Two issues - the rear U-joint and Travel Mode

[David T. Richelderfer]

1> In the past year I have noticed the RV did not want to enter Travel Mode, but each time eventually did enter Travel Mode after a few minutes or after traveling a city block or so.
2> This past Winter while in Yuma the RV lost its rear U-Joint on the drive axle.  This U-Joint is the one between the transmission yoke and the rear end of the drive line.  The bolts that hold the U-Joint end-cups in place had been damaged to the point the bolt's locking mechanism had broken, and the bolts backed out of the yoke.  Thus, one end-cup fell off and it wasn't long until the U-Joint completely disengaged.  We drove 1,250 miles from home (Hermiston, OR) to Yuma, got parked in our rental lot, and didn't move for 3 to 4 months.  But when we went to back out of the rental lot in February, that U-Joint fell apart on the street within 50 feet of the rental lot's entry gate.  We, of course, didn't know the U-Joint was failing, but our neighbors who happened to be nearby saw the end-cup rolling on the street as we pulled away.  We got about one mile before it completely disengaged rendering the RV immobile and sitting on 48th Street not far from the Yuma Foothills' Las Barrancas Golf Course.  Good Sam located a mobile repair guy who fixed the U-Joint and we got back to the rental lot.
3> Now we have returned home, but on the way home at the Mini-Mart/Gas Station at Schurz, NV, 38 miles South of Fallon on US-95, the RV again would not enter Travel Mode.  To get going, I manually raised the RV to as close to its travel height as I could guess, and we continued home without further incident.
4> Now at home, I have taken the RV to Eagle-Freightliner, and asked for both U-Joints and slack-adjuster axle to be checked; and the Travel Mode issue to be repaired.  The repairman said:
     a> the rear U-Joint has been slightly damaged by, what appears, the tag axle cross-member raising up too close allowing the U-Joint bolts to bang on the cross-member, and
     b> the ride height linkage, adjusters, and associated air valves aren't functioning.  He opened the HWH Control Box and checked for power at various points.  The auto and manual leveling functions work fine.  It's only the Travel Mode function that's not working.  The HWH Control Box is receiving power and the Travel Mode fuse is good, but the Travel Mode fuse is not getting input power.  Thus, there appears to be a break of continuity in the HWH Control Box BEFORE the Travel Fuse.

So what do I do?

1>  The repairman has talked to HWH, and HWH thinks the circuit board is bad.  Of course, being so old, HWH does not have any.  Should I risk sending the circuit board to HWH hoping HWH can repair it?
2>  Should I call Ken at BCS to discuss both issues noted above and see about getting an appointment at BCS?  I am thinking BCS probably has the most "local" knowledge of both issues to more properly make repairs, and may have HWH circuit board on the shelf.
3>  Should I take the Eagle-Freightliner's repairman's alternative to have a manual Travel Mode switch installed, and forget trying to repair the circuit board in the HWH Control Box?  The repairman thinks there is a chance the Travel Mode issue is related to the U-Joint issue because the RV doesn't get into Travel Mode properly.

[Mike Shumack]

what model HWH do you have?

There are some parts available here http://www.nwrvsupply.com/category/158.html

I would trust BCS over the mechanic you have now. I don't see how the HWH issue and the u-joint problem are related - unless... on my coach the rear HWH valve bank is located above/near the transmission output shaft - so if a u-joint cup flew out possibly it could have hit the HWH Travel solenoid or wiring. Has this area been inspected carefully.

I personally would not have the system rewired or by-passed unless there is no other choice.

If you have the HWH 2000 series, I have a troubleshooting guide. It's too large to attach to this post. Maybe it is availble in the Members library (it's publication ML31034 /M191.0024, 06May04) PM me if you want me to e-mail it to you.

[Joel Ashley]

I’m almost always a fan of repairing boards, as a nano-cracked solder point has turned out all too often to be a culprit for me, and not much else is easier to fix... just difficult to find.  And a capacitor, resistor, or diode are not exactly an arm and leg expense.  If you can get the board to an electronics tech, local or found online, that would be a primary option.  If HWH offers such, consider it.  Otherwise, yeah, call Ken or the BCS Parts office.

