[39 master]

Just discovered a second shock failure on the '39. Left shock has failed twice! Rear suspension is 4 bar/panhard bar with air bags. Detach the bags and shocks and the rear moves up and down smooth. Shocks are Monroe 32275 with a range of 10.5 to 15.5 inches. Ride height is about 13" depending on air pressure. Shocks are for a 2000 Ford Windstar with a rear weight rating of 2800 lbs. rear of the '39 comes in at 1750lbs. When I took the shock out there was NO resistance removing the bolt. That tells me there is no mis-alignment side to side. I can see one faulty shock but not two on the same side. Any ideas what will cause a shock to fail?

 

[ericnova72]

Soounds like you are running it out of travel, which direction is hard to say and either topping out or bottoming the shock internally.
The shock can't be used as a travel limiter

 

[39 master]

As far as I know the only reason for shock failure is topping or bottoming out. Why just the one shock failure but the other is just fine? I've disconnected the air bags and shocks, then used the jack to run the rear end thru it's travel. Have not noticed any strange movements. The air bags are hooked together so they have equal pressure. Hate to put another shock in and have it fail but it's the only way I can eliminate two faulty shocks. Still open to ideas.

 

[johnsongrass1]

Shocks fail for lots of reasons. The oil breaks down, the seals wear out, if it’s a twine tube the gas bag breaks, if it’s a mono tube gas shock, the gas can escape and airate the oil, and the defective disks wear out,
Running out of compression travel ruins the shaft seals, usually called the glands, running out of rebound breaks pistons and glands.
Factory type shocks are pretty junkie most of the time. You might wanna look at some aftermarket shocks that are built better in the $150-$200 each range.
Monotube, gas charged, 5/8 shaft. Beware the gas charge shock at 50psi will add about 25lb of spring.