blocks after flip instead of shackles

[cochino12]

The bolts in my factory shackles are frozen in the bushing and I'd rather not have to cut the bolts and press in new bushings as well as pay for shackles. I do have a pair of 2" blocks and ubolts from a project I didnt use.

So my question is, is there anything wrong with using blocks with my flip kit to gain an additional 2" of drop? Thanks

Adam

[68Timber]

Seems like it would make it easier to twist, or rotate under acceleration or braking. But I have no first hand knowledge there.

[68c10owner]

Not sure along with the flip kit but I know lowering blocks are used all the time on s10`s that already have the spring under the housing. If you were to weld on spring perches instead of the flip kit id say no problem but not sure I`d do the flip kit and a lowering block.

[dieseldawg142]

**

[jones9j]

I say cut your bolts and buy new shackles

[69heavychevy]

There's a guy on youtube that added blocks to his flip kit. Actually made them out of the over load springs. Milkcrate82 is his screen name.

[slotard]

Bruiser is right that blocks (whether lift or lowering) contribute to axle wrap, which is especially problematic with soft springs. Whether or not it's significant for you depends on your spring pack and how you drive.

[gasmn1620]

Just bite the bullet and do it right. Adding blocks will allow for more axle rotation which is going to lead to increased u-joint wear and eventually.... a roadside repair/tow home.

[68Timber]

Originally Posted by slotard

Bruiser is right that blocks (whether lift or lowering) contribute to axle wrap, which is especially problematic with soft springs. Whether or not it's significant for you depends on your spring pack and how you drive.

I've used them for lift a few times, what I was wondering was if there was any difference in potential for axle wrap if the axle is above the springs instead of below. Think about it, the argument is that blocks are the equivalent of a breaker bar, so it there any difference if you're pulling from the top vs the bottom of the leaf pack? I'm sure I'm over-thinking it. I'd cut the frozen bolts just because I'd be more concerned the shackle couldn't articulate properly and was making the ride harsher than it had to be.

[SkinnyG]

Flipping the axle above the springs moves the instant center of the rear suspension forward, which in this case will reduce anti-squat, resulting in ~less~ axle wrap than with the axle below the leafs.

But you will still likely have some axle wrap (grin).

[slotard]

I don't know much about suspension, but a free body diagram of the axle is easy enough to do. I'll ignore vertical for now. Force pushing forward at the contact patch, force and moment at the spring itself (wherever it is). The longer the distance between them, the larger the moment is, so I suppose drop blocks do reduce the moment applied to the leaf (and therefore axle wrap).

[SkinnyG]

No no, drop blocks ~increase~ axle wrap. They move the axle farther away from the leaf, which is like adding a pipe onto your breaker bar.

Flip kits ~reduce~ axle wrap.

But the effect of the blocks will likley be more apparent than the flip.

[lolife99]

I say do it.
Can't be any worse than a set of 4" blocks on a lifted truck.
I'm not sure how much room you will have between the frame and the axle tube,... even with a c-notch installed.

[ultrahd4me]

It will not work correctly with premade lowering blocks because the locating pin is in the center. The hole in the flip kit brackets are 1" forward, so you end up with the flip bracket hanging off the rear of the lowering block.

If you flip and weld on new pads then it will work just fine.

The best option I think is to make a 1" solid steel or aluminum block about 8" long with a hole in the center, then add it to the spring pack with a longer center bolt, which needs to be flipped also. This way there is plenty of support under the flip bracket.

[74CustomK20]

I view it having the same affects at a lift block, which mine is 5". It sucks, but as long as your not hot rodding and being dumb, works great.

[gasmn1620]

also, when I did my flip kit (cheap flip brackets from the guy here, and then western chassis) it sits on the bump stop. I removed the bump stop and now it's fine, but another 2 inches and it would be almost on the frame.

[lolife99]

Originally Posted by ultrahd4me

It will not work correctly with premade lowering blocks because the locating pin is in the center. The hole in the flip kit brackets are 1" forward, so you end up with the flip bracket hanging off the rear of the lowering block.

If you flip and weld on new pads then it will work just fine.

The best option I think is to make a 1" solid steel or aluminum block about 8" long with a hole in the center, then add it to the spring pack with a longer center bolt, which needs to be flipped also. This way there is plenty of support under the flip bracket.

Install the lowering block between the leaf spring and the flip kit bracket.
I've done it on low AOL bag set ups.

[slotard]

Originally Posted by SkinnyG

No no, drop blocks ~increase~ axle wrap. They move the axle farther away from the leaf, which is like adding a pipe onto your breaker bar.

Flip kits ~reduce~ axle wrap.

But the effect of the blocks will likley be more apparent than the flip.

If you look at a free body diagram of the axle + blocks (again neglecting vertical as it shouldn't cause any wrap), there's a force applied at ground level (from accelerating) and then a force and moment applied where the leaf prevents the axle from moving.

For a given force, the reaction force will be the same as traction force, and the moment applied to the leaf spring will be the force times the distance from the ground to the centroid of the leaf spring.

At first glance I expected drop blocks to increase wrap as well, but drawing a free body diagram convinces me otherwise.

[SkinnyG]

My old lowered Nissan Hardbody (3" blocks) didn't believe in the free body diagram, it had more axle wrap instead.

Actually had to run angled blocks to counter the increased spring wrap under acceleration - ie: it needed more pinion angle since the pinion was moving more.

My Silverado needed less pinion angle because the axle wrapped less after the flip.

But, every truck is different - what works for one, may not work for another, even if everything else is the same.

[slotard]

I won't claim to have any experience with them, I've never used lowering blocks. It's possible that there's something else going on. I'm just confused as to how lowering blocks would result in more wrap.

[izzy_Britton]

I have not read ALL of these responses... BUT

Do what ever makes you happy. LOL

I have made my own flip 'kits' with new spring perches and used lift/lower blocks dozens of times before without issues. just be sure to drill a new spring pin hole in the new spring perch to move the axle back an inch. then bolt it all together, get the right pinion angle and put a small stitch weld on each of the 4 corners of each perch. easy peasy, quick n dirty.

I have driven my trucks for years like this! some with stock engines some with a little more umph, some with a lot more umph. you MIGHT wear out a u-joint 50k miles down the road but eh! thats an easy 20$ fix 3-5 years down the road depending upon your driving habits.

yes potentially there would be MORE axle wrap, but unless your using 3+ inch blocks its not worth a second thought. plus if you are using 3+ inch blocks your gonna have to notch your frame because with 2 inch blocks you have less than an inch of travel before your frame hits the axle tube. then you gotta c-notch and all that and your back to having a bigger issue than replacing spring and hanger bolts and bushings. you should be fine with a new set of perches and a 2 inch block but you wont have much rear travel.

just my $0.18 (adjusted for O's inflation $0.02 get you nowhere these days).

[wraprail]

I have done this on my 74 c10 when I installed a 9 inch in the stock leaf springs using these lower mounting plates/shock mounts to relocate the shocks like on a dodge pickup.
http://www.speedwaymotors.com/Univer...late,4852.html

http://www.speedwaymotors.com/Speedw...-Tube,632.html
http://www.speedwaymotors.com/Speedw...Long,2154.html
With a 2 inch block also.
Drove it for 5 years no problems. Mounting both shocks behind the axle worked great also.