K30 to the frame...Front axle almost complete...Hydro Assist Install

[Russellk30]

The front axle is complete except for the cover and hydro assist tabs. I wanted to weld a couple of tabs to the center section. They are only a couple inches wide. If I preheat the center section, would there be enough penetration to provide adequate strength for such a load?

The axle is an inch too far forward for the high steer. I'm either going to drill new holes in the spring perches, or move the leaf springs back a notch and relocate the rear springs hanger a half inch down and to the back to take care of the shackle issue and axle location at the same time. Or maybe Ill do both but leave the springs in the same hole in the front leafspring hanger.

 

[Hogback Fabrication]

If you absolutely can, avoid welding anything to the center section. You can sort of weld it, especially if you TIG it with nickel rod (so I'm told) but even then its not super strong.

This was a truck I pulled out of Upper Helldorado in Moab a few years ago, granted they were link mounts but he broke both front shafts and couldn't even power the front end. The link mounts tore out of the front housing (and took pretty good chunks of the housing with it) just by me backing up, granted he was pretty stuck and I was pulling fairly hard. That front end is a D60 btw:

Also, you may want to look into plating your stock knuckles or buying aftermarket ones, highsteer and ESPECIALLY high steer with hydro assist is super hard on knuckles. I looked and couldn't find my pictures from trips I've been on but I've dealt with broken D60 knuckles due to high steer and that is one huge PITA trail recovery.

Basically high steer puts tons of stress on a part of the knuckle that was never designed for it and they break. That doesn't mean it will break tomorrow, maybe it won't ever break, but I've only seen D60 knuckles break with high steer and like I said, that's a BAD thing to break because almost no one has spares.

 

[Russellk30]

If you absolutely can, avoid welding anything to the center section. You can sort of weld it, especially if you TIG it with nickel rod (so I'm told) but even then its not super strong.

This was a truck I pulled out of Upper Helldorado in Moab a few years ago, granted they were link mounts but he broke both front shafts and couldn't even power the front end. The link mounts tore out of the front housing (and took pretty good chunks of the housing with it) just by me backing up, granted he was pretty stuck and I was pulling fairly hard. That front end is a D60 btw:

Also, you may want to look into plating your stock knuckles or buying aftermarket ones, highsteer and ESPECIALLY high steer with hydro assist is super hard on knuckles. I looked and couldn't find my pictures from trips I've been on but I've dealt with broken D60 knuckles due to high steer and that is one huge PITA trail recovery.

Basically high steer puts tons of stress on a part of the knuckle that was never designed for it and they break. That doesn't mean it will break tomorrow, maybe it won't ever break, but I've only seen D60 knuckles break with high steer and like I said, that's a BAD thing to break because almost no one has spares.

Thanks for the thorough response. I sort of regret not buyer diy4x knuckle bracing kit when I had the knuckle raw. Oh well. The leftover stock steering arm kinda bothers me anyway. Hopefully Reid Racing develops a knuckle without the arm.

Looks like the center section wont be welded on. Shat. It is the most practical place to put the cylinder while keeping it parallel with the tie rod. Though assist likely puts much less pressure on the weld than full hydro, it is also a heavier truck than the buggy you pictured. Is that you in the picture? You look pretty happy considering the situation.

 

[Russellk30]

Learned a couple of things today. First, once a steering stop has been bent, it wont go back to its original shape, but it will break off leaving half the bolt stuck in the knuckle.

Second, Yukon chromoly inner axles are too big for the knuckle. They outer corners of them will scrape the inner-c. They need to be shaved. In order to shave them, the entire axle assembly needs to be taken apart again. The knuckle also has to be taken off because the axles are too big to fit through the outer knuckle half. There goes an extra half days work gone forever. Apparently the company is aware of all this. I don't mind so much, just let me know before I put my entire axle together so I can shave them beforehand.

Third, aftermarket drive flanges have no way of positioning the axle. It just floats back and forth with the inner-c on one side and the inner spindle seals on the other side stopping it from going to far either direction. I took care of the problem by putting the old spindle/axle seal in between the puck and the small snap ring on the end of the axleshaft. When the drive flange cover is tightened down, it pulls the puck into the seal and sandwiches it to the snap ring, which pulls the axle into the proper location. Because all the parts around the seal do not move independent of each other, I imagine the durability will be good. The seal basically takes the place of the wide spring that you usually find in selectable hubs.

It looks like the only place the hydro assist cylinder will fit without interfering with other components through full suspension travel is on the front top part of the differential cover. I guess my awesome diff cover wont look as structurally clean as I wanted.

 

[Fred_M1010]

Nice clean build

About the ram mount, it looks like your diff-cover is cast as well.
I'm not sure that would be any better than welding it to the housing

How about getting a sheetmetal spring-plate, and weld the tabs to that...?

