Hydro steering question

[Tass]

I'm getting the stuff together to put full hydro steering on my truck with 404 axles. I need to know what length stroke I need for the ram. My axles are away being shortened right now and I forgot to get the measurements I need
Could someone measure their tie rod to see how many inches it moves from lock to lock?

Thanks
Tass

[EUROTRUCK]

Originally posted by Tass
I need to know what length stroke I need for the ram.

Tass,

I got the following info from the Unimog tech data book and went deep into my brain to pull out some radius and trig formulas.

Pitman arm length is 215 mm.
Steering box shaft rotation is 75 degrees.

If the pitman arm went in a full circle the circumference of the circle would be 2*pi*r or 2*3.1415*215mm which equals 1350.8 mm. From there I set up a ratio to figure out the distance the pitman arm travels around the radius with its 75 degrees of travel.

1350.8mm/360degrees=X/75degrees

X = 281.4 mm or 11.08 inches of radial distance.

However, the distance that really counts is the linear displacement. This is due to the fact that you are using a straight piston for your hydraulic steering. If you calculate the distance between the two pitman arm stops using a triangle, you come up with 10.7 inches of linear displacement. Since the length of the drag link remains constant, the steering arm should also be displaced 10.7 inches. So your ram should be have a range of motion of over 10.7 inches.

Now let's see what somebody comes up with as the measured value. Hopefully I used the right info from the book and I didn't screw up my calculations too badly. Now my brain hurts.


-EuroTruck

[unissamog]

WOW!!!!!

I was just gonna go and look at my steering box, but fter that, it just seems WAY too easy.....maybe if I dissasemble the whole truck measure everything, then re-assemble I'll be in the same league!

Well, measuring my steering box's travel yields about 9-9.5" of travel. but I don't know if that will give you full lock to lock on the axle.

[Tass]

Thanks for all the info guys. I just went out and measured the stock steering stabilizer and it has 9.5" of travel. I'm not sure if all of that travel is used though.
If someone could measure their tie rod travel in relation to the axle that would give me the exact number that I need.

Tass

[AGGIE_04]

btt, i need this info too, thanks

[cruiserrg]

Out in the garage today and measured the travel. I measured on the tie rod arm (behind the axle) and it was ~9" of travel stop to stop. I would get a ram with just under that for travel so you don't bend the arms. Also this measurement would changed if you made a custom steering arms and had the mounting hole further or closer to the axle.

HTH

[Tass]

Thanks for the info. I'll buy a 10" and put a spacer in it to limit travel.

Tass

[DanB]

you should talk to station from this board.. he knows shitload of stuff.. and very helpful and he sells the parts too.. and they are good pricing..

tell him i told you to go talk with him

[coachgeo]

Originally posted by DanB
you should talk to station from this board.. he knows shitload of stuff.. and very helpful and he sells the parts too.. and they are good pricing..

tell him i told you to go talk with him

I'll back ya on that. Station is one smart cookie he knows his stuff and has good prices.

[Tass]

I've already talked to him He's the guy that I'm getting my hydro stuff from.

Tass