Modified XJ Cherokee Tech XJ (84-01)
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Rear Bump stop Question

Old 02-21-2019, 04:26 PM
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Default Rear Bump stop Question

So I bought these beautiful spring plates from dirtbound

The question is should I bump from the plates to the body like this?

Or should I bump from the body to the plate like a dis?

I want to step up to 35's and would like to keep them from eating the body.

this is for a 98, roughly 5" lift and has a rear shackle relocation.
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Old 02-21-2019, 10:52 PM
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I would stay with the factory configuration only. By running inverted, the surface contact area of the bump stop is small and the contact area on the "frame" body is quite thin. The constant impact would probably deform the body rail over time.

In the factory location, the bump stop mounting plate provides a larger surface area and spreads the load better throughout the entire mount lowering the stress per sq in.
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Old 02-21-2019, 10:57 PM
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I run extended daystar bumpstops in the factory location in the rear . I can stuff the tire at full flex without factory flare damage on 4.5 lift with 32s. I think the screw in stops in the front are much better than what I went with or acos but I was on a budget and for my lack of wheeling they’re fine until I can trim and get enough flex to hurt something .
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Old 02-23-2019, 07:37 AM
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I like the way you think. I was thinking about using the factory side mount because its easier to shim the spring plate than the body but this works too.
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Old 02-23-2019, 09:49 AM
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Originally Posted by Domaas View Post
I would stay with the factory configuration only. By running inverted, the surface contact area of the bump stop is small and the contact area on the "frame" body is quite thin. The constant impact would probably deform the body rail over time.

In the factory location, the bump stop mounting plate provides a larger surface area and spreads the load better throughout the entire mount lowering the stress per sq in.

Not 100% sure what you are trying to say, but the side mount configuration will contact the body/frame in the same spot as the factory.

The factory bumpstop hits the axle tube just inside of the spring perch...not the U-bolt plate.

The side mount configuration will contact the frame body in the same spot that the factory bumpstop is mounted, so, when when going that route, you are either putting on additional 'bumpers', so the new one contacts the old one & the load spreading plate you talk about is still there..or you are putting in totally new 'bumpers', and you can cut the old bumpstop bumper material off (if it is even still there) and re-use the mounting plate to spread the load out if you are worried about it.

But, if you are hitting the bumpstops that much and that hard, you need more lift and a much better suspension.
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Old 02-23-2019, 09:50 AM
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Those are exactly what I need, my rear bumpstops are gone and I have 3/16" steel plate welded in that area on both sides because it had rust holes in it. Those inverted bumpstops will work great.
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Old 02-23-2019, 08:56 PM
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I have the Dirtbound setup with the bump mounted on the plate and love it. Its worked great for me for a few years. The bumpstops that DB sells mount on their plate. TBH I only went this route because I broke all 4 of my OEM bumpstop bolts in the frame and didn't want to play around trying to get them out.
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Old 02-25-2019, 12:45 AM
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Originally Posted by TRCM View Post
Not 100% sure what you are trying to say, but the side mount configuration will contact the body/frame in the same spot as the factory.

The factory bumpstop hits the axle tube just inside of the spring perch...not the U-bolt plate.

The side mount configuration will contact the frame body in the same spot that the factory bumpstop is mounted, so, when when going that route, you are either putting on additional 'bumpers', so the new one contacts the old one & the load spreading plate you talk about is still there..or you are putting in totally new 'bumpers', and you can cut the old bumpstop bumper material off (if it is even still there) and re-use the mounting plate to spread the load out if you are worried about it.

But, if you are hitting the bumpstops that much and that hard, you need more lift and a much better suspension.

My thinking was that if you mount the bumpstop inverted (on the plate) it has a narrower contact patch with the "frame". Especially since the "tip" of a extended bump stop may only be 4 sq in or so. The factory bump stop has about 10 sq in of area in contact with the frame at all times to spread the load and the 4 sq in area hits a much heavier material of the axle tube.When you turn its orientation around (inverted) the tin body will have to take all the impact and can be deformed on a large enough hit.

