Addressing rear shock limitations

UKTJ

UKTJ

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As I traverse the internet viewing Jeep porn, I often see TJs with outboarded rear shocks or coilovers. Invariably these TJs have an upper mounting point formed by notching a 'tower' into the frame. I've probably mentioned here before that making any changes to the frame requiring it to be cut is not possible in the UK if a Jeep is going to remain 'street legal' - it is possible to attach to the frame, either with mechanical fixings or by welding. My question, therefore, is if a UK build would reach the point where rear shock travel was a limiting factor, are there any options for addressing this without cutting into the frame? For example, I wondered if with wider axles (say from swapping in JK axles) enough space is created to attach towers to the outside of the frame without cutting in to it, of is it that the issue then would be the width of the tub?
 
@mrblaine has a few more outboards under his belt than I do.

Any hope of not cutting into the frame will require wider axles to. What I do not know is how much wider than factory would be necessary. My suspicion is that these axles would be significantly wider than stock to allow for proper travels and good packaging.

Clayton Off-road did a rear outboard kit with a weird gooseneck upper mount that put the shock out away from the frame. But I know nothing about how well that fit or what kinds of travel they were aiming for. We don't see it often and no one seems to have copied it. And most outboards, even with wider axles, will be cut into the frame.
 
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UKTJ said:
As I traverse the internet viewing Jeep porn, I often see TJs with outboarded rear shocks or coilovers. Invariably these TJs have an upper mounting point formed by notching a 'tower' into the frame. I've probably mentioned here before that making any changes to the frame requiring it to be cut is not possible in the UK if a Jeep is going to remain 'street legal' - it is possible to attach to the frame, either with mechanical fixings or by welding. My question, therefore, is if a UK build would reach the point where rear shock travel was a limiting factor, are there any options for addressing this without cutting into the frame? For example, I wondered if with wider axles (say from swapping in JK axles) enough space is created to attach towers to the outside of the frame without cutting in to it, of is it that the issue then would be the width of the tub?
Click to expand...

If I stand the shock tower straight up parallel to the inner wall of the frame, cut all the way through the frame to the outer face of the inner wall, play very carefully with the mounting angle by moving the lower back and forth, I can barely get a 35 to NOT rub on the shock body with 4" of back spacing in the wheels. That is with the shock approximately 90 degrees to the lower arm, the bias is roughly 50/50.

I don't see it being possible within any of those parameters and then moving the shock outward 2.5".

You'll need to find that clearance some place.
 
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mrblaine said:
If I stand the shock tower straight up parallel to the inner wall of the frame, cut all the way through the frame to the outer face of the inner wall, play very carefully with the mounting angle by moving the lower back and forth, I can barely get a 35 to NOT rub on the shock body with 4" of back spacing in the wheels. That is with the shock approximately 90 degrees to the lower arm, the bias is roughly 50/50.

I don't see it being possible within any of those parameters and then moving the shock outward 2.5".

You'll need to find that clearance some place.
Click to expand...

This 100%. I’m in the process of doing the rear outboard. This is my first time and I’ve just studied over the years how Blaine does it.

I took my time at cutting the frame at first, slowly inching closer to that inner frame. Cycle and repeat. Knowing what I know now, I would cut as Blaine mentions right to that inner wall of the frame so the tower lays flat against it. Would have saved me sooo much time!

Even then, I don’t have enough clearance at the tire and shock body at max compression. I need to play with the lower some more to get the clearance I need.

This mod is a game less than inches. There is not a lot of wiggle room at all.

I totally get why it’s often said to be the last mod you do!
 
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Thanks @jjvw , @mrblaine and @Superjay5 for sharing your experience / knowledge. Makes clear that this would not be a benefit of having moderately wider axles, such as those from a JK - though to be clear that is not to say there wouldn't be other benefits from such a swap.
 
jjvw said:
Clayton Off-road did a rear outboard kit with a weird gooseneck upper mount that put the shock out away from the frame. But I know nothing about how well that fit or what kinds of travel they were aiming for. We don't see it often and no one seems to have copied it. And most outboards, even with wider axles, will be cut into the frame.
Click to expand...
From what I have seen they still require the frame to be cut.
 
jjvw said:
Others may call it a gateway mod. 🤣
Click to expand...

Gateway mod meaning a better understanding on how it all works together in harmony? Or do you mean spending more money?

I hope it’s not the latter, as this has been abusive to the pocketbook!

EDEB6513-2B7D-46E3-8539-F38E7BFAA01C.jpeg
 
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Superjay5 said:
Gateway mod meaning a better understanding on how it all works together in harmony? Or do you mean spending more money?

I hope it’s not the latter, as this has been abusive to the pocketbook!

View attachment 471233
Click to expand...

It's a confidence builder. Many interesting mods become less intimidating after an outboard.
 
So this is not going to get you to the same level of performance or allow as much shock travel but it is better than leaving them in the stock position.

IMG_3381.jpeg
 
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jjvw said:
It's a confidence builder. Many interesting mods become less intimidating after an outboard.
Click to expand...

Agreed. After I get the rear done. It’s unto the front. I’ll be cutting off the stock upper mounts and using the poly towers there also. Curious if that will be harder or easier. Regardless, the rear outboard so far has been the hardest mod, makes installing the midarm seem easy!
 
Superjay5 said:
Agreed. After I get the rear done. It’s unto the front. I’ll be cutting off the stock upper mounts and using the poly towers there also. Curious if that will be harder or easier. Regardless, the rear outboard so far has been the hardest mod, makes installing the midarm seem easy!
Click to expand...

Front is more difficult because you aren't building off of anything that is straight or square.
 
I’ve been contemplating going to 3.75” BS to give my outboard a bit more room.

Also planning to cut into the frame all the way to the wall of the inner frame. Then fiddle with the angle.

This was all coming soon, but now I’m derailed by the transmission swap.
 
JMT said:
I’ve been contemplating going to 3.75” BS to give my outboard a bit more room.

Also planning to cut into the frame all the way to the wall of the inner frame. Then fiddle with the angle.

This was all coming soon, but now I’m derailed by the transmission swap.
Click to expand...

Mine are at 4" BS with mild rubbing on the shock body at full articulation.
 
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