major DW after 60 build...

[Archer]

Just got done installing a HP D60 out of a 79 F-350 into my 99 Dodge Ram.

It's a 4 link w/trackbar setup and 16" coilovers in front. Leafsprung in rear. Everything is new including kingpins hardware. The only thing I didn't replace was the cone which was almost spotless and had no wear.

My tierod and draglink are 1 1/2" X 1/4", my draglink is 1 1/4" X 1/4". I have the tierod above the knuckle and the draglink to highsteer arm. My draglink/ trackbar are running at parrallel angles but my trackbar is 2 1/2" shorter than my draglink.

I used heims for all applications except trackbar axle mount which I used a Rubicon express extreme poly bushing. 1 1/4" at link ends and all other ends 3/4" X 7/8".

have a hydro-assist setup but didn't run the lines yet.

I'm running 3/16" toe and -2 degress caster. Tires are 37"X 12.6" X 16" Maxxis Creepy crawlers aired up to 28 psi, they are not balanced yet.

After taking it for trial ride with my 34"x10" AT road tires the truck was stable and had no DW up to 60 mph, after switching on my trail tires I have MAJOR DW at about 30 mph that won't stop until I come to standstill. Couldn't tell you if it straightens out after that because my eyes wouldn't stop flooping around in my head long enuff to see the road.

Questions,

1. Could it be that the tires are not balanced, seems like it could be part of the problem but I have my doubts it's the only problem.

2. Should I try to switch it to -4 caster?

3. Even tho' I replaced everything in the kingpin would a shim still help?

4. Is the shorter trackbar causing problems, I knew I might have a touch of bumpsteer but didn't think it'd cause DW.

5. Any suggestions greatly appreciated...

[rockrknockr]

yep i would check the tire balance first. maybe swap rear tires with fronts.

[Grumpy_old_fart]

1. Could it be that the tires are not balanced, seems like it could be part of the problem but I have my doubts it's the only problem.
yes
2. Should I try to switch it to -4 caster?
yes
3. Even tho' I replaced everything in the kingpin would a shim still help?
maybe
4. Is the shorter trackbar causing problems, I knew I might have a touch of bumpsteer but didn't think it'd cause DW.
maybe, but I would start with the little things first. What are your spring rates f/r?

[BillaVista]

My suggestion.

Ballance the 37's and hook up the hydro-assist or a stout steering stabilizer.

[kwrangln]

When you say -2 castor, you mean that the upper kingpin is 2 degrees to the rear of the truck in relation to the bottom bearing correct? If its 2 degrees forward or aft of the lower bearing, then this is the first place I would look. I've always run between 5-8 degrees castor with the upper behind the lower, the more the angle, the more stable and less twitchy the steering is. Getting your angles right is a big first step to fixing deathwobble. Right behind that would be balancing the tires somehow, be it golf balls, airsoft pellets, or traditional lead rim weights.

[Archer]

Thanks for the replies...

Yes, I'm setting the digital angle finder on the outter edge of the kingpin. Didn't really know anywhere else to get the angle at equal spots on both sides.

I'm getting some beads put in the tires in the morning and then I'll try going to -4 on the caster and see if I get any improvement. I'm going to try -4 first and see which way it goes. Any other suggestions appreciated...

P.S. I only charged my coilovers with #100 of air until I can get to the shop tomorrow and have the #150 nitrogen put in. Poly-performance said that should be fine, could this be an issue?

Here's my setup...

FRONT









Coilover forward angle.



REAR

[bspencer]

id say your axle is rolled too far fowardwhen i swapping my 60 front i set it at -7 degrees

[kwrangln]

I'd also gusset the shit outa that drag link at the bends. I dont care how thick the material is, you started it bending, its going to want to keep bending when stress is applied. Other than that, go higher on the castor, 6-8 degrees should do ya right.

[stallion85]

When I put high steer arms on my Chevy D60 I got wicked death wobble afterwards. I put a few shims under the arms and it fixed it....

