I have read many of the threads on the timing mod and it seems that most of the people gaining from it have the 6spd and in one thread a comment was made about this mod not helping autos as much as the 6spds. I am all for fuel economy and am looking to do this mod but I am wondering what effect it will have as I am running with the auto. So for any of you with an auto and this mod please let me know what you think and/or what your results have been. Thank you in advance for your help!!!!!

John

 

There have been a good 3 threads many pages long discussing this mod, and now recently, a bunch of threads asking what was answered many times in previous thread. I don't want to sound mean or anything, but reading those threads will yeild 100x more information than just asking it here. The reason I say that is because 50 people aren't going to answer you, you'll most likely receive a 1-liner response. Please search for the previous threads. Thanks.

 

It doesnt work as well on the 04.5 , the biggest gains are mostly seen on the 03.

 

Well what I've read is the 04.5 and 05 show the biggest mpg increase.Not the 03s.Also the autos notice the low end grunt improvement more then a 6 speed.

 

I don't have an auto, but my advice would be to just try it and see what happens. It is such a simple and easy mod to do...and even easier to change it back if it doesn't produce the desired results.

I didn't notice much increase in low end grunt like some others did, but I did notice a significant increase in fuel mileage (approximately 2.7 mpg in the city).

 

And yet, others will tell you that the 555 engine (03-04) doesn't see as much of a gain as the 600 and 610 engines (04.5 - 06). Just try it and see. That's the only way to know for sure whether it will help you or not.

This mod is one mod that I believe EVERYONE should do.

 

I agree. And also this mod may prevent injector fouling which is a BIG bonus.

MikeyB

 

This mod is all about expectations. I have an 04.5 auto and did the timing via the sensor. I will admit I wanted more than I got. I still got 1mpg as much as I would have liked 2mpg. there is not down side to the mod. the upside for me was not as huge as some people post but there was deffinatly no negative affect.

I could not get over 500miles on a tank before this mod. now I can. so this is not overhead being fooled kind of increase it is real.

 

The problem with reading the threads is deciphering what peoples results are and what mods they have. I know I read the same thread 3 or 4 times trying to decipher it. It would be nice to redo them so that they stayed on an info topic rather than float back and forth. Maybe even modded verse stock truck kinda thing. I finally said to H#$% with it and did the mod. I cant be more pleased. Hopefully the milage comes up as my overhead readings went down. I dont drive this one much though, even though I racked up 20k miles in a year, as it is alot harder to park than my 12V.

 

Well I've got an '05 610 and a 6spd and I saw a definately low end power increase. We'll see this weekend when I fill up whether my milage is up or not.

 

My mileages w/ the 03 SO averaged out to be about the same as before but the low end grunt is definitely better. My truck is now tolerable while running w/ the box off. Now that's worth the 45 minutes it takes to do the mod. Honestly, it's so simple to do and if it doesn't work for you it's stupid simple to put it back the way it was! I don't know why anyone wouldn't try it.....

 

Ok, I did my tone ring a couple days ago and have only got to drive the truck one time. But I will tell you I can really notice the improvement down low. It seams to shift a little faster also, but that could be my imagination. The wife just filled the truck up so I will see how the milage thing goes. I would say well worth the 45 min. it took me, like Hoss said, this is one mod everybody should at least try.

 

For the 45 minutes it took me it was well worth the time. Here is what I've noticed with the mod. Not near as much clatter from the engine when it is in gear - engine seems to run a little smother and the truck seems to start easier not as much crank time. And for fuel milage who knows - alot better than the suburbian with the 8.0L I got rid of............. Doing the mod was very easy. I think hardest part was holding my short ratchet and getting the fan belt back on..........

 

Thank you all for the insight. I guess that I will just have to go ahead and do this mod. I can not wait to see what kinds of gains that I get. I currently run around 17mpg which is decent but I would like better. I am shooting for 20 some day but with 4.10s that will be a challange.

John

 

I agree a great mod but I do not see how it will help injectors . The best way to keep injector nozzles clean is to work this engine and create more heat , this mod lowers EGT 's and would make the problem worse not better . EGT's have been running 200 degrees lower with the timing change . That said I would still do this mod , I have seen allmost a 3 MPG increase with it . This is a cheap easy mod that I wish that I would have come up with .