Do you raise your tag axle?

[Ivylog]

Raising the tag axle came up in a non-related thread so I thought I would start a new one.
I did raise when making several tight turns when I first had our 04 dynasty…15 years ago. About the same time I started seeing spread axle trailers were the axles are 8 feet apart, not 44”. Also our tires age out, not wear out, and I cannot tell any difference in the turning radius raising the tag axle, or not.

The drive axle on our 08 Navigator is at 23,000 pounds so raising the tag would overload it by almost 50%…not a good idea. Bottom line, I haven’t raised my tag axles in over a decade. Your mileage may vary.

[Frank McElroy]

Whether a coach has the ability to actually lift the tag off the ground or to just release the pressure from the tag depends on the coach model and engine weight configuration.  The drive axle can carry a lot more weight and so can the tires if you a moving under 5 mph.  But there are limits.

On my 2008 dynasty with an ISL, the coach came from the factory with a tag air lift.  If drive axle ride height is adjusted properly, the tag will lift off the ground about 2" and yes, a see enough difference in turning radius to allow me to back into my drive with just one swing.

On many large Sigs with an ISX engine, that would be way too much weight for the drive axle.  So when you press the tag lift button, it just released air pressure from the tag axle because it doesn't have tag axle lift diaphragms.

[Nevada Rob]

I never raise mine. I don't see any wear marks on the tires or in the street and I make a sharp turn to back into our street. I mean steering wheel cranked all the way over. It is a nice option to have but I am with you in not overloading the drive axle. I am going to weight my coach tomorrow fully loaded with fuel, water, LPG, food and all gear in the bays. Along with our enclosed trailer loaded with the toys. At 72 ft. long I hope the scale weigh pads are spaced out right to get may axles.

How much weight is on your tag axle? 

 

[Ivylog]

7 minutes ago, Nevada Rob said:

How much weight is on your tag axle? 

10,500 on the tag and 14,400 on the steer…have gone to 315s on the front.

[Johnny Mo]

A few years ago when we got our Dynasty I had to take it to the DMV for a VIN certification. The entrance driveway had a tight turn, so I thought hey I should lift the tag... with the tight turn was followed by a steep incline, halfway through the incline I could feel the tow bar digging into the asphalt. When I got parked and checked out what was dragging and found there was no damage, except a gouge in the asphalt. I thought to myself what a dumb as#@! move. Since then I only lift the tag when backing into a tight space at a CG

[96 EVO]

Mostly just raise the tag when making a sharp turn in reverse.

Usually reversing into a back-in site.

[Nevada Rob]

Wow 10,500 on tag and 23,000 on the drive is right at legal limit for the combination of tandem axles. I am surprised it is that heavy. Are your front hubs/bearings oil bath or packed grease? Do you know what the MFG rating is for the front axle as well as the weight rating for the wheels? Did you buy new front wheels for the 315's? 

[Ivan K]

I know that lifting the tag gives me at least 2 feet of tighter turning radius in 180 degree turn. Saved me from running into deep sand coming out of a tight dump station circle the second time. First time, without lifting it, it got a bit sketchy. I don't lift it in gravel, it just makes a deep groove as the wheels stop turning. I can definitely see the thread edges rounding on the tag tires. Not that it is a problem. My tag lifts off the ground on pavement. In gravel the drives just sink deeper.

[KevinH]

I only raise my tag when I’m on concrete. If I don’t I definitely see a lot of rubber.

[willbo777]

I almost never raise my tag.  My drive is very close to the 23,000# as it is, loading it up with the extra tag weight makes me a bit uncomfortable.  Actually can't even think of the last time I raised it.

[Ivylog]

5 hours ago, Nevada Rob said:

Wow 10,500 on tag and 23,000 on the drive is right at legal limit for the combination of tandem axles.

Front axle rated 15,160 and rims rated 7600 or 15,200 for a pair. Not sure what the 34,000 tandem commercial truck limit has to do with our weights or even the 20,000 lb limit on a single axle??? In 2012 a Highway bill made 24,000 lbs on a single axle legal for MHs and buses. Several times I’ve had the “Truck must enter the weigh station” sign come on at the newer station that weigh you on the fly… I wave as I blow on by.

Ive been using 315s on 8.25” rims for 10+ years and close to 100K miles… no wear issues and I decrease the psi 12 lbs. Yes, fewer manufacturers are listing 315 on 8.25” rims today. The issue is not the width of the rim, it’s the 7600 lbs max rating of the 8.25” rims. If your axle weight was over 15,200 you would need to go to 9” rims for the higher weight rating. 315s on 8.25 used as duals , have always been approved since you are not going to even come close to exceeding the 2 rim’s 15,200 combined rating… 30,400 lbs on a single axle.

