Steering and Poor Stability

[Tinerfeño]

The stabilzer returns nothing. It damps vibrations.

IMHO it is not able to dampen vibrations (small, fast movements of front wheels turning back and forth, also called wobble) but instead it reduces steering response in slower and larger movements like one wheel hitting an obstacle. Power assisted steering has made it less important but with manual steering boxes it was very important.

Steering wobble is tackled in LR solid axles by adjusting swivel pin pretensions (RH+LH) to specified value after bearings have worn. I know cars that drive without damper but do not suffer from wobble.

 

[RobP]

I lowered tire pressures, and it was definitely better. I'd like to turn off the warning. I don't know if there is a way to reset what the expected pressures are, or maybe I just need to add a little air back.

I installed the Fox steering damper last night. Installation was trivial except for the line "It may be necessary to slightly pry open the oem mount to fit the new stabilizer." That's when I moved from the floor to the lift.

My test drive was only about 5 minutes at 85mph. I think this is a pretty big step in making it easier to drive, but I wouldn't say it suddenly has precision handling. It's definitely a much bigger improvement than lowering tire pressures. My goal is to get to where I can steer with just my left arm on the window for long stretches of straight highway because that's how I could do long distances. But as dumb as this sounds, I'm a bagpiper, and this weekend was St Patrick's Day. If you live outside the US, you might realize that the Great Highland Bagpipes are Scottish, not Irish, but that is a nuance lost on the vast majority of my fellow Americans. My point is I played 8 shows this weekend, and my left arm is absolutely dead. I am optimistic that once I'm recovered I will find this to be a great solution.

I admit my other car is a 911, but I've generally kept one small car and one big car. Most recently the big one was an F150, so I'm not comparing to the an X5 or anything like that. The way this guy described steering is pretty consistent with what I saw, but the dealer says I already have my 2 degrees of caster, which has been my concern.

View: https://www.youtube.com/watch?v=OiQ7E7a8Gds

Did it lighten up the steering effort at all? When I spoke to them they said it would lighten it up a bit. Thoughts?

 

[ZemTyrion]

Yes, it's definitely a bit lighter.

 

[Javasipper]

My pressures from the dealer were 45 front and 49 rear. Last night I lowered them to 38/40. I might go lower, but I haven't had a chance to test it. It's been snowing since last night, and we're expecting a foot today so I don't think I'll be going much over 60mph on the roads right now.

Hopefully that will do it, but I also ordered the Fox steering damper. It looks like we can't get OME in the US (not that I found anyway). I am optimistic that at least one of those will do something. Thanks!

I have a Trialmaster, with 350 miles on it. Yestersday I added an Old Man Emu Steering Stabilizer (Part # OMESD24). I've only driven 50 miles with it on, but there is a noticable improvement in the wonky steering.

 

[anand]

I have a Trialmaster, with 350 miles on it. Yestersday I added an Old Man Emu Steering Stabilizer (Part # OMESD24). I've only driven 50 miles with it on, but there is a noticable improvement in the wonky steering.

Could you be more specific in regards to what constitutes your statement of "wonky" steering? and in what ways you've noticed an improvement?

 

[Javasipper]

Could you be more specific in regards to what constitutes your statement of "wonky" steering? and in what ways you've noticed an improvement?

Wonky in that the IG will "drift or wander" ever so slightly left and right going at highway speeds, and return to center was not happening as I like after making turns. The OME steering stabilizer has improved the wandering and return to center, but only a wee bit. I've just now set the caster to 1º+, and that seems to have taken the wandering out of play.

 

[anand]

I've just now set the caster to 1º +, and that has also taken the drifting out of play.

So you've decreased caster over factory? (Factory spec is +2°)

 

[Javasipper]

So you've decreased caster over factory? (Factory spec is +2°)

yes, just slightly

 

[evomind]

I lowered tire pressures, and it was definitely better. I'd like to turn off the warning. I don't know if there is a way to reset what the expected pressures are, or maybe I just need to add a little air back.

I installed the Fox steering damper last night. Installation was trivial except for the line "It may be necessary to slightly pry open the oem mount to fit the new stabilizer." That's when I moved from the floor to the lift.

My test drive was only about 5 minutes at 85mph. I think this is a pretty big step in making it easier to drive, but I wouldn't say it suddenly has precision handling. It's definitely a much bigger improvement than lowering tire pressures. My goal is to get to where I can steer with just my left arm on the window for long stretches of straight highway because that's how I could do long distances. But as dumb as this sounds, I'm a bagpiper, and this weekend was St Patrick's Day. If you live outside the US, you might realize that the Great Highland Bagpipes are Scottish, not Irish, but that is a nuance lost on the vast majority of my fellow Americans. My point is I played 8 shows this weekend, and my left arm is absolutely dead. I am optimistic that once I'm recovered I will find this to be a great solution.

