Epiphany Gets new Axles

[87MH]

Originally Posted by HiHoAgRV

... The top graph is Airstream WithOut Weight Distribution, the next is With Weight Distribution and the bottom is the truck.....

What a great comparison - Many thanks, HiHo


I'm amazed that the Vert Acc WITH WD appears to be almost the same as the VA WITH OUT WD - I would have thought that linking the trailer suspension to the "better" (and softer) suspension of the truck (via the WD hookup) would have made more of a difference...

Also amazed that the traler did not pickup the "speed bumps" (especially WITH the WD) that were evident in the "truck" strip.

Can't wait to see the same trip post axle replacement -

BTW, how is fitment and/or replacement of the new axles coming along?

Enquiring minds want to know!

[Action]

Originally Posted by HiHoAgRV

-The shocks on my unit are ineffective. They either have the wrong damping frequency, they are completely shot or the suspension rate has shifted away from the norm and the shocks don't work at that frequency. Thus trailer bounces down the road at a consistant frequency. This may be what caused my wall damage, the consistant hammering.

-The suspension is not bottoming as this would be observed by a huge spike.

-The ride differs considerably inside the truck and the camper.

I am not clear on your statements.

Are you referring to the shocks on your trailer or the truck?

This was done before any suspension work on trailer or truck?

Other data that would be helpful would be:
time frame and distance this test took place over
the year make and model of the truck
the mileage on the truck
tire size and make for both truck and trailer
tire pressure for both truck and trailer
actual weight of truck and trailer
GCWR of truck
last time shocks were replaced on both truck and trailer

If you are referring to the ride in the truck, this brings back memories of the Ford truck commercial. Where there was a stick strapped to the cab and the frame. Then it was driven over a rough surface with the stick was centered between lights. The point was to give a visual of the smooth ride in the cab.

>>>>>>>>>>>>>Action

[HiHoAgRV]

Originally Posted by Action

Are you referring to the shocks on your trailer or the truck?

Trailer only, truck still rides like a 3/4 ton

Originally Posted by Action

This was done before any suspension work on trailer or truck?

Nope, everything is just like we have been using it for the past two years

Originally Posted by Action

time frame and distance this test took place over
the year make and model of the truck
the mileage on the truck
tire size and make for both truck and trailer
tire pressure for both truck and trailer
actual weight of truck and trailer
GCWR of truck
last time shocks were replaced on both truck and trailer
>>>>>>>>>>>>>Action

All the data was gathered on a approx 5 mile loop, same start and stop location, Saturday just before we went camping for the evening. TV is a 2006 Ram TD 3/4 ton, 60k miles (High highway usage, I think I'm the Highest Average Speed record holder on another thread ), Michelin LTX 265 17's/Marathons at 55TV/65TT psi. The weights are published for the truck, the TT was dead on top of the factory weight prior to the remodel, no weight taken since (guess +300 lbs?), 1/4 tank of water, Holding tanks empty. Original TV shocks, ???on the TT guessing original or at least well aged, no leaks.
The total amount of data taken is roughly 800,000 points per run. The TT suspension seems to have a natural frequency at 3.1hz. If the bounce was due to tire/wheel/running gear I would have seen a 8 hz, thus the observation of the shock/suspension mismatch.

[HiHoAgRV]

Originally Posted by 87MH

What a great comparison - Many thanks, HiHo


I'm amazed that the Vert Acc WITH WD appears to be almost the same as the VA WITH OUT WD - I would have thought that linking the trailer suspension to the "better" (and softer) suspension of the truck (via the WD hookup) would have made more of a difference...

Also amazed that the traler did not pickup the "speed bumps" (especially WITH the WD) that were evident in the "truck" strip.

Can't wait to see the same trip post axle replacement -

BTW, how is fitment and/or replacement of the new axles coming along?

Enquiring minds want to know!

