what is a tone ring mod, what does it do, how do you do it, and is it easy?

 

I have not done it but this is what I copied after I did a search.

Basically, it is doing about the same thing as the RokkTech Cam sensor. Behind the Crank Pulley there is a Tone Ring (looks like a chain sprocket). It has 4 bolt holes and a dowel pin hole. Take off the belt, loosen up the crank pulley and you will see how loose that is, it wiggles a little. If you are in front and looking at the motor, it needs to turn CLOCKWISE a tad. This will advance the timing a little bit. So, what people are starting to do is to take OFF that tone ring gear and grind out the dowel pin. Not to enlarge it but to slot it a little. It needs to be done on the CCW side (if having the dowel pin at NOON position, slot to the left). Then upon installing, it will now turn CW just some more. Even if you slot too much, the 4 bolt holes will stop it from going too far.

People have noticed a little increase in MPG (me, about 1.5 - 3 around town) and better take off power. I went from stock tires (265) to 315's and lost power of course. This mod feels like I am back to stock power AND getting better MPG also.

Now, not saying that the ROKKTECH sensor doesn't work (don't have one) and you shouldn't think about getting that. But this is a free mod that takes about 20 minutes, maybe less if you let the motor cool down first. Crank Pulley is hot after shutting down the motor

 

I see that you are in CA. Do you have to get emissions tests? If so how does that mod affect your emission readings?

 

I have not done the mod. Diesels do not get tested in California.

 

I have some questions about this mod too.

Is this basically the same thing as installing the Rokktech sensor? What happens if you do both mods?

Also, if you're running a box that adds timing is this mod still effective?

 

Once you add timing then it becomes touchy. With a box like a Quadzilla box you may get a bit of timing rattle on the higher settings. On my 03 With a TST box I had so much rattle that I had to back the TRM off back to stock.

 

So the Quad XZT will basically take care of the timing advance and the tone ring mod/Rokktech sensor isn't really needed? Would there be much to gain by doing the tone ring mod/Rokktech if you're running the XZT?

 

Yes, I would still do it especially if you are running the XZT. They work well together. Back to your other question about doing both the Rokktech and TRM. I think that would just be too much timing since it's off idle and not subject to RPMs.
I have a Rocktech on the way to me now because doing the TRM on the 07 looks like more work than on the 03 I used to have....

 

Got it. Thanks a lot for the info!

 

The Predator is T&D and I use just as much tone ring timing with the Predator as I used without it. You just have to try it and see. Craig

 

I've got an 05 CTD and am interested in the TRM. How much advance is acceptable? ANybody know how much advance is too much? How much advance does the Rokktech sensor provide? Is there a good source of tech information that can advise the maximum advance before being detrimental to the engine? ANy wisdom you guys can provide would be greatly appreciated. Thanks.....Lektrikman

 

I believe the Roctek sensor is about 2 degrees. You can only advance the tone ring so far when you enlarge the dowel hole. If you want to advance it more, you would also have to enlarge the bolt holes. From what I read, you only want to enlarge the hole about a 16th of an inch, any more and it starts to run rough. That is how I did mine, 1/16 and it it improved bottom end torq and gave me about 1-1.5 mpg around town. Also gave me back a little of that diesel rattle.

 

You will know if you have gone too far by the sound of the engine...