Loss of power in 4th & 5th gear

I have a 2003 S-10 standard and a similar conditions as this discussion, but my issue is not with the engine bogging down. The engine RPMs increase, but the truck does not pick up speed until I let the engine settle, then push the gas again. If I drive too long the truck will start doing this in 3rd and not just when I shift gears. It’s like the power is just not making it to the wheels. There’s a disconnect in the power transfer or something.

The clutch (clutch kit), flywheel, master and slave cylinders, and the lines to the cylinders have all been replaced; some twice. I just had the transmission and differential fluids replaced. Is this a transmission issue or could this still be something to do with the clutch? Or is it something else entirely?

If the RPM increases but the vehicle speed does not, the clutch is slipping, pure and simple…

I had a TR-3 do this once…it turned out to be a pin-hole leak in the transmission casting allowing a tiny amount of oil to continuously find it’s way onto the clutch disc…The disc will look shiny and black and it will slip as you describe…A very small leak past the transmission main-shaft seal will do the same thing…

As @Caddyman says, the clutch is slipping. There’s nothing else l between the engine and the wheels that can slip and cause this symptom. It’s very unlikely to be the xmission, or the differential or the driveshafts. There’s no horrible grinding noises, right? Just the slipping? Almost certainly the clutch is the problem. There is some very slight chance that something in the clutch linkage isn’t working properly, which is preventing the clutch from fully engaging. Very unlikely though. You could ask a mechanic to check the clutch pedal free play.

The clutch is SLIPPING!

Your clutch is toast, again. Stop keeping your left foot on the pedal in between shifts.

As @Caddyman says, the clutch is slipping. It may be a problem with the linkage, but after a clutch slips for very long, it’s too late.

"The clutch (clutch kit), flywheel, master and slave cylinders, and the lines to the cylinders have all been replaced; some twice."

You’re not going to like this…

Take your mechanic for a ride (you driving), so he can tell you exactly what it is that you are doing which is wearing out your clutches. Yes, you are burning out your clutch. It may be what oldtimer11 says - resting your foot lightly on the clutch pedal when you are not shifting. Or using the clutch to hold the truck on a hill when you have to stop for a light.

But I’ll bet money that it’s something else (or both). I think that when you are shifting, you step on the gas BEFORE you have fully released the clutch, and you are holding the clutch pedal at the friction point much too long. This is a common habit, practiced by those thinking this is how to get a smooth shift. It’s not.

On level ground, you should be able to start from stop and fully release the clutch without stepping on the gas AT ALL. No, I’m not kidding, you should be able to do that, even if it’s not the normal way we drive. It’s all in your feel for the clutch “friction point”.

In normal driving, you apply the gas a split second after your foot comes off the pedal, NOT while the clutch pedal is at the friction point. Same when shifting between gears - lift your foot to the friction point, hold it there for a tiny fraction of a second, and then lift the remainder of the way and get your foot off the pedal. Then step on the gas.

I replaced a clutch on my old Nissan pickup in 1998, not because it needed it, but because something had come loose in the transmission at 303,000 miles and I had to pull the transmission for the repair. But anyone knows that if your transmission is out, you replace the clutch because with the transmission out, it’s a simple job.

After that clutch job, I used that little four cylinder truck on a major renovation and continuing work on rental property. I regularly hauled heavy loads like a lot of sand, or often pulling my relatively heavy utility trailer full of soil or compost, or in one case, pulling the trailer with a bunch of broken up concrete, among other things, all of which put extra demands on a clutch.

Even with that heavy overuse of the little truck, the clutch was fine 13 years later, after 100,000 exclusively around town miles, when the head gasket finally let go.

Hate to break it to you - you need instruction on how to use a clutch.

Not much left to say. Get another clutch and learn to drive.

First, thank you guys for your input. I’ll take this information to a mechanic and have them see what they can find. Second, don’t talk talk to me like I’m some old grandma trying to figure out the mysterious interwebs. I’m talking oldtimer11 and Rod Knox. You act as if my driving is causing me to burn through clutch after clutch. If that were the case, I’d have gone through 8 or more by now, just on this truck. I’ve had the thing for 10yrs and I had a Nissan before that I NEVER had a clutch problem. That’s with using them both for delivering auto parts for 2yrs each. So, thank u=you and I appreciate the input, but don’t be dicks.

You asked for advice and you got it. It might not be right, but we can’t see you drive or examine your car. If you want to build self esteem, I wouldn’t know what website to send you to.

I’m not sure what the “clutch kit” entails in terms of parts. There are springs that put the pressure on the clutch disk, pressure plate, and flywheel. Weak springs, or a bent part could reduce the tension and allow the clutch to slip. An old gouged out flywheel or pressure plate will also allow slippage.

You may need to redu the clutch again and make sure the flywheel is resurfaced (or replaced if necessary) get a new pressure plate, and new springs and all should be well.

My advice is worth every cent…

It’s clear that your clutch is slipping, the question is “why”.
I’d suggest that you try another shop. The fact that the hydraulic components were changed in an attempt to fix the symptoms you’ve described suggests to me that your cuurrent shop is throwing parts at the car to try to solve the problem without thinking…all at your expense. That even suggests that perhaps the shop said they put in a clutch “kit” but perhaps only put in a clutch disc…perhaps…as already alluded to. Or perhaps he used the wrong parts. Perhaps you still have the original pressure plate assembly and for some reason it can no llonger keep the pressure on the disc when under high load.

This problem should not be rocket science to correct. It’s simple, basic stuff. The fact that the shop has done so much without fixing the problrm is a bad sign to me.

BTW, @Pike1331, after re-reading the OP I must say that your first paragraph was indicative of someone totally unfamiliar with the operation of a clutch. Best of luck to you.

+1 for @the same mountainbike. Try another shop.