Transmission Delays - 4l60e ?

[TRCM]

08 Silverado, 5.3, HD towing package, 4x4, < 22k on the ticker

 

I noticed today when towing my boat that there is a significant delay (~1/2 sec) between the time you move the gas pedal and the time it takes the truck to start moving. It's almost like you can feel the truck wait to engage the gears, and then the gear engagement is positive, but not harsh. I can deal with it on level ground, but 2x today when loading/unloading my boat, when the person in the truck put the truck in gear to pull up the ramp the truck started rolling backwards because of this delay. It was bad enough both people freaked and hit the gas pretty hard, resulting in tire spin and one time almost pulling the trailer out from under the boat.

 

Now this ramp was not steep, I'd say average, and the boat/trailer weighs ~ 3000 lbs, well within the capabilities of this truck, so I/m not sure what is going on.

 

Every automatic trans vehicle I have had before, if you put the vehicle in drive, it will hold itself there on a moderate incline, but this truck seems like it is in neutral until you actually give it gas, and the ~900 lbs of trailer behind it exacerbates the proiblem. I got rid of a manual trans cummins dually because (among other reasons) no one else could drive it loading and unloading a boat, and now, this truck seems to have similar issues.

 

Is this another of the torque management nannies ? or is it something else ?

 

I know I personally, when I am driving someone elses truck at the ramp, I use my left foot to hold the truck with the brake, and then let off as the truck starts to pull against it and move forward, JUST so I know the truck won't roll backwards if the transmission is weak. Do I need to teach everyone else how to drive ???

[jro909]

yes sir torque management at its finest...its awsome too at shifts, that nice dead zone feeling them goes into gear..

[stewy_05]

My truck does the same. I have to put left foot on brake and give little gas when I start to pull boat up ramp.

[TRCM]

yes sir torque management at its finest...its awsome too at shifts, that nice dead zone feeling them goes into gear..

 

OK...do you know if a tune will get rid of some of this ?

 

Nothing like putting fear in you watching your truck start rolling towards your boat and the water, knowing there's nothing you can do about it but pray the guy in it hits the brake !!

 

Also just read that my boat is light enough I don't have to use tow/haul....which will help the mpg too.

 

thanks.....just got the truck 2 weeks ago, and since it was used, I was afraid the transmission had issues that weren't seen during the test drives.

[jro909]

yeah a tune you can't cut the tm down or remove it all the way...i may have misread earlier but did you mean it rolls like a manuel trans does on an incline? if so i'm not sure if that tm, i know that if the truck rolls too far say forward in reverse it will kill the motor to stop the truck from damageing the drivetrain and vice versa...

[TRCM]

yeah a tune you can't cut the tm down or remove it all the way...i may have misread earlier but did you mean it rolls like a manuel trans does on an incline? if so i'm not sure if that tm, i know that if the truck rolls too far say forward in reverse it will kill the motor to stop the truck from damageing the drivetrain and vice versa...

 

Yes, it acts like it is in neutral on an incline.

 

Sitting at the ramp, in the time it takes to move your foot from the brake pedal to the gas pedal, it will start rolling backwards.

[TRCM]

yeah a tune you can't cut the tm down or remove it all the way...i may have misread earlier but did you mean it rolls like a manuel trans does on an incline? if so i'm not sure if that tm, i know that if the truck rolls too far say forward in reverse it will kill the motor to stop the truck from damageing the drivetrain and vice versa...

[jro909]

i'm not 100% sure but i think its because the torque converter dosen't have enough pressure to compensate for the incline to keep the truck still or rolling forward...no worries just use the parking brake if you have to, pop it on and flip it off just before your reading to go...its normal my truck does it too now that i think about it...just remeber its better then trying to juggle gas pedal and clutch pedal hoping not to roll backward into something lol

[alwcurlz]

I've always read this rollback on an incline while in drive as a failing transmission on older vehicles when not loaded. I would say while on an incline and loaded it wouldn't be abnormal. I've had different vehicles that would do this, rolling back while in drive on an incline. My truck seems to do that, roll back while in drive sometimes. I think it's the computer controlling those functions and not always analyzing properly what is going on. Some days I wish I had a TH350 in this truck.

