[r0nin89]

To be honest with you I don't really care about losing 1-2" in lift to get a safer ride.

Wow lol you're redefining the kind of people that drive trucks like that :flipoff2:

Go for it then. Shorten the straps up about an inch and lower it 2.

 

[axisT6]

Much better... I actually did have the pins made out of a little higher grade metal 4140 and not heat tempered so it will be a bit more elastic. ..engineer in me wants to figure out how to make this work.

WHOA! That is the wrong way to think about it bud. Untreated 4140 has a yield strength roughly 64,000 psi. That is less than a grade 5 bolt. You need to pay attention to yield strength.

Example:

Grade 5 bolt (diameters to 1") - 92,000 psi min yield, 120,000 psi min tensile.
Grade 8 bolt (diameters to 1.5") - 130,000 psi min yield, 150,000 psi min tensile.

People argue that grade 5 bolts are more elastic than grade 8 bolts. That is wrong. Grade 5 bolts have a higher plastic range so they DEFORM more than a grade 8 bolt would before breaking. As you can see, at 130,000 psi yield, the elastic range of the grade 8 bolt exceeds both the elastic and plastic (tensile) range of the grade 5 bolt making it the better choice for heavy duty applications like automotive suspensions.

This is the reason why you see grade 8 and class 10.9 (metric) fasteners on automotive suspensions.

It would be in your best interest to use heat treaded 4340 pins.

Shorten the limiting straps. I would highly suggest you let the front down some. I know you probably dont want to hear that but dropping that front end 1-2" by lowering the torsion bars would do wonders for your range of motion with wheel travel.

He has coilovers.

You need to remove the coilovers and cycle the suspension to ensure there is no binding and no intereference. Once you have done this AND once you have determined your max droop and compression, you need to do as Ronin said set you limit straps and bumpstops so that THEY limit your suspension movement, and no the suspension components themselves.

 

[sjracer]

my vote:
ditch the IFS. much past stock height they bring the suck. not really meant to go that high. for the money your dumping in making that lift work you could have had a solid axle conversion done.

cliffs: remove ENTIRE front suspension; sell to some stupid kid for him to ruin his truck; install solid axle out of a late model dodge (retains ABS and such); done.

 

[Jason4x4]

am I missing something, or can't the OP just drill out the knuckle and run a bolt?

 

[r0nin89]

WHOA! That is the wrong way to think about it bud. Untreated 4140 has a yield strength roughly 64,000 psi. That is less than a grade 5 bolt. You need to pay attention to yield strength.

Example:

Grade 5 bolt (diameters to 1") - 92,000 psi min yield, 120,000 psi min tensile.
Grade 8 bolt (diameters to 1.5") - 130,000 psi min yield, 150,000 psi min tensile.

People argue that grade 5 bolts are more elastic than grade 8 bolts. That is wrong. Grade 5 bolts have a higher plastic range so they DEFORM more than a grade 8 bolt would before breaking. As you can see, at 130,000 psi yield, the elastic range of the grade 8 bolt exceeds both the elastic and plastic (tensile) range of the grade 5 bolt making it the better choice for heavy duty applications like automotive suspensions.

This is the reason why you see grade 8 and class 10.9 (metric) fasteners on automotive suspensions.

It would be in your best interest to use heat treaded 4340 pins.



He has coilovers.

You need to remove the coilovers and cycle the suspension to ensure there is no binding and no intereference. Once you have done this AND once you have determined your max droop and compression, you need to do as Ronin said set you limit straps and bumpstops so that THEY limit your suspension movement, and no the suspension components themselves.

I saw that in the pictures. For some reason it didn't register lol.

Sent from my C771 using Tapatalk 2

 

[gmagictsp]

Shorten the limiting straps. I would highly suggest you let the front down some. I know you probably dont want to hear that but dropping that front end 1-2" by lowering the torsion bars would do wonders for your range of motion with wheel travel.

am I missing something, or can't the OP just drill out the knuckle and run a bolt?

I wanted to do exactly as you state but the pin is tapered and didn't know if that made any different what so ever. Can anyone suggest other wise if I took the knuckle and just drilled out the taper to fit a solid both through the knuckle and bearing assembly?

 

[Grumpy_old_fart]

its tapered for a reason. dont drill it.

have your machinist replace it with the strongest steel you can get your grubby little dickbeaters on. something like 300m material, though that might end up being too brittle.

honestly, you will be miles ahead doing the swap, and have something you can depend on.

im sure you can sell the cheesy lift and get your money back.

Big Gay Truck Land called. they are missing their Village idiot. They dont want you back yet though.... not until you kill a busload of nuns.

 

[rockbuggy84]

Is the lower arm touching the knuckle at any time? sure looks close.
That would cause repeated breakage.

