Cub Cadet FAQ's
ISO Mount and Engine Cradle Upgrade
Originally done by David Kirk back in 1999
With an Update by Richard Christensen
Secret info on this page submitted by Myron Bounds.
Using your old engine rail system
Or buying a new rail system
Remove the rear cross brace
Some comments on the Cub Cadet ISO mount rubbers. First of
all to my knowledge NAPA has never sold a replacement kit for the Cub Cadet ISO
rubbers. They sell a kit to replace the rubber mounts for a car suspension
system. To advertise it as a Cub Cadet ISO Mount replacement kit is wrong.
I did not come up with the idea for using the MOOG kit in place of the correct Cub Cadet Iso mounts but I did try them and found they did work and when I posted the picture of the Rail mount modification dimensions that I had come up with I believe I posted the picture of the MOOG kit and said I was using it in several cubs on a trial and it was working good. It was not my intent to mislead anybody into thinking this was a direct replacement. After using the Moog rubbers for some time I felt they caused too much vibration and have removed them from all of my Cubs.
One reason I tried the MOOG rubbers was the new Cub Cadet ISO rubbers were extremely stiff and caused a lot of vibration when installed per the specs that came with them. Later I found if you didn't tighten the Cub Cadet ISO mounts bolt more than to the point where 1 thread was showing on the top of the nut it didn't vibrate as bad and with time it actually gets pretty good.
Through time and different test I have come up with different ways to do the job and have some suggestions.
First of all I think the original Cub Cadet ISO mount rubbers were good and got a bad rep due to the rails coming loose. This can be corrected by doing the Rail modification. Maybe they made the newer ISO mounts stiffer to compensate for the rails but I don't know that for sure. Any way unless you were fortunate enough to locate some of the old ones you are going to have to use the newer ones now.
My first preference when replacing the Cub Cadet ISO mounts is to check the old ones when I pull them out, usually the top 4 will be good as the weight is on the bottom 4. If I can find 4 good old rubbers I use them on the bottom of the modified rail and then buy two new Cub Cadet Iso mount kits which will give you 4 new rubbers and I use them on the top of the rail. Tighten the nut on the bolt so just about 1 thread is showing on the top of the nut. This will give you the least vibrating system and should last a long time.
Another way to go if money is a real issue is to see if you can find 4 good old used ISO rubbers to use on the bottom of the modified rail and then buy one MOOG K5252 kit and use the 4 rubbers that come with that kit for the top 4 rubbers. Buy 4 new 3/8 x 16 nylon lock nuts and 4 new flat washers and mount it like this picture. This will give you much less vibration than using all MOOG kit rubbers.