But as a side note, I do use my bump stops on a regular basis and I use them hard. I may hit my bump stops hundreds of times a day on the trail but I run the desert and have installed hydraulic bump stops for my application. For light trail running an low speed I'm sure inverted would be fine.
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Old 02-25-2019, 03:23 PM
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Originally Posted by Domaas View Post
My thinking was that if you mount the bumpstop inverted (on the plate) it has a narrower contact patch with the "frame". Especially since the "tip" of a extended bump stop may only be 4 sq in or so. The factory bump stop has about 10 sq in of area in contact with the frame at all times to spread the load and the 4 sq in area hits a much heavier material of the axle tube.When you turn its orientation around (inverted) the tin body will have to take all the impact and can be deformed on a large enough hit.

But as a side note, I do use my bump stops on a regular basis and I use them hard. I may hit my bump stops hundreds of times a day on the trail but I run the desert and have installed hydraulic bump stops for my application. For light trail running an low speed I'm sure inverted would be fine.

That's why I said to use the original mounting plate on the frame....to spread the load out.

Yes, high speed running is about the only time you will hit them hard enough on a regular basis.

I still stand by my better suspension comment, you should not be hitting the bumpstops hard that much......shocks should limit travel so you don't have that jarring impact.

Hydraulic bumps are better than what the OP is talking about tho, and a whole different area of use..
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Old 02-25-2019, 09:13 PM
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Originally Posted by TRCM View Post
That's why I said to use the original mounting plate on the frame....to spread the load out.
Must have missed this, should work out just fine


Originally Posted by TRCM View Post
I still stand by my better suspension comment, you should not be hitting the bumpstops hard that much......shocks should limit travel so you don't have that jarring impact.

Hydraulic bumps are better than what the OP is talking about tho, and a whole different area of use..
I think you might have typed this up wrong? Bump stops are there to remove the jarring impact from your shocks bottoming out. Using your shocks as limiters is fine if you use cheap white body shocks, but please don't use quality shocks as limiters either up or down. Any quality shock will specifically tell you not to in the installation manual.A properly tuned suspension ssytem will take into account the bump stops and their nominal compression rates. As an example, my front and rear suspensions are tuned to come to a full stop(including bump stops) with 1/4 of shock shaft left in travel. The last thing I want to do is smash my hiem ends into my shock caps or pistons into the shock bodies.
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Old 02-26-2019, 03:54 PM
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Originally Posted by Domaas View Post
I think you might have typed this up wrong? Bump stops are there to remove the jarring impact from your shocks bottoming out. Using your shocks as limiters is fine if you use cheap white body shocks, but please don't use quality shocks as limiters either up or down. Any quality shock will specifically tell you not to in the installation manual.A properly tuned suspension ssytem will take into account the bump stops and their nominal compression rates. As an example, my front and rear suspensions are tuned to come to a full stop(including bump stops) with 1/4 of shock shaft left in travel. The last thing I want to do is smash my hiem ends into my shock caps or pistons into the shock bodies.

NO, didn't say it wrong.

For most of us, shocks would limit down travel, and ideally, the bumpstops would prevent compressing your shocks all the way. The shocks would also be good enough to stop the upward movement of the suspension at speed so it never hits the bumps...not my compressing the shock, but by slowing the suspension down enough it stops moving upward.

Only time I have even hit the bumpstops at high speed hard was when my shocks failed catastrophically and I had no damping to stop the suspension from moving up as far as it wanted except the bumpstop.

Factory style bumpstops will give you a hard hit if you hit them running fast. most of us, when we get on the stops, are moving slow trying our hand at rock-crawling.

Hydraulic bumps like you have won't...that's why I said they were a whole different area.

Right now, my tires are my bumpstops.....


.

Last edited by TRCM; 02-26-2019 at 03:57 PM.
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