The front shock mount on my T-bucket keeps coming loose. The mount is held on by 2, 3/8" bolts into Rivnuts. The Rivnuts on the right keep pulling out. What would be best. Just get the mount welded on? Or take a piece of steel, maybe 1/4", and weld it to the side of the frame rail, drill and tap the holes? Maybe either is just as good. With the shock off and the headlight mount off would that be pretty easy to get at to weld? Mount - Bolt heads that hold mount on, 2 bolts to the left of brake line- Thanks, Bill
welded, both sides, by someone who knows how. Those riv-nuts are not designed to take the abuse that the shock mounts are subject to.
Can you drill through to the inside without hitting anything? If so you could put an Allen head bold in from the inside and a nut on the outside.
Nut and bolt is always stonger than a weld.Allens are a min of 80.000 psi while grade 8 are 40.000.Go this route.
Looking at your photo,it looks like ya could drill two holes for through bolt along the back side,one above the other vs how they are now in center and front and back. This would let them clear front cross tube and ya keep your paint. If needed,move it back 1in. to get trough bolts to clear.
The front bolt is in the middle of the tubular front cross member. The rear bolt is right where the tubing cross member is. May be part of the problem. When I drilled the hole for the rivnut I hit the cross member. The front cross member goes all the way to the outside of the frame rail. Hard to see but you can see the bolt heads. The rear one very close to headlight inline with rear of front cross member. Partly first time builder problem. When I bought the partially completed project it had a friction shock that mounted transverse, parallel to axle. After driving that didn't seem to work. There wasn't much room left. Bill
On your last photo, the location of the brake line scares me. It seems like it could be damaged pretty easily. I'm hoping it's an optical illusion.
In my humble and pretty useless opinion, I'd weld some tapped bungs onto the frame and bolt away. To Gary above, please remember bolts are only as strong as the material they are fastened to. If you could through bolt, I agree as long as the frame was sleeved. As a side note, many welds can easily get into that range in tension and shear. The SoCal mounts are some of the best I've seen and they bolt to bungs welded in the frame. On that note, you might consider a pair of their forged mounts which are a lot nicer looking and would really clean up the front of your bucket. Another option would be the Pete & Jakes mounts, which are weld ons and also incorporate a headlight mount. Fryguy has them on his blue roadster and they work super slick. New look for the front of your beastie. I have most of this stuff laying around if you want to see what they look like on your frame. Give me a shout if you want to borrow some.
I hope it's an illusion. The car has p***ed the NSRA 23 point 6 times. Doesn't mean they see everything!! Thanks, more eyes are better. Bill
Just about everything in this info is wrong. There is no comprehensive bolting is stronger than welding. Allen bolts come in hundreds of different grades, and grade 8 is not 40,000 psi.
I may just have to get them welded on. Looking at some of the mounts mentioned I don't think that they will fit. Thanks for the suggestions though. I do like the Pete and Jake's but they will be too wide. My other option would be open the holes in the frame so a nut or bolt head would fit. Weld bolts or nuts to a plate that is welded to the outside of the frame. Bill
This entire statement is totally incorrect. A great reference is ANY decent mechanical engineering book. Almost all will have strength of materials sections. Excellent bedside reading. (smiling...not meant to be vicious)
Jeez, mine is going over 4 years with hair pins and a tube axle, better not let it know it's a no-no.
Get someone who knows what they are doing to weld them on. IMO, the bolts are positioned wrong anyway. With just two bolts on a bracket that takes its load in that direction the bolts should be above each other...not side by side. If I were doing this to rebolt in place...even with thru bolts, I would add a piece to the bottom of the shock plate for a third bolt or add a tab that goes over the top of the rail for an additional bolt.
And I've seen stress cracks on eight sets, and accidents caused by two total failures, one with injuries. Sure, your results may vary, but why fight with the laws of physics? In the end, physics always wins.
Think about it long and hard, and you'll realise that this setup makes the tube axle act as a sway bar, which is not it's design. Since it is VERY hard to twist the axle, something else has to give. Not sure what it is?? Keep driving, you will find out. I did. Side note: just because something has "worked for years" does NOT mean that it is good practice; it just means you are lucky. 299 rule kinda fits. Cosmo
Not to get this thread off topic but it's amazing how many are out there and still being sold in the same manner.
I use 11018 rod. 110,000 psi. Neither much matters as the steel you're fastening to is likely around 30,000 psi. Are the shocks bottoming out?
If your frame is the typical 11 gauge, a direct welded shock mount may eventually break out the surrounding metal. I would convert the existing mount to three or four bolts on different planes as mentioned, then weld a slightly larger piece of 3/8" plate on the rails. Once the plate was in place drill and tap it to match your shock mount. The plate will spread the load over the area that has holes in it already and should give you approx. 1/2" thread depth which should be adequate. Since the actual mount remains bolted on it also allows some option for change in the future.
Yup, I'm not convinced either. From shock mounts, to brake lines... welding vs. bolts and tube axles with hairpins, this thread is full of wacky half-baked information.
Boy, ain't that the truth... Thank god I never read this thread before I built my 3 supermodified ch***is... and who knows how much other stuff.