I'll do some comparison of the pitching with and w/o WD, I expect to see the biggest different there. The truck actually rides smoother w/o wd, by the seat of my pants.
I think the trailer floats over the speed bumps then bounces for the next few seconds, unlike the truck that nails it and then settles down.

I also want to see the 'post' data, waiting on feed back from Dexter on what can be done...If I was not posting all of this, I would have torn into the install but I thought I'd wait see how Dexters response to a dealer or customer (probably the customer... ) mixup

[87MH]

Originally Posted by HiHoAgRV

Trailer only, truck still rides like a 3/4 ton...All the data was gathered on a approx 5 mile loop, same start and stop location, ....

What was the average speed on the loop? - was it about the same for all three runs?

It appears as if there are about 6 stabilized areas of similar harmonics on both of the trailer runs (events do not correlate on the truck run, though) - would it be possible to over-write on the strip the approximate speeds and road conditions on each of these 6 event horizons?

Really interesting info - especially the low g's on the "worn out" trailer axles as compared to the 3/4 ton -

A run on the truck with the 600 to 700 lbs from the tongue load on the rear end would be interesting. I had a E-350 Ford dually Cabriolet that rode as rough as a cob - until you put a thousand pound load in the bed -

[HiHoAgRV]

Originally Posted by 87MH

What was the average speed on the loop? - was it about the same for all three runs?

I appears as if there are about 6 stabilized areas of similar harmonics on both of the trailer runs (events do not correlate on the truck run,though) - would it be possible to over-write the approximate speeds and road conditions on each of these 6 event horizons?

Really interesting info - especially the low g's on the "worn out" trailer axles as compared to the 3/4 ton -

A run on the truck with the 600 to 700 lbs from the tongue load on the rear end would be interesting. I had a E-350 Ford dually Cabriolet that rode as rough as a cob - until you put a thousand pounds in the bed -

My truck rides better with the trailer than without, with the best ride being w/o wd.
Where this snapshot was taken the speed was 40 mph. The loop is in 3 sections, the 1st at 40 mph the second part of the loop was at 30 and the final section was 55 mph on a 4 lane. All section showed the same harmonic.
I shoud be able to do an overlay summary of all three runs in a 'displacement' mode, but I will have to use a different computer. The last time I did that it took 20 minutes of computation time on a dual quad core machine , my laptop will puke kilobytes out of it's usb ports and kick over dead if I try it now.

[Action]

Originally Posted by HiHoAgRV

My truck rides better with the trailer than without, with the best ride being w/o wd.

This is what I would haved guessed for a 3/4 ton vehicle. Especially with a TD. There is a bit of weight packed in the front end of that, so designing a suspension that works well w/o a load and with load becomes a challenge.

With 60K on the clock on an '06 you don't let the vehicle get much rest. Changing out the OE shocks may provide a better ride empty with a premium replacement. Another way to play with the ride charistics is to change inflation in the TV tires. It's a hassle and it does help. Or just put up with the ride when not towing.

I am a little surprised at the the better ride diff w/o the wd.

[HiHoAgRV]

For those of ya'll that have done a Dexter swap, you might recognize the highlighted spec. These axles won't be going under my trailer since I don't need a 5,200lb (axle #1) + 5,200lb (axle #2) + 500lb (hitch) = 10,900 lb GVWR...

[byamcaravanner]

Originally Posted by HiHoAgRV

For those of ya'll that have done a Dexter swap, you might recognize the highlighted spec. These axles won't be going under my trailer since I don't need a 5,200lb (axle #1) + 5,200lb (axle #2) + 500lb (hitch) = 10,900 lb GVWR...

The plot thickens! I assume this is good news or is this order number two? I have to think Andy is enjoying this.

[HiHoAgRV]

Originally Posted by byamcaravanner

The plot thickens! I assume this is good news or is this order number two? I have to think Andy is enjoying this.

