Rear Driveshaft/Crossmember Clearance

[jsalbre]

Ok, so with the Thuren long travel rear coils and the Fox 2.5 shocks at full droop (actually before it even gets that far) my rear driveshaft hits the crossmember that the gas tank skid and skid bars are attached to.

I see that @Atl-atl notched and re-welded his crossmember, but I’m not seeing anyone else talk about this issue. There’s lots of lifted Power Wagons on here and they’ve all got the same skids that my truck has. Surely others have run into it before. How’s everyone else solving the problem?

 

[Atl-atl]

Thuren offers drop brackets but the last thing I wanted was to lift my truck for clearance and then lower the skid plates back down negating the clearance gain.

 

[jsalbre]

Thuren offers drop brackets but the last thing I wanted was to lift my truck for clearance and then lower the skid plates back down negating the clearance gain.

I found some drop brackets from Carli, but nothing from Thuren. Calling them they mentioned that the side brackets on that crossmember should be slotted and allow some downward movement, but mine have no where to move from where they are, and like you I'd rather not lose ground clearance. I'm still wondering where everyone else that has lifted these things is hanging out?

I may end up doing what you did if I can't find a better answer, but I'm concerned about the strength of that crossmember being sectioned like that.

 

[Atl-atl]

I found some drop brackets from Carli, but nothing from Thuren. Calling them they mentioned that the side brackets on that crossmember should be slotted and allow some downward movement, but mine have no where to move from where they are, and like you I'd rather not lose ground clearance. I'm still wondering where everyone else that has lifted these things is hanging out?

I may end up doing what you did if I can't find a better answer, but I'm concerned about the strength of that crossmember being sectioned like that.

Ahh sorry, I was thinking it was Thuren but it must be Carli that makes the drop brackets. Im willing to bet almost nobody that has lifted these trucks ever wheels them hard enough to fully droop the rear axle.

 

[jsalbre]

Ahh sorry, I was thinking it was Thuren but it must be Carli that makes the drop brackets. Im willing to bet almost nobody that has lifted these trucks ever wheels them hard enough to fully droop the rear axle.

Probably true. I've caught air before, and had a rear wheel hanging, so I really don't want to risk busting a driveshaft. That tends to do a lot of damage if you're at speed when it goes.

 

[Atl-atl]

Probably true. I've caught air before, and had a rear wheel hanging, so I really don't want to risk busting a driveshaft. That tends to do a lot of damage if you're at speed when it goes.

Damn haha. yeah you dont want to be hitting an aluminum shaft on a steel crossmember.

 

[Rockcrawlindude]

You know what needs to be done :salute:



Seriously, though you can chop n channel that crossmember or run limit straps. Or run limit straps til you sort out the clearance issue. I think I would bend a piece of DOM tubing to make my clearance channel but I just like using my tube bender.

 

[jsalbre]

You know what needs to be done :salute:

View attachment 84974

Seriously, though you can chop n channel that crossmember or run limit straps. Or run limit straps til you sort out the clearance issue. I think I would bend a piece of DOM tubing to make my clearance channel but I just like using my tube bender.

Hah! I like the idea of some tubing. I don’t own a tube bender or a welder though, so I’m going to see if I can figure out what the simplest and cheapest solution is.

 

[Atl-atl]

Hah! I like the idea of some tubing. I don’t own a tube bender or a welder though, so I’m going to see if I can figure out what the simplest and cheapest solution is.

If you want to come to Phoenix Id be happy to do yours up like I did mine. Be quick though, its getting hot here ha

 

[H3LZSN1P3R]

Not knowing what those skids look like is it possible to re drill the mounting holes to move it a bit so it wont hit?

 

[Atl-atl]

Not knowing what those skids look like is it possible to re drill the mounting holes to move it a bit so it wont hit?

Initially thats what I was going to do. Then I got underneath and looked at it. It became obvious that clearancing the crossmember was going to be the easiest solution. Some of the "skids" are just metal tubing that run front to back and are bolted to the crossmembers. More of a skid "bar" than a skid plate. The gas tank skid is actually stamped steel though and mounts to the same crossmember. It would have been way more work to try to relocate the crossmember. Here is what I did.

 

[jsalbre]

If you want to come to Phoenix Id be happy to do yours up like I did mine. Be quick though, its getting hot here ha

Hah! I'd take you up on that if I were closer. It's a bit of a drive for Boise to there. I did manage to get about an 1/4" more clearance by loosening the bolts on the crossmember and pulling down a bit. It won't clear at full droop, but that's an improvement over what it was. I'm going to keep poking Thuren for a solution. They told me on multiple conversations that the parts I was buying from them were all I should need.

