Super noob shock mount question (1 Viewer)

[BrianSanDiego]

Whats up guys,
Pardon the stupid question here in Hardcore Corner, but I thought you metal fabricating guys would know best.

My stockish FJ40 has a 1-2" leafspring and shackle lift. I have 2" longer shocks than stock, and they are bottoming out before the bumpstops do. I am going to spacer down the bumpstops this weekend so I don't kill my shocks.

But as a permanent solution I think I can relocate my upper shock mounts inboard of the original location to make room for the longer than stock shocks.

My question is, can I drill through and install good bolts as shock mounts in the crossbar. Or would I need to have some studs welded in to preserve the crossmember's strength?

Here is a pic of where I'm asking about bolting in or welding in mounts. (Not my rig)

Thanks for letting me waste your time on a dumb question!

Much appreciated,
Brian.

 

[Z()LTAN]

if you see the stock mount bolts are also just bolts through the crossmember.

What u are doing is called a shock inversion and works quite well.

It allows more flex and a longer shock to be used, the only payoff is that the shocks have less dampening effect.

I have done the same as you are going to do.

 

[BrianSanDiego]

Very cool,
Thanks for the response!
I guess I'm not as dumb as I thought ... this time at least

I've got Rancho adjustable shocks on there too, so I'll be able to deal with the resulting change in damping.

Looks like I'll be installing shock mounts this weekend instead of bump-stop spacers! I'd much rather increase my travel than reduce it!

Thanks Z,
Brian.

 

[BrianSanDiego]

Hey Z()LTAN,
Another question for you,
I can't tell from your pic, how far does the shoulder of the bolt extend toward the shock? Do you have a nut between the cross-member and the shock, or only one nut to hold the shock onto the bolt?

If that makes any sense at all... Maybe like this, One nut on each side of the shock, or just one nut on the outside.

And, did you run some sort of sleeve between the threads of the bolt and the shock, or just let the shock bushing ride on the threads?


Thanks again. Still noobing out, but at least my original idea wasn't bad
Brian.

 

[Z()LTAN]

Hahaha no worrys mate,

I got bolts with a shank length equal to the width of the crossmember, 2 washers, the shock eye and another washer so the bush isnt running on a threaded section.

Here is a quick pic, i used 2 washers on the inside for a sliding surface when the shocks want to articulate and a lock nut to hold it on with a slight amount of tension. (dont make it too tight as it wont allow the shock to rotate around the bolt)

 

[BrianSanDiego]

That great buddy,
You just saved me a bunch of time and effort trying to figure out how to do this.

Very much appreciate
Brian.

 

[Stumpalama]

Here is another way to do it that gets your upper shock mounts a bit higher and eliminates the need to inboard them so much while getting the absolute maximun travel from your shocks (in my case, Rancho RS500 12"ers:
Get a 2.5-3 foot piece of 1/8" x2" square tube and cut it lengthwise to remove one side, effectively making a peice of U channel. Mount your shocks on the axle mounts, center the channel open end down on the crossmember, marking both center lines. It should just about bisect the crossmember or set just a bit higher. Now extend and move your shocks upper eyes where you want them to mount on the channel and mark it with a Sharpie. You can do multiple holes and weld the rancho nuts on the inside of the uchannel, just make sure the nuts are set with a flat edge parrallel with the floor to ensure they will clear the crossmember. Once you've welded the mounting nuts, you can stitchweld the channel to the crossmember and mount your shocks. I did this for my spring over because it was, quite frankly, easier than redrilling my crossmembers and trying to weld the top of the upper shock mount with the tub still on. I could do 90% of my cutting fabbing and welding on the bench. Also when it came to mounting it, I only had to make some straight stitch welds while under the truck.
This fits right under the rear bed with a 1/4" or so to spare. The big advantage here is more stability at road speeds where the shock is allowed to function at closer to it's ideal angle. I think Mace identified the negative impact of a shocks angle to it's dampening capabilities.

Good luck, I'll see if I can get a picture to explain it.

Cheers-
-Mike

 

[Mace]

Couple of things..

Just running a bolt through some holes in the X member is not the best way to do it. It concentrates the stresses on the top portion of the xmember instead of all the way around the xmember. it is MUCH stronger to sleeve the hole and run the bolt through that. Yes the stock shock mounts were just drilled, but they were also welded all the way around. And that welding made for a much stronger mounting position.


By inboarding the shocks you are not only reducing their dampening ability, but you are also reducing the ability of the shocks to counter the rolling effects whicle cornering.

If you can find a different way to do it. I would.

I have done that exact same thing before tho..

 

[mookie]

when i had leafs back there, i cut the crossmember out, took some 4" 1/4 flat plate and used it to extend the crossmember up flush with the bottom of the body, then made a new crossmember out of 2x2 1/4" and welded it between the two plates. if you have a body lift it gives you a few more inches of shock travel and lets you reduce the inboard angle of the shocks

 

[BrianSanDiego]

Thanks for the additional ideas guys.
Things have gotten real busy for me so I haven't had a chance to get on the shock mounts.

I also like Stumps channel Idea. It sounds simple and sturdy enough, and would be nice to prefab before getting under the rig.

Appreciate the ideas fella's !

B.