I admit my other car is a 911, but I've generally kept one small car and one big car. Most recently the big one was an F150, so I'm not comparing to the an X5 or anything like that. The way this guy described steering is pretty consistent with what I saw, but the dealer says I already have my 2 degrees of caster, which has been my concern.

View: https://www.youtube.com/watch?v=OiQ7E7a8Gds

I saw that vid, good vid.
He did say he would have liked to see at least 3 degrees of caster but the vehicle only allowed 2.
I guess they are being delivered with some variance.

 

[Tom109]

Crested 1000 miles and have a long weekend trip coming up tomorrow. I don’t have wonky steering or poor stability, just a big grin on my face.

 

[AWo]

Wonky in that the IG will "drift or wander" ever so slightly left and right going at highway speeds, and return to center was not happening as I like after making turns. The OME steering stabilizer has improved the wandering and return to center, but only a wee bit. I've just now set the caster to 1º+, and that seems to have taken the wandering out of play.

I don't know if that is your first car with a solid front axle. But that behaviour is normal, of course only to a certain extend.

Why?

The toe setting of the Grenadier and almost all 4WDS is toe-out. Which wheel rules and gives the direction for a particular moment depends on which wheel has to to take the highest load. Driving with one wheel on a small obstacle like all the small bumps on an uneven road increases the load in for that particular moment for this one wheel and it becomes the boss. So if you drive on a small hump with your left front wheel, the car tends to go to the left, at least for that small moment until the load distribution change again and again and again....etc. etc.

What you feel thereby might be the normal behaviour of a solid axle car and you feel it more and more as a fuzzy steering, the higher the speed is.

BTW, it seems that front and rear axle have bin mixed up here regarding the toe setting. Rear solid axles do have a toe setting of zero (so that the drive shafts do not twist) and the front axle has value of not zero.



AWo

 

[Javasipper]

So you've decreased caster over factory? (Factory spec is +2°)

We've reset the Caster back to +2º. We had intended to "Increase" Caster +1º, not decrease. We're back to factory specs now. NOTE: It wasn't possible for us to increase the Caster greater than +2º as hoped for.

 

[CORE Ineos]

I don't know if that is your first car with a solid front axle. But that behaviour is normal, of course only to a certain extend.

Why?

The toe setting of the Grenadier and almost all 4WDS is toe-out. Which wheel rules and gives the direction for a particular moment depends on which wheel has to to take the highest load. Driving with one wheel on a small obstacle like all the small bumps on an uneven road increases the load in for that particular moment for this one wheel and it becomes the boss. So if you drive on a small hump with your left front wheel, the car tends to go to the left, at least for that small moment until the load distribution change again and again and again....etc. etc.

What you feel thereby might be the normal behaviour of a solid axle car and you feel it more and more as a fuzzy steering, the higher the speed is.

BTW, it seesm that front and rear axle have bin mixed up here regarding th etoe setting. Rear solid axles do have a toe setting of zero (so that the drive shafts do not twist) and the front axle has value of not zero.

View attachment 7849239

AWo

I hear people saying that this wandering is normal for a solid front axle vehicle.
As an owner of at least 30 solid front axle vehicles, from mostly high end Unimog builds Dodge trucks,Suzuki Samurais, Jeeps new and old, old Land cruisers etc. , the highway wandering of my Grenadier, nicknamed Pong after the video game describing how it wanderes, is the worst if ever experienced!

There has got to be something we can do for this. I'm going to experiment and add a couple more degrees of caster to this by probably taking maybe 15mm out of the upper links . I think this will be a little easier and safer than molesting the lowers .

If it helps, we'll look at making some adjustable lowers in the future and returning the uppers back to stock?

Any other suggestions?

FYI , I own a higher end overland vehicle fab shop and have been messing with link suspensions for over 30 years so please don't scold me too much on how dangerous this is. I'm definitely aware.

 

[AWo]

I don't know if you can set the camber by adjusting something at the IG, but the spec sheet shows, that it seems to be possible to have positive or negative camber. As the IG is not a high speed racing car, you may want to try positive camber, which softens the ride and steering forces.

AWo

 

[Tom109]

For two days I have been driving around DC and NoVA with one hand on the wheel. Gren feels solid and stable. No untoward steering issues.

 

[dreamalaska]

Some newer vehicles with recirculating ball bearing gear boxes are using variable flow hydraulic steering pumps, called Variable Assist Power Steering. These pumps decrease the hydraulic fluid flow through the pump as the engine rpm increases, allowing much better feel and control at highway speeds.

I cannot find if Ineos and Bosch are using this system on the Grenadier, but if not, this should be required during their next update/refresh.

