55-59 CPU Rear axle Flip Kit

[michaelnolimit]

Here is No Limits axle flip kit. Very easy to install. On this truck we used a rear end housing out of a late 80's camaro. Heres how we did it.

#1 You must cut all camaro brackets off and clean housing so we can weld some new axle pads on the housing

#2 Unbolt old housing and the rear leaf spring hanger. Throw the stock housing away its no good unless your building a stock pickup.

#3 Remove the rivets holding the rear leaf spring hanger in place.

#4 Once the rivets are out Flip the shackel hanger so it now rests on top of the frame, Move it 5/8 of an inch forward, drill new holes and bolt it back in.

#5 Slide the new axle on the the leaf springs and reconnect the stock leaf springs to the now flipped shackle hanger.

#6 Now put your new axle pad under the axle and on top of the leaf, bolt the u bolts and the new u bolt plate with the shock mounts together and snugg. Dont tighten everything becuase you still need to center the housing and set the pinion angle. If its snugg you can still slide the axle side to side and adjust the pinion angle.

#7 after the housing is centered and the pinion has been set you can weld the axle pads to the housing and tighten up the ubolts.

#8 Bolt in the shocks and your done.

[michaelnolimit]

hers a couple more. Also wanted to point out or 21 gallon aluminium fuel cell that bolts into the stock chassis.

[Trucknut57]

So what is the advantage to flipping the rear shackel mount?

[michaelnolimit]

There are a couple of reasons for flipping the shackle.

#1 By flipping the axle we lower the truck about 7 inches. When you flip the shackle hanger your actually going to lift the truck about an 1 1/2.

So if you want it as low as it will go dont flip the shackle hanger and remove the bumpstops and install a small c notch.

#2 We also do this to make the truck ride smoother. If you look at the stock style shackle hanger it is designed to carry a large load AKA a load bearing suspension. By flipping the shackle hanger we are duplicating a passenger car syle leaf spring which is a progressive supsension. Therefore the truck rides smoother like a passenger car and not like a truck that can carry two tons of hay.

[Trucknut57]

So with a flip of the axle, you get 7" drop. Plus a shackle flip nets you a 1.5" rise. So in all you ended up with a 5.5" drop?
Even with grade 8 bolts, aren't you putting a lot of trust into the bolts that hold the shackle to the frame?

[67swb72klb]

Originally Posted by Trucknut57

So with a flip of the axle, you get 7" drop. Plus a shackle flip nets you a 1.5" rise. So in all you ended up with a 5.5" drop?
Even with grade 8 bolts, aren't you putting a lot of trust into the bolts that hold the shackle to the frame?

that what i was thinking ?

[michaelnolimit]

Lets think about this. Lets say the truck weighs 4,000 pounds. The back half of the truck only is carrying about 1,400 pounds. Now there are two leaf springs so you can divide that 1,400 by two and youll see that each leaf spring is only supporting 700 pounds. Now the leaf spring has two hangers one at the front and one at the back. So if each leaf supports 700 pounds divided by two spring hangers you get 350 pounds on each of the four spring hangers. Now each spring hanger has four rivets or bolts holding that to the frame. Two bolts are on a vertical plane and two bolts are on a horizontal plane. So they will have to shear in two different directions if shearing is possible. 350 pounds per hanger divided by four bolts is 87.5 pounds per bolt. So each of the 16 bolts supporting the leaf springs is only carrying 87.5 pounds.

Now lets say you load the back of your truck with with 1400 pounds. Thats a pretty big load. You have now doubled the wieght in the back of your truck. To save me a bunch of math you can just double the wieght on the bolt so now each bolt is carrying 175 pounds. A 3/8 24 grade eight bolt is capable of supporting much more than 175 pounds.

Yes I trust that each bolt will do its job and support well over 200 pounds.


Since you guys have your thinking cap on think about this.

A 3/8 24 grade 8 bolt and nut costs about 10 cents.

If theres 100 bolts on the chassis thats about 10 dollars in nuts and bolts

If they build a 1,000,000 trucks times 10 dollars a truck thats 10,000,000million dollars in just nuts and bolts

A rivet on the other hand cost about 1 penny

Multiply by 100 rivets per chassis and you have one dollar per chassis

1 Dollar per chassis times 1,000,000 chassis equals 1,000,000 in rivets.

So gm makes a decision should we spend an extra 9 million dollars on nuts a

bolts or should we save 9 million dollars and use these cheap rivets.

So they used rivets to save money not to make the fastener stronger

TruckNut57 Yes we did end up with about a 5.5 inch drop. It may have been a little more becuase we put a shorter tire on it. I did not measure the stock wheels compared to the new wheels so im not sure what the difference in overall tire heigth was.

[Trucknut57]

You keeping stock drums on rear or upgrading to disc's?

Different question: What are you doing with the front suspension? Stock, IFS, Clip?

[michaelnolimit]

This is a customers truck and dont dont know if he plans on adding disc brakes later. For now he said he will keep the drums and when money allows he may invest in disc brakes for the rear.

On the front we did a 70-81 camaro clip. I posted a thread on the camaro clip. We also installed one of our bolt on brake kits and a 21 gallon fuel cell.

[nikwho]

I would trust grade 8 bolts much more than rivits! Plus, you have two bolts vertical and two bolts horizontal on each shackle hanger! not only would you have to shear two grade 8 bolts to have a failure, you would also have to rip the nut off of the end of two grade 8 bolts! not gonna happen!

