Sanity check on 98 XJ steering being built to U4 4500 rules

DobermanRacing · Mar 21, 2020

Ok so quick intro on the XJ. Currently running a stock box tapped for assist to a 1.5" dia. ram on a 06 Ford d60 with barnes4wd high steer arms, 04 Grand Cherokee p/s pump, 7/8"-3/4" FK heims, homemade pitman arm, and a steering brace.

I've killed the box again so I'm looking to change up my steering and wanted to see if anyone sees a flaw in my plan.

I plan on running a manual steering box, a sweet mfg servo, and a 2.5"x10" double ended ram as my tie rod. Keeping a drag link so I conform ultra 4 4500 class rules which state you must retain a mechanical linkage.

4.7 STEERING
4.7.1 All vehicles must retain some type of mechanical steering linkage (e. g. 'full-
hydro' steering is not permitted, unless factory-equipped matching frame),
and said linkage must be capable of controlling the direction of the steering
wheels/tires without the benefit of any additional power-steering aids. Rear-
steer is not permitted.

extremetownie · Mar 21, 2020

If you run the servo,you will not need the ram.

MonnlightRacing77 · Mar 21, 2020

Local team I build shafts for has a 4600 class grand cherokee.They run a 10in ram with a tapped box.Drag link hooked up but they ground down the teeth on the sector shaft gear so it still has a "mechanical link" They never have been checked on it in the 3 years they raced Ultra 4

TBItoy · Mar 21, 2020

extremetownie said:
If you run the servo,you will not need the ram.

What would you hook the servo valve to if you didn't have a ram?

extremetownie · Mar 22, 2020

TBItoy said:
What would you hook the servo valve to if you didn't have a ram?

The servo connects directly to the imput ( the steering shaft) of the steering box. It applies assist in the direction of rotation(making it easier to turn the steering wheel). It has a full mechanical steering with hydraulic assist.

TBItoy · Mar 22, 2020

extremetownie said:
The servo connects directly to the imput ( the steering shaft) of the steering box. It applies assist in the direction of rotation(making it easier to turn the steering wheel). It has a full mechanical steering with hydraulic assist.

Thats not how the sweet servo valve works.

It is just like the front input servo valve in a power steering box, which directs fluid to either side of the rack piston inside the steering box. Except with the remote mount servo valve, you use it to directly power a hydraulic ram. The mechanical box is just there to provide resistance in the direction you are turning to flex the torsion spring in the valve and direct fluid to the ram. The idea is that the double ended ram on the axle takes all the abuse/does all the work.

The application it was originally designed for uses a mechanical rack and pinion, with the sweet valve mounted at the input shaft, and a double ended hydro ram piggy back on the rack.

Lil ugly · Mar 22, 2020

Wow, that actually looks like a sweet set up. pun intended. Kind of the best of both worlds. although the shafts on the ramp look a little on the small side for taking the kind of abuse you will see in ultra 4 style racing. What size tires was it originally intended for and at what speed?

extremetownie · Mar 22, 2020

I stand corrected. I have seen a similar device on a tractor with no ram and a mechanical steering gear. I thought that was what this was. My bad. I found what i was thinking about. It is a torque generator.

TBItoy · Mar 22, 2020

Lil ugly said:
Wow, that actually looks like a sweet set up. pun intended. Kind of the best of both worlds. although the shafts on the ramp look a little on the small side for taking the kind of abuse you will see in ultra 4 style racing. What size tires was it originally intended for and at what speed?

that Sweet rack is for roundy round race cars. Similar are made for trophy trucks and IFS ultra4 cars but much beefier.

jeeppoor · Mar 22, 2020

Have you looked in replacing the steering box with one from a H1?
A friend put one his CJ. It is over twice the size of the stock one he pulled off. And bolted right up in place. No frame mods.
We also drilled it for hydro assist.