I had posted about how I'd put Monroe's on about 4 years ago but that now they appeared to be shot, and had asked opinions on what folks recommended.
One well informed person suggested that if I still had the original receipt, I should get replacement Monroe's as they have a lifetime warranty. I'd forgotten about that as I'd bought them four years ago and I didn't think I'd be able to find the receipt, but it turns out I'd stashed it with the truck papers in case just this situation occured.
The Parts guys simply handed me new shocks. They didn't say "Monroe" on them but I'm assuming they are Monroe's in everything but name. Or perhaps they are replacement shocks that are cheapo throw-away's, don't know for sure.
Replacing the shocks is no fun, unless you have a torch, which I do, and are not afraid to use it, and I'm not. I remembered that the last time I'd replaced the shocks I had busted off one of the three studs that lock the top of the shock into the top cradle and had replaced it with a bolt. I did not at that time weld the bolt in place so removing it required the torch. Since I couldn't get a wrench on the bottom of the bolt I protected the inside of the fender well with chimney protectors which I keep around for this purpose, and nipped it off with the cutting tip.
This time, when I put the shock back together, I took the time to weld the new bolt in place so that I could unscrew the nut from it next time I have to replace the shocks. I also took the time to clean up the stud holder and repainted it to protect it against the salt mist.
Using a 1/2" air rachet helps with the spring compressors. The top nut was locked solid to the shock shaft and I had to heat it cherry red to get it to spin off. An occupational hazzard living in New England where salt is used to reduce ice and snow on the highways. The salt corrodes everything making removing small bolts or nuts on studs problematic as they frequently just bust off.
Anyway, when I got them back on the vehical and test drove it, I noticed that the hammering and vibration was gone. The truck basically glided over the bumps that before were literally causing a palpable deceleration from the violence of the tire and suspension's reaction when driving over small sharp bumps. I mean it hasn't turned into a BMW, but at least the hopping and vibration are no more.
I'd been thinking that the tires were actually adding their own jounce rate to the springs but even if they were, the new shocks are taking care of it.
This is after four years of ordinary driving on normal roads here in northern New England. I do plow with the truck, but only my own driveway. In other words I don't go driving all over with the plow on the front end, Normally I just take care of the driveway and then remove the plow.
One thing that might affect the shock life is that in the winter I remove the two original forward bump stops (there are actually two per side, one for each leg of the A arm) and replace them with a bump stop that is five times the size of the stock units. This acts as a second spring and aids in keeping the plow lift frame off the road when the plow is lifted. Without them, the clearance is about half an inch (it's impressive to see how much the front end dives when the plow is lifted). With them it's about 2 inches, which still isn't much but it's a lot better than 1/2 an inch. The huge bump stops become part of the suspension because they get hit on even minor bumps. The suspension is a lot more stiff in the winter with those things on. But I'm not sure that affects the life of the shocks.
Air shocks, that could be adjusted from inside the truck would be best, but I doubt they'd last long and besides, the cost would likely be prohibitive, if they could be found.
Corky Scott