true. There are holes all over these frames that do not cause problems. That does NOT mean you can go drilling holes willy-nilly all over the place. Generally speaking, adding holes in the flanges should be avoided, though it is sometimes necessary. Holes in the web (the big vertical part of the frame) are more acceptable, but should be minimal in size and kept toward the center if possible. Most of the static and dynamic loading of the frame is vertical. So the top and bottom see tensile and compressive stresses. The center of the web sees the least amount of stress. Therefore, that is where holes have the least amount of weakening affect.

right ! now do you think I should cut/ drill out the old rivets and get bolts that fit the factory hole size once I drill out the rivets or should I go a size up for more strength?

 

[sgtsandman]

right ! now do you think I should cut/ drill out the old rivets and get bolts that fit the factory hole size once I drill out the rivets or should I go a size up for more strength?

I would step up a size and only open up the hole as little as you absolutley have to in order to get the bolt in the hole. As in big enough not to mess up the threads on the bolt but as tigh as possible, preferably tighter than just being to put the bolt in by hand.

 

[alwaysFlOoReD]

I use a step drill because it produces a round hole. Drilling thin metal a regular 2 flute drill bit tends to make a triangular hole. I go to 1/2" because that's the largest size on the most common cheap step drill, and makes easy to get the same size every time. Step drill don't do 7/16" AFAIK. 1/2" is common size for bolts, 7/16" not as much.

 

[RobbieD]

Step drill bits are well worth having. It's also the best bit for drilling holes in Plexiglas and plastics.