Originally Posted by alank
I have a coach with three Swintek slides and have always been concerned about the damage a twisted coach chassis could do to the slides. I always level my coach manually and when leveling side to side as per LCI directions, the hydraulic leveling system can put a significant twist on the coach. I think this twisting of the coach body is largely responsible for the problems with the slide system.
In order to get my coach body nearly parallel front & back, I have installed levels on each end. The right readout is connected to a level bolted to the rear jack mounting bracket. The left level senses the position of the front of the coach. To set them I simply leveled the floor with a 4' level and a digital level setting on top of it to have two to compare. Once the floor is level, just push the "0" set button on the readout. The same procedure is done with the front level. From then on you know the amount of twist that is being applied by the leveling jacks.
In the picture you'll notice the front is .3* to the left and the rear is .4* to the left. This is setting in my drive and is in excellent position to extend the slides.
The other answers you've been given are good. I will add that, since I don't know who the maker of your leveling system is, and or, what model, I'm not sure just why you're TWISTING the frame and or, coach, while moving or, using the side jacks. As has been stated, at least the HWH system utilizes TWO jacks on any operation, be it either side or, either end.
So, let's say when you arrive at a campsite or RV parking spot and, it's low in the front some and, leaning to left some. Well, if it were mine, the first thing I'd do is, put out blocks or ramps under the front tires to drive up on to get it primarily level. Maybe a ramp and an extra piece of wood, under the left one 'cause it was lower than the right side.
Based on just how low you might be, the ramps might be really close in primary level. Then, I'd lower the jacks in the front, to do the finalizing of the front. Now you're level, end to end. Now, it's time for the side leveling. If I had to, I'd place blocks under the jacks 'cause they're already high due to the fact that you (or me) have driven up on ramps etc. to do the primary leveling.
Then, simply lower the low side jacks 'till they came in contact with the blocks. Then, continue to raise that side 'till you're level, side to side.
Now, also what's been stated is that you seem to be going to some extreme to make front and rear dead parallel. Well, again, not knowing your jacks, in an HWH system, both side jacks will raise the coach simultaneously. There should be no TWEAKING of the frame or body.
Everyone's got their own tactics on leveling. Just how you accomplish the end result is up to you. If you feel you need to do all that you've stated, well, I guess if it works for you, then by all means, do what makes you happy. Good luck.