 

[sweetk30]

got anymore info on the yukon shaft fitment ?

got mine i need to install soon. thay are out getting clerenced for the 300m joints now at c&M performance machine.

and i got reid ( dedenbear ) knuckles so dont know if any diffrent fit threw the whole .

trying to get my info ready to get them installed and done.

 

[Hogback Fabrication]

Though assist likely puts much less pressure on the weld than full hydro, it is also a heavier truck than the buggy you pictured. Is that you in the picture? You look pretty happy considering the situation.

No and my buggy is not the broken one, that guy was in the Range Rover and he does look happier than he should

Nice clean build

About the ram mount, it looks like your diff-cover is cast as well.
I'm not sure that would be any better than welding it to the housing

Looks like a Crane cover which is cast chromoly steel. The diff is iron, that's why its not really weldable. Welding steel is fine even if its cast.

BTW seems like most people with high steer and hydro assist build a bracket off of the axle tube rather than welding to the diff or cover.

 

[Russellk30]

Nice clean build

About the ram mount, it looks like your diff-cover is cast as well.
I'm not sure that would be any better than welding it to the housing

How about getting a sheetmetal spring-plate, and weld the tabs to that...?

Thanks. Im going for simple, neat, and strong.

The cover is a cast chromoly, which is fully weldable with mild steel wire. I have read that there are a few pre and post procedures to make the welds stronger, but even without them the welds are still plenty strong. A post heat to 1000 is the most important with a natural cool off as well as welding when the material is above 70 degrees.

I was thinking about welding the hydro tabs to a spring plate, but am not sure if that would put too much shear force on the ubolts or lead to any other problems. I couldn't say either way and have never seen anybody do it.

 

[Russellk30]

got anymore info on the yukon shaft fitment ?

got mine i need to install soon. thay are out getting clerenced for the 300m joints now at c&M performance machine.

and i got reid ( dedenbear ) knuckles so dont know if any diffrent fit threw the whole .

trying to get my info ready to get them installed and done.

I only had a problem with inner-c clearance. The outer knuckle half and outer axles were fine, so the aftermarket knuckles wont help axle clearance any. The Reid knuckles also have the same precision dimensions as the stock knuckles. The spindle has a small flange that fits inside the knuckle hole, so I doubt the size is any different. I don't know if I would be comfortable shaving along the corner of the axles (within the yellow line) which would be required to make sure they fit through the knuckle hole. Who knows, maybe you got a different batch than me so certainly test everything first.

In the picture above, if you look closely you can distinguish between the blue paint on the axle and the ground corners (within the black line). It is difficult to tell how much material will need to be removed without the axles at least mocked up. You want to remove as little material as possible, so having the machine shop do it without the axle to measure against might be difficult. I had to grind and recheck fitment a few times for each corner. I am also going to sand the corners to remove any burrs from the grinding.

Let me know how the install works out for you. I'd be interested in any differences.

 

[Russellk30]

BTW seems like most people with high steer and hydro assist build a bracket off of the axle tube rather than welding to the diff or cover.

I was certainly thinking about that too. The only problem (which I later found out would be a problem with welding to the differential as well) is that with the cylinder parallel with the tie rod and mounted behind it, during suspension compression their could be contact with the already high clearance engine crossmember. The only way to fix the problem while still welding to the axle tube is to mount the cylinder at an angle, starting from the axle tube and incline up to the tie rod. I heard that this is not ideal, and puts a lot of twisting force on the tie rod and on the upper king pin bushing. I don't know if it would be excessive though.

I'm only going to have about 3-4" of lift, so there is not a lot of room in there. I might measure again though, cause I would much rather have the cylinder protected above the axletube while keeping my cover unmolested.

 

[Fred_M1010]

I was thinking about welding the hydro tabs to a spring plate, but am not sure if that would put too much shear force on the ubolts or lead to any other problems. I couldn't say either way and have never seen anybody do it.

You might have a point there, I guess there will be some serious forces on the u-bolts.
But there are some people that have done it that way, you could ask them if you wish.

I saved a lot of links and pictures when I researched my build.
Heres a couple with the tabs on the spring-plate:

http://coloradok5.com/forums/showthread.php?t=225757

http://www.pirate4x4.com/forum/showthread.php?p=9709762

http://coloradok5.com/forums/showthread.php?t=257219

http://coloradok5.com/forums/showthread.php?t=245464

But I guess you might get more clearance issues with the crossmember with this setup though...

 

[Fred_M1010]

The only way to fix the problem while still welding to the axle tube is to mount the cylinder at an angle, starting from the axle tube and incline up to the tie rod. I heard that this is not ideal, and puts a lot of twisting force on the tie rod and on the upper king pin bushing. I don't know if it would be excessive though.

I don't think it's a good idea to mount the cylinder at an angle, and I see no reason you would have to either, even if you weld the mount to the tube.
If you're gonna weld it to the tube just weld the mount so it places the cylinder right under the tie-rod.


