Batteries making my rig lean?

[Just_Jeff]

So...took the rig for a little drive after I got 3x220AH batteries into the newly welded box, which is a little over 500lbs added to the driver's side. Alignment was a little off.

Took it on a longer trip to CW for some warranty work (house door replaced) with my wife following, and she said it was leaning to the left enough for her to notice it. It also felt less stable like it was swerving a little, but it was very windy here in Colorado so that's not an uncommon feeling. The wind also could have made the lean worse but I suspect that was more due to the extra weight on one side.

What are the considerations for this? Any danger? I plan to get the alignment fixed shortly, and if the lean is bad enough maybe I'll add a leaf to that suspension or something.

I'm driving from CO to VA early next month so I don't really have time for significant work before I head out. If it's an issue, I'll just take a battery out to balance the weight until I get to VA.

Thanks!

[12thgenusa]

HiTech wrote:
If it was right even between axles, it is equivalent to adding 1000 pounds to the rig. If right over a single axle, it has the same impact on that axle as adding 2000 lbs. overall. At the least tire pressure adjustment is in order.
Jim

I would like to understand the math here. This doesn't follow any of the rules of weight and balance that I am aware of.

[MEXICOWANDERER]

FIRESTONE individual fill overload bag spring assists on the rear. Been there done that dept 🙂

[OnaQuest]

HiTech wrote:
If it was right even between axles, it is equivalent to adding 1000 pounds to the rig. If right over a single axle, it has the same impact on that axle as adding 2000 lbs. overall. At the least tire pressure adjustment is in order.

Really you are supposed to air up all tires on the axle for the heavier load. I like to air the outsides on dualies a few pounds higher than the inside tires for stability (up to a 5 psi difference is still within Ford specs).

Could you explain how this happens?

So, if I add 500 lbs exactly on top of each axle, it's really adding 4000lbs overall?

[OnaQuest]

HiTech wrote:
More lean is party from sidewall flex in the tire.

If there was enough sidewall flex to cause noticeable leaning in a motorhome of that size, the tire would have to be dangerously and obviously under inflated, period.

HiTech wrote:
I corrected my prior statement, remembering that you need symmetry on the axle. Apparently you decided to not quote that statement?

I posted my comments at 10:45, you corrected your statement at 11:15, am I supposed to be clairvoyant?

HiTech wrote:
No I won't quote the ford spec for pressure differential

Because you can't quote something that doesn't exist. Sorry, but I didn't think it necessary to quote the rest of your yada yada so I deleted it.

[HiTech]

More lean is party from sidewall flex in the tire.

I corrected my prior statement, remembering that you need symmetry on the axle. Apparently you decided to not quote that statement?

No I won't quote the ford spec for pressure differential but you are welcome to look it up if you are curious. Clearly tires will not all be the exact same pressure when there are 4 on an axle. You can be within the spec and have more air pressure on an inside tire (not fun for stability -effectively creating toe in), or more pressure on the outside tire. They will never be exactly equal. I have found that more on the outside is preferable, especially since hot, the inside tires tend to hold more heat and inflate higher if an attempt is made to set them to exactly equal cold pressure.

Airing up the outside tire effectively creates a slight toe out. Toyota first introduced it as a fix for their little class C's and the handling problems they had when heavily loaded. It has worked very well for me for years. Feel free do do it or not.

Jim

[OnaQuest]

HiTech wrote:
First off add air to the tires on that side in proportion to the extra weight they are carrying from the weight table for your tires. Also check that your outer dually tires do not have even a pound less air than the inners.Jim

How do you figure that adding air to the tire is going to correct, or even compensate for the chassis suspension leaning?

Significantly different air pressures in tires on the same axle can cause excessive tire wear, steering/handling and ride problems.

HiTech wrote:
If it was right even between axles, it is equivalent to adding 1000 pounds to the rig. If right over a single axle, it has the same impact on that axle as adding 2000 lbs. overall.

I thought I understood leverages and fulcrums, but the logic here escapes me.

HiTech wrote:
Really you are supposed to air up all tires on the axle for the heavier load. I like to air the outsides on dualies a few pounds higher than the inside tires for stability (up to a 5 psi difference is still within Ford specs).Jim

This sounds like more voodoo logic and I'm really confused as to what "Ford Spec's" have to do with the subject.

Can you quote the spec?

[HiTech]

If it was right even between axles, it is equivalent to adding 1000 pounds to the rig. If right over a single axle, it has the same impact on that axle as adding 2000 lbs. overall. At the least tire pressure adjustment is in order.

Really you are supposed to air up all tires on the axle for the heavier load. I like to air the outsides on dualies a few pounds higher than the inside tires for stability (up to a 5 psi difference is still within Ford specs).

Jim

[ksg5000]

Many rigs are a little off - if it's way off then I would take it into shock/suspension shop - might be easy to fix.

[Just_Jeff]

Ok - didn't think of that but it sounds pretty important! Thanks.

[HiTech]

First off add air to the tires on that side in proportion to the extra weight they are carrying from the weight table for your tires. Also check that your outer dually tires do not have even a pound less air than the inners.

Jim

Correction. Add air to both sides in proportion to the heaviest load on either side to improve handling.