Using Stage 8? Watch Out

[flarider]

I am having a problem with my kitchen slide on a 2018 DSDP. In doing some research I read that the Stage 8 system bolts were loose. So, I decided to check my bolts. In the end, all the bolts that had the Stage 8 system were loose. It is probably more of what the bolts screw into than the Stage 8, nevertheless, if you are using the Stage 8 system or probably any system, (safety wire) you might just have a false sense of security.

Marc

 

[Texas Clodhopper]

Do a forum search "slide motor bolts" and you will find several remedies for the bolts coming loose. BTW, it should be Grade rather than Stage.

 

[Rich W.]

this is what he’s referring to: Stage 8 They can’t come loose by turning but may the bolts are stretched or as he said it may be whatever the mount to.

 

[Neemer]

There’s a guy on another forum who documented his experience with this. The problem is with the pot metal (or whatever it is) of the motors and the internal threads stretching, deforming, etc. With Stage 8, the bolts themselves cannot move. My takeaway is to not overtorque the bolts.

 

[Rich W.]

I think I saw a post showing a through-bolt solution to this although it might not be possible to access the necessary spaces in all applications.

 

[Kevin D Pem]

I think I saw a post showing a through-bolt solution to this although it might not be possible to access the necessary spaces in all applications.

The answer used in the aircraft industry with aluminum parts, are helicoils. The other is thread inserts effectively increasing thread diameter in both circumstances.

Internal Threads don't stretch, they strip! The term I use for (clear my throat)pot metal is crap metal, or I leave metal out of it completely. That said helicoils are not only a way to prevent thread failure, they can also be used to repair a stripped thread.

 

[scottramer]

I think you might have read my post about the bolts with the Stage 8,s coming loose on another blog. It appears that the threads are stretching in the aluminum gear housing and oblonging the bolt holes.

A couple weeks ago I did my bedroom motor and just yesterday I finished reworking my kitchen slide motors, all using the studs that I JB welded in along with Nord-locks.

I can't blame the Stage 8's as they did there job of keeping the bolts from turning. Hopefully with the studs epoxied in place this will be the last time I have to mess with them.

 

[Joe Hogan]

If you want a deep dive on thread repair options

 

[Richpatty]

I put in Stage 8 in June 22…so far, so good. I do check them from time to time.

When I put in my Stage 8 bolts/bars, my bolts were not loose, nor had they had become loose in any major way prior to me replacing them last June. Is it possible that once they get loose, they round out the holes and it becomes harder to correct the situation?

 

[Kevin D Pem]

If you want a deep dive on thread repair options

Joe the research man!!! In aircraft the solid insert is used with a paint that reduces corrosion. More with magnesium parts than aluminum. The insert corrosion is the least of worry. It is the galvanic corrosion that is of most concern.

On aluminum parts in the marine environment stainless screws are coated with loctite red for corrosion reduction.

It has been said in engineering, that the helicoils roll when pressure is applied and that allows the insert to increase its bite. Honestly I don't know how I would test to prove that theory,other than to check the form of the thread before and after the load test with a mold of the tested thread.

Anyhow, thanks Joe for finding that video!!!

 

[Buly]

I agree metal inserts are the best, but in our case I’m concerned about two issues:
* To do it properly, you have to remove and reinstall the motors. Not that easy.
* Drilling and tapping the pot metal bosses with a bigger diameter drill to accommodate the helicoil, will weaken even more the pot metal area that takes all the torque force of the motor.

 

[Kevin D Pem]

I agree metal inserts are the best, but in our case I’m concerned about two issues:
* To do it properly, you have to remove and reinstall the motors. Not that easy.
* Drilling and tapping the pot metal bosses with a bigger diameter drill to accommodate the helicoil, will weaken even more the pot metal area that takes all the torque force of the motor.

Are the bosses breaking or the threads stripping?

So if it fails on a trip is that less inconvenient?

Of course, the choice is always yours!

 

[Rich W.]

I think you might have read my post about the bolts with the Stage 8,s coming loose on another blog. It appears that the threads are stretching in the aluminum gear housing and oblonging the bolt holes.

A couple weeks ago I did my bedroom motor and just yesterday I finished reworking my kitchen slide motors, all using the studs that I JB welded in along with Nord-locks.

I can't blame the Stage 8's as they did there job of keeping the bolts from turning. Hopefully with the studs epoxied in place this will be the last time I have to mess with them.

The motor I recently replaced was a through-bolt design so it doesnt have this problem. I have used heli-coils sucsessfuly but I’m not sure they can take the torque necessary to hold this in place (maybe with a generous portion of red lock-tite?) and I don’t think there is enough metal for an insert such as found in alloy engine cases for head studs. Maybe the JB will hold together for the duration. Fortunately one can always close these slides manually as I had to do a few months ago.