Lowering OBS

hfoote · Aug 3, 2012

Hey guys.

I am wanting to do more pulling and racing with my truck, currently its sitting on 4 inches and 35s. I know that isant ideal for either so I would like to take it a little lower then stock. Slam it a little and run some wider wheels and tires. I know about going to a D60 and have a lead on one, but how can i get it lower then stock? I know about shackles for the rear but what about the front?
Thanks and sorry for the drawn out post!!

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hfoote · Aug 4, 2012

Nobody has done this?

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fatsix · Aug 4, 2012

hfoote said:
Nobody has done this?

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I've been looking at doing this, but there are quite a few obstacles if the vehicle is going to be streetable with a d60. As for lowering it, there are a few options. The first one I have looked into, the others not so much. I'm waiting to get the truck back together so I can see how the ride height is effected.

1. RSK with excursion U code springs. These springs are not recommended for street use. They will give a terrible ride, MIGHT be fine for just pulling.
2. Lower spring rate on the stock springs. I'm not sure how much a 250 spring will lower the front.
3. Drop shackle on the front.
4. Hanger flip.
6. Flip the axle so it is on top of the stock spring.

Typically you would do a combination on lowering a 2wd depending on how low you want to go. Hanger flip, drop shackle and axle flip, will get 4-6". But you don't have the solid axle to worry about hitting everything.

If you go lower than 2" or so the bump stops will start hitting.
If you go lower than 3-4" you run into the axle tubes hitting the frame and the pumpkin hitting the cross member and oil pan. Yes you could notch the frame rails, and put a tubular cross member in and modify the stock pan to work.
I have my engine out and front clip removed, so I can see and measure what is going to hit.

I don't know the pulling rules for the front end and if you can let it sit on the front bump stops.

This is what I am looking for, but I get the feeling its going to be a way bigger headache.

hfoote · Aug 4, 2012

Ok that makes sense, Im only looking for 2-3in below stock, so maybe a set of 250 gasser springs would get me the right effect?

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jngreen · Aug 4, 2012

F250 springs are more stiff than f350 springs (on an OBS 4x4).

Just about the only way to lower a 4x4 OBS with a solid axle is to use worn out or de-arched stock f350 springs. You can't go very low before the axle hits the crossmember up front.

jngreen · Aug 4, 2012

I think you are confused on a few things.

1. U code springs come stock on excursions, some consider them too soft for use on a diesel some dont.

2. F250 springs are not a lower spring rate than f350 springs and won't lower an f350 with a dana 60.

3. I don't think drop shackles exist for OBS ford 4x4. The front springs pretty much bolt to the bottom of the frame so drop shackles arent really an option.

4. Same thing as #3, I think you are confusing 2 wheel drive rear suspension, with 4x4 front suspension.

5. You forgot #5

6. You can't flip the axle, unless you want your pinion sticking out of the front, or on the passenger side of the truck. Flipping the springs below the axle is also not gonna happen, sorry.

There already is not much room between the Dana 60 and the frame/crossmember on a stock height truck. That is why they sit so high on stock suspension. That is also why you will not find lowering kits for an OBS 4x4. The f250 independant axle is much more capable of lower ride heights than the solid front. If you want to go low, you could try f350 springs on your f250 axle, but don't be surprised when you bottom out the suspension or ride around on the front axle.

You will never be close to as low as that 2wheel drive lightning, unless you want solid front suspension.

fatsix said:
I've been looking at doing this, but there are quite a few obstacles if the vehicle is going to be streetable with a d60. As for lowering it, there are a few options. The first one I have looked into, the others not so much. I'm waiting to get the truck back together so I can see how the ride height is effected.

1. RSK with excursion U code springs. These springs are not recommended for street use. They will give a terrible ride, MIGHT be fine for just pulling.
2. Lower spring rate on the stock springs. I'm not sure how much a 250 spring will lower the front.
3. Drop shackle on the front.
4. Hanger flip.
6. Flip the axle so it is on top of the stock spring.

Typically you would do a combination on lowering a 2wd depending on how low you want to go. Hanger flip, drop shackle and axle flip, will get 4-6". But you don't have the solid axle to worry about hitting everything.

If you go lower than 2" or so the bump stops will start hitting.
If you go lower than 3-4" you run into the axle tubes hitting the frame and the pumpkin hitting the cross member and oil pan. Yes you could notch the frame rails, and put a tubular cross member in and modify the stock pan to work.
I have my engine out and front clip removed, so I can see and measure what is going to hit.

I don't know the pulling rules for the front end and if you can let it sit on the front bump stops.

This is what I am looking for, but I get the feeling its going to be a way bigger headache.

hfoote · Aug 4, 2012

Ok makes sense thanx for the info

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fatsix · Aug 4, 2012

jngreen said:
I think you are confused on a few things.

Confused, Nah. Guilty of thinking out loud without checking, yes. :doh: I did preface my comment by stating, " I've been looking at doing this, but there are quite a few obstacles if the vehicle is going to be streetable with a d60. As for lowering it, there are a few options. The first one I have looked into, the others not so much."

1. OBSWIZ said not a good idea, so I left it at that.
2. You can order custom rate springs, I was not sure if the 250 were lower
rate, I learned something.
3. YUP, I was thinking the back was the same as the front.
4. YUP, I was thinking the back was the same as the front.
5. Deleted and never renamed.
6. Axle flipping, is swapping the spring to the other side of the axle. Not
flipping the actual axle. All the steering linkage and sway bar is in the
way of the spring.

jngreen said:
There already is not much room between the Dana 60 and the frame/crossmember on a stock height truck. That is why they sit so high on stock suspension. That is also why you will not find lowering kits for an OBS 4x4. The f250 independant axle is much more capable of lower ride heights than the solid front.

I agree. If its strictly a pulling truck, you could get away with it. You have about 3-4" on the stock 350 suspension before you hit the bump stops. You could modify them, but then you run into the crossmember/oil pan issue.

jngreen said:
You will never be close to as low as that 2wheel drive lightning, unless you want solid front suspension.

Hmmm..I believe I already said that.
"This is what I am looking for, but I get the feeling its going to be a way bigger headache."

Here are some pictures. The bump stop is 4 1/2" on the left side and 4 5/8" on the right side, above the axle.

jngreen · Aug 4, 2012

I wasn't trying to attack you, I was just trying to provide accurate info to the OP.

I was being a smart ass though.

fatsix · Aug 4, 2012

hfoote said:
Ok makes sense thanx for the info

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I guess just put bigger tires and rims on it to make it appear lower. 22's and 35's. At least that is my next plan after I unhook the springs and see what is close to hitting when its on the bump stops.

jngreen · Aug 4, 2012

Or take your lift kit off and run your f250 axles, or swap to a dana 60 and run stock f350 suspension.

hfoote · Aug 4, 2012

Yes i think Im going to try and take the lift off first and see where that puts me.

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fatsix · Aug 4, 2012

hfoote said:
Yes i think Im going to try and take the lift off first and see where that puts me.

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This post should help with measurements and pictures.

http://powerstrokenation.com/forums/showpost.php?p=1501826&postcount=24

35's might be tight with no lift. Some people have issues, some don't.

Your stock suspension should be somewhere around here: Depending on the condition of the springs, body mounts and tire size.
Front Driver/passenger: 21.5/22
Rear Driver/Passenger: 23/23

This is measured from the center of the hub to the lip of the fender.