Bad clutch?

I've only owned a couple of standard transmissions on vehicles so I haven't had a tranmission go bad yet. I bought a 4runner last year and it's always had power problems since I bought it. High revs would not produce more power to the wheels. I couldn't take it over 45 MPH no matter how much gas I gave it, so I thought maybe the clutch was slipping. Hard to tell when you don't know what a clutch should feel like if you never had a vehicle with one before.

Anyway, because of those problems I parked it for a while. My landlord requested I moved it tonight so I fired it up to put it in another spot and it none of the gears would engage. Finally I found reverse and it took a lot of RPMs to get it going, but then I started getting some grinding and the rear end felt like it was going to lift up and the wheels were gonna fall off. Smoke too, almost like bad brakes (but I already replaced the brakes and lines to the rear). The engine isn't perfect but everything I felt going wrong was coming from beneath the vehicle, like something had locked up. But it also felt like it was trying to turn sideways, a very unsettling experience.

Is that symptomatic a bad clutch, or maybe the rear diff locking up?

Welcome to the AF!

It sounds like your brakes are engaged. Jack up the wheels and make sure they all turn freely. If any are locked up (with the truck in neutral and parking brake off), then check the brakes on that wheel. If it's the rear, make sure the parking brake is correctly adjusted, then try turning the adjusting wheel inside the drum to loosen up the brake shoes. If it's the front, they may be stuck for a number of reasons. Time to take the brakes apart (either front or rear) and get them in excellent shape (pads/shoes and drums/rotors).

Your problem may be other things, but this is the place to start.

You may have a bad clutch also, but fix the brakes or whatever locks up your drivetrain first.

Brian R,

Thanks, I'm glad to be here.

Yeah, that was what it was. The emergency brake was still partially engaged, but disengaged enough for the light to turn off. Thanks!

I drove it for a bit just to remember what was wrong with it before, so I tried to get it up to speed. Once I get into 5th gear the power completely drops off and no matter how much gas I put into it the vehicle actually slows down on flat terrain. The same is true for any gear. After a certain RPM has been exceeded, the engine will rev but nothing seems to be going to the wheels. It feels sort of like it's falling partially into neutral. Any ideas?

Tell us more about the truck, year, mileage, stock or larger tires, etc ?

Larger tires with stock gears results in a power loss, as well as a clogged cat conv, worn engine, worn/stretched Timing Chain, etc.

What symptom did adjusting the emergency brake cure? It sounds like nothing has changed in your two descriptions. What has changed in the way your truck behaves?

OK,

I inherited a host of problems with this truck. It's a '91 4runner standard 3.0L V6. The engine runs rough and gets even poorer mileage than worst case in top condition - about 4.5 MPG highway (a 600 mile trip was 133 gallons in fuel). So yes, terrible; I suspect a couple of cylinders might not be firing.

The muffler is about falling off. It was butted up against the spare on a long trip and the spare ended up catching fire. The tires originally seemed to be oversized, but I replaced them with standard sized tires. The brake caliper siezed up and blew the brake line, which I replaced with new lines, rotors and calipers. Due to the oversized tires, the alignment is way off and cannot be fixed without replacing major components in the front end. The oil pan is also dripping and the power steering pump is holding fluid for at most a week.

Adjusting the emergency brake simply got me to where I was before - movable but very slow - wheels didn't overheat so I'm pretty sure the e-brake isn't engaged still. I know the engines are underpowered, but I've actually been reading some of the information you've provided Brian (thanks, it's very helpful) and even by those standards the loss of power is out of the expected range.

For this truck

1st drops off in power at about 2000 RPM going 15-20 MPH
2nd drops off in power at about 4000 RPM going 20-35 MPH
3rd drops off in power at about 4000 RPM going 35-45 MPH
4th drops off in power at about 4000 RPM going 45-55 MPH
5th drops off in power instantly and only nets an increase in speed on a downgrade.

I can reach 55 MPH pushing it really hard, but on a slight upgrade I can only get 45 MPH max in 4th gear. Actually one of the reasons the spare caught fire is because I 5th was unusable to maintain highway speed on level terrain and running it in 4th just to keep up with traffic caused the muffler to overheat.

Interestingly enough, I had the best fuel mileage and performance on my trip when I was in Colorado and had descended from 8000 feet to a 6000 and then leveled off. Fuel mileage was obviously good going downhill, but right after I filled up the tank at the bottom and travelled level for a while it had no appreciable loss of power - I could reach 65 MPH on level terrain and when I stopped to refill again the pressure in the fuel tank was very very good; so good in fact that when I opened the gas cap it sprayed gas all over me.

So yes, I have suspected a great many things - fuel pump, filter, bad cylinders, clutch, or maybe a combination of those things. I'm just really wondering where I should start troubleshooting. When I took the vehicle in to get new tires, they told me a front alignment could not be done on it and handed me a $2000 estimate just to get it into a state where the alignment could be done. It does tend to pull to the right during braking.

But most importantly, back to the first thing I want to take care of - the loss of power. I get excessive RPMs but nothing goes to the wheels after a certain point. From what I've read on here that happens even in good condition. I've tried starting the car from other gears to test the clutch and the engine stalls. I don't know expected play for the clutch pedal because it's a truck and I expect slightly more clutch play, but I'd say it's at least an inch. It definitely doesn't shift like my tercel.

Are there any better methods to troubleshoot exactly what is causing the power issue?

I would tell you to do a compression test and see if your engine is healthy.

The easiest way to know if your clutch is slipping is if at speed you mash the gas and the engine revs (watch the tach) but your speed stays the same or decreases the clutch is slipping. BE very careful I had a Toyota truck that was worn so bad the friction plate on the cluch disk wore off. This will definetly ruin your flywheel.

A lot of good thing have been mentioned, compression check, checking for high revs while in gear with no movement etc..

I have a '93 and it also has an hydrollic clutch system, I believe the 91 also has the same system. Check this for leaks and make sure your clutch is adjusted right. This web site is for a 93 but a lot pertains to the 91. Good luck and let us know the out come.
http://personal.utulsa.edu/~nathan-buchanan/93fsm/

Hey Jackson, your in the position I was in just a few months ago, I have a 94 4Runner 3 Liter V6 , with auto tranny though, and it almost drained me financially but after quite a few dollars I did get it fixed. I replaced everything to no avail, no one could fix it, and finally I got a name of an older gentleman thats was good with toyota's and I took it to him BUT he wouldn't tell me right out how he fixed it, saying he doesn't let other mechanics know how he fixes problems no others can fix. But I got this much out of him, when the head gasket was changed there was a sensor at the very back of the engine that was damaged when the gasket was being changed. Also on the passenger side of the engine, mid way, theres a chrome metal tube with 2 wires coming out of it connecting to another plastic connector, check that cause the wires could be damaged and finally he said something about adjusting The idle or throttle body sensor. I hope this may be of some Help to you, I know I went over 6 months without being able to drive my 4Runner besides it being like yours with lack of Power , it would just die out completely whether on the highway or just in the driveway.
Good Luck Jackson, I hope you get your 4Runner fixed, because your truly missing out on how good A 4Runner really performs, with all the problems your having.

OzzyO :smokin: