Community Forums

Crasher · 12-25-2013, 11:13 AM

You are absolutely correct regarding maintenance both past and present. I used to do it all myself. My business had expert mechanics and a shop to perform what was needed. We did it all including complete transmission flushes every 50,000 miles on all of our Allison equipped trucks. I can't emphasize enough the importance of proper servicing and preventative maintenance. That should be a main consideration for anyone purchasing a used motor home. Some are just driven with little care given to the hard to get to items. If properly serviced, a MH chassis and drive line will be trouble free for the life of the coach.

ahicks · 12-25-2013, 12:57 PM

Quote:

Originally Posted by targaboat

It is all in the category of tinkering with something which is not fully understood, and which is not broken. That is in the genes of many people. There are many other items in a 14 year RV with can and should have maintenance done such as lubing the air brake stuff on the rear wheels which is often over looked. And are the slack adjuster working properly?

I don't get it, so I it's not broke. Wonderful logic.

This really has gone on long enough for me to have lost interest a few pages back, so one last comment, for what it's worth....

If you have an 1100lb side for side weight discrepancy on a coach you're weighing for the first time, and you don't think that's an issue worth investigating, I wish you well.

Merry Christmas everyone!
-Al

targaboat · 12-25-2013, 05:10 PM

I went back and analysed the ordinal weights we have from the first post which is the only real data we have available to us. The left to right and front to back data should give the same total weight and front a back weight. There is a difference of 180 for total weight. A difference of 100 for the front, and 280 for the rear. Then the left to right and front to back gives a total of 600 lb diagonally which is probably the true side to weight difference. I believe many are thinking that value is 1100 which is not really the case. I see not real problem. Besides on all of the scales I have been involved with the surface beside the scale is not at the same height which will account for much of the side difference. To be meaningful the surface the RV is sitting on must be level over all four sides. There is also validity in how you last stopped the rig which was discussed in one of the posts. Air valves are not very accurate location devices and have a relatively large hysteresis characteristic. This is probably shown by the 100 and the 280 values from the above.

I would like a picture of the front axle of the subject vehicle. This might change lots of my opinions. 23,000 lb is not heavy for current DPs but I am not familiar with the older vehicles.

ahicks · 12-25-2013, 05:34 PM

<<< Front R/3700 L/4800 >>>

You can logic your way around this any way you like, but if you look at those numbers and don't see an issue worth looking into, well... have a nice day. That's all I'm sayin...
-Al

Crasher · 12-25-2013, 06:37 PM

I guess I am one of those people that feels that if a mechanical adjustment is needed on something I own, I would rather "tinker" to get it properly adjusted before it breaks. But, to each his own.

On another forum that I frequent, it is common practice to insure that the ride height is correct before adjusting the air in our tag axles which in turn affects the steering axle weight. This is done by Power Glide and Freightliner chassis owners. It is no different for a non-tag coach. I hope the OP understands what I have tried to explain and not confused by the differing opinions expressed here. It will be up to him to sort through the chaff and decide what to do.

Like ahicks, I have said enough and will move on.

Doug

jimbo2013 · 12-25-2013, 07:43 PM

Quote:

Originally Posted by ahicks

<<< Front R/3700 L/4800 >>>

You can logic your way around this any way you like, but if you look at those numbers and don't see an issue worth looking into

Al the weights you're quoting are the first weights I did the send was

RF 3960 LF 4740

So the difference is not 1100lbs it is now 780lbs, I think when I change the ride heights in the fronts which are incorrect it will lessen that differential further.

dengraham · 12-25-2013, 08:16 PM

If you carefully read VanDiemen's posts you will realize that you first need to check the ride heights, weigh all corners, adjust left to right weights if you can, and then, in truth, put different air pressure on each corner. If one corner is carrying 300-400 more weight, it will improve your ride if you add more air but if the other side of the axle is carrying 400 lbs less then it doesn't need as much air. You will, in fact, correct the incorrect twist in the chassis by adjusting the tire pressures. Or, stated another way, by having different air pressures you will insure each tire has the same number of square inches touching the surface of the road. If you talk to some of the engineers at the tire companies they will agree with this logic (even though their charts only talk about using the higher air pressure for the whole axle).