 

[Pearce]

I would go with limit straps. You don't want to suddenly fully extend those nice shocks anyway. I'm my experience after a build and I take it out wheeling because it's done enough, the rig performs better when limit straps are finally added. Articulating at that full droop is not necessarily more traction. But that's a different topic for a different thread. My crawler has straps in the rear, still not gotten around to them in the front. lol

 

[jsalbre]

I would go with limit straps. You don't want to suddenly fully extend those nice shocks anyway. I'm my experience after a build and I take it out wheeling because it's done enough, the rig performs better when limit straps are finally added. Articulating at that full droop is not necessarily more traction. But that's a different topic for a different thread. My crawler has straps in the rear, still not gotten around to them in the front. lol

The shocks are expected to be the effective limit, but I get where you're coming from. I don't do a lot of rock crawling so full extension of the suspension is more likely on desert or beach whoops and is less about traction and more about reducing the amount of air time the axle gets, or being there to soften the landing.

I guess I need to see exactly how much droop I'd be sacrificing by limiting it. Maybe pull the crossmember and then let the axle hang. Then I need to figure out some way to attach limiting straps back there if that's the way I want to go.

 

[Rockcrawlindude]

The shocks are expected to be the effective limit, but I get where you're coming from. I don't do a lot of rock crawling so full extension of the suspension is more likely on desert or beach whoops and is less about traction and more about reducing the amount of air time the axle gets, or being there to soften the landing.

I guess I need to see exactly how much droop I'd be sacrificing by limiting it. Maybe pull the crossmember and then let the axle hang. Then I need to figure out some way to attach limiting straps back there if that's the way I want to go.

Maybe this is only halfway thought out but I feel like since it’s a driveshaft clearance issue and not a typical limit strap scenario maybe you could just limit the axle in the center and not sacrifice any side to side articulation hmmmmmm

 

[jsalbre]

Maybe this is only halfway thought out but I feel like since it’s a driveshaft clearance issue and not a typical limit strap scenario maybe you could just limit the axle in the center and not sacrifice any side to side articulation hmmmmmm

I'm no suspension scientist, but that sounds fairly reasonable. Might be able to use the power hop damper bracket as a mount point.

 

[Pearce]

Yeah or a center one. If that axle power hop shock mount is strong enough, triangulate two from the frame each side of it.

Edit: what you said

 

[jsalbre]

Found a thread on here from a few years ago where someone else dealt with the same issue by reshaping the crossmember a bit. Unfortunately no pics and the guy hasn't been on since 2022.

Post in thread '22 Power Wagon Build Update'

Apr 8, 2022

Nice build! I'm curious about the crossmember mod for the driveline clearance. Did you just cut it out more?

The shop heated it up and bent it down, there wouldn't have been anything left if we cut. Still some clearance issues on the front track bar (full droop) that I am less concerned about. Only real fix on that would be limit straps vs cutting according to the shop I had it at.

• JamesEvan

• 

 

[Rockcrawlindude]

Found a thread on here from a few years ago where someone else dealt with the same issue by reshaping the crossmember a bit. Unfortunately no pics and the guy hasn't been on since 2022.

Post in thread '22 Power Wagon Build Update'

Apr 8, 2022

Nice build! I'm curious about the crossmember mod for the driveline clearance. Did you just cut it out more?

The shop heated it up and bent it down, there wouldn't have been anything left if we cut. Still some clearance issues on the front track bar (full droop) that I am less concerned about. Only real fix on that would be limit straps vs cutting according to the shop I had it at.

• JamesEvan

• 

Based on ATL’s crossmember modification photos I have to say that it makes zero sense that a shop could just “heat it up and bend it down”. That was a pretty sturdy rectangular tubing crossmember or perhaps they are not talking about the same cross member?

 

[H3LZSN1P3R]

Initially thats what I was going to do. Then I got underneath and looked at it. It became obvious that clearancing the crossmember was going to be the easiest solution. Some of the "skids" are just metal tubing that run front to back and are bolted to the crossmembers. More of a skid "bar" than a skid plate. The gas tank skid is actually stamped steel though and mounts to the same crossmember. It would have been way more work to try to relocate the crossmember. Here is what I did.
View attachment 84979
View attachment 84980
View attachment 84981

I like the approach I would do similar but instead I would cut a 3/8 plate and bend it to make a one piece weld in replacement. I don’t have the need to do it yet since I have a 2 piece shaft but if I go to a 1 piece aluminum I would likely need to so that.