Clutch Chatter on takeoff when warm

[OffroadTwin]

Hello, I have been searching and reading the forum,, after buying a 99 4Runner 3.4 manual. It has bad clutch chatter only after driving for 15-20 minutes at full operating temp, absolutely nothing when cold. If I am moving even 1mph or on a downhill takeoff, it isn't bad and sometimes nonexistent, but when taking off level ground or worse an uphill, it gets really bad to the point where sometimes I have to engage the clutch 2-3 times to make it stop shaking. I have read about this problem but it seems like no one has a solution. Suggestions for things to test? I check the engine and trans oil and no leaks that I've found (the t-case is leaking but I doubt it would cause anything like this). If you have suggestions or fixes please let me know!!!

I also have vibration above 60mph, which may or may not be related. Also have tested for driveshaft wobble and found nothing.
Thanks for any help!!

 

[Kanoe]

I had an old corolla that did that for years. I was told it's called a hot spot on the flywheel. I think it's just a spot that grabs, not really hot as such. I lived with it. I believe the fix is to resurface your flywheel and install a new clutch. If you are having to feather the clutch excessively you might end up at that point sooner or later.

I'm no expert, others will have a more informed opinion. What mileage are you at? Is it the original clutch still?

 

[OffroadTwin]

I had an old corolla that did that for years. I was told it's called a hot spot on the flywheel. I think it's just a spot that grabs, not really hot as such. I lived with it. I believe the fix is to resurface your flywheel and install a new clutch. If you are having to feather the clutch excessively you might end up at that point sooner or later.

I'm no expert, others will have a more informed opinion. What mileage are you at? Is it the original clutch still?

Thanks! Ya I've heard that before, just worried about what is causing the issue so if I install a new clutch/flywheel it doesn't happen again a year later. 200K miles, not sure about original or not but I think it is.

 

[OffroadTwin]

Forgot to add- the clutch pedal squeaks when releasing pedal slowly intermittently, about 1/3 of the time I'm shifting

 

[kolelt]

Forgot to add- the clutch pedal squeaks when releasing pedal slowly intermittently, about 1/3 of the time I'm shifting

That could be the spring on the pedal. Mine squeaks ALOT lol. Sounds like a old door with a old spring.

My buddy had a bad chatter noise in his 94 Supra. Was because of his heavy duty flywheel. So maybe something is up with your flywheel.

 

[Tyler James Inc]

Sounds like you need a new Aisin clutch kit, and to get your flywheel resurfaced.
The squeaky pedal is common with this gen 4Runner and Tacoma. They used a stupid over-engineered torsion spring that helps with pedal return AND pedal assist. It's actually not stupid at all, but they didn't quite build it out right. The bushings wear out, then the spring starts wearing the spring seat on the pedal. You can replace the bushings, but if the spring has already wallered out the seat, the bushing won't last at all. I pulled the spring out of mine, and have had no ill affects that I can feel. Pedal feels great, it returns to the top of the throw, and- best of all- no more squeaking! [emoji1360]

 

[JayRolla]

Like stated above you need new clutch and flywheel surfaced. You have a build up of disk material on the flywheel in a "hot spot". It's the same feeling you get with "warped rotors" when they get a hot spot.

 

[OffroadTwin]

Ok, if I end up replacing the clutch/flywheel I will probably do the rear main seal as well. Anything else I should check on or change out while I am in there?

 

[JohnMc]

Pilot bearing/release bearing, but those should be in your clutch kit.

How many miles on it? If it was somewhat low, I'd be slightly tempted to leave the RMS alone if it was absolutely bone dry. But only slightly tempted, there is some risk of making a leak where there wasn't one if you don't do it right. I.e. scratch the crank sealing surface getting the old seal out, not installing the new one right.

You might also check motor mounts to see if you're just getting some drivetrain lurch?

I replaced my clutch a few months ago, it's pretty easy as far as clutch replacements go. Nice amount of room around everything compared to some cars.

 

[OffroadTwin]

Pilot bearing/release bearing, but those should be in your clutch kit.

How many miles on it? If it was somewhat low, I'd be slightly tempted to leave the RMS alone if it was absolutely bone dry. But only slightly tempted, there is some risk of making a leak where there wasn't one if you don't do it right. I.e. scratch the crank sealing surface getting the old seal out, not installing the new one right.