[TRCM]

i'm not 100% sure but i think its because the torque converter dosen't have enough pressure to compensate for the incline to keep the truck still or rolling forward...no worries just use the parking brake if you have to, pop it on and flip it off just before your reading to go...its normal my truck does it too now that i think about it...just remeber its better then trying to juggle gas pedal and clutch pedal hoping not to roll backward into something lol

 

 

That was my thinking, and I wasn't sure if putting it in tow/haul mode might increase line pressure to correct for it.

 

The problem isn't me....it's when others drive my tuck.....I, like I said above, always use the left foot brake right foot gas on an incline.

 

Today tho, when the guy felt it rolling and gunned it, he pulled forward so fast the boat slid back on the trailer and the only thing that kept it pn the trailer was the safety strap @ the winch, and it yanked pretty hard on the bow hook. Didn't seem to do any damge to the boat, but it could if someone takes off any harder.

[alwcurlz]

Sorry, my messages are posting at the top here...the site is messing up I think. .....Anyway, I would have to say the person who was driving your truck didn't know what they were doing. Pretty much anyone who has backed into and back out of a lake ramp knows you need to keep brake pressure and eccelerator pressure otherwise, as you noted, something bad or REALLY BAD can happen where people can get hurt and possessions lost. Some ramps around our lakes when the lakes were low were dangerous if you didn't realize that there were drop offs in some places off the ramp! Glad nothing catastrophic happened but, I would check that winch anchor on the boat to make sure it's secure.

i'm not 100% sure but i think its because the torque converter dosen't have enough pressure to compensate for the incline to keep the truck still or rolling forward...no worries just use the parking brake if you have to, pop it on and flip it off just before your reading to go...its normal my truck does it too now that i think about it...just remeber its better then trying to juggle gas pedal and clutch pedal hoping not to roll backward into something lol

 

 

That was my thinking, and I wasn't sure if putting it in tow/haul mode might increase line pressure to correct for it.

 

The problem isn't me....it's when others drive my tuck.....I, like I said above, always use the left foot brake right foot gas on an incline.

 

Today tho, when the guy felt it rolling and gunned it, he pulled forward so fast the boat slid back on the trailer and the only thing that kept it pn the trailer was the safety strap @ the winch, and it yanked pretty hard on the bow hook. Didn't seem to do any damge to the boat, but it could if someone takes off any harder.

 

[jro909]

i'm not 100% sure but i think its because the torque converter dosen't have enough pressure to compensate for the incline to keep the truck still or rolling forward...no worries just use the parking brake if you have to, pop it on and flip it off just before your reading to go...its normal my truck does it too now that i think about it...just remeber its better then trying to juggle gas pedal and clutch pedal hoping not to roll backward into something lol

 

 

That was my thinking, and I wasn't sure if putting it in tow/haul mode might increase line pressure to correct for it.

 

The problem isn't me....it's when others drive my tuck.....I, like I said above, always use the left foot brake right foot gas on an incline.

 

Today tho, when the guy felt it rolling and gunned it, he pulled forward so fast the boat slid back on the trailer and the only thing that kept it pn the trailer was the safety strap @ the winch, and it yanked pretty hard on the bow hook. Didn't seem to do any damge to the boat, but it could if someone takes off any harder.

 

 

ok as far as line pressure, look at it this way..say your trucks idleing high and you put it in gear, you know the sudden quickness it has from the rpms being higher? thats because the motors cranking the torque converter more to make the pressure...loading/unloading on a truck i would think you probably have the truck almost idleing, which it would have to be if your holding the brakes down to deal with the boat....i've never heard of it being a failing transmission, its the same deal if you put the truck on park it will roll until the weights on the parking pin(which is bad i might add) so if the trans dosen't have enough pressure to keep the truck standing still on an incline its going to obviously take the point of lease resistance...

