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rwjejts · 07-29-2005, 05:23 PM

Does anyone know of any good online resources that explain the basic operation of hydraulic slides..or does anyone have experience with these?

Problem is as follows..

I have a 98 Gulfstream Seahawk 31' 5th wheel. Bought it used and have owned for about 12 months. The unit has a single hydraulic slide slide (dinette & couch) about 13' in length. I have moved the slide in/out at least 2 dozen times since ownership on trips, at home, etc.. w/o problems.

On a recent two week 3k mile trip, I noticed that the slide was pulling in somewhat "cocked"....one side (to the rear) would pull in all the way against the seal but the front side would stop short with about 1" gap. I've slid the slide in/out several times since noticing this with the same result...gap on front side.

I've looked underneath and see no evidence of faulty hydraulic lines lines or leakage. I'm pretty ignorant on these things but noticed there are (2) I'm guessing called "ram rods" ....round shiny metal rods underneath along with a steel cable system on pulleys. How does this system work...do the ram rods push the slide out and the cables pull it in...or do the ram rods do all the movement in/out? It looks like there is some adjustment that can be done on the ram rods as they are threaded on the end with large nuts...but I'm bothered as to what in the first place casued the slide to not pull in evenly.

Any net links or previous experiences would be appreciated. Thanks!

rwjejts · 07-29-2005, 05:23 PM

Does anyone know of any good online resources that explain the basic operation of hydraulic slides..or does anyone have experience with these?

Problem is as follows..

I have a 98 Gulfstream Seahawk 31' 5th wheel. Bought it used and have owned for about 12 months. The unit has a single hydraulic slide slide (dinette & couch) about 13' in length. I have moved the slide in/out at least 2 dozen times since ownership on trips, at home, etc.. w/o problems.

On a recent two week 3k mile trip, I noticed that the slide was pulling in somewhat "cocked"....one side (to the rear) would pull in all the way against the seal but the front side would stop short with about 1" gap. I've slid the slide in/out several times since noticing this with the same result...gap on front side.

I've looked underneath and see no evidence of faulty hydraulic lines lines or leakage. I'm pretty ignorant on these things but noticed there are (2) I'm guessing called "ram rods" ....round shiny metal rods underneath along with a steel cable system on pulleys. How does this system work...do the ram rods push the slide out and the cables pull it in...or do the ram rods do all the movement in/out? It looks like there is some adjustment that can be done on the ram rods as they are threaded on the end with large nuts...but I'm bothered as to what in the first place casued the slide to not pull in evenly.

Any net links or previous experiences would be appreciated. Thanks!

WesWesthaver · 07-30-2005, 09:22 AM

rwjejts, I put together a diagram of the mechanism used on my Forest River Wildcat:

Slide-Out Diagram

I have no way of knowing if it is the same as you unit but it is probably similar. I would start by inspecting the cables to see if they have jumped off the pulleys and to see if they are stretched tight. Also check to see if the cable mounting points are bent. If everything checks out, reply back and maybe one of us on the forum can help you further.

rwjejts · 07-30-2005, 12:18 PM

WesWestenhaver - thanks for the info. Mine is very similar to your diagram except I have(2) hydraulic rams...about 1" to the exterior of each support arm. The cable and pulleys set-up is just about as your drawing indicates.

I've looked at cables and pulleys and things are on track.

Each ram is threaded on the end with large nuts for the in/out limits. I suspect I can just screw in one of the nuts on the side that is not pulling all the way, but it bothers me how the unit came out of alignment. I don't think any of the nuts turned outwards by themselves as dirt/grime on these make me think they haven't moved.

Also while traveling on the road...the gap does not increase / decrease in size...so I don't think a fauly hydraulic seal is my problem..but I could be wrong. Any help would be apprecaited and thanks for responding back.

zip · 07-30-2005, 02:20 PM

It's possible that over time the cables have stretched enough to cause the gap. Adjusting the cylinder rod end nuts is the cure. If there's enough threads on each, you may try adjusting the front nut in and the rear nut out . This way you are using both rods to take up the slack, intead of just one.

rwjejts · 07-30-2005, 02:59 PM

zip - thanks..I'll give that a try and let yall know how it turns out.

It seems to have occured pretty sudden...one day it closed securely, the next day when prepping for travel I had a gap. I'm probably just paranoid, but it bothers me when things like this just happen.

Just for my info, do the ram rods do the pulling out and pushing in, and the cables are just there for support and keeping thinks lined up? Thanks Again!!

doc · 07-30-2005, 03:42 PM

With the way you described the situation, I am betting that it is not a stretched cable. Sounds like it happened 'overnite'. Have you checked on top of the slide to make sure there is nothing stopping it from going all the way in? I left a scrub brush on our slide and when I put the slide it, the brush stopped the full retraction. (duh!!) I was trying to clean the slide topper.

zip · 07-31-2005, 10:39 AM

Yes.That's good advice from doc. After I posted I thought of other things you should check, like obstructions, level of hyd. fluid,lubrication on the rails, etc.
If there's a low hyd. oil level, the slide cylinders may not operate completely. The cylinder closest to the pump will receive fluid first, while the cylinder farther away will follow.
The cables keep the slide in alignment, as Wes described.That's why he suggested to look for bent things, like mounting brackets and pulleys. Hope we've been of some help.

rwjejts · 07-31-2005, 11:57 AM

Yep, thanks to all. The trailer is in storage so I'll have to wait a few days before going to check on things. On mine the top of the slide always pulls in first then the bottom follows...and the top is closing correctly...just the bottom corner near the front of the trailer is staying "kicked" out.

I remember looking for obstructions underneath when I first noticed it not acting right and didn't see any...but I'll look closer.

Thanks again. If I determine the cause, I'll post an update. I just hate paying a dealer for repairs I can figure out....my labor is a lot cheaper than theirs.

rwjejts · 08-05-2005, 04:56 PM

Well, found the problem. Went to the storage place today with intentions of adjusting the limiting nuts on the ram rods to help close the gap. I did this several times and the problem was getting better but something just wasn't right. It was clear that these hadn't moved by themselves from the original set-points.

After looking this over a little closer, I found that there are (2) brackets (front & rear) that attach to the trailer frame and serve as guides for the ram rods and track supports. The bracket closest to the front was loose...the bolts that hold it to the frame were all missing (4 of them).

Anyway at least I know what caused the misalignment to happen. I'll probably need a good half day to fix as serveral of the insulating panels underneath will have to be removed so I can get to the backside of the frame to attach new nuts/bolts...

Anyway, fyi, thanks to all for the suggestions.