Still order #1. Today was the first day I was able to look at them in the daylight and noticed the engraved '5200' on the beam. Dealer& Dexter conversations are onging...feedback is due tomorrow.

If anyone has a couple vintage single axle 'streams that need some 5200 lb axles I think I know where some might be availble...

[PizzaChop]

The dealer and I have gone over what happened, but no explanation of HOW it happened. Rather than start a usless finger pointing contest, we both agree to see how the axles can be made useable. We are both hoping Dexter will allow me to ship them back for mods, he doesn't want to get stuck with them, I would prefer to have a set that match the dimension I need.

Vern,

I'm not sure this is a useless finger pointing contest, considering the $$ amount of the error. (Not only were your OB measurements off, but the axle rating as well.)

As I like to say around the pizza shop...

There are really only 3 reasons for mistakes...

Lack of training

Lack of experience

Lack of attention

When a mistake is made in my business (and unfortunately, it does happen), the feelings of the person responsible are secondary to the importance of determining WHY it happened. (This has gotten me into hot water at times, but I always manage to smooth things out later.)

I can't stand it when things go wrong after I have done everything in my power to assure that they don't. (As I like to say...procedures are in place for a reason.)

I almost ordered from a local trailer manufacturer and he was adamant about wanting to come out and measure the axles himself, as he knew the ramifications of a wrong measurement.

When I did finally order (through another forum member), I faxed a separate order sheet to the Dexter facility to make sure that the measurements matched what was ordered. (I was absolutely paranoid about going through multiple channels for fear that the specs would somehow get messed up)

The dealer should be able to produce a copy of the order form (with your signature) which was faxed to the factory, and this should tell the tale.

I cannot imagine how the factory would take these back and "re-engineer" them to the proper specs (at no cost), and still send them out with a blessing.

A more likely scenario is to order a set of bare axles (proper specs, of course) and salvage your hub assemblies from the wrong axles.

If adequate blame cannot be ascertained, perhaps the dealer would be kind enough to split the cost with you.

I have to think Andy is enjoying this

I doubt it, but could you blame him?

I wish you the absolute best in resolving this thing. You have displayed more patience and good cheer (at least on the forum) than I probably would've.

[HiHoAgRV]

More information I didn't expect...not with the axle order, but with the logged data.

When I tow w/o wd, it seems the bumps result in more TV pitching. Like wise I assume the wd binds the TV and TT together (as it should) and one of the effects would be less angular pitching (bobbing?)
Guess what-No such effect inside the TT. The attached shows one of the events with the yellow being TT pitching w/o wd and the red being with wd. No statistical difference with or w/o wd

[markdoane]

Nice data. No significant difference at what confidence level?

As I look at the chart there does seem to be slightly more maximum deflection in the negative direction. Of course the yellow might be laying over the magenta line and obscuring it.

Are you OK with sharing the data? This is fascinating.

[HiHoAgRV]

I'll gladly share the data files but be warned, they are large. 6 meg per run, 34,000 records of the following;
LAT, LON, DIST(m), TIME, SPEED, XACC, YACC, ZACC, ROLL, PITCH, ROLLRATE, PITCHRATE, YAWRATE
(I sized the run so the data can still be imported by excel for manipulation)

One of the problems I have with sumizing the 3 runs is the Airstream data does not have GPS logs (No antenna extension ). Therefore some of the fields do not have the data I would normally use to sync the various runs. This limits my ability of removing gyro drift over the length of the run.
The three main things that I am interested in are-
What is the effect of WD? (assumption; rougher ride, less pitching)
Are the shocks effective? (assumption; not gonna make a big difference)
Do new axles ride different than new? (assumption; old axles bottom out and ride stiffer)
I have the answer to a couple of these and need to get this huge mess on my new axles sorted to continue.

PM me if you want the files.

