Bumpstops and flipped U-bolts

[DUDELUX]

Ok, so Ive just fitted the IFS rear springs, and ext shackles to my Lux.
The stock length shocks would allow the bottom U-bolt plate to sit under the axle where its supposed to, so I fitted the U-bolt flip kit instead.
Now my question is...

The stock U-bolts used to hold the bumpstops down on the top of the springs, but now Ive got the flipped U-bolts there, how do I go about mounting the bumpstops.

I dont have the rear shocks in place yet, hopefully Saturday, the inverted rear shock mount will get welded on, and Ill be running a set of 10inch Bilsteins.

So, how do I mount the rear bumpstops??
I have heard about some Lux guys fitting 80series bumpstops?? Why??

Should I just weld a piece of RHS to the bottom of the bumpstop, and then weld that to the U-bolt plate??

Thanks guys.

[brad 93hilux]

Should I just weld a piece of RHS to the bottom of the bumpstop, and then weld that to the U-bolt plate??

Thanks guys.

That's what I did, and it works well.

I had 80 series ones and a end up selling them, too tall for what I wanted.

Brad

[DUDELUX]

Could you please post up a pic or 2 for me??

Also, if anyone can give me some info on why some guys run the 80series bumpstops, Id appreciate it.

[TWISTY]

Pretty sure I've seen the standard bump stops just tacked/welded to the u-bolt plates before.

[howsie]

Mark (markil on here) did his by welding a bit of box tube to the plate then the standard mount onto the box tube from memory. Shoot him a pm he should be able to help in much greater detail having looked at all this before

[brad 93hilux]

not real good pic but since i am in SA and my 4b is in NSW its the best i can do..

Its on the front but u bolt flip up kits are the same basic thing, gives u a idea...

these are done with flat bar and i notched out the corners so i could still tighten the nuts with a socket.





Brad

[DUDELUX]

Thanks Brad, are they just welded to the U-bolt plate??

[brad 93hilux]

I have 2 pieces of flat bar welded to the plate vertically and a horizontal piece
Welded to that, then the bump stops are bolted to that..

I tried some poly ones off eBay from the states and they tore off after about 4 trips.

I'm happy with these and if I break one they are a cheap replacement

[DUDELUX]

Thanks heaps Brad. Looks like a good idea.

I might just do something similar myself.

Cheers mate.

[coopster]

you can put them on chassis rail

[DUDELUX]

Yeah Ive seen that somewhere Coopster.
I think Im going to do something similar to Brads pics, make an extension and weld the bumpstop to that.
I already have the Lux bumpstops here, so no need to buy others. And from looking at it, the plate on the chassis rail has to be removed/relocated back about 2inches aswell, as the rear diff went back about 2inches with the IFS springs.

So my next question....
How do I work out how high to make the bumpstops extensions?? Like Brad has posted above??
Ive read that you want 2/3rds down travel and 1/3rd up travel, how do I measure/set it up properly??
Im going to lift up the rear wheels(one at a time) with the engine crane when the sun comes out again and take some measurements and have a looksee.

[Willy Hilux]

When mine is in the static position, the stops are only about 50mm from hitting. This is on the front.

[Z()LTAN]

It all depends on what kind of bump you are using, hard rubber ones need more room and softer more progressive ones need less.

I like the 80s rear progressive bumps. Set them up like willy said with about 50mm gap at ride height.

Bump stops both save your suspension (shocks) and force flex through leverage.

[DUDELUX]

Ill be using the stock Lux bumpstops, setup similar to the way Brad has posted in the pics above.

[brad 93hilux]

Not saying it is the right way but I measured the length of stroke left in shocks sitting in a static position then measured between the top of flip plate and underside of chassy.
Then subtracted them from each other, then added an extra 30mm for compression to stop the shocks bottoming out plus the height of bump stop

If that makes sence

Works for me, 30mm compression has been enough to stop shocks bottoming out on these stock bump stops.

But I like to use every bit of the shocks travel..

Brad

[brad 93hilux]

Not sure if u can see in the pic but because I move my diff forward 35mm I just offset my bump stops to match up to the plate on underside of chassy..

Even with out the flip up kits I did this when I first lifted my truck back in 2006 an I still run the same shocks, so obviously couldn't be doing any damage to shocks.

I just transferred the idea to the flip up kits when I did in about 12 months ago..

Brad

[DUDELUX]

Im going to do some measuring tomorrow, and just want to make sure I am doing it correctly.
I have IFS springs with 200mm ext shackles, inverted rear shocks, and they are 10inch Bilsteins, those shiny shockies arent cheap, so the last thing I want to do is bottom one out by not setting up my bumpstops properly.

Heres a pic, its sitting on pretty much flat ground(half in the shed), Im not sure if this helps, but you can see my set up. The contact plates on the chassis rails will need to be moved back about 2inches to be inline with the rear housing.


I was just going to do something similar to what brad has done, as I already have the Lux bumpstops here. I just need some advice on how to measure it for the extensions.
Brad posted how he measured his, but more advice is needed please.

