4” rear lift options?

[HawK5]

Howdy y’all!
I’ve done some googling but want to make sure I haven’t missed anything. PO did a 4” lift block with factory leafs, BUT also clocked rear end leaf perches..
I’ve committed to a super duty front CV drive shaft(for the rear drive shaft) and t case adaptor, to help reduce axle wrap I’m needing to go lift leafs and remove blocks, here is what I Know:
1. Shackles flips won’t work bc my axle is clocked
2. Budget lift leafs are $400 but ride VERY rough
3. ORD badass flex leafs are $1000, amazing performance, but hard to drop 4 figures on rear leaf springs alone..

What are my “In between” options? Saw the skyjacker soft ride options haven’t seen a lot of real life feedback. Trying not to drop a G, but also don’t want a down grade or crappy rear leafs.
Thanks!

 

[kennyw]

I have 4" tuff country rear lift springs with Bilstien shocks in my M1028. I think it rides very good.

However, a shackle flip is still an option for you. You can replace the spring mounts and get it set up right. I know someone capable of doing it locally.

 

[Blue85]

If the spring perches have been clocked on the axle, how will an off-the-shelf lift spring work right with a C/V shaft? My guess is it won't and you're looking at moving the mounts or some big angle wedges either way. ORD has a little flexibility with how the pinion angle turns out, but I would hate to get weird shaped custom springs to avoid setting the axle up right. Remember that you are going from the pinion and T-case in parallel to the pinion pointing at the T-case.

Definitely do measurements of distances and angles. With stock length shackles (4"), a shackle flip on a 52" spring lowers the rear spring eye about 8", which tilts the pinion angle up 8-9 degrees. Of course you have to also add/subtract whatever angle your block has on it. This angle can vary depending on where you install the shackle flip and resulting angle of the shackle.

Super opposed to cutting and welding? How about swap the rear axle housing? You could also cut off your spring perches, buy new ones and bolt everything together until the angle is perfect. Then carefully mark where the perches should go and take the axle to someone else to weld it. Or hit up a local CK5 buddy to come over with a welder?

 

[muddybuddy]

If you cant weld, I would just find an unmolested axle with same gear ratio and swap it in. You will be able to sell yours and recoup most of whatever the axle costs you. Then no funny business with big shims and more ability to dial your setup in the way you want it.

 

[muddybuddy]

Another option could be a 2.5” shackle flip and a zero-rate or 2” rear springs. The smaller shackle flip wont tilt pinion up as much

 

[Wes Harden]

If switching to a cv type at t case op will need to reposition pinon angle no matter what.

Tuff country BDS lift are acceptable ride for what they are. This is highly a subjective statement, many variables. Different tire size, and amount of side wall, ply rating will change the felt ride on the same truck. Weight of truck compared to another. Your mileage will vary no matter what you read on the interwebs.

Our first and second questions, are always intended purpose of truck with lift, and how comfortable are you with making changes and or ability. No good mod goes w/o another.

With out knowing your desired tire size any recommendations here are guesses. The ass end on our rigs normally ends up a little lower than the front, so an easy inch, 6" shackles might work to level out.

What's in the front?

 

[HawK5]

If the spring perches have been clocked on the axle, how will an off-the-shelf lift spring work right with a C/V shaft? My guess is it won't and you're looking at moving the mounts or some big angle wedges either way. ORD has a little flexibility with how the pinion angle turns out, but I would hate to get weird shaped custom springs to avoid setting the axle up right. Remember that you are going from the pinion and T-case in parallel to the pinion pointing at the T-case.

Definitely do measurements of distances and angles. With stock length shackles (4"), a shackle flip on a 52" spring lowers the rear spring eye about 8", which tilts the pinion angle up 8-9 degrees. Of course you have to also add/subtract whatever angle your block has on it. This angle can vary depending on where you install the shackle flip and resulting angle of the shackle.

Super opposed to cutting and welding? How about swap the rear axle housing? You could also cut off your spring perches, buy new ones and bolt everything together until the angle is perfect. Then carefully mark where the perches should go and take the axle to someone else to weld it. Or hit up a local CK5 buddy to come over with a welder?

The axle was clocked so it is pointing at the T-case with a flat leaf, and then they put in a square lift block with no angle. By eye it actually looks like it might be over clocked, so I added a shim in backwards to try and bring it closer to point at the T-case.. so dropping the back of the leaf would cause the diff to point to far up.. essentially it was clocked for a CV shaft, but then they put in a custom length double u-joint shaft. Not sure why, it didn’t seem to cause any known issues, but the truck did have lot of vibrations so possibly switching to a CV shaft will eliminate some of that..

I’m definitely not opposed to cutting the perches off and and welding new ones in, i kind of like the idea of bolting it altogether and getting it all setup right, I have shop about 5 miles down the highway that has done custom little welding projects.

