Mar-28-2023 09:11 AM
Apr-01-2023 08:50 AM
mkirsch wrote:Turtle n Peeps wrote:
Modern computer controlled trucks do not over rev. It's impossible because of the computer.
Anybody that is worried about over reving their "modern" truck is worrying about nothing. They need to go a rev anonymous meeting. They are held at their local race track. I haven't been to any in a long time but when I did I took my 572 to 7,000 RPM time after time. And this thing has pistons as big as a small coffee can.
Let it rev.
That's true when you're stomping on the go pedal, but is it when you are being pushed down a grade by a big trailer with your foot off the gas?
When you're being pushed you can cut the ignition all you want and it's not going to limit anything. The only thing that will bring RPMs down is an upshift, and I don't know of anyone who has let their rig go that far to see what would happen.
For science, I've let my 8.1L/Allison go to 5000 before I hit the brakes, and there was no indication of it upshifting or doing anything but dropping another gear in a futile attempt to maintain speed by engine alone.
Mar-31-2023 09:20 AM
Mar-31-2023 06:53 AM
Turtle n Peeps wrote:
Modern computer controlled trucks do not over rev. It's impossible because of the computer.
Anybody that is worried about over reving their "modern" truck is worrying about nothing. They need to go a rev anonymous meeting. They are held at their local race track. I haven't been to any in a long time but when I did I took my 572 to 7,000 RPM time after time. And this thing has pistons as big as a small coffee can.
Let it rev.
Mar-31-2023 05:31 AM
Lantley wrote:Turtle n Peeps wrote:Lantley wrote:
I'm not suggesting the OP has a problem with their truck. But I can attest to my 07 LBZ Duramax overheating due to excessive revving on steep declines. Is a 2007 a modern truck?
The exhaust brake was aftermarket which may have been the root of the problem. Nevertheless the tranny would and did overheat if you let it.
Any modern diesel truck or gas truck for that matter, cuts all fuel off to the injectors while going down hill. There is no heat being made because there is no combustion going on. This has been going on since 1994.......at least for GM.
That all sounds good, I don't dispute your claim. But that 2007 truck would definitely overheat if you let it. I managed to control the overheating by not letting the truck rev as much on steep declines.
Again it had an after market exhaust brake that could had been faulty and ultimately caused the problem.
My 2019 has a factory exhaust brake and does not have that issue.
Mar-31-2023 03:47 AM
Turtle n Peeps wrote:Lantley wrote:
I'm not suggesting the OP has a problem with their truck. But I can attest to my 07 LBZ Duramax overheating due to excessive revving on steep declines. Is a 2007 a modern truck?
The exhaust brake was aftermarket which may have been the root of the problem. Nevertheless the tranny would and did overheat if you let it.
Any modern diesel truck or gas truck for that matter, cuts all fuel off to the injectors while going down hill. There is no heat being made because there is no combustion going on. This has been going on since 1994.......at least for GM.
Mar-30-2023 07:49 PM
Lantley wrote:
I'm not suggesting the OP has a problem with their truck. But I can attest to my 07 LBZ Duramax overheating due to excessive revving on steep declines. Is a 2007 a modern truck?
The exhaust brake was aftermarket which may have been the root of the problem. Nevertheless the tranny would and did overheat if you let it.
Mar-30-2023 05:48 PM
Turtle n Peeps wrote:
Modern computer controlled trucks do not over rev. It's impossible because of the computer.
Anybody that is worried about over reving their "modern" truck is worrying about nothing. They need to go a rev anonymous meeting. They are held at their local race track. I haven't been to any in a long time but when I did I took my 572 to 7,000 RPM time after time. And this thing has pistons as big as a small coffee can.
Let it rev.
Mar-30-2023 05:05 PM
Turtle n Peeps wrote:
Modern computer controlled trucks do not over rev. It's impossible because of the computer.
Anybody that is worried about over reving their "modern" truck is worrying about nothing. They need to go a rev anonymous meeting. They are held at their local race track. I haven't been to any in a long time but when I did I took my 572 to 7,000 RPM time after time. And this thing has pistons as big as a small coffee can.
Let it rev.
Mar-30-2023 03:39 PM
Mar-30-2023 12:21 PM
Boomerweps wrote:
A minor trick with the F150 10 speed on hills:
If you set the cruise control before the top of the hill going down, it will aggressively downshift to maintain speed 5mph or so above the set speed. I’ve not tried this towing.
Mar-30-2023 10:33 AM
Mar-30-2023 09:44 AM
Mar-29-2023 09:10 PM
plasticmaster wrote:
I have a 2017 F150 with the 5.0 engine. When I tow my TT in tow haul mode, it seems to me that Ford has overdone it with the engine braking. As I apply the brakes, it downshifts really hard and revs really high to the point of making me wonder if it could damage the engine or transmission. On my last trip, I would disengage tow/haul when I knew I was getting ready to hit the brakes. Should I be concerned about this, or just let it do its thing?
Mar-29-2023 08:24 AM
Grit dog wrote:MFL wrote:
On a steep downhill, with 10K pushing me, I prefer to not use t/h, and manually select gear I want to use. This works best for me, on long downhills, that also include lots of turns.
Jerry
Not sure I’ve seen a manual mode (+/- button) on any newer truck that will prevent further downshifting if the truck calls for it. Either slowing down below min speed for the top gear selected or in a grade braking scenario.
From the old 6 speed Fords that the OP has to new GM 10speeds.
They’re great at limiting up shifts to whatever top gear you want to maintain.