[Archer]

The more I think about it the more I agree with the caster, seemed way too easy to turn and light in the steering wheel...

I thought about gussetting the draglink but I figured alot of the stress is going to be eliminated with the hydro-assist. Maybe I'll still gussett it. I actually may try using a high misalignment spacer on the highsteer arm like I did at the pitman and try and go with a straight draglink... I was surprised how much more misalignenment I got with the spacers.

[rock-it man]

Nice work, I would agree with about 6 to 8 - caster I run -8 myself , good luck?

[rcurrier44]

Gen speeking more caster means more return to center. When you are getting death wobble you tires are trying to turn on you and not returning to center. I set most everything to around 6-8 degrees and have no problems.

[cisco]

Originally Posted by stallion85

When I put high steer arms on my Chevy D60 I got wicked death wobble afterwards. I put a few shims under the arms and it fixed it....

How much shim? Are we talking one washer, roughly a 1/16th inch thick or more? where are you putting it? Between spring and bushing? spring and retainer? on top of the retainer? any of the above?

[Archer]

Had tires balanced with beads, changed caster to -5 and toe to 1/8". No improvement...

I'm gonna setup my hydro-assist tonite or tomorrow and see if that helps, all else fails I may try a shim under the kingpin even tho' they were just rebuilt...

I do need to makeup a swaybar and have the c/o's charged. Too much lean...

Could it be the c/o's not being all the way charged? Should I just wait till I have them charged before I changed anything else.

BTW, their 16" King 2-1/2" 350/250 rates...

[kwrangln]

Originally Posted by Archer

Could it be the c/o's not being all the way charged? Should I just wait till I have them charged before I changed anything else.

Ummm, ya think?

What does a shock do anyway? It controls the bouncing of the suspension. What is death wobble? The uncontrolled bouncing of the suspension. Thinkin they might be related a bit.

So far you've done the equivelent of troubleshooting every sensor on an engine to see why it wont start, then asking if your battery being dead may have anything to do with it.

[Red Chevy]

Originally Posted by kwrangln

Ummm, ya think?

What does a shock do anyway? It controls the bouncing of the suspension. What is death wobble? The uncontrolled bouncing of the suspension. Thinkin they might be related a bit.

So far you've done the equivelent of troubleshooting every sensor on an engine to see why it wont start, then asking if your battery being dead may have anything to do with it.

Bullshit! WHen I did my first SAS on my rig I had worn out 6" springs up front and no shocks when I did the first test drive. It had some death wobble, came home and added some more -caster and drove again and everything was fine.

[bspencer]

death wobble is the front wheels going back and forth not the suspension/wheels going up and down

[Wilson]

Originally Posted by bspencer

death wobble is the front wheels going back and forth not the suspension/wheels going up and down

Yep it's realted to steering components and or geometry. Try some Kingpin shims now since you corrected your caster and toe. Can you get any more caster out of it? I don't run less than 6 and am running 12 on my Fj40 currently

[Archer]

Yeah I don't have wheel hop which I'd think it'd give if it was the shocks, it's definately DW, the tires are flopping back and forth like a fat chick's ass doing the 50 yd. dash...

I can go more on the caster but without seeing any improvement when I moved it to -5 I wasn't sure if I was going in the right direction. When you guys say you ended up with -7 or -8 did you work up to that point or is that closer to spec with your given vehicle or is it more axle specific. The Dodge FSM says the OEM is around 3 1/2"...

Since I just rebuilt the kingpins should I start with an 1/8" shim? I did some searching and came up with most are using up to 1/4" but that seem to be with worn out kingpins, mine are new...

P.S. Considering this is my first D60 build I'm not real familiar with the specs. I noticed that I actually have up to -.03 more caster on the d-side than the p-side no matter how I adjust the links. Is this normal, am I dealing with a bent axle or is it just that I have to get the angle off the highsteer arm vs. the regular kingping cap and that's where the difference is?