[shorty_f0rty]

flex it up and compress one side and measure the space between your bumpstop areas.. minus the height of your bumpstop = the height of your extension.. depending on what material your bumpstop is and how much it compresses, add some extra so on a hard hit it wont bottom out the shock.

oh and I'd try and flex it up somewhere where both ends are working.. ie, not on a ramp ..

[DUDELUX]

Just to add to this thread.

I lifted up the passenger side rear wheel(using my engine crane) today, to try and figure out my bumpstop extensions. I lifted up the passenger side wheel until the drivers side wheel started to lift off the ground, and then got some measurements, and a pic.



I took measurements from the top of the U-bolt plate to the bottom of the stock contact plate on the chassis rail, this measurement is 155mm.
Ill be using the stock Lux rear bumpstops, which are 95mm high.
So, going off this, I need to make a 50mm extension, using something like 50x50 box section.
Is this correct??

The stock contact plates on the chassis rails will need to be cut off and refitted 2inches back to suit the longer springs Im running.
So should I just cut them off, then lift up and measure again??

When I lift it up again, should I have someone pushing down on the drivers side rear wheel to try and compress the passenger side rear shock more??

Please help point me in the right direction as I want to get this done asap.

Thanks guys.

[shorty_f0rty]

Hey Tony,

Do you have a place where you can flex up your lux similar to this? even using a drainage ditch on a side road for example. Its important to make sure opposite corners are compressed/extended.


If you can slowly flex up and you will most likely compress opposite corners so your shocks limit any more up travel. If you do this slowly it shouldn't damage the shocks at all. Then measure the compressed front and rear sides from top of ubolt plate to bumpstop mount. with that distance (it should be the same on each side, but check theres no interference with your steering) add some buffer for bumpstop compression (10-20mm?) and thats should give you the size bumpstops you need.

Flexing it up like you have there doesn't apply weight to both ends and means that your suspension isn't 'maxing out' flex.. this is what you need when you're measuring up bumpstops..

[DUDELUX]

The front end hasnt been touched yet, Ive got a bit to do to the front, but its still a daily driver so I cant take it off the road to cut the front end out just yet.
I just want to set up the rear so I can at least go wheeling again.

I dont know of anywhere that I can drive into that will give me that sort of flex pose, not without bumpstops or a handbrake that works properly anyway.

I think if I cut the contact plates off the chasssis rails, then lift up the rear wheel again, with someone pushing down on the other side wheel, that should allow the shock to compress so I can get an accurate measurement, well my guess anyway.

[ZOOK60]

I have a good place for you too test it out just up near bunnings.
You won't get anywhere near the results you are after with the engine crane. If you can wait till sat we could
Go out there and work out what you need in terms of bumpstops.

[DUDELUX]

Saturdays no good mate, PM sent.

If I cut off the contact plates on the chassis rails, then lift it up again, and have Mel push down on the other side wheel to compress the shock, then measure the gap between the top of the Ubolt plate and the bottom of the chassis rail, would that give me a more accurate measurement??

Then weld something to the Ubolt plate, and weld/bolt the bumpstop to that, and make a new contact plate out of box section and weld that to the chassis rails.
Would that work??

[TWISTY]

What about using the engine crane to lift one tyre up in the air. Pack underneath it with something (other tyres, bricks, wood, wheely bin etc).......lower it down then go use the crane on the opposite corner. Should get it all flexing as needed to measure it.

[DUDELUX]

Dave, youre an ideas man.

[DUDELUX]

Okie dokie, I went for a drive today hunting for a ditch or a rut that I could drive into, so I could get both front and rear flexing.
I found a rut on the side of a dirt track halfway up a hill, going into the local state forest. I drove into it facing down the hill first, got some measurements, then drove into the same spot facing up the hill.
Heres a couple of pics...





Passenger side rear against chassis rail.


Drivers side rear almost against chassis rail.


I didnt get the shocks to compress completely, but, the tyres were rubbing on the chassis rails, as you can see in the pics.

So, heres some numbers...
While facing downhill(passenger side rear up), from the top of the Ubolt plate to the bottom of the chassis rail is 220mm.
While facing uphill(drivers side rear up), from the top of the Ubolt plate to the bottom of the chassis rail is 215mm.
So, lets say 210mm each side for safetys sake.

Going off these numbers, if I make a 30mm spacer similar to what Brad has posted above on the Ubolt plate, then bolt/weld the bumpstop to that, and weld some 50mm box section to the chassis rail, I should be good.
How does that sound to you guys??

My bumpstop is 95mm high.
So 95mm+30mm+50mm= 175mm Which leaves me with 35mm to spare.

Am I right or wrong??

[DUDELUX]

Ok, my measurements are good, but I think the way I was going to do my bumpstop extensions was all wrong.
I've been thinking about it and the tyres hit at 220mm, but not at 215mm, so I need to make uptravel stop at 215mm.

Can someone please tell me if ive finally got it.
The sooner the better if possible, so I can make them.

Thanks guys.