Extended bump-stops or bump stop extensions for lifted 80

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Feb 5, 2013
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Portugal
Hi,

I use to run OME850 and 860 along with some custom shocks that had the measures of the OME L shocks, after some use I had some issues with the shocks.
Nowadays I'm running Kind Springs HD in my rig, KTFR-69HD and KTRR-70HD , along with the same shocks.

Last week I've sent my shocks for maintenance and the builder said that the shocks weren't in great shape due to over-compression, they even had some stuff broken inside. So this bump stop issue came to my mind and here I am with a couple of questions to mend this issue.

Since I can measure my rig cause it's at the mechanic... I'll go with some made up values just to check if I understood this....

With the truck sitting at ride height, measure the exposed shaft on the shock. Then measure the gap between the bottom of the bumpstop and the axle housing and subtract 1".
Shock shaft - 4''
gap - 3'' -1'' = 2'' ( basic!!)

If the exposed shaft length is longer than the gap between the bumpstop and housing, that is the minimum extension you need for the bumpstop.
So my case would fill in this scenario, what would be the minimum measure for the bump stop extension? the gap minus 1'' in my example 2'' extension? Is this the correct thought?

Cheers
 

lumbee1

Native American
Joined
Sep 21, 2011
Messages
2,688
Location
Holly Springs, NC
Hi,

I use to run OME850 and 860 along with some custom shocks that had the measures of the OME L shocks, after some use I had some issues with the shocks.
Nowadays I'm running Kind Springs HD in my rig, KTFR-69HD and KTRR-70HD , along with the same shocks.

Last week I've sent my shocks for maintenance and the builder said that the shocks weren't in great shape due to over-compression, they even had some stuff broken inside. So this bump stop issue came to my mind and here I am with a couple of questions to mend this issue.

Since I can measure my rig cause it's at the mechanic... I'll go with some made up values just to check if I understood this....


Shock shaft - 4''
gap - 3'' -1'' = 2'' ( basic!!)


So my case would fill in this scenario, what would be the minimum measure for the bump stop extension? the gap minus 1'' in my example 2'' extension? Is this the correct thought?

Cheers
I might have been drinking when I wrote that previous post because I don't understand it.

You want the exposed shock shaft to be more than the gap between the bumpstop and axle housing, otherwise the shock will bottom out first. Ideally, you want the bumpstop to be 1" closer to the axle housing than the exposed shock shaft. The 1" is for deformation and compression of the bumpstop. The shock bumper is much smaller and only has about 1/4" of compression before the shock bottoms out.

From your example: the exposed shock shaft is 4", you want the gap between the factory bumpstop and axle to be 3" for maximum flex and protection of the shock. If the gap is bigger than 3", then you will need to make a spacer for the bumpstop that brings it down. If the gap is less than 3", then you are limiting your flex.
 

LandCruiserPhil

Peter Pan Syndrome
Supporting Vendor
 
 
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Mar 10, 2004
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24,148
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Scottsdale Arizona
You can make bump stop extension out of just about anything. In order to determine the perfect sized bump stop you want to remove your springs and cycle your suspension. I run J springs and L shocks with 2" shock extensions requiring a 1.75" bump stop spacer and spring retainers.

1954457

1954458
 
Joined
Feb 5, 2013
Messages
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I might have been drinking when I wrote that previous post because I don't understand it.

You want the exposed shock shaft to be more than the gap between the bumpstop and axle housing, otherwise the shock will bottom out first. Ideally, you want the bumpstop to be 1" closer to the axle housing than the exposed shock shaft. The 1" is for deformation and compression of the bumpstop. The shock bumper is much smaller and only has about 1/4" of compression before the shock bottoms out.

From your example: the exposed shock shaft is 4", you want the gap between the factory bumpstop and axle to be 3" for maximum flex and protection of the shock. If the gap is bigger than 3", then you will need to make a spacer for the bumpstop that brings it down. If the gap is less than 3", then you are limiting your flex.
Hi,

So I took some measurements of my suspension and I got the following:

Front
Bump stop to axle - 5.1''
Shock exposed Shaft - 6.7''

Rear
Bump stop to axle - 7.7''
Shock exposed Shaft - 5.7''

So... Front should be OK, right?
But... The rear should have a 3'' bump stop extension... Correct?

Per my previous post I believe my shocks have the measurements of the OME L shocks and I think they should be as OME "normal shocks", from what I could find they have around 2'' difference.

Cheers
 
Joined
Sep 4, 2017
Messages
820
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Arizona
The rear shocks are angled, so the rate of travel is slowed compared to the spring. 1.5” of shock shaft travel might be 2” of axle travel. Youll need to see what it flexes to and then measure. There are formulas for this, but i like real world.
 
Joined
Oct 8, 2011
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609
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Toronto, NSW, Australia
Re Slee's products, there is an Oz agent but they don't carry a full range so they'd need to be ordered direct.

Re using some 2" square tube that's a pretty nifty idea!

I'm probably going to lower the front bumpstops also (mine only has the inside-coil ones).
 

Bambusiero

SILVER Star
 
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Apr 11, 2005
Messages
402
Location
Chandler, AZ
As an alternative, you can raise the upper shock mount until the shock does not compress.
Limited by tires hitting things, of course.
That leaves more of the travel as up travel.
People will argue about what's better. I don't know.
It's probably more of a technical mod though, and maybe some bump stop extension is needed too, in balance.
There's only a limited amount of upward shock mount room available in the back. (which a body lift would increase)
 
Last edited:
Joined
Dec 17, 2007
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Sydney, Australia
As an alternative, you can raise the upper shock mount until the shock does not compress.
Limited by tires hitting things, of course.
That leaves more of the travel as up travel.
People will argue about what's better. I don't know.
It's probably more of a technical mod though, and maybe some bump stop extension is needed too, in balance.
There's only a limited amount of upward shock mount room available in the back.
This is my preference, but requires some fabrication and welding.
OP has said he doesn't have these capabilities
 

Bambusiero

SILVER Star
 
Joined
Apr 11, 2005
Messages
402
Location
Chandler, AZ
I'm probably going to lower the front bumpstops also (mine only has the inside-coil ones).
My front only has the inside-coil bumps stops as well.
That seems to be the normal OEM situation.
With both installed, you would have a more strongly rising rate "spring" at the upper end of travel, allowing you to cut it finer (wasting less of the shocks up-travel). Just a thought.
 
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