Ask Dave: Why does RV’s slide ‘pop’ and the cable keep breaking?

Dear Dave,
What causes the main slide to pop as it starts going out? This only happens after moving and the first time the slide is driven out. After the initial drive-out, it does not occur. After a few setups, the top front cable will break. The cable has been replaced numerous times with the same result. This problem has occurred since the trailer was new. Thank you for an answer. —Ralph, 2017 Keystone Outback RL326

Dear Ralph,
Typically Keystone uses the BAL^® Accu-Slide cable slide, which uses a single gear driven electric motor mounted above the slide room inside. This gear has a chain driven mechanism that is attached to blocks and pulleys that pull the cables to extend and retract the room. A popping noise is generally a sign of misalignment or a twisted cable. The need to replace the cable several times indicates not only a problem, but one that is not being addressed by whoever is working on it.

I would start by inspecting the room and taking measurements on the side at the top and bottom and on both sides. Do this with the room extended a few inches and then again fully extended. Next inspect the rollers underneath to make sure they are turning freely and the weight of the room is directly on them. Misalignment can cause one side to shift and actually lift off the roller so the room is wearing against a sidewall or other part of the rig.

Look at chains and cables

If all that is good, then we need to go inside and look at the chains and cables. If there is a grinding noise the cable is too tight. Visually inspect the cables to ensure they have a little “give” in the cable but not more than a 1” amount of slack. Here is a diagram from the BAL Service Manual.

Here is the specification of what each of the cables and blocks need for adjustment:

The Accu-Slide is a give-and-take system between the cables. If the inside and outside opposing cables are too tight you will cause the motor to be over-worked, leading to trouble later on. When the room is seated full out, the OUTSIDE cables should be slack enough to move the cable approximately 1/2” up or down (1” total movement) by hand.

The holding power is actually on the INSIDE cables pulling the standoff brackets tight against the frame. When the room is seated full in, the INSIDE cables should be slack enough to move the cable approximately 1/2” up or down (1” total movement) by hand. The holding power is now on the OUTSIDE cables pulling the standoff brackets tight against the frame.

Chains work same as cables

The chains work the same way as the cables. When the room is full in or out, half of the chain on each side of the motor will be slightly slack and half of each chain will be tight. After all final adjustments, tighten 1/4-20 jam nut against cable/chain adjuster bracket on all chain connections. Tighten the jam nuts on the cables by using a wrench on both the jam nut and the coupling nut. Failure to do so will result in a malfunction of the system!

There should be a sticker on the wall next to the mechanism that shows each block and adjustments.

This is what one of the blocks looks like on a Keystone Raptor we worked on a couple years ago.

If the tension is not an issue, then inspect the cables, pulleys, and all brackets. If this has been an issue from the start, it is possible the standoff bracket was not properly aligned during installation.

Here is the adjustment procedure according to the Service Manual.

Stand-off bracket alignment procedure

1. Adjusting the interior and exterior stand-off bracket.

a. Adjusting the interior Stand-off, run the room to the extended position. Stop six to eight inches before the room is completely extended.

b. Adjusting the exterior Stand-off retract the room to the in position, stopping six to eight inches before room seals.

c. Remove the four fasteners in the round hole on stand-off. Loosen the two fasteners in the slot on bracket.

d. With a hammer and at eye level with Cable, adjust stand-off accordingly until the cable is running straight into the punched hole in jamb.

e. Tighten screws in slot, pre-drill the four holes removed in step c, install the four fasteners, using new if needed.

I would also recommend visually inspecting the pulleys as a cable could have jumped to the wrong pulley.

After that, make sure the “H” column or trim that is fastened to the opening of the sidewall is secure. Loose screws or rivets can cause the trim to be loose and move as the cable goes in and out, which would also cause resistance.

 You might also enjoy this from Dave 

My slide room is tearing up the floor! How can I fix it?

Dear Dave,
The front slide drags in the kitchen area and rips up the flooring. The half in the living room is fine. I’ve tried to adjust it but nothing seems to work. How can I fix it? —Kenneth, 2002 Winnebago Journey

Read Dave’s answer.

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here. 

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