made the change from 3.73-4.30 in my 2000 cc 4x4 it pulls better my only question is that when i towed my four place snowmobile trailor this weekend when only half in the throttle at about 3000-3500 the tranny seems to shift into overdrive even when under acceleration is this the norm it even does it with overdrive locked out any help thanks

 

What you are feeling may be torque converter lockup rather than upshift to OD.

 

Yeah, that might be the TC lockup.


Did you reset the computer?

 

this happens even when not in od it still happens so what can be done to help this problem so it will just keep pulling and not lose rpm's just when needed also the computer has not been reset when this is done what will this help or will it have no effect at all thanks

 

Unplugging the computer will force the truck to relearn things over again. The computer is used to having the 3:73s back there and the tranny is used to shifting with the 3:73s. Since you added the 4:30s the shift points will be different due to less load on the engine.

My SCT adjusts the axle ratio and tire size amongst other things. After tuning for the larger 33's I noticed the transmission shifted different. Basically going to 4:30s is like putting on a smaller diameter set of tires.

 

how do you reset the computer

 

Disconnect one of the battery cable for 10 min or so. Put the cable back on and your done.

 

when you do this all of the info for the radio is it lost and needs to be reset i only ask because if it was done by the repair shop then i would have needed to reset all the info and i did not have to do this when i picked it up thanks

 

I deally, you should disconnect the neg battery cable - lesser risk of arcing on something.

Also, once disconnected, turn on the headlights (of course they won't come one), this will drain any residual current reamining in the system. Leave the lgiths on and cable disconnected for about 10 minutes. BTW - You'll want to write down all of your preset radio stations first, as they will be gone when you reconnect. If the shop did this, they may have reprogrammed everything for you and you'd never known it.

10 minutes later...
Turn off the lights and reconnect the battery cable. For about the next 500 miles, things may feel different (shifting, accelerating), this is the time period that the PCM will need to relearn the truck and your driving habits.

I also suggest doing this after any maintenance to the intake (fliter change, MAF cleaning, any new sensors) - this will give the PCM a fresh start when these things are done. Overtime, the PCM would relearn all of this stuff to begin with - but by resetting it, it learns faster.

How much did you gear change cost? What brand gears did you go with? I've been thinking of changing gears, but I can't decide if it would be worth the cost for the 1000 or so miles per year that I tow.

 

I've reset my PCM a few times by disconnecting the battery, and never had to re-program the stations. It lost the currently tuned station, but the presets were still there.

YMMV.

 

i reset the computer and all the presets were lost my gear change cost was $2500 because when in there the ball joints were replaced as well as the front discs and pads as well as one u-joint was going bad all this was done because it was all apart but just the gear change would have been $1600 plus rear oil and tax i can not tell you yet if it was worth this because i really have not towed far with it yet i only tow about 500-1000 miles a year but the truck was kind of a dog or so i felt on the flat it would tow like an animal but on a grade it liked to jump around to much for me

 

BD diesel has a TC lock up device that can manualy over ride the TC lock up or keep it unlocked.

here's a link to the info
http://www.bd-power.com/ford/autoloc_torqloc.html

i personaly don't have the torc-loc from BD, but i put one on a friends truck while he was over seas, it made a big difference pulling his 44's around!!

i have the BD diesel PreassureLoc part #1060380 , and it works great, there's no lag or "easing into lock-up" and when you gas on it it keeps the TC from locking early. and it also help the TC stay inguaged, so you don't get the occasinal unloc/lock type thing! combined with the by-pass-eliminator kit, i could tell a big difference in my trans performance!

i made a manual over ride switch for the torque converter. the TC works off a negitive (ground) connection. if there is no ground connection it woun't lock up. when a ground is made, it will lock the plates in the TC. i used a 3 pos switch and spliced into the TC wire under the hood. one setting is OEM, one setting is OFF, and the last position is MANUAL LOCK. i use it when i'm towing or on a good stretch of straight-a-way, interstate type stuff.

 

You don't have to be in OD when the TC locks. It actually locks in 3rd BEFORE the shift into OD. Team Mudd has the best suggestion to prevent it from locking...although most who tow WANT it locked to keep the heat down.

You don't need a computer reset you need your PCM programmed for your new gears. There is a value in the PCM that has the gear ratio in it. Any good dealer can do the change.

 

That's a good point - the speedo doesn't need to be recalibrated, but the PCM still has the wrong gear value I believe.

 

Thanks for the informative post, there is member pricing available though the forum. Let me know if anyone has any questions please.