So that’s why my front axle is so heavy

[fla tom]

Originally Posted by Cutch

This adjustment would also be nice if you happen upon snowy road conditions like we experienced this May in Yellowstone. I too think my tag is not allowing enough weight on the drive axles. Fully loaded I can break the drive wheels loose on wet roads during a hard take off after crossing over the stop bars at an intersection. (Stop Bars are the large white stripe that goes across the road). This indicates to me that there is not enough weight on the drive axles? Would be extremely beneficial to have a valve in the drivers area that can be adjusted on the fly depending on road conditions.

I have been reading this thread with great intrest and intend to do this mod. Your post has made me realize how much it is needed.2 months age we were at a stop light in the rain on a slight uphill grade when the light turned green I tried to start forward motion the tires broke free and the traction control kicked in.

[DeeGee]

I feel that in general, and certainly with some models, Entegra is dropping the ball by not specifying correct pressures. While we all would like a means of adjustment, in reality it is not required. For any given floor plan, Entegra could set the pressure to give appropriate ratios between the drive and tag axles, while reducing the weight on the steer axle, but they simply accept what Spartan gives them. That, in my opinion, is a gross dereliction. There is no excuse to sell me a coach where filling the fuel tank puts my front at max gross, even with very little in the basement, especially when it could be mitigated. I'm sure that once I figure out the correct balance I won't have to touch it, but d@%n it, it should come that way from the factory.

I'm exasperated, as I just spent the day rearranging the contents of the basement, trying to get something legal to drive on the highway. And my dishwasher just broke again - I looked at it, and the new part that NIRVC supposedly installed turns out to be the old part, with a glob of silicon caulk to attempt to glue it together. Bah. I need another drink.

[757driver]

Originally Posted by DeeGee

I feel that in general, and certainly with some models, Entegra is dropping the ball by not specifying correct pressures. While we all would like a means of adjustment, in reality it is not required. For any given floor plan, Entegra could set the pressure to give appropriate ratios between the drive and tag axles, while reducing the weight on the steer axle, but they simply accept what Spartan gives them. That, in my opinion, is a gross dereliction. There is no excuse to sell me a coach where filling the fuel tank puts my front at max gross, even with very little in the basement, especially when it could be mitigated. I'm sure that once I figure out the correct balance I won't have to touch it, but d@%n it, it should come that way from the factory.

I'm exasperated, as I just spent the day rearranging the contents of the basement, trying to get something legal to drive on the highway. And my dishwasher just broke again - I looked at it, and the new part that NIRVC supposedly installed turns out to be the old part, with a glob of silicon caulk to attempt to glue it together. Bah. I need another drink.

My guess is Spartan would wash their hands of any chassis warranty claims for handling, shocks alignment, etc, etc if Entegra were to mess with Spartan’s engineering of the tag/drive weight ratio. I am sure it is something that Entegra would not touch with a 10’ pole.

[Gordon Dewald]

Originally Posted by Cutch

This adjustment would also be nice if you happen upon snowy road conditions like we experienced this May in Yellowstone. I too think my tag is not allowing enough weight on the drive axles. Fully loaded I can break the drive wheels loose on wet roads during a hard take off after crossing over the stop bars at an intersection. (Stop Bars are the large white stripe that goes across the road). This indicates to me that there is not enough weight on the drive axles? Would be extremely beneficial to have a valve in the drivers area that can be adjusted on the fly depending on road conditions.

Set the tag dump on auto and until you get up to the minimum speed the tag will be dumped with extra weight on the drive.

Why in the world would you want to accelerate that hard on a wet surface?

[fla tom]

Originally Posted by Gordon Dewald

Set the tag dump on auto and until you get up to the minimum speed the tag will be dumped with extra weight on the drive.

Why in the world would you want to accelerate that hard on a wet surface?

We do not have auto tag dump(which on Winnebago from memory works when going in reverse) I can assure you I was not “accelerating that hard” when my drive tires spun and activated the traction control.pushing the tag dump at every wet stop light would be onerous.

[Gordon Dewald]

Originally Posted by fla tom

We do not have auto tag dump(which on Winnebago from memory works when going in reverse) I can assure you I was not “accelerating that hard” when my drive tires spun and activated the traction control.pushing the tag dump at every wet stop light would be onerous.

Sorry - our Freightliner chassis has the option to set the tag to dump automatically in forward at less than 8 mph. Once it is turned on it stays on until the engine is shut off or it is turned off manually.

[fla tom]

Originally Posted by Gordon Dewald

Sorry - our Freightliner chassis has the option to set the tag to dump automatically in forward at less than 8 mph. Once it is turned on it stays on until the engine is shut off or it is turned off manually.

I miss that feature it was nice

[757driver]

Finally got to a scale today and here are the results.