 

[gmagictsp]

it never actually touches but is very close like you said. There are not wear marks on CV housing.

 

[r0nin89]

Is the lower arm touching the knuckle at any time? sure looks close.
That would cause repeated breakage.

This is what I was saying. Gotta be hitting when the wheel drops out in a pothole.

 

[FordX4-offroad]

This is what I was saying. Gotta be hitting when the wheel drops out in a pothole.

i really have nothing to add except holy fawk BGTL.

but something about hearing "it probably breaks when the wheel drops out in a pothole" on a hardcore offroad site. is pretty fawkin funny idc who ya are :flipoff2:

 

[78-90chev]

You are either really brave or really stupid. Mall crawlers should stay at the mall. You WILL be money ahead to do a SAS, sell that IFS junky ass lift. (as stated before again). i'm suprised you havnt had more trouble out of CV shafts.

You said you got a good deal on it, what did you pay for all this bling?

 

[Tech Tim]

AxisT6 has it right, not HT'ing that 4130 was nit a smart idea.

WHOA! That is the wrong way to think about it bud. Untreated 4140 has a yield strength roughly 64,000 psi. That is less than a grade 5 bolt. You need to pay attention to yield strength.

Example:

Grade 5 bolt (diameters to 1") - 92,000 psi min yield, 120,000 psi min tensile.
Grade 8 bolt (diameters to 1.5") - 130,000 psi min yield, 150,000 psi min tensile.

People argue that grade 5 bolts are more elastic than grade 8 bolts. That is wrong. Grade 5 bolts have a higher plastic range so they DEFORM more than a grade 8 bolt would before breaking. As you can see, at 130,000 psi yield, the elastic range of the grade 8 bolt exceeds both the elastic and plastic (tensile) range of the grade 5 bolt making it the better choice for heavy duty applications like automotive suspensions.

This is the reason why you see grade 8 and class 10.9 (metric) fasteners on automotive suspensions.

It would be in your best interest to use heat treaded 4340 pins.

4340 or 300m heat treated along with making sure nothing is binding and prying that pin apart will get you going.

something like 300m material, though that might end up being too brittle.

How is 300m too brittle?

Everything looks so close, cycle the living hell out of it throughout the travel and at all angles of steering to check for clearances everywhere. Keep in mind that 1/16"of clearance with no load might be contacting when there is a load.

Don't worry about the IFS haters, the future is coming and they'll hang onto their precious live axles as long as they can.... :flipoff2:

Keep working at making it better and start un-bro'ing that thing!

 

[gmagictsp]

I talked with the machinist today and he is going to turn 4140 and I asked him to turn one of the misalignment spacers onto the pin so that I can get more girth in the spot that I keep breaking (hopefully this will buy me some time to figure out what is wrong). I also talked to the lift manufacture to see if they can give me any suggestions on how I can get the geometry right.

I found these but they are pricey.

http://www.rcvperformance.com/categories-cv-axles.aspx?catID=RCVP_ULT_IFS_CV_AXLES_ALT

I have read quite a bit about the IFS vs straight axle and I really want to make the IFS work but I just need to get some pointers on how to measure all the geometry correct. Most of the stuff that I have read state exactly what you say about the straight axle guys all what to rip out IFS even though the IFS is superior technology. Just depends on how much money I want to spend to get the truck set up right.

I paid 15K less than KBB for the truck for whoever what asking.

 

[Tech Tim]

I talked with the machinist today and he is going to turn 4140

What part of 4340 or 300m did you miss? Just do it right the third time around and you don't have to worry about the 4th or 5th time.... That is as long as everything else is good with no binding anywhere through its range of travel and steering.

The only advantage 4140 has over 4340 is that it is easier to machine, but it is not as strong. Have him machine it to .005" oversized, heat treat and then finish machine.

I found these but they are pricey.

RCV Off-Road Performance Products - CV Joints, Axle Kits, Tools

RCVs are worth the coin.

I have read quite a bit about the IFS vs straight axle and I really want to make the IFS work but I just need to get some pointers on how to measure all the geometry correct.

The starting point is to find out how it works and what is happening through the range of travel. If you don't already have the knowledge it would be best to start reading some suspension books and do some measuring. It isn't something that is quick and easy to spell out unless you have some basic understanding of IFS suspension geometry.

I'd start out with:
Herb Adams - Chassis Engineering
Carrol Smith - Tune to Win

Then you need to measure all your suspension points, plot them out and see what they do. Maybe you can find a friendly alignment shop that will plot out your suspension at static and at a couple different spots through the travel.

Just keep in mind you are stuck with most of what you have unless you are willing to change mounting points.