Joel

[David T. Richelderfer]

I have been in contact with Ken at BCS.  With second-hand knowledge from me relating the Eagle Freightliner tech's explanation, Ken said he would have the HWH board extracted and sent to HWH for diagnosis and repair.  Thus, earlier in the week I authorized that with Eagle Freightliner.  Pursuant to the U-joint issue, the tech thinks it may be related to the lack of travel status in the HWH system.  My thinking from the tech's explanation is if the coach isn't riding high enough on the bags, then the tag axle cross member may be banging on the U-Joint on bumps, etc. while traveling.  Ken seemed to recall from his experience that this type of damage has happened on other Monaco built coaches.  But Ken did not remember if Monaco had a fix and he was going to ask Sean (in the BCS Service Department) if he recalls a fix.  Outside of a fix, Ken mentioned perhaps a stop could be installed to prevent it from happening in the future.

The coach is in the shop along with all its manuals, so I will have to go to the shop to see if I can locate an HWH model number.  I assume by now the shop has removed the circuit board and sent it to HWH.  We'll see.....

[steve zannella]

David

I had HWH install air leveling on my coach a few years ago and they had problems with u-joints rubbing on the upper frame when testing the system at max ride height and on the tag cross axle when in max low ride mode. Apparently as you have experienced the bolt heads on the U-joint caps were the first point of contact to rub on the chassis. It was also noted that some rubbing had already occurred before the HWH installation so we replaced the cap bolts.
The chassis max limit straps were a potential source of the problem.
I had previously noticed on two occasions that unusual clunking sounds came from the rear of the coach when engaging the Jake brake almost like axle wrap I used to get on 57 ford.
Anyhow, HWH had  to reprogram the control board that prevented driving at any speed in either of the max modes.
One of the main features that I wanted from the air system was to raise the coach at low speed to avoid curbs and other obstacles.
So I went to Source Engineering in Coburg and had them install shorter chassis limit straps to prevent u-joint rubbing at max ride height. HWH then reprogrammed the control board to allow max ride height.

Steve

[David T. Richelderfer]

Steve - My understanding is the U-Joint damage can occur only when the coach is down or low on its airbags and/or the tag axle has been raised to its high position.  The tag axle cross member is horseshoe-shaped such that the cross member goes below the driveline and U-Joint.  Thus, either the coach has to stay above the cross member (that is, must stay at least somewhat up on its bags) or the cross member has to stay below the driveline and U-Joint (that is, the tag axle cannot be raised too far).

The reprogramming by HWH to limit lowering the coach by limiting deflating of the airbags or installing stops to limit raising the tag axle both sound like logical ideas.  Also, the U-Joint and cross member contact with resulting damage to the U-Joint occurring when the coach is lifted to the top of the airbags is something I had not been told about or considered.

Per your post, it sounds like HWH has heard of the problem and may have some suggestions for a fix.  Since my HWH circuit board has already been sent to the HWH headquarters, I may as well wait until I hear something.

Thank you...

[steve zannella]

David

HWH ran several test driving the coach on an elevated rack showing me the u-joint rubbing on the chassis cross member with max bags inflated and rubbing on the tag axle with bags deflated.

I had to agree to their concerns although I was not happy. We agreed to have chassis limiter straps installed to limit max raise so the U-joint would not rub but for max lower, no solution was discussed and from my perspective the rubbing was much more severe and no solution was apparent.   In both cases their immediate solution was to disable any max or minimum ride height in the computer.

After installing chassis limit straps HWH provided me with a new computer that only disabled max lower in drive mode.

From HWH's perspective it was a major safety problem if the u_joint should fail I could lose my jake brake or worst drop the drive shaft.

I'm not sure as to why my coach was affected this way. Certainly many HWH systems were installed on Magnum era coaches although Beaver did the installs. HWH still had the original shop drawings for my coach and no notations indicated a problem.
So maybe Beaver dealt with the problem and not HWH.

[Mike Shumack]

I was doing a little reading on this subject in the HWH manual - and wanted to point out (something I was not aware of, that) the air-solenoids on the HWH manifolds are all "normally closed" (when no power is applied there is no air flow through the solenoid). So if the Travel solenoids are not getting 12V they will not open and will not allow the "height control valve" to control air pressure to the air bags. I think it would have been better if the Travel Solenoids were normally open, then a HWH controller failure would have at least let the coach level and drive normally - but that is not the way HWH designed the system.

Since there are HWH Travel solenoids at the front and rear of coach, and tag axle, it is unlikely that all the Travel Solenoids have failed - it much more likely that the HWH controller has failed - as your mechanic suggested.