I do have one concern though, and maybe you can answer this for me Micheal? I am using a mustang fuel tank. I have cut the cross member out that goes between the two shackle hangers. I will make a new cross member to put behind the fuel tank(my original one didn't look too good). I dont have the new crossmember from frame rail to frame rail behind the new tank yet, but it seems like the frame flexes and twists way too much! What do you do about this? do you box the frame at all?

[dwcsr]

The only issue I see with the flip is that in the original position the rivets are more place holders and would have to shear off for the hanger to fail. The hanger saddle sits under the frame and takes 80% of the load stress.

With the hanger flipped up on top of the rail the bolts take all the stress. I think its should have a 3/8-24 #8 flange bolts, flange nuts and a #8 flat washer for bolts. Flange bolts are better for frame attachments like this because they increase the clamping force without increasing the bolt diameter. I think I would also require a specific torque be applied when installed so installers don't just impact them on over streching the bolts.

[nikwho]

That does make a lot of sense!

[kaycee]

How far off the ground would the front bumper be ballpark figure?I see guys complaining they have no room to run a wide tire could a guy put the springs on the inside of frame or not.Just trying to get some ideas sorry for the dumb ???

[Trucknut57]

kaycee, the springs dont limit the tire size because they are in-board of the bed side. If you wanted to run wider tires you would need to clearance the bed side first, then you could relocate the springs and gain even more clearance.

[chopsspcc]

I just bought a stock 59...I want to lower it asap. I have been looking around and doing my research about how to get it done. Looking at this, would allIhave to do is just flipthe axle to get it that much lower? What all do I need parts wise to do this? Any help would be greatly appreciated. I want to lower the front too, so any ideas on that would be great. Thanks!


Chops

[ChuckDriver]

I like it!

[Trucknut57]

Chopsspcc;
If you flip the axle from the bottom of the leafs to the top of the leafs the rear of the truck will drop by 3.5" to 4.5" depending on the axle mounts that you use.

[chopsspcc]

thanks trucknut, any thought for getting the rear a bit lower? How about the front?

[Trucknut57]

Chopsspcc,

Sorry I didn't take into account the height of the springs, so add the measurement of you springs into the above dimensions.

As for the front, if you are sticking with the straight front axle, then you are limited to either a drop axle from one of the aftermarket places or removing a few of the front leafs.

If you are thinking about a GM subframe, Mustang II, or custom bags, then you can go as low as you want. You are only limited by your money and/or ideas.

Hope that helps

[Trucknut57]

Michaelnolimit;

What kind of plates did you use on the bottom of the springs to mount the axle and attach the shocks??

[chopsspcc]

Thanks again...my budget is well, like everyone's too little. I know for a fact I want new wheels, but I may lower it later on. I want to be able to get it sitting lower, but I can't spend a ton right now. But...I did pick up a brand new 700R4 "high output" from a Camaro from my tranny guy for $500, so that was sweet.

I'm always open to more ideas, so let me know! Thanks as always!


Chops

[SHORTDOG99]

How much is that "Flip kit" from No Limit? and how does it compare to the one they sell at CPP?

And on a side note: Why not just weld on the flipped shackle hanger?

[tmoble]

>>> "Why not just weld on the flipped shackle hanger?"

cast doesn't weld very good, even cast steel.

[Dave K]

Does no limit sell the lower shock mount alone? I am running the stock shock mounts on my flipped axle truck and they hang mighty low.

Thanks

Dave

[troy54gmc]

michaelnolimit Re: 55-59 CPU Rear axle Flip Kit

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Lets think about this. Lets say the truck weighs 4,000 pounds. The back half of the truck only is carrying about 1,400 pounds. Now there are two leaf springs so you can divide that 1,400 by two and youll see that each leaf spring is only supporting 700 pounds. Now the leaf spring has two hangers one at the front and one at the back. So if each leaf supports 700 pounds divided by two spring hangers you get 350 pounds on each of the four spring hangers. Now each spring hanger has four rivets or bolts holding that to the frame. Two bolts are on a vertical plane and two bolts are on a horizontal plane. So they will have to shear in two different directions if shearing is possible. 350 pounds per hanger divided by four bolts is 87.5 pounds per bolt. So each of the 16 bolts supporting the leaf springs is only carrying 87.5 pounds.

Now lets say you load the back of your truck with with 1400 pounds. Thats a pretty big load. You have now doubled the wieght in the back of your truck. To save me a bunch of math you can just double the wieght on the bolt so now each bolt is carrying 175 pounds. A 3/8 24 grade eight bolt is capable of supporting much more than 175 pounds.

Yes I trust that each bolt will do its job and support well over 200 pounds.


Since you guys have your thinking cap on think about this.

A 3/8 24 grade 8 bolt and nut costs about 10 cents.

If theres 100 bolts on the chassis thats about 10 dollars in nuts and bolts

If they build a 1,000,000 trucks times 10 dollars a truck thats 10,000,000million dollars in just nuts and bolts

A rivet on the other hand cost about 1 penny

Multiply by 100 rivets per chassis and you have one dollar per chassis

1 Dollar per chassis times 1,000,000 chassis equals 1,000,000 in rivets.

So gm makes a decision should we spend an extra 9 million dollars on nuts a

bolts or should we save 9 million dollars and use these cheap rivets.

So they used rivets to save money not to make the fastener stronger

TruckNut57 Yes we did end up with about a 5.5 inch drop. It may have been a little more becuase we put a shorter tire on it. I did not measure the stock wheels compared to the new wheels so im not sure what the difference in overall tire heigth was

.

man this is the most in depth and funny answer to a question that i have read in a long time...