[Ivylog]

6 hours ago, Nevada Rob said:

Are your front hubs/bearings oil bath or packed grease?

Grease but at 50K miles I took the caps off and drilled/tapped 1/4” pipe plugs in the ends. Put approx 1/2 cup of 90 gear oil in as I was leaving on a trip. The problem with grease is it hardens over time and the tapper bearings tend to push the grease out of the bearing. Softening the grease up with 90 weight let’s it flow some but not enough to get past the wheel seals. 
 

Haven’t repacked trailer bearings in 40 years as long as the bearings are tight. Put 90 weight in the cap and slap it back on. Your mileage may vary.

[96 EVO]

That may get some fresh grease on the outer bearing, but not the inner bearing!

Edited September 2, 2021 by 96 EVO

[Ivylog]

6 hours ago, 96 EVO said:

That may get some fresh grease on the outer bearing, but not the inner bearing!

So oil bath only lube the outer bearing?

[96 EVO]

Oil bath hubs will lubricate both.

[planodp]

Have anyone converted to oil bath hubs? Oil bath hubs must be a better option since it's use in all newer trucks. If anyone did this conversion what is required to convert over to oil bath hubs? Thanks 

[dl_racing427]

50 minutes ago, planodp said:

Have anyone converted to oil bath hubs? Oil bath hubs must be a better option since it's use in all newer trucks. If anyone did this conversion what is required to convert over to oil bath hubs? Thanks 

I converted my Dynasty years ago.
You can research what is needed for your particular hubs, and get everything from a truck supply house.

You do have to remove the hubs and clean out ALL the grease, as well as install an oil seal in place of the grease seal, or it will leak into your brakes.

Once it's done, all I have to do is pop off the wheel center cap and look at the oil level in the clear hub covers.

I used Lucas hub oil, and I'll likely never accumulate enough miles for it to need changing.

They also make a different locking kit for the hub nuts, to allow for preloading the bearings instead of running clearance.

I devised a way to do it with the existing double nuts, but it involved a dial indicator, and quite a bit of measurements to make sure I didn't set them too tight.  (Hint: The double nuts have some play in the threads, and you have to account for this when tightening the outer nut, as it pushes the inner nut in further, and can result in too tight bearing preload.)

Edited September 3, 2021 by dl_racing427
Add info.

[willbo777]

I had Josam's change ours out.  It was only slightly more money than repacking the bearings with grease.  I don't remember the actual cost, it was some time ago.

[moxy1962]

On 9/1/2021 at 11:46 AM, Ivylog said:

10,500 on the tag and 14,400 on the steer…have gone to 315s on the front.

I expect your coach is well balanced you weights are very close to limits, wouldn’t take much imbalance to overload your individual hubs and tire combinations

[Hypoxia]

I raise the tag frequently when on soft ground and when I need a tight turn radius.  It takes a few minutes to come up and for the drive air bags to adjust height so I don't do it on the fly.  On soft ground the tag has to be raised so the drives don't spin.  It also allows more wood to be added for levelling.

[dl_racing427]

You also need to consider the additional side loading caused by dragging the tag and drive tires around sharp turns.

I was on a job earlier this year, where the site had hired two large tour buses to shuttle employees to/from the parking lots.
One driver told me they corded a set of tag tires in just a few days, and a few hundred miles.  These buses didn't have the ability to raise the tag.
After going through several sets of tires, he actually chained the tag up to force the drives to carry the whole weight. LOL

[Ivylog]

And we worry about raising the tag because of excessive tire wear???

[moxy1962]

17 minutes ago, Ivylog said:

And we worry about raising the tag because of excessive tire wear??

Those large axle spread tires skid significantly more that tag axles 

[moxy1962]

1 hour ago, dl_racing427 said:

You also need to consider the additional side loading caused by dragging the tag and drive tires around sharp turns.

I was on a job earlier this year, where the site had hired two large tour buses to shuttle employees to/from the parking lots.
One driver told me they corded a set of tag tires in just a few days, and a few hundred miles.  These buses didn't have the ability to raise the tag.
After going through several sets of tires, he actually chained the tag up to force the drives to carry the whole weight. LOL

When I'm slow speed maneuvering I throw the switch and take the weight off the tags