You might also check motor mounts to see if you're just getting some drivetrain lurch?

I replaced my clutch a few months ago, it's pretty easy as far as clutch replacements go. Nice amount of room around everything compared to some cars.

200k miles on it. How difficult is the RMS? I have done a clutch replacement once before in a Jeep TJ, and it wasn't terrible. And as far as the motor mounts, what are the wear signs I am looking for to see if they are good or not? Thanks!

 

[JohnMc]

Replacing seals is always just a bit of a PITA. I tried using a seal hook on mine but it broke. I never liked that seal hook.

My back-up technique is to *very carefully* drill a few small holes in the seal and screw in small sheet metal screws, and then use those to pull the old seal out. Then chill the new seal in a deep freeze (makes it slightly easier to get in), slather the outer and inner edges with oil, and carefully tap it in. It won't want to go in straight. It helps to have something round that will fit around the crank end and allow you to apply force to the whole seal at once, otherwise it's just a finicky task of tapping the high spot as it slowly goes in. Don't rush it too much, of the seal shell bends you need to get a new one.

I really would not recommend taking the seal housing off, that's where you're really likely to create future leaks.

As for the motor mounts, I'd just look more for broken mounts than anything else. When I did my clutch I discovered that the trans mount was completely separated from the metal. There's a bit metal bolt there that acts as a backup, but it still allows some unfettered movement of the rear of the drivetrain before the bolt stops it. You'd probably notice the shifters bouncing around a little, but it's hard to know how much bounce is normal.

 

[OffroadTwin]

Replacing seals is always just a bit of a PITA. I tried using a seal hook on mine but it broke. I never liked that seal hook.

My back-up technique is to *very carefully* drill a few small holes in the seal and screw in small sheet metal screws, and then use those to pull the old seal out. Then chill the new seal in a deep freeze (makes it slightly easier to get in), slather the outer and inner edges with oil, and carefully tap it in. It won't want to go in straight. It helps to have something round that will fit around the crank end and allow you to apply force to the whole seal at once, otherwise it's just a finicky task of tapping the high spot as it slowly goes in. Don't rush it too much, of the seal shell bends you need to get a new one.

I really would not recommend taking the seal housing off, that's where you're really likely to create future leaks.

As for the motor mounts, I'd just look more for broken mounts than anything else. When I did my clutch I discovered that the trans mount was completely separated from the metal. There's a bit metal bolt there that acts as a backup, but it still allows some unfettered movement of the rear of the drivetrain before the bolt stops it. You'd probably notice the shifters bouncing around a little, but it's hard to know how much bounce is normal.

Thanks for the help, I appreciate the tips. Now for a stupid question, does the oil need to be drained out of the engine before changing the RMS? And what about the transmission oil before removing it from the engine?

 

[4Reak Show]

Mine has chattered the exact same as you described since I swapped the 3.4. Used a cheap napa clutch and never doing that again.... Aisin or nothing. A work around in the meantime I've noticed is to rev the engine a bit more on take off, like 1800-2000 and then release the pedal a little quicker without dumping it and that tends to get it to hook up a little better.

You don't need to drain trans but it's one of those "while you're there" maintenance things. Neither with engine oil. A tad might seep out but static level is below the seal I'm pretty sure.

 

[OffroadTwin]

Mine has chattered the exact same as you described since I swapped the 3.4. Used a cheap napa clutch and never doing that again.... Aisin or nothing. A work around in the meantime I've noticed is to rev the engine a bit more on take off, like 1800-2000 and then release the pedal a little quicker without dumping it and that tends to get it to hook up a little better.

You don't need to drain trans but it's one of those "while you're there" maintenance things. Neither with engine oil. A tad might seep out but static level is below the seal I'm pretty sure.

Ok, good to hear. I am planning on a LUK clutch, they are cheaper than aisin and I've used them before with great results

 

[JohnMc]

Thanks for the help, I appreciate the tips. Now for a stupid question, does the oil need to be drained out of the engine before changing the RMS? And what about the transmission oil before removing it from the engine?

No on both. With the caveat on the trans question being that you keep it pretty much level, if you tilt it on the side, or upside down, oil will start to come out. But keep it somewhat level, no need to drain it.