Who needs cad programs, when you've got MS-paint

Btw. make sure to measure how long throw you need.
With those short arms I'm guessing you'll only need something like a 4-5" cylinder, but on the other hand it would need to have a larger diameter than a cylinder for "non hi-steer hydro assist" to make up for it strength-wise.
But you probably knew that already.

 

[Russellk30]

I don't think it's a good idea to mount the cylinder at an angle, and I see no reason you would have to either, even if you weld the mount to the tube.
If you're gonna weld it to the tube just weld the mount so it places the cylinder right under the tie-rod.


Who needs cad programs, when you've got MS-paint

Btw. make sure to measure how long throw you need.
With those short arms I'm guessing you'll only need something like a 4-5" cylinder, but on the other hand it would need to have a larger diameter than a cylinder for "non hi-steer hydro assist" to make up for it strength-wise.
But you probably knew that already.

That's a great idea! Thanks for the advice, and the links. That is probably the route I'll go. I like the paint skills too. Did you eyeball the lines to make them parallel or is there some paint function to line them up?

My throw is too long at 8", and yes, I only need 5". Better that it is too long than too short The cylinder is 1.75", which should be fine. I don't want to sacrifice too much steering response. I might trade if for a smaller throw cylinder for compact fit, but shipping is a bitch.

 

[Russellk30]

A fella came over to my house a little while ago to buy some DVD's I posted for sale. I was wearing coveralls and said sorry for my appearance but I'm restoring my truck. He got all excited so I let him see it. After analyzing it he said "oh, so your building a monster truck?" in a less than enthusiastic and slightly disappointed manner, like I'm going to use it to run over Bambi and destroy pretty forest meadows while sucking down thousands of gallons of fuel per minute or something. Since when is a truck with a couple inches of lift and 35" tires a monster truck?! That's what I get for living in Seattle.

 

[Fred_M1010]

I hear you, even my dodge with 31" have been called a monstertruck

Glad you liked my wicked MS-paint skills

You could always limit the throw of your cylinder to 5" by taking it apart and placing a 3" long tube around the rod inside it.

But I'm a little concerned that 1.75" could be a little on the small side.
A 1.75" cylinder with a 5" throw, gives the same strength and response as a 1.38" cylinder with a 8" throw (when using stock tie-rod location).

Btw. what kind of bushings do you have on your cylinder?
If they're spherical you'll probably dont even need the "bend" in my drawing.
Thats just to allow the cylinder to swing a little to the front and back, since the tie-rod moves slightly front and back when steering.
But if it's not spherical, I just realized the tie-rod end mount in my drawing would probably not work so well...

 

[Russellk30]

But I'm a little concerned that 1.75" could be a little on the small side.
A 1.75" cylinder with a 5" throw, gives the same strength and response as a 1.38" cylinder with a 8" throw (when using stock tie-rod location).

Btw. what kind of bushings do you have on your cylinder?
If they're spherical you'll probably dont even need the "bend" in my drawing.
Thats just to allow the cylinder to swing a little to the front and back, since the tie-rod moves slightly front and back when steering.
But if it's not spherical, I just realized the tie-rod end mount in my drawing would probably not work so well...

I always though in a non-compressible hydraulic system, the only major factor in output force were input force of the fluid and piston face area. How would the throw length affect output power?

It is spherical, but the side to side tolerances are pretty small. Unless I make some spacers, I think that movement will be a factor anyway. I also noticed that for my cylinder to fit in that position, I would have to trade for the 6" cylinder anyway. I guess that takes care of a few issue's!

 

[Fred_M1010]

Sorry, I expressed myself poorly

It's because of the shorter arms, you need a cylinder with a bigger diameter.
Compare it to placing the ram on the tie-rod in the stock location.
Those arms are 8" long, and lets say that the high-steer arms you have now are 4" long.
Then you'll need twice the piston area in the cylinder, to achieve the same thing.

 

[Russellk30]

Sorry, I expressed myself poorly

It's because of the shorter arms, you need a cylinder with a bigger diameter.
Compare it to placing the ram on the tie-rod in the stock location.
Those arms are 8" long, and lets say that the high-steer arms you have now are 4" long.
Then you'll need twice the piston area in the cylinder, to achieve the same thing.

Ah, that makes a little more sense. I was going for a little undersized anyway to maintain steering response. Also wouldn't want to put too much pressure on those stock knuckles. Maybe they will hold out until something without stock arms comes out.

 

[Russellk30]

Hydro assist is close to finished. Just need a couple more reusable JIC6 90 degree fittings. After that, the axle will be painted the rest of the way and the cab stripped and painted.

After considering the cylinder location some more I decided behind and slightly below the tie rod would be best. What's the point of putting the cylinder forward and low when the point of high steer is to move the steering up higher? There would have been drag link clearance issues in the forward location too. I'll just have to cycle the suspension to make sure no contact is made with the engine cross member.

 

[76zimmer]

Nice stuff Russell...can you get a shot of the tierod from one end to the other from the drivers side looking to the pass side? Just my curiosity wants a look.