Topic: Spring over shock placement Q's

[BoringDave]

I'm to the point I need to figure out how to mount my shocks. I've bought some Ford towers and prepped the frame rails for them. I don't want to do any welding until I figure out the size and get my tires installed. At that point I can fully cycle my suspension with my shop crain. This is what I've done so far.


Cleaned up the frame rail.


And clamped a Ford tower in place.

Ultimately I would like to only have enough up travel so the springs go flat or maybe just past flat.  In order to figure this out I tied a string from the front spring eye to the back. Of corse this is with all the weight on the springs. I then measured from the top of the spring pack to the string. This showed me that I could push the spring pack up just over 4" and it would be flat at this point.

 Now this is where I would like to bump stop at. Then move my shock location so I have no more then 5" of rod sticking out. My thought is all the rest of the shock can run in droop?

Does all this sound Resonable?

 Also I would like to make my shock mount on the axle tube like this.

Never mind the bolt, I just have it there for spacing.

But with it mounted there I have 10" of rod sticking out. And if I were to use 16" travel shocks I would have 7" hanging out.

 Would there be any problem incorporating my lower shock mount into my top spring plate alsong with my bump stops?

Any thoughts?
 

[sharpxmen]

lower shock mount should be parallel to your axle, 90 deg from what you have it now. get the max length shock at your full axle drop and go from there, it could be too short if you put the lower mount bolt at the top of your spring, you'll have to calculate it based on extended length at the lower point then find a suitable location with the axle rested at full uptravel on the stop (take the leafspring out on 1 side and put a piece of 2x4 on top to space out for the spring and plate or whatever the thickness is, if you have room left to push the rod in it's better of course, you don't want to bottom out on the shock).

another thing, to me it looks like you'll need extended stops or have something on the spring plate, seems a little gutsy to aim for all that uptravel to be honest with leaf springs.

[BoringDave]

lower shock mount should be parallel to your axle, 90 deg from what you have it now.

another thing, to me it looks like you'll need extended stops or have something on the spring plate, seems a little gutsy to aim for all that uptravel to be honest with leaf springs.

I don't understand why I would want the shock bushing perallel with the axle. Wouldn't that cause bushing bind at full articulation? My plan is to build a lower shock mount like the factory Cherokee rear but not hang down past the tube. This way as the axle articulates the bushing twists around the mount and don't bind up.  Am I missing something?

 Do you think 4" of up travel is to much? Thats where the spring would be flat. I have not started on the bump stop setup yet that's why there so much room in there. My plan there was to weld a tube to the center of my spring plate that would have a flat top on it so the OEM bump stop would just hit it. I also planed to make them adjustable like the jack stands that have the holes and a pin.

Dave

[sharpxmen]

I don't understand why I would want the shock bushing perallel with the axle. Wouldn't that cause bushing bind at full articulation? My plan is to build a lower shock mount like the factory Cherokee rear but not hang down past the tube. This way as the axle articulates the bushing twists around the mount and don't bind up.  Am I missing something?

the way i see it axle wrap  and movement under torque and braking is more than the angle by the axle due to up/down travel and occurs way more times. Also, the closer you are to the axle tube the more "rotation" is a factor. anyway, it's just the way i see it. If you had a 4 link or upper/lower arms and track bar and the axle wouldn't rotate under load then the story would be different

Do you think 4" of up travel is to much? Thats where the spring would be flat. I have not started on the bump stop setup yet that's why there so much room in there. My plan there was to weld a tube to the center of my spring plate that would have a flat top on it so the OEM bump stop would just hit it. I also planed to make them adjustable like the jack stands that have the holes and a pin.

Dave

yeah, that's fine - i missed that part in your other post.

[neale_rs]

Stock length shock towers would have been fine or very close (although there is an advantage to having an eye mount at the top of the shock).  By just moving up the lower mount, you would get all the droop your springs can provide.  Having the springs over the axle provides a bump stop extension automatically.  Now you are looking at using more expensive long travel shocks with more travel than the springs will ever provide.  I would recommend measuring the actual spring travel and getting shocks with just a bit more travel, and then lowering the upper shock mount as required. This will give you all the wheel travel available and keep down the shock cost.

[FourbangerYJ]

If you mount them they way you have it pictured it's in single shear. Turn it 90* you would be in double shear. (Plate on both sides) You can make the brackets or buy them.
Like Neale said, measure the travel and see what length shocks are out there.

[Jeffy]

$20 for a pair of weld on shock mounts.

He could also weld a stud to the U-bolt plate as well.

[BoringDave]

This is what I had in mind.



It may only be single shear but should hold up just fine. I'm not building a KOH rock buggy just something to do some more advanced weekend offroading.

[Jeffy]

Is that a screen shot of a pic on your ipad?    Looks nice. 

[BoringDave]

Yes it is.

[Bounty Hunter]

I would recommend not leaning the top of the shock towards the rear of the Jeep as the axle travels forward during compression.  I would leave the shock vertical.

I have the same setup, SOA with RE 1.5" springs and the Ford shock towers.  I used the longest Bilstein shock available.  I have my spring compression limited to when the springs are flat, or just a little negative arch.  Anything more will greatly reduce the life of the springs due to repeated over-compression.

Once you know where your uptravel is limited to, allow for an extra 1" of shock up-travel.  The rest will be droop.  I used the stock Waggy shock mounts that are flush with the bottom of the axle tube and it's plenty of shock travel in both directions.  I believe I have 4" up and 10" down, or 5" up and 9" down.

[BoringDave]

I would recommend not leaning the top of the shock towards the rear of the Jeep as the axle travels forward during compression.  I would leave the shock vertical.

I have the same setup, SOA with RE 1.5" springs and the Ford shock towers.  I used the longest Bilstein shock available.  I have my spring compression limited to when the springs are flat, or just a little negative arch.  Anything more will greatly reduce the life of the springs due to repeated over-compression.

Once you know where your uptravel is limited to, allow for an extra 1" of shock up-travel.  The rest will be droop.  I used the stock Waggy shock mounts that are flush with the bottom of the axle tube and it's plenty of shock travel in both directions.  I believe I have 4" up and 10" down, or 5" up and 9" down.

Thanks for pointing out the shock location, I don't know what I was thinking.  I now have the front shock tower pointed streaght up.

 I think I've figured out a plan. I'll post up what I do in my build thread.