Currently it sits on 35x12.50r15s Maxxis Razrs, the tires work great and are almost new, but with a 4” suspension and 2” body lift they need to be bigger, but I’ll wait until these are worn out, then probably go 37/13.50 Iroks or something, and with 4.56s and an SM465 the 350sbc is singing over 65mph. It’s a wheeler that goes around town and drives around the state to find snow/mud/rocks/trails..

Here’s a couple vids, the second one is the pinion guard digging into the drive shaft due to axle wrap(hence the reason to ditch to the lift blocks) and some pics of the carnage

 

[Wes Harden]

yes you would very much have vibrations with the pinion pointed at t case out put, and a parallel 2 u joint shaft. Definitely get a cv style.

Here is what I did for my k20 Suburban. 56", 26" front 30 rear, stock 1 ton springs 2600 pd capacity, 200 less than the spec for the stock 3/4 ton 52". 4" ORD shackle flip. I first used 4" rear hangers but the angle was to tight, and up to 6" hangers and now the angle is perfect. Currently using 6.5° shims to correct the pinion, for a cv style drive shaft. 5.5-6° might be better for me. Had 33" for a awhile, got a flat and up size to 37s. With the 37's the tire looks like it needs to move rearward, to be centered in wheel well.

The rear does sit a little higher than the front and I am stock body pucks. If you have 2" body lift a 2-2.5" shackle flip stock springs 52-56" and 2 front lift and you should clear 37s. Plan on moving the rear axle rearward 3/4-1" for the 37s in your drive shaft calcs.

 

[Blue85]

Yeah, maybe you're a set of lift springs and a shim from being setup for a C/V shaft. That might be the easiest route, but the spring will have a lot of arch to it. I would avoid aluminum shims and get steel ones that are as big as the spring/pad. They make angled spacers that go under the head of the center bolt to properly bolt it to the spring pack.

An anti-wrap bar requires welding and the shackle flip requires removing the gas tank and a bunch of rivets, so simply cutting out the spring bushing bolts and U-bolts may the easiest install, as well.

 

[USSkoval]

Is it possible that the pinion angle being that far off for use with a standard u-joint shaff could be a large contributor to the axle wrap?

 

[HawK5]

Is it possible that the pinion angle being that far off for use with a standard u-joint shaff could be a large contributor to the axle wrap?

Im not sure if it’s starting clock position would contribute to how much it was rotating during axle wrap, however, it being already over clocked certainly reduces the amount of rotation before u-joints, drive shafts and pinion yokes make contact and explode..

 

[Wes Harden]

The blocks are more to blame than the pinion angle. those 4" blocks are a big lever. I you had 3/4 or 1 ton spring stack with over loads those kind of springs would resist that leverage better, but the ride would suck.

If you change the pinion angle shoot for 1-2° down. So under wrap will be close 0°.

 

[HawK5]

I was wondering if you made “longer” lift block that would rotate up into the bottom leaf under load, that would eliminate at least upward rotation..

 

[Blue85]

I was wondering if you made “longer” lift block that would rotate up into the bottom leaf under load, that would eliminate at least upward rotation..

Please clarify, as it seems like a strange idea. A longer block does change the leverage of rotation from axle torque, but it also puts strain on the leaves outside of the U-bolts. In the ultimate incarnation, the block is as long as the spring and clamped rigidly to it. Now there is virtually zero axle wrap, but also virtually no spring travel, so you could just replace the spring with a solid I-beam or something.

The area between the U-bolts is essentially a solid block of steel.

 

[HawK5]

Yeah it’s more of a half baked “why wouldn’t this work” idea..
But in theory, if the 4” lift block was ~24” long, one end flush on the back of the leaf pad with ~21” sticking out forward of the axle, then when the axle rotated upward, the lever end would move up and contact the bottom of the leaf.. maybe with an adjustable rubber bumper based on needs..
Not saying I’m going to the trouble of this, just wondering why they don’t make lift blocks like this to begin with..

 

[Wes Harden]

ladder and snuber bars were invented like that. Still have to have the correct pinion angle to start.

 

[Blue85]

You're proposing combining a lift block with a snubber bar. I don't know why it wouldn't work, as long as the spring has enough arch to fit the snubber. The problem is that you'd have snubber bars, and therefore almost no uptravel from the spring.

 

[HawK5]

Ahh yeah, up travel

 

[Wes Harden]

I was politely trying to point out Op is attempting to reinvent the wheel.

Heavy overload springs will help with wrap and have "some" up travel

 

[cheavyk10]

You're proposing combining a lift block with a snubber bar. I don't know why it wouldn't work, as long as the spring has enough arch to fit the snubber. The problem is that you'd have snubber bars, and therefore almost no uptravel from the spring.

View attachment 509005

Y'all remember the traction bar lift kits from the 80's all the show trucks had? They were gold zinc plated and made by now defunct companies like Rugged Trail.