I have had 2 trucks with over 200k without replacing them. It's more of a rust situation than a mileage factor.

 

If you can get your hands on a borescope, you may be able to check the condition of them.

The right side (passenger) motor mount generally goes out more often than the left. This is due to the clockwise rotational torque created during acceleration and when pulling a considerable load. The rubber bushing can handle an incredible number of cycles in its lifetime, but hard acceleration and towing can cut that short. The left one generally doesn't seem to be affected as much primarily due to the fact that we don't spend our lives driving backwards.

For most vehicles, a couple of decades is not out of line.

To check this without a borescope, open the hood and have a partner try to move it forward. Set the e-brake, chock the wheels, then, try power braking and watch to see if the engine lifts up on the right side. If the mount is broken, it will look like the engine's trying to climb out. Try the same in reverse. Doing this with a borescope will help you gauge just how much or little visible stress you currently have.

i went 165k on my '94 and there were no obvious signs of wear when I replaced a blown engine. I opted to just go with new ones on the new engine.

You can replace them yourself if you have access to a hoist. You unbolt the lower rubber housing from the frame, pull the through bolt, and lift the one side just enough to slide the old one out and the new one in. Doesn't take but maybe 2" of lift on each side. For safety, be sure to block the exhaust manifold up while you have your hands under there. It may be easier to access the mount bolts if you pull the through-bolt first and then lift to get a ratchet on the other bolts.

Be careful when lifting that you don't crush anything attached to the rear of the engine against the transmission tunnel.

 

Thank you for that great information! I don't think I am near having any "clunks" yet, all seems very smooth and well while driving. Is there a way to tell if there is "wear" on an engine mount rather than a broken engine mount? I am wondering if there is a way to see (or test) at least with the passenger side mount if there is any cracking, leaking, or other sign that it may be breaking down. There are no symptoms that either myself or my boyfriend can see/hear/feel. It is a manufacturer recommendation to change at 100,000, but I think that is a number that is probably associated with hard driving conditions, in the north, lots of salt, and conditions this vehicle has not seen. I have not looked for that passenger side mount, I will pass this info to my boyfriend. I may end up springing for the borescope, if there are no other options.

 

On my last truck it was 17 years old with 325K miles on the original engine mounts and I pulled a 21ft 6,000 lb RV. Engine mounts are good until they break, there is no predicting it for the purpose of a maintenance schedule, IF they were to be replace at a certain age or mileage it would be listed in the maintenance section of the owners manual along with the other scheduled things.
If I was going to have the engine out for some other reason then I would probably do new mounts just because I was there, but with only 106K, even if I had the engine out I would most likely put the old mounts back in. You need to find a honest dealer or mechanic to do your work, this one is either trying to rip you off or just trying to get you to buy newer. Either way unless the mounts have already failed and this is a repair, he is trying to rip you off by lying.

 

On my last truck it was 17 years old with 325K miles on the original engine mounts and I pulled a 21ft 6,000 lb RV. Engine mounts are good until they break, there is no predicting it for the purpose of a maintenance schedule, IF they were to be replace at a certain age or mileage it would be listed in the maintenance section of the owners manual along with the other scheduled things.
If I was going to have the engine out for some other reason then I would probably do new mounts just because I was there, but with only 106K, even if I had the engine out I would most likely put the old mounts back in. You need to find a honest dealer or mechanic to do your work, this one is either trying to rip you off or just trying to get you to buy newer. Either way unless the mounts have already failed and this is a repair, he is trying to rip you off by lying.

Thanks for the info! I suspect I am going to leave them alone for now. I would love to find a good local mechanic. Being new to the area, I do not know who to go to. The dealer has been a little aggressive with their list of items that are coming due for maintenance, but I did ask them what was coming due at the 100,000 mile mark. So, I am trying to choose wisely for trailering, first and foremost. If I ever do have to have the engine pulled for any reason, I will certainly get them done, as you did above.

 

245,000 miles and no motor mounts needed.