Engine braking a little rough?

[santanvalleydirt]

I've got a 5 speed transmission, and I understand that if you let go of the gas and don't press in the clutch, you'll start to slow down since you don't go into neutral like an automatic does... but I feel like on my truck it's doing it in a way that's not so great. If I'm in anywhere from 1st to 3rd gear and I let go of the gas, my vehicle acts like I just hit a large animal in the road or something and it gives me a good jolt that's not so comfortable. Is that normal?

 

[Bad_Vision]

Engine braking is relative to RPM and vehicle speed.
If you don't shift match properly to the speed and RPM you will leerch and jump around like you hit a speed bump.
Keep in mind that brakes are cheaper and easier to replace then your clutch so I recommend using the brakes!!

 

[santanvalleydirt]

Engine braking is relative to RPM and vehicle speed.
If you don't shift match properly to the speed and RPM you will leerch and jump around like you hit a speed bump.
Keep in mind that brakes are cheaper and easier to replace then your clutch so I recommend using the brakes!!

Yea I'm aware. I got a new both of those things. I almost always clutch and brake but sometimes I'm doing something specific and I don't press the clutch and notice it.

 

[levi.watson]

On my 89 I have something a little similar, but it doesn't sound as bad as yours. Are you pulling off the gas really quick, or letting it out slow? We I let it out real fast it will give a jolt, but when I do it slow, it feels pretty normal.

 

[santanvalleydirt]

On my 89 I have something a little similar, but it doesn't sound as bad as yours. Are you pulling off the gas really quick, or letting it out slow? We I let it out real fast it will give a jolt, but when I do it slow, it feels pretty normal.

Yea it's just when I quickly release completely off the gas.

 

[KidVermicious]

It's called compression braking. When you release the gas pedal, the engine is still spinning, the pistons are still pushing and generating compression in the cylinders, but there's not as much fuel being ignited in order to keep the pistons turning so if your clutch is still engaged, that compression acts like a giant brake on the drivetrain and slows the truck down. And for what it's worth, an automatic trans does it too, it doesn't "go into neutral" . The reason you don't notice it is because the torque converter soaks up most of the effect.

https://en.wikipedia.org/wiki/Engine_braking

Compression braking is harder on your truck than just using your brakes, but you should use it to keep your speed in check any time your brakes are in danger of overheating. On long steep descents, just keep the truck in 4th or even 3rd with the clutch let out and save your brakes for the corners.

 

[nicnmike]

How does the truck act when engaging the clutch from a dead stop? Vehicles I've had in the past with clutches starting to go, or flywheels that needed resurfacing would always shutter a little, or a lot depending on how bad they were.

 

[flyinhawaiian01]

I think the OP is talking about the slop from the diff, its called backlash. If its an open diff, there shouldn't be too much backlash, but if you have a locking diff, you will notice a lot more backlash.

Read this and see if that's what you're noticing:

https://en.wikipedia.org/wiki/Backlash_(engineering)

I don't recall at the moment how much you can turn the driveshaft while in neutral, but I believe it should be less than a quarter turn if its an open diff. If its a locked diff, I think its a little over a half turn, or maybe it was just under a half turn.

That backlash can open up on you if your pinion bearing is going out, or the crush sleeve is damaged (iirc), so if you're just noticing the backlash now, its possible something has shifted or is going out in the rear diff.

 

[AzuraT4R44]

Like it was said earlier though, rpm and speed have a lot to do with it. I have a 5 spd as well and it does it in just about anything with a manual I'm pretty sure. You said it happened in 1st- 3rd which are the peppier gears. I would think what's happening would be normal if you are doing rev matching to slow yourself down

 

[santanvalleydirt]

How does the truck act when engaging the clutch from a dead stop? Vehicles I've had in the past with clutches starting to go, or flywheels that needed resurfacing would always shutter a little, or a lot depending on how bad they were.

Nothing weird there. Just got a new clutch in. I press it in and nothing unusual happens or anything. It only happens when I'm going like 10-30 mph and I'm driving and I let go of the gas without pressing in the clutch.

 

[santanvalleydirt]

I think the OP is talking about the slop from the diff, its called backlash. If its an open diff, there shouldn't be too much backlash, but if you have a locking diff, you will notice a lot more backlash.

Read this and see if that's what you're noticing:

https://en.wikipedia.org/wiki/Backlash_(engineering)

I don't recall at the moment how much you can turn the driveshaft while in neutral, but I believe it should be less than a quarter turn if its an open diff. If its a locked diff, I think its a little over a half turn, or maybe it was just under a half turn.

That backlash can open up on you if your pinion bearing is going out, or the crush sleeve is damaged (iirc), so if you're just noticing the backlash now, its possible something has shifted or is going out in the rear diff.

If the problem was the diff, wouldn't it happen even if I had the clutch in?

 

[nevada]

Nothing weird there. Just got a new clutch in. I press it in and nothing unusual happens or anything. It only happens when I'm going like 10-30 mph and I'm driving and I let go of the gas without pressing in the clutch.

sounds normal to me.

ease off the throttle, or push in the clutch.

you get similar results when stabbing the throttle. it will be harsh if you hit it fast, if you ease into it, or work the clutch, it will be nice and smooth.

 

[santanvalleydirt]

sounds normal to me.

ease off the throttle, or push in the clutch.

you get similar results when stabbing the throttle. it will be harsh if you hit it fast, if you ease into it, or work the clutch, it will be nice and smooth.

I know how to get it to be smooth, its just sometimes after a couple hours of driving my clutch foot gets super tired so I'll let go of the gas w/out the clutch just for laziness purposes. I just wanted to make sure it wasn't some problem with my truck. :laugh:

 

[RAD4Runner]

Assuming nothing is broken...
IF you are on the higher rpm end of gear you're in (ie., 30 mph in 2nd gear, or 40 mph in 3rd gear) and release the gas, you will abruptly slow down.

 

[theking11863]

Sounds normal dude but bring it over one of these days and I'll check it out :thumb: