If the pressures are regulated differently between the 4.0 and 5.0, that could be causing a problem with mine, if there is nothing wrong with the current rack.
Could be I got a bad rack out of the box.
I have heard there is a difference in years, with different turning ratios.
This new info of different widths isn't a concern to me, as it is minimal.
I know the lines from the pumps are different shaped, but don't know if they are different in volume.
I want to exchange this 5.0 rack with the same, just to save $$ on purchasing the 4.0. This is a gamble, if the same issue happens doing this.
On a scale of 1-10 for the assist, it is a 5 right now. No return to center, and you need full grip on the wheel to turn it. When I went from Colby ks to Ouray co, it was a 0. That took both hands, and full strength to turn the wheels, and impossible to turn unless the rig was moving. That wore me out!!
When on a trail, and put into low range, 4wd, something gave, and freed it up somewhat, and was about a 6. After we flushed the system, it got a little worse. Took it 1200 miles home like that, with a trailer. Talk about a rough time. Lol
The reason why mine is going to be a pita, is if I have to remove the big front skid plate, it isn't easy. They bash bar connected to the cross member blocks the lower bolts. To remove the bar, I have to remove the coil overs. The bar is bolted using the front bolts on the lca. That means an alignment is needed after. My fault for not turning the lca bolts 180, with the nuts facing forward.
Always something!!