[Action]

I agree with your assumptions ... however,

the part I dissagree with is your assumption about new shocks on a new axle. (Assuming you run the test on the new axle with and with out new shocks.) My assumption (or therory) is new shocks on a new axle will make a difference that can be felt barely and can be measured definately. The real question in my mind is if the difference worth the cost. (You define this as a big difference) Since that is a value judgement, different people will have different thresh holds as to the answer. The risk is about $80 for shocks and new brackets on the new axle. Not a great cost and my therory is the result will not be all that great either.

I further believe that the shocks on the TV are due for replacement. You have a base line test for that with the existing shocks. I assume that there will be improvement there too. Course this is all your funds and not mine however with 2 to 3 years of use and 60,000 miles IMO those shocks have reached the end or near the end of their service life.

>>>>>>>>>>>>>>Action

[HiHoAgRV]

Originally Posted by Action

I agree with your assumptions ... however,

the part I dissagree with is your assumption about new shocks on a new axle. (Assuming you run the test on the new axle with and with out new shocks.) My assumption (or therory) is new shocks on a new axle will make a difference that can be felt barely and can be measured definately. The real question in my mind is if the difference worth the cost. (You define this as a big difference) Since that is a value judgement, different people will have different thresh holds as to the answer. The risk is about $80 for shocks and new brackets on the new axle. Not a great cost and my therory is the result will not be all that great either.

I further believe that the shocks on the TV are due for replacement. You have a base line test for that with the existing shocks. I assume that there will be improvement there too. Course this is all your funds and not mine however with 2 to 3 years of use and 60,000 miles IMO those shocks have reached the end or near the end of their service life.

>>>>>>>>>>>>>>Action

My assumption on not needing the TT shocks could be wrong, we'll see how the testing goes, I did order the shock brackets after all . I originally assumed the test would show the shocks had no effect but I'm not so sure the test will bear that out.

As far as the truck, it's outside the scope of this study.

[87MH]

Originally Posted by HiHoAgRV

More information I didn't expect...not with the axle order, but with the logged data.....The attached shows one of the events with the yellow being TT pitching w/o wd and the red being with wd. No statistical difference with or w/o wd

What about the Y Acceleration - do you have the same duplication of graph characteristics on the Y axis as with the pitch? I always thought that "Y" vibration and movement is what did the most destruction - or do you think that pitch is the main culprit?

I do understand how pitch could be important, since the true "Y" movement is not amplified over the trailer height, but pitch amplitudes would be much worse at the + 7' level than at floor level.

Can't wait to see the same run with the new axles.

Wouldn't it be a hoot if the new run would show no improvement at all!

Man, you NEED to get the GPS working inside the trailer.

[azfiredog300]

What about the Y Acceleration - do you have the same duplication of graph characteristics on the Y axis as with the pitch? I always thought that "Y" vibration and movement is what did the most destruction - or do you think that pitch is the main culprit?__________________
Dennis

I think my head just exploded!

[HiHoAgRV]

Originally Posted by 87MH

What about the Y Acceleration - do you have the same duplication of graph characteristics on the Y axis as with the pitch? I always thought that "Y" vibration and movement is what did the most destruction - or do you think that pitch is the main culprit?
I do understand how pitch could be important, since the true "Y" movement is not amplified over the trailer height, but pitch amplitudes would be much worse at the + 7' level than at floor level.

My nomenclature uses "X" fore and aft/Pitch, "Y" left and right/Roll(Lean) and "Z " is up/down/yaw(turn)

My main interest for pitch revolves (ha! get it!) about the ends of the trailer and the results of them flopping up and down. I assumed the flopping would be reduced with WD, thus a justification to use it (minimize rear end issues, bikes on the bumper{ }).
I might have a chance in the next few days to look at the rolling axis and see if there is anything there, my assumption is no difference, w or w/o wd.

[HiHoAgRV]

As soon as posted the last response my brain jumped back in gear and reminded me it was easy to show roll over the same spot. No math analysis so far, but boy do both lines look similar!