CAT C12 Starter Removal/Install

[Bryan J Callahan]

Hi Guys and Girls! I have a 99 Patriot Thunder with a Cat C12,,, my starter appears loose and requires an 8 point wrench/socket to tighten. There is not enough clearance between one bolt head and the starter body for a wrench or socket.... Is there a special tool or am I missing a trick to tighten (and locktite) this??? Any ideas short of slotting a wrench like for brake lines???
Thanks in advance!

[Dale Walker]

I may be wrong, but a 12 point socket will work on those bolts, and you need a long extension.


Good luck!

[Mike Shumack]

Like Dale said, the starter bolts will be "12-point" wrench or socket. The bolt heads are 16mm.
There are many curved, s-shape, and swivel sockets available to get into tight spots. IIRC I was always able to get the bolts loose with a socket and extension (maybe I used swivel head or wobble-ned extension).  Be careful, those starters are heavy.

The bolts should have lock washers - so loctite compound not needed.

Here's a pic of a typical C12/C13 starter. Is this what your working with?

[Dave Atherton]

Gentleman, would like to add a suggestion when changing out starter and installing different starter. Do not assume the nose cone on the starter has same alignment as starter you are removing. In many cases they are a little different and nose cone has to be turned. This can be done by removing the Allen socket bolts on outer part of nose cone. I've seen several people get a new starter and cannot figure out why it is not going in properly, then assuming they have the wrong starter.
Harbor Freight or auto parts stores have a wrench set with 12 point box ends and a half moon radius that works real good on the inside top bolt.
Dave Atherton Retired Cat Mechanic