Steering and Poor Stability

[pmatusov]

Going from 35 to 40 psi in 6000 pound truck on an E rated sidewall wouldn't be noticeable. It would be like playing the Pepsi challenge with 4 cups of Pepsi. If I had a truck that went from dangerous high speed handling to calm by changing a few PSI, I's sell it, because something is waaaaaaay out of wack.

When you air down in the Grenadier from 43 to 28 psi you definitely see the sidewall flex. Would I see it between 40 and 35? Probably.
On the subject of front/rear tire pressure differential - I always suspected that on the D1/RRC it was means to introduce understeer, and I think Ineos is doing the same. I like the truck's handling at even 45/45 better than at 43/49 psi.

 

[Zimm]

When you air down in the Grenadier from 43 to 28 psi you definitely see the sidewall flex. Would I see it between 40 and 35? Probably.
On the subject of front/rear tire pressure differential - I always suspected that on the D1/RRC it was means to introduce understeer, and I think Ineos is doing the same. I like the truck's handling at even 45/45 better than at 43/49 psi.

Introducing a slight bit of under-steer isn't quite the same as people describing their truck as dangerous at high speed with tires in the 40's, and people suggesting to add a few pounds as a solution. These trucks have skidpad numbers in the .5's Between the low 30's and up to 50, all I've ever noticed on 4 different LC models, a defender, a trooper and a G, is ride quality.

The steering IS unusually odd in this truck, but if its got the 2* of caster, and there isn't anything loose in the linkage or steering-box, I'm thinking some people aren't used to the sailboat effect on a box truck in cross winds at high speed combined with sloooooooow turning and a swartzeneggar strength dampner.

I bet the rig would feel much more normal without the dampner altogether.

 

[Lord Ripon USA]

I bet the rig would feel much more normal without the dampner altogether.

Catastrophic shimmy.
That's a hard no.

 

[grenadierguy]

As do I - otherwise flipping people off is too difficult. As is eating rames, playing Candy Crush, and shaving.

Was that you waving at me today Krabby?

 

[bigleonski]

Coming from Nitto Ridge Grapplers to BFG AT’s, the sidewalls on the BFG’s bag out considerably more.

 

[grnamin]

The bracket is just a little narrow for what you are shoving in there, particularly because there are two fat washers, so you need to line up the holes in all three at the same time. This was the only tricky part of the install, and why I put it on my lift after starting on the garage floor. But what I eventually worked out would probably have worked on the floor.

Without the damper, I partially threaded the bolt back into place in the bracket. Then I used a bearing puller to shove the bolt in all the way. The nut is welded onto the bracket, so this pushed the two plates apart. I let it sit like that for a few minutes. It was just enough to get everything in there. I think once you see it this will make sense, but I'm going to make use of my incredible Paint skills here. The goal is to just spread apart the C bracket a little bit. Also, I don't know how to draw a bearing puller.

View attachment 7853535

Is the bearing puller the same one used to remove bicycle headsets?

 

[Korg]

When I picked up my Grenadier Trialmaster a few weeks back the steering was sloppy with around 10 degrees of "play" in the steering wheel. It was very hard to keep the car straight at 100km with a lot of steering input required. I have checked and adjusted the tyre pressure, caster, camber and wheel alignment to spec (all were out). This improved the steering but did not fully address the wandering due to the slop. 3,500km later on a trip to the South Coast the steering wheel rotated from the 12'o clock position to about 1pm. Alarms for the ESC, uphill assist, downhill assist etc. etc. all bing bonged and have stayed on since. On the way back from the South Coast the steering moved now to 2:30 pm for dead centre wheels but .... the steering is actually much better in respects to the slop has now almost gone. Car goes into service Tuesday.

 

[OGrid]

‘Wandering due to slop’ - I think you’ve summarised the steering experience of others (myself included) quite well