death wobble with 35's ????????????

Questions about 4WDs and related topics

Moderators: FORDification, Doug Comer

User avatar
averagef250
100% FORDified!
100% FORDified!
Posts: 4387
Joined: Fri Mar 17, 2006 12:58 am
Location: Oregon, Beavercreek

Re: death wobble with 35's ????????????

Post by averagef250 »

So... What's the caster, camber, toe, spring pad angle, etc?

Gotta have numbers if you want to figure this out. If everything is right it won't be acting up.

Tie rods are solid on these old trucks.
1970 F-250 4x4 original Willock swivel frame chassis '93 5.9 Cummins/Getrag/NP205/HP60/D70
User avatar
1971ford
100% FORDified!
100% FORDified!
Posts: 5565
Joined: Wed Jul 04, 2007 1:05 pm
Location: Placerville CA

Re: death wobble with 35's ????????????

Post by 1971ford »

I spent about 4 hours one day tweaking the toe and making sure it was right at 1/8", i'd like to think it's exactly 1/8"...
If i park the truck in my level garage and put a degree finder on the spring pad that should give me a good reading, yes? I can do that tomorrow.
Camber... anything i can butt the angle finder up against to find the camber angle in my garage? Would the hub give me any idea? Or atleast if the camber is off enough, it would show me somethings out of whack
caster can be measured using the spring pad angle, yea?

If I can't measure these things close enough in my garage then i guess it's off to the alignment shop
-Ryan
User avatar
averagef250
100% FORDified!
100% FORDified!
Posts: 4387
Joined: Fri Mar 17, 2006 12:58 am
Location: Oregon, Beavercreek

Re: death wobble with 35's ????????????

Post by averagef250 »

You need something that's +/- .5 degree or better.
1970 F-250 4x4 original Willock swivel frame chassis '93 5.9 Cummins/Getrag/NP205/HP60/D70
User avatar
1971ford
100% FORDified!
100% FORDified!
Posts: 5565
Joined: Wed Jul 04, 2007 1:05 pm
Location: Placerville CA

Re: death wobble with 35's ????????????

Post by 1971ford »

ahh. so i need an alignment rack.
-Ryan
User avatar
averagef250
100% FORDified!
100% FORDified!
Posts: 4387
Joined: Fri Mar 17, 2006 12:58 am
Location: Oregon, Beavercreek

Re: death wobble with 35's ????????????

Post by averagef250 »

A machinist protractor works fine too, but an alignment rack and somebody who actually knows how to use it (not the dipsh*t tire monkey) is your best bet.
1970 F-250 4x4 original Willock swivel frame chassis '93 5.9 Cummins/Getrag/NP205/HP60/D70
User avatar
woods
100% FORDified!
100% FORDified!
Posts: 2121
Joined: Sat Apr 02, 2011 10:34 am
Location: Washington

Re: death wobble with 35's ????????????

Post by woods »

Everytime I have had this happen, it was too much caster. I ended up with a truck not too long ago that drove terrible. The guy had put wedges between the front axle and the spring, but had them pointed the wrong way. Took them out (which fixed the caster) and it fixed it right up.
User avatar
1971ford
100% FORDified!
100% FORDified!
Posts: 5565
Joined: Wed Jul 04, 2007 1:05 pm
Location: Placerville CA

Re: death wobble with 35's ????????????

Post by 1971ford »

TOo much positive or negative caster?

I just made longer shackles for the front of the truck for the superduty springs (new length at 5.25"center to center). Stock length is 3.75 or something.
And put the 35's back on. Weird thing is.... I haven't gotten any death wobble, granted i've only driven it a couple days. I assume it is too much positive caster that causes death wobble? Because the negative camber given by the shackles doesn't seem to be making things worse at all! Steers a tad slower, other than that, no wobbles... yet atleast. Planning on making a new front crossmember/hitch/hangers dropping the front down about an inch..
-Ryan
User avatar
woods
100% FORDified!
100% FORDified!
Posts: 2121
Joined: Sat Apr 02, 2011 10:34 am
Location: Washington

Re: death wobble with 35's ????????????