Tireman9 · 12-25-2013, 08:33 PM

I wonder what the numbers are with nothing loaded.
I wonder what the manufacturer says about this weight unbalance and what the spec is for this unit when new.

targaboat · 12-25-2013, 09:13 PM

http://www.irv2.com/forums/f278/flor...ng-186296.html

Here is an interesting thread which applies to your project.

ahicks · 12-25-2013, 10:16 PM

Quote:

Originally Posted by jimbo2013

Al the weights you're quoting are the first weights I did the send was

RF 3960 LF 4740

So the difference is not 1100lbs it is now 780lbs, I think when I change the ride heights in the fronts which are incorrect it will lessen that differential further.

I didn't go back through all this to check, but weren't the second set of weights taken with airbags deflated, and tanks topped? If I'm remembering that right, the second set of numbers would be further evidence of incorrect ride height or some other reason for an imbalance to exist. Whatever. If it were me, and this were my coach, these numbers would be all the evidence I would need to look into it further. Maybe that's just the way this coach is, or maybe something is broken, worn, or maladjusted? You can't possibly know which until you look into it further?

If ignoring the side to side difference were going to be your approach going into it, why in the world would you bother to get a 4 corner weight? You had all the info you need for proper tire inflation with just the axle weights? Maybe people should stop wasting their time/money on individual weights? Or, maybe people that waste their time doing that are doing it because they don't understand what's going on? They should be looking at their slack adjusters or taking apart clocks or something...

Sorry Jimbo, I'm obviously out of patience here. Hopefully there's enough info here for you to proceed. It's unfortunate that all of us were not able to come to an agreement on a reasonable plan of attack regarding your issue. -Al

VanDiemen23 · 12-25-2013, 10:45 PM

Targaboat does bring up one important and possibly overlooked point. If you weigh corners using a platform scale and the height of the pavement on one side is different from the height of the pavement on the other side, then every measurement will be way the hell off. One way to take that error out would be to use just one side of the scale and turn the vehicle around, given that the pavement on one side is fairly level from front to back. If it's off in both directions then there's no way to make an accurate corner measurement off a platform scale.

jimbo2013 · 12-26-2013, 05:36 AM

Quote:

Originally Posted by ahicks

I didn't go back through all this to check, but weren't the second set of weights taken with airbags deflated, and tanks topped?

The airbags were deflated after getting lined up on the scale, then completely aired up before weighting. Yes the tanks were topped also

Quote:

Originally Posted by VanDiemen23

Targaboat does bring up one important and possibly overlooked point. If you weigh corners using a platform scale and the height of the pavement on one side is different from the height of the pavement on the other side, then every measurement will be way the hell off.

Before using the scale I got down low to look across that deck, both scales were built well, almost like a pool table.

I think the left front is heavier due to the slide, it is like that on many unnoticed for years most owners don't know it or bother to adjust it.

For now I plan on setting the (2) ride heights on the fronts which are off on quick measurement by almost an inch.

In so doing I have a 1/4" +- to play with or a total of upto a 1/2" to shift weight around.

The rear ride height looks good.

targaboat · 12-26-2013, 06:49 AM

Jimbo, you appear to be taking all this advise in stride as it should be. I am not impatient and have learned a lot from this thread. I see nothing wrong with it at all for people in general have different opinions. The fact that you have a mission with your toy does not have to apply to everyone and the people less inclined should not get excited about their coaches. I see examples of people who do nothing to their units and they seem to get alone just fine. Please keep us informed for we often never hear how things turn out.

targaboat · 12-26-2013, 08:16 AM

I have had another thought. 1 inch in 40 feet is 1/40x12 is 0.2%

I doubt that most people can detect that small of a change visually. And so far we are talking about about half of that in the height adjustments. Looking at it this way lends new consideration as to the validity of moving the RV around the scale for individual wheel measurements. I think that is reflected in the comments on airing down and up and making sharp turns in getting on the scale. Friction in the joints of the coach are influencing the measurements.

I am beginning to think that this exercise is a learning experience for not all of us, but many of us who have the patience to stick with it. You are probably into a couple hundred dollars so far at many RV service facilities.