5th wheel jack failure

[r2millers]

while picking up our 5th wheel for Christmas to house out of town family, lifting up the jacks, I had a loud thump Noise. Then the pass side jack wouldn't move up or down. I tried moving it manually without success.

I pulled the pass side jack totally out, knowing the internal threads sometimes go bad, thinking I'd need to replace the upright assembly.
Once apart, there wasn't any sign if stripped threads?
All was still greased up pretty well and no sign of metal flakes, etc.

A bit confused, I pulled on the crossover bar and it came right off of the motor assembly. I'd never climbed back up in there before but I knew that couldn't be right, as it has to connect to both sides, and needs to stay secure.

Climbing up over the generator, I found the bolt that holds the crossmember on to the motor, had unscrewed and popped out under pressure.

A simple replacement with a grade 8 bolt and nylon insert nut and I was good to go. Probably not a bad thing to pull the unit apart and re-grease anyways.
I didn't pull the driver's side unit apart and will re-grease at another time.

A simple fix to what appeared to be a costly project. Something I felt needed to be shared with others if that problem comes up while on the road.

[Lloyd]

Good post and info Bob. Thanks.
Do you think a grade 8 bolt is necessary, or would it be better to have something softer that could shear before damaging the motor or gears?

[Loneoak]

Thanks for sharing. We have not had any problems, but we will save this link in case we ever need it.

[r2millers]

Originally Posted by Lloyd

Good post and info Bob. Thanks.
Do you think a grade 8 bolt is necessary, or would it be better to have something softer that could shear before damaging the motor or gears?

Lloyd,
Good observation, however, both towers have the traditional type "ring and pinion" assembly on top for lack of a better description, that most trailer tongue assemblies have.
On the top of the shaft drive gear is a shear pin that protects the assembly just in case of that issue.
The original bolt had a Allen head and I couldn't tell if it was a grade 5 or 8 bolt so I decided to go heavy.
The crossover bar housing Hole had been distorted, while the bolt showed no wear, hence the thought it was a tempered bolt.

[socoguy]

Good post Bob and Lloyd. Good information and observation. It is what makes this a valuable forum. Thanks.

[sleepyT]

I always try to read stuff like this just in case it happens to me at another time...Thanks for sharing...

[DavisK]

Great information. If I ever have a problem with mine, I'll check this out.