Post by woods »

Too much possitve.
Yeah, you just gave it more negitive caster and should of darn near fixed it if caster was you problem. I see this with Jeeps all the time (the older CJ's). Number one...they don't drive wonderful anyway and caster was all over the place right out of the factory. I have seen four degrees negitive and up to four degrees possitive on factory Jeeps. Then I see guys using longer shackles and since the shackles are in the front, this creates even more possitive. Take something that does not drive great anyway, then put more positive caster in it...that will keep you awake. The last CJ7 I bought...A trip to the store made me feel like I had ran the dakar rally. It was so positive that I had to cut and turn the knuckles to get it right. Once I did, it actually drove pretty good. I could motor down the freeway at 70 without feeling like I would die at any second.
User avatar
1971ford
100% FORDified!
100% FORDified!
Posts: 5565
Joined: Wed Jul 04, 2007 1:05 pm
Location: Placerville CA

Re: death wobble with 35's ????????????

Post by 1971ford »

haha that's funny, because a buddy has a CJ7 and that thing is all over the road!

I think i need to tigthen or replace my steering box. I never actually really worried about the play it has until my dad moved the truck out of the driveway once and informed me. I was used to it, and thought it was normal for manual steering, he says it is very loose.
I can turn the steering wheel about a 1/3 a revolution without the wheels moving at all. Its probably not helping anything, anyways..
-Ryan
hazelnut
100% FORDified!
100% FORDified!
Posts: 1928
Joined: Fri Oct 23, 2009 1:06 am
Location: Williamsburg,Virginia

Re: death wobble with 35's ????????????

Post by hazelnut »

Ryan, Have you checked the steering column u-joint bearing. When i had my truck apart i lost mine somehow and had LOTS of play in the steering wheel. Found some and replace them now my steering is nice and tight.
User avatar
1971ford
100% FORDified!
100% FORDified!
Posts: 5565
Joined: Wed Jul 04, 2007 1:05 pm
Location: Placerville CA

Re: death wobble with 35's ????????????

Post by 1971ford »

Nope i have not. I was going to tighten up the steering (if i can) in a little bit. It's so damn hot out..
I'll check that
-Ryan
Racer Z

Re: death wobble with 35's ????????????

Post by Racer Z »

A new vehicle with manual steering has no measurable play at the steering wheel. After a "few" miles the play is measured in inches. A half inch of movement at steering wheel is normal and acceptable for a newer car (50,000 miles / five years). A quarter turn is about 12 inches of play and way out of manufactures specs. But, having had many older cars/trucks, they all have gobs of play like this and we keep on driving them anyway.

The power-steering vehicles are subjected to the same amounts of play, but it gets absorbed into the "power" part and we don't notice it so much. Try checking the play with the motor off, then you see where the play really is. This has the side effect of hiding worn steering parts like bad tie-rod ends.
User avatar
1971ford
100% FORDified!
100% FORDified!
Posts: 5565
Joined: Wed Jul 04, 2007 1:05 pm
Location: Placerville CA

Re: death wobble with 35's ????????????

Post by 1971ford »

I checked it out a little bit. The play is all in the box. Having no idea how to tighten the steering box, i loosened the nut on the side of the box and screwed the deal in a couple turns. No difference. How do i get this thing tighter? new box?
-Ryan
Racer Z

Re: death wobble with 35's ????????????

Post by Racer Z »

The two gears wear mostly in the near straight ahead position. If you tighten the adjuster screw too much, it will be over-tight at full-lock where the gears are not worn. In some cases this can crack the gear box housing.

There are shops that can rebuild steering gear boxes. I think I saw some on the O'Reilly web site. Possibly you can find another used box with less wear. New might be available, but I bet it's not cost effective.
User avatar
1971ford
100% FORDified!
100% FORDified!
Posts: 5565
Joined: Wed Jul 04, 2007 1:05 pm
Location: Placerville CA

Re: death wobble with 35's ????????????

Post by 1971ford »

Thanks for the info. Sounds like I won't bother. I'll be putting power steering on the truck in not too long
-Ryan
Post Reply