 

as far as tow mode, if your towing/hauling through hills where the truck has to constanstly upshift and down shift(or "hunting" as its sometimes called" i'd highly recommend pushing the button...the only harm the button will do is eat more gas, where as forceing the trans to hunt over and over and over will eventually burn up the trans....

[alwcurlz]

Yeah, drives me nuts when I see people put it in park and let the vehicle roll back and bounce on the parking pin, not using the parking brake. The work truck I drive at my company has a towhaul button but it doesn't function so I just put it in 3rd gear. Simpler and easier on the transmission especially with all the hills I'm dealt with. Better to be running the truck in it's best torque curve, keeping fluid pressures higher.

i'm not 100% sure but i think its because the torque converter dosen't have enough pressure to compensate for the incline to keep the truck still or rolling forward...no worries just use the parking brake if you have to, pop it on and flip it off just before your reading to go...its normal my truck does it too now that i think about it...just remeber its better then trying to juggle gas pedal and clutch pedal hoping not to roll backward into something lol

 

 

That was my thinking, and I wasn't sure if putting it in tow/haul mode might increase line pressure to correct for it.

 

The problem isn't me....it's when others drive my tuck.....I, like I said above, always use the left foot brake right foot gas on an incline.

 

Today tho, when the guy felt it rolling and gunned it, he pulled forward so fast the boat slid back on the trailer and the only thing that kept it pn the trailer was the safety strap @ the winch, and it yanked pretty hard on the bow hook. Didn't seem to do any damge to the boat, but it could if someone takes off any harder.

 

 

ok as far as line pressure, look at it this way..say your trucks idleing high and you put it in gear, you know the sudden quickness it has from the rpms being higher? thats because the motors cranking the torque converter more to make the pressure...loading/unloading on a truck i would think you probably have the truck almost idleing, which it would have to be if your holding the brakes down to deal with the boat....i've never heard of it being a failing transmission, its the same deal if you put the truck on park it will roll until the weights on the parking pin(which is bad i might add) so if the trans dosen't have enough pressure to keep the truck standing still on an incline its going to obviously take the point of lease resistance...

 

as far as tow mode, if your towing/hauling through hills where the truck has to constanstly upshift and down shift(or "hunting" as its sometimes called" i'd highly recommend pushing the button...the only harm the button will do is eat more gas, where as forceing the trans to hunt over and over and over will eventually burn up the trans....

 

[TRCM]

ok as far as line pressure, look at it this way..say your trucks idleing high and you put it in gear, you know the sudden quickness it has from the rpms being higher? thats because the motors cranking the torque converter more to make the pressure...loading/unloading on a truck i would think you probably have the truck almost idleing, which it would have to be if your holding the brakes down to deal with the boat....i've never heard of it being a failing transmission, its the same deal if you put the truck on park it will roll until the weights on the parking pin(which is bad i might add) so if the trans dosen't have enough pressure to keep the truck standing still on an incline its going to obviously take the point of lease resistance...

 

as far as tow mode, if your towing/hauling through hills where the truck has to constanstly upshift and down shift(or "hunting" as its sometimes called" i'd highly recommend pushing the button...the only harm the button will do is eat more gas, where as forceing the trans to hunt over and over and over will eventually burn up the trans....

 

 

Agree, but 90% of where I tow is flat. If I am in a hilly area, I will use tow/haul. I trtied both with & without T/H mode, and the trans didn't seem to care around here, except for the higher rpm and increased fuel use.

 

Now, when I am moving my campoer, that's another story, as it is 5500 lbs. Definite tow/haul territory there.

 

Also just today found out about the tap to signal feature........very nice thing