fj45 rear bumpstop options

[65swb45]

Normally I'd just link over to a post elsewhere to save on bandwidth. I think that this kind of 45 specific tech should be readily 'found' when needed, and Pirate is not quite as good at that as it used to be. So here we go!

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Now that I've got the new Alcans on the back of the 45, there's no way the stock bumpstop configuration was going to be tortured into any further utility. With 13" bewteen the bottom of the frame and the top of the axle, it was time to take the next step into the world of 'modified'.

As it was, I added a couple of 2" tubes to the upper factory mounts to try and get some utility out of the stock setup while I was running the add-a-leafs.

I looked briefly at the 'stepped' bumpstop setup that came factory on the back of the 40 series. Rancho extensions are still working for me on Ruftoys. Unfortunately, the step and snubber combo would only net me a total of 7". I figure I'd like to have something closer to 10" to keep the wheelwells intact if I'm running some bigger meats down the road.

I called Mace last week to go over some design ideas. As you all know, I don't spend much time in fab-land, so I figured I'd ask someone who's learned from a few mistakes!

As you can see from the stop furthest to the right, I settled on a design that mimics the factory mounting at the top, with both under and outside frame mounting, and a second mounting plate for the snubber.

 

[65swb45]

I took some 2 inch tubing I had laying around and cut off two 7.5" sections and beveled both ends. Then I took some 5/16ths by 1.5 plate scraps and cut and drilled them to match the horizontal mounting section of the factory stop. I had purchased a half dozen or so 4 inch square, 1/4 inch thick precut steel plates a few months back from the local steel supply house. I took one of the predrilled ones and turned it on point to make a mounting plate for the factory snubber, and took another one to turn on point to make the 'side' mount for the bracket onto the frame.

In the pic, I've marked where I intend to cut the excess metal.

 

[65swb45]

A pic of the predrilled plate with the snubber:

 

[65swb45]

I cut off the outer 'tab' from the snubber mount [the side closer to the tire] I figure that as the axle comes into contact with the snubber, chances are it will only apply an upwards and slightly inwards force, not an outside one.

I will have a chance to test these out next weekend in Death Valley, where I'm usually driving way too fast for a truck with manual steering and brakes!

If it turns out the stops are being pushed inwards, I have the option of using the inboard point of the diamond-shaped snubber plate to attach some sort of supplimental support to counteract the inboard pressure. Jason and I were thinking that running a brace to the shock tube in the frame might be an option. Strangely enough, on the FJ45, the front of the rear shock tube is almost 5" behind the axle! So much for that idea.

I'll keep you posted.

 

[IDave]

Kool, Mark. Thanks for posting. Is that stop to the left what the original looked like on yours? I have a 3 inch tube pointed down with no snubber.

 

["N8"]

is it me or is that going to seariously limit your articulation?

 

[nuclearlemon]

is it me or is that going to seariously limit your articulation?

that's the point on his rig. he's trying to save his fenderwells.

 

[Mace]

Mark, even 5" of offset would add the strength you are lookin for.
Any triangulation is better than none..

 

[65swb45]

Dave, yes those are the factory snubber targets. I call them targets because the actual rubber snubber was mounted via an arched steel plate to the top of the axle housing, with the U-bolts holding it in place.

I think I have an extra pair in the stash.

n8, the 45 has never suffered from a lack of articulation, even with the mondo add-a-leafs that were in the old spring packs. Photo in July '06 TT will vouch for that [the infamous seat belt photo!];p I am currently looking at moving my upper shock mounts [already moved the lower mounts] in order to accomodate the serious droop the Alcans now give me. Also, if you do a thread search on Pirate [I did] you'll find that several rigs that are fairly well known have very little 'up' travel compared with down.

Mace, I hear you. Here's why I haven't done it yet. I've been thinking about it for a bit. The stock rear 40 stand with the Rancho snubber [third in the photo] has been on Ruftoys consistently for several seasons now. It has NO lateral support, and never did. I've crossed that suspension up hard many times over the Rubicon and the Dusy without budging the mount. In fact, the only wear marks on the snubbers are from the MAF flip kit u-bolts I installed earlier this year.

So I'm thinking that if I haven't budged a mount that only utilizes the bottom of the frame, wheeling harder than I wheel the 45, I don't think I should have a problem with a mount that utilizes the outside of the frame as well as the bottom.

Then again, the mount IS a LOT longer than stock, so there is some additional fulcrum that the 40 didn't have to deal with. That's why I haven't 'closed the book' on this yet.

Did I mention that the 45 rear sway bar linkage is in 'the line of sight' of the shock tube?

 

[IDave]

I hear ya Marcus.

Looks like what I have is an original target with an add-on. No snubber, though.

 

[65swb45]

The plate on your'target' looks big enough to use as a base to mount a REAL snubber onto, instead of having that tubing section that's got to make a heck of a noise when it hits the axle!

Looks like you could use some rear spring bushings.

 

[IDave]

The plate on your'target' looks big enough to use as a base to mount a REAL snubber onto, instead of having that tubing section that's got to make a heck of a noise when it hits the axle!

Looks like you could use some rear spring bushings.

Yeah, I need the real thing. I can't understand what the PO who put those on was thinking. And new bushings for sure. But that's a project when I don't have to chip ice off of them first.

 

[merbesfield]

not to hijack this, but i think this question is close. i posted this once, but got no answers. does anyone know where to get these stock bumpers? came off my LV axle. weird thing was there were rubber bumpers on both the axle and the frame. is that normal?

 

[cruiser ken]

I should have a set of those soon in good shape. I am going to run a MAF u-bolt flip kit and I'll have to get rid of the axle bumpers. Shoot me a PM.