Author Topic: 2001 Thunder SMC leveling Jacks - Information Request  (Read 3062 times)

Dale Barham

  • BAC Member
  • *
  • Posts: 21
  • Thanked: 5 times
2001 Thunder SMC leveling Jacks - Information Request
« on: June 25, 2017, 08:48:58 PM »
We have an appointment at Beaver Coach later this week, following up under "warranty" the repair work they did on our SMC leveling system, including their manual leveling work-around system, installed.  We had a stuck jack earlier in the month and were able to eventually retract, but now running the jacks up and down to check how they are working. 

Here is what we do:  Manually let all air out, then extend jacks one at a time until they hit the frame.  Next we run both front or both back jacks up a bit (so as not to torque the frame), then add a bit on one or the other jack to simulate leveling.  Last, we start the coach and air up fully, then use the "All" or individual retract buttons.  We do this on an already level pad, and with the slides IN as there is not room in our shop to open them. 

Here is what we noted:  The coach is about 4" higher when aired up.  It takes about 1 minute and 45 seconds to get all jacks UP (back jacks 30-40 seconds, front jacks take 1 1/2+ minutes).  This is OK, if normal.  When all air is released, the front jacks are about 3- 3 1/2"  from the frame.  When front jacks are fully extended, there is about 8-9" total extension, allowing only 4-5" for leveling adjustments once the jacks hit the frame.  Does this sound correct?  The jacks only extend 8-9" total, including the 3+" before they even seat?

The other concern is that the left front jack seems to "stutter" when extending.  Like it is slipping or something, but still eventually extends.  The right front has this issue to a lesser degree; back jacks seem to work very smoothly.  Is this a problem that should be addressed, or is it normal?

Last, somewhat unrelated:  What are the straps that are between the two horizontal frame members of the chassis?  They have lots of slack (see photo), but last winter during a bad repair shop experience, the shop extended the jacks and had the coach so high we could not air it up further to release the jacks - and these straps were TIGHT.  We are still trying to figure out if there was any damage done; they had to bleed out the hydraulic fluid and pound on the jacks to finally get them up.  They were just supposed to be replacing our hydraulic pump/motor, which they never were able to figure out! 

Any helpful comments so we can try to put our hydraulic nightmares to rest and enjoy our "new to us" coach would be greatly appreciated!
Dale & Sue Barham
With Vizslas Lux & Gypsy, & Cat Tweety
2001 Beaver Patriot Thunder
2011 Honda CRV Toad

Edward Buker

  • Guest
Re: 2001 Thunder SMC leveling Jacks - Information Request
« Reply #1 on: June 26, 2017, 03:05:35 AM »
Dale,

I think your leveling procedure sounds rational. Landing the jacks on the pads after dropping air and then incrementing the leveling based on small adjustments is the gentle approach. Airing up first for retract is also the most gentle approach. I had the smc system in a 2002 Marquis and the only suggestion would be to air up first and then incrementally bump the retract position switches in small steps until the air leveling over the road system started to fill the air springs in the positions where the air valves where not already activated. You have to drop the coach off of the hydraulic leveling jacks far enough to open the air valves. Basically you want to pause at that point to allow the coach to fill the air springs with the engine running, in order to be resting on air. Once you are done with the weight handoff to the air system, then you can do the full hydraulic retract. Even though I had a working SMC auto leveling system, I would use the manual retract in this manner, given it was the more gentle suspension hand off method.

As far as the studder in the hydraulic jacks on retract in the front, I am not sure what the cause is. In retract the system is not powered, the jacks are not driven downward (retract) with the pump, allowing for a pressure drive. You are just opening a valve to allow fluid flow back to the reservoir. The rear of the coach is heavy and that may make the rear system more responsive and smooth on drop while the front may not be so smooth in response. BCS may have some insight as to what is considered normal in this regard.

As far as the straps are concerned I believe that was part of the chassis design to limit the travel so that the coach suspension could not exceed the stroke of the shock and cause damage. Seems the jacks tested the straps and put everything under tension. It does not seem likely that caused any permanent damage if all was left in tact when the jack retract was enabled with the help of some hammering. Hope this helps.

Later Ed

Dale Barham

  • BAC Member
  • *
  • Posts: 21
  • Thanked: 5 times
Re: 2001 Thunder SMC leveling Jacks - Information Request
« Reply #2 on: June 26, 2017, 03:34:43 AM »
Thanks, Ed.  This information is helpful!  Seems like we keep going back to Beaver Coach Sales - just a 3 1/2 hour drive for us - and leaving without feeling like everything is fixed.  Understanding is our best ally, so we can ask appropriate questions and get answers.  We've spent over $10,000 on just the hydraulic problems in the last 6 months.  Otherwise the coach has been fine, aside from normal maintenance.

Appreciate your response!
Dale & Sue Barham
With Vizslas Lux & Gypsy, & Cat Tweety
2001 Beaver Patriot Thunder
2011 Honda CRV Toad

LaMonte Monnell

  • BAC Member
  • *
  • Posts: 563
  • Thanked: 163 times
Re: 2001 Thunder SMC leveling Jacks - Information Request
« Reply #3 on: June 26, 2017, 06:24:28 PM »
I understand your pain with all the hydraulic issues. I have a 2001 Contessa which had the SMC jacks to the axle leveling system.
When we bought the coach 5 years ago we were having issues with a left rear leaking jack. At that time I found no help with having it rebuilt. I talked with HWH and they advised me that they could remove the jacks, cap the lines and custom build an air leveling system to my airbags on the coach. I chose that route and have been happy since. I actually still have a front and a rear working jack in my shed. HWH does not do that conversion anymore from what I have been told. We drove to HWH in Moscow, IA. to have it done over a three day period. $5000 for the new install with all new wiring, control pad, air lines and new compressor. Removal of the jacks also was included.

Good luck getting it properly repaired.
Lamonte & Patti Monnell
2001 Beaver Contessa Naples DP 40' 2 slides
CAT 3126B
2021 Chevrolet Silverado Trail Boss

Weeki Wachee,Fl
The following users thanked this post: Dale Barham