How bad is changing the ISO mounts?

Mon Jun 28, 2010 1:24 pm

There's an odd rattle in my 1250 at RPMs much above an idle, and the engine dances around a lot more than I think it should.

I'm thinking 34-year-old tractor and who knows how many hours of operation... ISO mounts are shot.

How big a job is it to change out the ISO mounts? Does the engine need to be pulled?

Re: How bad is changing the ISO mounts?

Mon Jun 28, 2010 3:29 pm

I just did this on my 1200 and we pulled the engine. But i think it can be done with just lifting the engine enough to slide out the iso mount brackets.

Re: How bad is changing the ISO mounts?

Mon Jun 28, 2010 8:42 pm

Remove the engine, it is easier in the long run.

Re: How bad is changing the ISO mounts?

Tue Jun 29, 2010 7:34 am

You've hit the nail on the head. If the engine id bouncing around, the ISO mounts are definitely shot.

If you have an engine hoist, you may be able to just undo the driveshaft coupler, slide the engine forward a few inches, then lift it up 4 or 5 inches with the hoist, without having to undo the electrical connections, throttle and choke linkage, and the fuel line. If that does not give you enough room, then you might as well go ahead and undo the connections above, and pull it up out of your way.

Also, being a quietline setup, you might as well take the opportunity to remove some of the engine sheet metal and clean out all the cooling fins really well. I know it's a real pain in the rear, but it will definitely prolonge the life of the engine to give it a good cleaning.

Overall, you could do everything in a couple of hours, easily. I once took a 10-hp engine out of a 108 and installed a 14-hp engine in less than 30 minutes, but I had every wrench ready and sitting there, however I did use an 8' step ladder with a comalong for the engine hoist. Yes, sometimes you have to improvize :D


Re: How bad is changing the ISO mounts?

Tue Jun 29, 2010 12:48 pm


I just went through this whole schmere myself with my 1200 Cub Cadet. I have a Harbor Freight electric hoist to do the lifting, and that was a huge benefit to me.

On top of my engine, there is an "L" bracket that fastens into the head. I assumed (yeah, I know what that means! :lol: ) it was a factory installed thing for lifting the engine. As a former sailboat owner/skipper, I still have some sailing shackles left over after I sold my last boat. I think it was a 5/16" D shackle - stainless steel with captive locking screw. I mounted this into the hole for the "L" bracket, then hooked the Harbor Freight hook into the stainless steel shackle. Hit the button on the lift and get it to the right position to remove the bolts for the engine ISO mounts.

About 10 minutes later, I'm replacing the mounts and going back with the new mounts. I did pay for the fancy dancy ones that are some serious $$$$. The instructions say to torque them to 8 ft/lbs. Fortunately, I had a 3/8" torque wrench that measured in in/lbs, so I was set.

Word or warning: You'll think you had to break your fingers and arms in several places to get those locking nuts back in place. It is very tight around those areas. Once I had everything cinched in place and torqued, I let it sit for a while, cooled off some, then retorqued everything three more times before saying, "enough is enough". I'll keep a check on it like the book says to do. Oh, on the two mounting bolts at the rear of the engine: I had to use a small shafted straight edged screwdriver to hold the locking nut in place and screw the bolt from the bottom of the chassis to get them started. It's hard to do, but it is doable.

My lower back is fused in two places, so this limits my mobility a great deal. If I can do this the very first time in my life, then I'd think most anyone with normal abilities can do the same thing with proper patience.