On the attached diagram, you can see the air flow through the travel solenoids to the air bags.

With that said, maybe having a by-pass switch wired in to provide 12V to all the Travel solenoids (in event of HWH system failure) to allow coach to go into travel mode, is not such a bad idea. I then would only be concerned over what would happen if you had this by-pass switch On (and forgot about it) and then went into Leveling mode.

But hopefully your HWH board can be repaired or replaced and you wont need to do the by-pass switch.

Good luck

[Mike Shumack]

Just to add, if the Tag Axle is "lifting too high", the chain that lifts the Tag can be lengthened one link (on each side) so the axle does not lift as high.

In the attached photo, I drew the mechanism at the bottom of page to show how the lift works. Basically, there are two arms (made of tubular metal), one on each side of coach, that do the lifting. When air is applied to the lifting chamber (it looks like a type #30 service brake chamber) the rod extends out of the chamber and pushes down on one end of the lift arm causing the Tag axle to lift.

[David T. Richelderfer]

I have been in contact with the HWH headquarters in Iowa.  The response I received is that HWH will either repair the control board or replace it.  HWH seemed to indicate a guarantee that the control board will work like new when it's replaced in the Marquis.  We did not discuss timing to get the control board back to my shop nor what the HWH price might be for a repaired versus replacement board.

Once the board is back in the Marquis and verified correctly operational, we will then attack the issue of the U-Joint yoke and end-cap bolts striking either the chassis or tag axle cross member.  So... repairs are moving forward - slowly.  I am glad I have no travel plans for a few months, although I believe the Marquis will be ready for a trip much sooner than that.

[David T. Richelderfer]

This post should serve to wrap-up this chapter of the continuing saga of owning a high-end coach.

The Travel Mode problem was fixed by sending the circuit board to HWH.  The HWH charge for that repair was $86.38.  Unfortunately, the charge from Eagle-Freightliner for diagnosing the problem, removing the circuit board, sending it to HWH, and reinstalling the circuit board was just under $1,100.  That seems a bit high to me, but reading the description showed substantial tracing of wiring and checking electrical continuity between the control panel, the circuit board, and solenoids.

I asked Eagle-Freightliner to closely inspect the U-joints and driveline after having the rear U-joint fail and need repairs/replacement while in Yuma, AZ.  You will recall there was also damage to the yoke on the transmission where the rear U-joint was attached.  During the return trip from Yuma to Oregon, the new rear U-joint cap bolts again experienced extensive damage and required replacement.  My understanding is the bolt heads we rounded severely and were very difficult to remove.  Eagle-Freightliner's charge for this assessment and repair was over $500.

I asked Eagle-Freightliner to check and replace the air dryer cartridge.  The cartridge was "full."  Of what I don't know; I am guessing it was full of water.  The cost to inspect and replace the desiccant cartridge was about $100.

I asked for the SCA "filter" and hoses to and from the engine to be removed and to plug the hose connection points on the engine.  This cost was about $75.

The chassis, especially the U-joints and driveline, were greased.  This cost was about $60.

After the HWH circuit board was repaired and replaced, I asked for an analysis of the U-joint hitting either the chassis or tag axle cross member.  The airbag heights were measured while in Travel Mode and looked to be 8.5" front to 9.5" rear.  In Travel Mode this gave good clearance for the U-joint from hitting.  They checked U-joint clearance with the airbags deflated and determined the U-joint could hit the chassis above the driveline.  With the airbags at full height, all was good.  The cost for this inspection was about $75.

Adding parts and supplies the total bill was $2,120 including about $1,900 of labor.

[Mike Shumack]

After the HWH circuit board was repaired and replaced, I asked for an analysis of the U-joint hitting either the chassis or tag axle cross member.  The airbag heights were measured while in Travel Mode and looked to be 8.5" front to 9.5" rear.  In Travel Mode this gave good clearance for the U-joint from hitting.  They checked U-joint clearance with the airbags deflated and determined the U-joint could hit the chassis above the driveline.  With the airbags at full height, all was good. 

Did you confirm in your Owner's manual that those air bag settings are correct for your coach? The '05 Patriot manual says the ride height is the same for front and rear, at 10". I recognize that our coaches are different models so the height settings may be different - I just don't trust repair shops to have the correct specifications for everything that comes into their shops.