Original Axle Weights

Tag axle air bag pressure 90 psi

Front 17120 lbs
Drive 15540 lbs
Tag 11000 lbs

Total 43660 lbs

Front axle over weight by 120 lbs.

First Weigh

Tag axle air bag pressure 50 psi

Front 16460 lbs
Drive 20560 lbs
Tag 6800 lbs

Total 43820 lbs

The 50 psi pressure for the tag axle was just a guess and it turned out to be close but as you can see the drive axle was now over weight by 560 lbs.

Second Weigh

Tag axle air bag pressure 55 psi

Front 16620 lbs
Drive 19500 lbs
Tag 7700 lbs

Total 43820 lbs

Success at last! With full fuel, full water, and packed for travelling all three axles are under their respective gross limits and a whopping 3300 lbs has been removed from the tag axle.

[Gasman 2]

Don, glad you got the results you were hoping for. I'm sure you feel it was worth the effort especially since your front axle weight is now under the rated capacity. Thanks for reporting back with the results.
Richard

[bevandtomH]

Don, I can’t remember if you commented on the ride with regards to porpoising in the other on going thread.
Do you have that issue as well?
If so, any change?
Can’t help but think these things are all interrelated.
Great job, btw.

[Smitty77]

Don - And this is with a new battery weight diet too!

Not trying to pick on Entegra. But do feel they as the integrator and builder of teh coach. Should either provide the spec's to Spartan for specific chassis they are buying for each model/length combination. And or, as part of build process, set the pressure that provides the best overall balance for each specific model and length combination. They are they are the builders. They're engineering is responsible for the full integration of the sold to the customer package. And IMO, these are safety related items. And overweight Tag, would have more stress on a tire, which could cause a higher odd's for blowout's. Plus, they have legal responsibility to certify the coach is compliant with axle ratings.

Glad you got your's sorted out. And this info can help others with awareness of the potential need to have their's recalibrated.

Best to all of you from a SOB owner. Drive safe, have fun,
Smitty

[96 Wideglide]

Originally Posted by 757driver

Finally got to a scale today and here are the results.

Original Axle Weights

Tag axle air bag pressure 90 psi

Front 17120 lbs
Drive 15540 lbs
Tag 11000 lbs

Total 43660 lbs

Front axle over weight by 120 lbs.

First Weigh

Tag axle air bag pressure 50 psi

Front 16460 lbs
Drive 20560 lbs
Tag 6800 lbs

Total 43820 lbs

The 50 psi pressure for the tag axle was just a guess and it turned out to be close but as you can see the drive axle was now over weight by 560 lbs.

Second Weigh

Tag axle air bag pressure 55 psi

Front 16620 lbs
Drive 19500 lbs
Tag 7700 lbs

Total 43820 lbs

Success at last! With full fuel, full water, and packed for travelling all three axles are under their respective gross limits and a whopping 3300 lbs has been removed from the tag axle.

Excellent results! Welcome to the world of operator adjustable axle loading !

[757driver]

Originally Posted by bevandtomH

Don, I can’t remember if you commented on the ride with regards to porpoising in the other on going thread.
Do you have that issue as well?
If so, any change?
Can’t help but think these things are all interrelated.
Great job, btw.

No problem with porpoising either before or after the change.

[757driver]

Originally Posted by Smitty77

Don - And this is with a new battery weight diet too!

Not trying to pick on Entegra. But do feel they as the integrator and builder of teh coach. Should either provide the spec's to Spartan for specific chassis they are buying for each model/length combination. And or, as part of build process, set the pressure that provides the best overall balance for each specific model and length combination. They are they are the builders. They're engineering is responsible for the full integration of the sold to the customer package. And IMO, these are safety related items. And overweight Tag, would have more stress on a tire, which could cause a higher odd's for blowout's. Plus, they have legal responsibility to certify the coach is compliant with axle ratings.

Glad you got your's sorted out. And this info can help others with awareness of the potential need to have their's recalibrated.

Best to all of you from a SOB owner. Drive safe, have fun,
Smitty

Smitty,

I hear what you are saying but Spartan puts out one standard MM chassis for all the manufacturers that is within limits on all three axles and leaves it up to the manufacturers to keep it there. One thing Entegra did a few years back was to move the batteries from the front to the rear of the basement and Spartan also moved the three air tanks fron behind the generator to between the drive and tag axle. They both knew they had a problem with the weight on the front end and instead of upgrading the front axle to an 18000 lb version as Newmar did they found it cheaper to shift weight but with limited results that did not account for every model.

My gut feeling is that what ever Spartan is using to proportion the psi from the drive axle to the tag axle is not consistent or is failing as time goes by and is allowing more pressure to the tag axle air bags.