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I am going to the changing gears in my Silverado but I am going to have to drive the truck before I am able to get it retuned for the gears. Is there any other problem I will run into other than the speedo being wrong? Will it mess with anything on the ABS? I have had bad luck with trucks that the ABS light was on.
Your shift points will be very messed up.
the speedo will be off, you will have the ABS light on and the park brake light on and to disable the ABS you can simply unplug it, there is a main power plug, really easy to find its a plug going into the ABS block with a think black and red wire
i just did my 14 bolt swap from 4.10 to 3.73 and didnt have any issues except speedp is off .been too lazy to load my 3.73 tune back in.shift points are fine ,no abs light ,no parking brake issues
ratio's are close enough to where it wont make all that stuff happen, your speedo is prob off by about 5mphQuote:
Originally Posted by Ramsey
Yeah, get farther off in ratio and more stuff happens.
I heard the ABS light and such had something to do with the fact that the 4x4 measures something at the front and back differently and trips some stuff. Which is maybe why Ramsey didn't have any problem?? Dunno, just throwing it out there.
Looks like I may be drive the ole 4 banger saturn next week...
When I did mine, I had an abs light, and a service engine light.
My mph way WAY off.
If it's way off the PCM thinks the trans is slipping. If it's kinda far off the ABS is confused about VSS vs. WSS. Only a little off will make the shift points kinda goofy.
When I went from 3:23 to 4.11s My shift points were so screwed up, ABS and parking brake light was on to. I had it re-calibrated and the shift points still arnt right. Guess Someone has to set them in the tune. I figured it would re-set it's self with the re-calibration
I don't quite understand how the shift points can be off. the truck shifts based on RPM, correct?
I got the 4.56's installed and am going to send the PCM for the re-tune. I was wondering if I would notice any driveability/performance difference or if it is just practically a re-cal of the speedo
No help?
truck shift points are based off RPM and MPH but thats only at WOT...otherwise all part throttle shifting is based solely on MPH and at that also the toque converter lock up and unlocking is also based on MPH
When I changed from 3.42's to 4.10's and also went from 31" to 30" tires the speedo was WAY off and the ABS and E-BRAKE lights were on. With Wheatley tune,problem fixed!!
Should have a good deal more pep, and accelerate much easier. Take it easy on them till they break in! It's gonna be tempting.....Quote:
Originally Posted by MKader17
I went from 3.42 to 4.10 in my sierra, and all the shift points were really messed up! It was funny to see the speedo with the computer thinking I still had the 3.42 in play. I just used a hypercrap till I recieved my nelson tune. I am currantly on a different truck, so this time around I am going with 3.73 so I still have the second gear down shift at 60....
When I changed the gear ratio my abs lights come on and off all the time. Some time it will be off and others on. Code is for mismatch wheel speed signals. nelson program only corrected my speedo. These trucks have a three sensor syste, and the rear sensor at the trans output reads faster than the front. The pcm/ebcm will read differnet signal. front will be low and the rear will be high. I been playing with resistors in the signal circuit to lower the voltage output the match the front. And dont run auto 4wd on the street untill you get it programed, you could burn your clutches in the transfer case.
Dale tuned my truck, before and after gear change. After the gear swap I had the ABS and E-Brake blinding me, had Dale update for the 4.88's and bingo, no more lights. Haven't had any issues with the ABS light coming on.
I question the 3 to 4 channel change in 03. The GMT900 trucks and utilities have 4 channels but all the 800's are three.....rear wheel speed is off the OSS and fronts are alone.