Front Bump Stop Q's

[skrypj]

I didn't really see much around regarding the front bump stops. Poking around my truck I noticed that the truck has two front bump stops on each side, and that the front and rear bump stop positions are not even. The front bump stop contacts the LCA first and then the rear second. So a couple questions:

1. Why run the offset bump stops? I assume its to make it more progressive but the Toyota OEM bump stops are pretty stiff, hence why Durobumps and Perry Parts exist.
2. Could you delete the front bump stop without causing issues with the shocks? Would the rear stop the uptravel early enough to prevent bottoming the shock?

Seems like you could gain a bit of up travel, or at least tune your uptravel better, buy only using the rear bumps. I was thinking I may pull the bump stops off and gingerly run my truck up on some ramps to see where the shocks stop the suspension and where that is relative to the bump stop pads.

 

[kcjaz]

Good questions and I don’t have the answers but I’d be cautious deleting the front stops. I’m not sure why the stops are not even but I am sure Mr. T likely has a reason and if the front could just be deleted why is it there to begin with.

That said, I wondered about the front ones too when I replaced the rears with Timbren stops. The Timbren kit I bought only had the rear ones for the front. They are taller and meant to come in contact sooner but be more compressible. I’ve never tested if the front comes in contact anymore at full compression.

 

[skrypj]

Good questions and I don’t have the answers but I’d be cautious deleting the front stops. I’m not sure why the stops are not even but I am sure Mr. T likely has a reason and if the front could just be deleted why is it there to begin with.

That said, I wondered about the front ones too when I replaced the rears with Timbren stops. The Timbren kit I bought only had the rear ones for the front. They are taller and meant to come in contact sooner but be more compressible. I’ve never tested if the front comes in contact anymore at full compression.

I am running PerryParts bumps I was just kinda wondering if anyone had cycled the suspension and figured out where the shocks actually bottom out.

 

[TeCKis300]

You'll find some of that info here. I can share more after I get back from a camping trip.

Long Travel AHC

Probably no surprise, but I've been a big proponent oh AHC. Damping always dialed in regardless of load. Large fluid volumes and remote accumulator damper that stays cool with extended off-road travels. Actively pressurized for long term performance and durability. Combined with unique...

forum.ih8mud.com

Here's slammed on bump stops (on 35s).

 

[TeCKis300]

1. Could you delete the front bump stop without causing issues with the shocks? Would the rear stop the uptravel early enough to prevent bottoming the shock?

Thinking out loud. It's certainly possible. We know more extreme rigs like Monica the race truck running in stock full class with stock arms, harvests suspension travel in both down and uptravel.

Question is this would need to be done in wholistic fashion. The tops of proper larger tires will top out for fender clearance about the same time of the bumps. The shocks likewise will top out. It's really important that the factory bumps bear the primary forces. While I can't speak for exactly why there is two staggered bumps, it's likely for good reason and part of what sets apart the 200-series to take more extreme abuse and loads without failure.

I'm all for upgrading bumps (Durobumps are working great for me), but then there's other things to attack first like suspension, bigger tires, body lift, etc. before bump stop limits are a constraint

Monica

.

 

[skrypj]

I put the truck in Low mode and then drove the front left and right rear up on ramps and this is where it ended up. I think there was maybe a little more uptravel left because it did seem to move a little when I would hop on the side step.

This is how to stock bump sits thickness wise comparatively.

So it appears if you were somehow able to fully crush the stop, the metal cup of the rear stop would stop the suspension right around where the shock would bottom out.

 

[TeCKis300]

I put the truck in Low mode and then drove the front left and right rear up on ramps and this is where it ended up. I think there was maybe a little more uptravel left because it did seem to move a little when I would hop on the side step.

View attachment 3629522

This is how to stock bump sits thickness wise comparatively.

View attachment 3629523
So it appears if you were somehow able to fully crush the stop, the metal cup of the rear stop would stop the suspension right around where the shock would bottom out.

Good stuff.

There's other bushings at play, namely the LCA chassis pivots that would deform at limit too. I could see the LCA pitching to engage the staggered UCAs. IIRC, the rear LCA pivot position hash a larger bushing.

 

[nwfl4runner]

You know there is at least some give because Toyota let’s you run OEM spacers

 

[skrypj]

You know there is at least some give because Toyota let’s you run OEM spacers

Just for clarity for everyone, this test was done specifically on a stock LX570. YMMV

 

[nwfl4runner]

Just for clarity for everyone, this test was done specifically on a stock LX570. YMMV

Same stroke on both platforms - your best bet though is still to yank the coil and cycle it till the shock bottoms out. Ramping it is close, but if you’re talking about yanking a bump stop you need to know exact compression. You could cheat and discharge the front accumulator, it’ll let you cycle easier.

 

[skrypj]

Same stroke on both platforms - your best bet though is still to yank the coil and cycle it till the shock bottoms out. Ramping it is close, but if you’re talking about yanking a bump stop you need to know exact compression. You could cheat and discharge the front accumulator, it’ll let you cycle easier.

I’ll be doing my AHC fluid soon so I’ll try to mess with it then.