Redhead Steering Gears in Auburn Washington specializes in rebuilding steering gear boxes to eliminate the “slop”. The Grenadier isn’t on their radar yet, but I suspect that’ll change in time.

 

[evomind]

Just from reading through a history of discussions on this board I have to think these trucks are being delivered with some kind of variation in settings or tolerances from the factory.
I say that because some people drive it and say its fine on the highway at 80mph or whatever, and others report its all over the place.
Can both be true?
I guess...maybe.
Wranglers have a very similar setup and some of them report wobbles, issues, but many do not.
I think most of what we are seeing is the normal operation of a recic ball steering, but not all of it.
I had an H1 that I drove on stock tires then switched to 40s and I never felt the steering was an issue. Of course I dont think I ever drove it faster than 70mph for extended periods....Bursts of 75. Not because of the steering so much but the truck as a whole, rpms etc.
I thought it steered fine but it felt like a truck.
Because it was a truck.
Ive driven Wranglers and didnt have any issues. I see them doing 75-80 all the time on the highway.
I think we are just not used to how trucks drive.
Its just a by-product of the parts with some variances from the factory thrown in.
I do not believe all of them are perfect, I DO believe some folks are having some issues. I also believe that once the performance shops start seeing more of these we will learn more, especially in variances from truck to truck.

I had a very limited drive in a Grenadier for about 5 mins and the one I drove seemed perfectly normal to me.

Another problem is that for years manufacturers like BMW, Merc, and Porsche have been designing sedans and SUVs that handle closer to sports cars to one degree or another and folks have grown accustomed to that.
To me, those vehicles are the anomaly.

 

[dreamalaska]

Just from reading through a history of discussions on this board I have to think these trucks are being delivered with some kind of variation in settings or tolerances from the factory.
I say that because some people drive it and say its fine on the highway at 80mph or whatever, and others report its all over the place.
Can both be true?
I guess...maybe.
Wranglers have a very similar setup and some of them report wobbles, issues, but many do not.
I think most of what we are seeing is the normal operation of a recic ball steering, but not all of it.
I had an H1 that I drove on stock tires then switched to 40s and I never felt the steering was an issue. Of course I dont think I ever drove it faster than 70mph for extended periods....Bursts of 75. Not because of the steering so much but the truck as a whole, rpms etc.
I thought it steered fine but it felt like a truck.
Because it was a truck.
Ive driven Wranglers and didnt have any issues. I see them doing 75-80 all the time on the highway.
I think we are just not used to how trucks drive.
Its just a by-product of the parts with some variances from the factory thrown in.
I do not believe all of them are perfect, I DO believe some folks are having some issues. I also believe that once the performance shops start seeing more of these we will learn more, especially in variances from truck to truck.

I had a very limited drive in a Grenadier for about 5 mins and the one I drove seemed perfectly normal to me.

Another problem is that for years manufacturers like BMW, Merc, and Porsche have been designing sedans and SUVs that handle closer to sports cars to one degree or another and folks have grown accustomed to that.
To me, those vehicles are the anomaly.

I believe your are correct. In a previous post I posted a PDF that explains the process for a manufacturer to minimize the slop in a power steering gearbox. Long story short, it’s an iterative process that’s labor intensive. But that’s not how things are built on an assembly line. All parts are built with an acceptable tolerance within a bell curve. After assembly Quality Control verifies that the minimum tolerances are met. So some gear boxes have more slop than others, but are still within tolerance.

 

[wolftimj]

I hear people saying that this wandering is normal for a solid front axle vehicle.
As an owner of at least 30 solid front axle vehicles, from mostly high end Unimog builds Dodge trucks,Suzuki Samurais, Jeeps new and old, old Land cruisers etc. , the highway wandering of my Grenadier, nicknamed Pong after the video game describing how it wanderes, is the worst if ever experienced!

There has got to be something we can do for this. I'm going to experiment and add a couple more degrees of caster to this by probably taking maybe 15mm out of the upper links . I think this will be a little easier and safer than molesting the lowers .

If it helps, we'll look at making some adjustable lowers in the future and returning the uppers back to stock?

Any other suggestions?

FYI , I own a higher end overland vehicle fab shop and have been messing with link suspensions for over 30 years so please don't scold me too much on how dangerous this is. I'm definitely aware.

Look forward to reading about your findings.

 

[Jackattack13]

I wonder what the issue is that is causing such a variance in vehicle handling from car to car. The demo I drove was a bit on the "odd" side, as it handled unlike any other vehicle I had driven up until then. My MM that I was supposed to take delivery of was squirelly as hell and almost unbearable on the test drive. The Eldoret Blue model I ended up purchasing feels great on the road, no issues at all when it comes to handling. But the steering wheel is a bit crooked when tracking straight, so going to have the dealership do steering wheel alignment on it.