[kwrangln]

Originally Posted by Red Chevy

Bullshit! WHen I did my first SAS on my rig I had worn out 6" springs up front and no shocks when I did the first test drive. It had some death wobble, came home and added some more -caster and drove again and everything was fine.

Great, so you're a redneck who drove around with no shocks, thats conclusive.

What part of what I wrote is bullshit? That shocks control the bouncing of the suspension, or that death wobble is the uncontroled bouncing of the suspension? Or was it that I thought him leaving out the part about the shocks not being charged was kind of vital to figuring out his problem?

Dont forget that his coils are alot different than your leafs since they dont have the interleaf friction to help slow movement.

[kwrangln]

Originally Posted by bspencer

death wobble is the front wheels going back and forth not the suspension/wheels going up and down

Then how do out of balance tires contribute so much to DW? With a mechanical steering linkage, rapid cycling of the suspension even with a flat drag link will result in some steering input which if uncontrolled will multiply upon itself untill its pretty scary. I've had DW as a result of worn shackles on a leaf spring rig, just a lil play in one of the locating methods of the axle can cause it.

[bspencer]

Originally Posted by Archer

I can go more on the caster but without seeing any improvement when I moved it to -5 I wasn't sure if I was going in the right direction. When you guys say you ended up with -7 or -8 did you work up to that point or is that closer to spec with your given vehicle or is it more axle specific. The Dodge FSM says the OEM is around 3 1/2"...


P.S. Considering this is my first D60 build I'm not real familiar with the specs. I noticed that I actually have up to -.03 more caster on the d-side than the p-side no matter how I adjust the links. Is this normal, am I dealing with a bent axle or is it just that I have to get the angle off the highsteer arm vs. the regular kingping cap and that's where the difference is?

i measured off the top of my hi stear arm

when i ordered my arms from Trevor at WFO he said the arm should be point up towards the bumper about 7-8 degrees.... thats what i went with..... the way my springs set i was at about 0 so i added an 8 degree wedge and tightened teh fawk out of the spring plates to help keep them in.. took it out for a test run. came back adjusted my toe out a lil and its been great since..this is running unbalanced 38" TSLs on H1 wheels

im using a chevy D60 if it matters any

[Archer]

Originally Posted by kwrangln

Then how do out of balance tires contribute so much to DW? With a mechanical steering linkage, rapid cycling of the suspension even with a flat drag link will result in some steering input which if uncontrolled will multiply upon itself untill its pretty scary. I've had DW as a result of worn shackles on a leaf spring rig, just a lil play in one of the locating methods of the axle can cause it.

I understand where your coming from thats why I asked about the pressure but I'm not getting any up and down movement before they start to flop, all movement is from side to side... Wouldn't I get atleast a bit of wheel hop if it was the shocks?

I may have not mentioned the pressure in my very first post but I did mention it in my next one 2 hrs. later... I tried to think of as many possible causes as I could but it slipped my mind at first. Age'll do that too ya...

Got the hydro ready to go, just have to finish running and bleeding the lines in the morning and we'll see what that does. Even if it works, am I just masking the problem? Should I try and fix the DW before moving on to the assist?

Sorry if I am getting ahead of myself without charging the shocks completely but I have a ride coming up and I need this thing done. It's been a TOO LONG of a build...

[Cal4xRam]

the death wobble has nothing to do with shocks. alignment and loose steering components are all that really affect it. tires being out of balance make it worse or make the problem show up to begin with but thats never the whole problem. check the joints on the track bar( even a tiny bit of play there can cause it)

[Wilson]

On all of the housings I've narowed and turned, I've found between 1.5 - 2 degrees difference in caster. Jack the weight off the vehicle, grab a tire and try to rock it. If you notice ANYTHING loose start checking. make sure wheel bearings are tight, kingpins, etc. Something is likely loose. 6 degrees caster is a common # for factory setups. I used to shoot for that, but have now begun running around 12 degrees, for better biting on vertical climbs and excellent tracking on the road. The tires make a bit more noise on twisty roads, but that's it.