Outer Limits 4x4 Board

I swapped my steering box to a gu one. It works fine except for under load or highish revs it locks. Farking dangerous, one minute you can steer next you cannot! It is very consistent too ie every corner under the same loads.

As the box came from a crashed truck (wreckers) It could be damaged, although it seemed very smooth while hand turning and has no obvious damage.
I would run with this except:
A mate had exactly the same drama (and knows of others too) and they still haven't completely fixed it. they have replaced the box, all lines for genuine new ones, had the pump rebuilt and pressure checked etc.

I am running a Gen 3 and holden pump, gq lines etc, gu box.
When It locks you can just muscle a turn but it is hard as hell.
My gq box never had a drama also with the holden pump. The fox dampner is fitted the same way as before, nothing is close to fowling etc

I have to fix this NOW as it is holding up testing of the truck.

ANY ideas will be appreciated. I will fix what is need the last thing i need at OBC is locking steering!!!

Thanks all

Cheers BRU

is the prv cutting out? or any linkages binding.

if all was working before the change over that is what i would be looking for.

a hydraulic pressure gauge should tell you what your pump is doing.

hope this helps

Sounds to me like its running dry of fluid, maybe pump aint big enough. I had a similar problem with a pump failing in my old Bronco, I had tio wrestle it around corners to get it home. Check your pump out.

ive heard that wrecks are prone to twisting the shaft inside the box itself

could this be the problem?

yeah could be a twisted shaft, or one of the little edges the balls inside run on could be damaged or broken off
pull the box apart n have a look ............. dont lose the 300000 balls inside tho

Thanks guys. No linkages are binding. I am unsure if a gu box requires different flow to the gq. I have never had a drama at all with the gq box. Also I am reluctant to assume the box is bent as a mate has had the same problem with his factory fitted box, as has 2 of his mates. Any ph numbers of a good steering box guy in qld?

I really hate mods that go backwards.

Cheers Bru

i have had the same problem with a GU that was running all nissan gear. We had the box rebuilt and the pumps stripped and checked and from memory it was crap in the lines get in to the check valve and causing no pressure. You could rev the engine and generally get the steering back. i would get both the pump and box stripped and checked and while its apart flush all the lines.

any ideas at the dollars involved?

cheers bru

My gu does the same thing if i load up the steering ie turning into ruts or on a imbankment steering locks up solid even with diff locks out nealy always have to reverse to free it up seems worse if running low tyre pressure i think running big tyres and suspension is just to much load on these boxs

Obvious one - not the high RMP throwing the PS belt out and letting it slip?

it doesn't seem to make a noise. By high rpm I mean anything over 3k, and by load I mean turning on the street. I might try to back the box off. How do you increase the belt tension on an auto tension system? Bigger spring?

If this is common because of bigger tyres etc i will go back to the gq box and keep the gu as a spare.

mines fine on the street i have to put a lot of load on for it to seize but when it does theres no turning the wheel. for yours to lock up that easy it must be a problem in the box its self even if you disconected the pump you would still be able to steer it when moving it would be a little heavy but still drivable

try it with the pump disconected and see if it sill locks up if it does then its in the box if it doesnt then you have a hydraulic problem either a valve or blockage somewhere

We used to have this problem with rochester pumps on race cars.
From memory under thr pump high pressure fitting is a drilled bolt which is a flow restrictor, we used to remove this bolt and run the next size drill through it

dogbreath_48 wrote:Obvious one - not the high RMP throwing the PS belt out and letting it slip?

Agree 100%

Tighten the belt up and re check. Seen this before.
Doesnt make any noise

Bazzle

i am running a GU steering box on my GQ and i have fitted a GU power steering pump and all GU hydrolic steering lines to mine and have had no dramas at all. you need to find a 4.5l petrol GU pump and its all bolt on, you need to buy a new belt as the pulley size is different which could affect the flow of fluid? I am not sure on the technical information of flow etc.

some people have said to me that going to a GU box on a GQ makes the steering a little heaving, but i have noticed no difference on mine.

although the hydrolic lines are slightly different compared to a GQ, you can still fit em in there.