loud "thunk" retracting the slide

[klm]

I have a 02 Newmar. The main slide out made a new and worrisome sound. The clunk, thunk noise seemed to be in the area of the front rail. The slide extended and retracted normally, but I am concerned that there is a problem. The slide is currently extended. I did look at that front rail, nothing looked unusual, but I know nothing about mechanical things. There is a threaded rod, what I can see again looks ok. I cannot see the far end
of either rod or rail. Any ideas?

UPDATE!!!!! The slide has operated normally since that 1 time loud thunk clunk by the front rail. I had the coach serviced at a Newmar facility today. I mentioned the slide issue. Turned out the roller was bad, just that 1, all others good. Replaced with new $17 roller.

Thanks

[klm]

Op here. Thanks everyone. I have a mobile tech coming tomorrow. The motor is very easy to access, I'll check those bolts in the morning. The tec is not Newmar specific, so I hope he can resolve this.

I'm not sure if this is relevant, but the thunking sound happened the last foot of retracting and the first foot of extending. Rest of movement was normal.

[dougrainer]

There are 4 bolts that hold the motor/trans to the mount plate. Verify those 4 bolts are tight. If they are slightly loose, you will get that "thunk" sound. Doug

[J-Rooster]

I had that sound happen to me once in the 90's when I owned a Fleetwood. The shear pin broke.

[dougrainer]

ScottG wrote:
Just to help you find it better, the square tube that incorporates the shear pins is parallel to the frame of the trailer - not perpendicular to it.
BTW, the shear pins look like a regular grade 8 bolt but are actually special shear bolts. You can use a regular bolt but you loose a safety margin.

There is no such thing on a Newmar slide system. Doug

[ScottG]

Just to help you find it better, the square tube that incorporates the shear pins is parallel to the frame of the trailer - not perpendicular to it.
BTW, the shear pins look like a regular grade 8 bolt but are actually special shear bolts. You can use a regular bolt but you loose a safety margin.

[dougrainer]

Newmar's do NOT have shear pins or any such type pin. Newmar slide room motors/transmissions are secured to the slide system by a Transtorque bushing connected to a 1 inch round driveshaft. NO holes or pins or bolts. That threaded rod is just the manual stop in case the amp control does not stop the room at the correct time on extension to prevent over torqueing of the inside slide Fascia's. That rod may be the source of your clunk. The "Thunk" can be normal on a 12 year old Newmar slide mechanism from normal wear and tear. I would have it checked out by a Service Facility that has ACTUAL experience on Newmar slides as Newmar Slides are patented by Newmar and are the ONLY type system out there that Newmar uses. Doug

[TennesseeBob]

I had a loud thunk on my bedroom slide and it was the bracket that the threaded rod passed thru had broken off and hanging up

[wa8yxm]

Two thoughts, the shear pin is one

The other.. If for some reason the side is out of sync the rack will JUMP a tooth on the pinion.. This causes a loud THUNK, this can happen if something blocks it moving all the way in or out, or if the pin shears.

[newman_fulltime]

look between the front tire and infront of the cargo bay there should be a trap door with two screwstake them out drop the door.
you might want to get a grade 8 1/4 by 1 1/2 with a few washers to replace the shear pin with

[klm]

OP here. I will check in the morning. Thank you, I think you guys gave me good advice. If it's the pin at the far end is it accessible? Also I am mechanically inept, is this something a mobile tech can fix?

[ScottG]

I agree it sounds like a shear pin.
Look under the slide for a square tube that runs the length of the slide. At each end of this tube there will be a bolt where the gear connects. This is the shear pin. The bolt may still be in place but one end of it will be broken off.

[newman_fulltime]

the soundyou are describing sounds like the shear pin on the end that connects the rod to the farther gearbox.Your pin might be loose and walding out the uole and the clunk is the rod turning then catching as it gets to theend of the hole