Transmission Clunk Felt Rolling from a Stop

[mtbtim]

Frontier719 started a thread describing an issue I've also been experiencing with my Automatic Transmission. I decided to start my own thread with a title labeling the issue so maybe we would get a better response on the thread.

Please read below what we are experiencing and what I think is happening. Let me know what you think could be causing this. Thanks!

Frontier719 wrote:
I've never had a transmission go out on me so I don't know what the signs are, but I think mine is starting to go. After sitting at a red light, I'll let off the brake and feel some kind of clunk as the transmission engages.

This was my response:
You know Frontier719, I bought a 2000 4runner 4x4 with 111,000 miles on it last September and it makes the same clunk you are experiencing with yours. I also have changed my transmission fluid and all my u-joints and slip yokes are well-greased.

I've spent some time trying to diagnose what's causing this, and I think it's just the fact that sometimes the transmission hasn't dropped into the lowest gear before coming to a stop. After you left off the brake and start rolling forward, the transmission finds the lowest gear and drops in giving you that clunk feeling. What I've noticed is I experience the clunk after letting off the brake if I come to a stop quickly and didn't give the transmission a chance to make it into the lowest gear yet if that makes sense. To see if my theory made sense, I would drive through residential streets and come to a slow stop giving the transmission a chance to drop into the lowest gear before coming to a complete stop and I wouldn't get the clunk after letting off the brake. I keep my hand on the shift lever and I can feel the transmission dropping into gear when I experience the clunk.

I understand some think it's a driveline issue but I truly believe it's just a situation where the transmission hasn't dropped into the lowest gear yet. The lowest gear on these automatic transmissions is pretty darn low. I detect it shifting up into second at around 10mph. That means when it's downshifting, it's not going to drop into that gear until you slow back down to around 10 mph. If you come to a complete stop quickly, I just think the transmission didn't have a chance to shift into the lowest gear yet. Taking the foot off the brake and rolling forward allows the transmission to finally drop in.

I've never experienced this with an automatic transmission and it possibly means that maybe we both might be having to do a transmission rebuild or replacement at some point. My transmission has no problems shifting or downshifting and I don't detect it slipping at all. It's just that weird clunk I feel rolling from a stop sometimes. As long as the transmission isn't slipping, I'm not too concerned about it but it would be nice to get a definitive answer what exactly is causing this. Since my 4runner had very low miles for it's age, I think most of it's miles were around town and the transmission probably got a lot more shifting through the gears than one that was driven on the highway mostly.

Does anyone else have any theories on what we're experiencing?

 

[Brveagle]

My 99 4runner sr5 automatic has always done the same thing. I also believe it to be the non harmful and your explanation makes sense.

 

[mtbtim]

I've done more researching through the threads and many think this is a rear driveshaft slip yoke issue. I've greased the crap out of mine and no change in the clunk symptoms. The previous owners weren't mechanical types so maybe whoever they brought it to for regular services neglected to grease the u-joints and slip yokes and the slip yoke was pretty much dry when I bought it. I greased all the joints and slip yokes when I bought it at 111,000 miles and I've re-greased during all the regular interval oil changes. I now have 125,000 miles.

The driveshaft slip yoke compressing on a hard stop and then releasing when you let off the brake makes sense to me too, but so far with my experience, greasing has done nothing to lessen or prevent the clunking.

 

[UTEP]

Frontier719 started a thread describing an issue I've also been experiencing with my Automatic Transmission. I decided to start my own thread with a title labeling the issue so maybe we would get a better response on the thread.

Please read below what we are experiencing and what I think is happening. Let me know what you think could be causing this. Thanks!

Frontier719 wrote:
I've never had a transmission go out on me so I don't know what the signs are, but I think mine is starting to go. After sitting at a red light, I'll let off the brake and feel some kind of clunk as the transmission engages.

This was my response:
You know Frontier719, I bought a 2000 4runner 4x4 with 111,000 miles on it last September and it makes the same clunk you are experiencing with yours. I also have changed my transmission fluid and all my u-joints and slip yokes are well-greased.

I've spent some time trying to diagnose what's causing this, and I think it's just the fact that sometimes the transmission hasn't dropped into the lowest gear before coming to a stop. After you left off the brake and start rolling forward, the transmission finds the lowest gear and drops in giving you that clunk feeling. What I've noticed is I experience the clunk after letting off the brake if I come to a stop quickly and didn't give the transmission a chance to make it into the lowest gear yet if that makes sense. To see if my theory made sense, I would drive through residential streets and come to a slow stop giving the transmission a chance to drop into the lowest gear before coming to a complete stop and I wouldn't get the clunk after letting off the brake. I keep my hand on the shift lever and I can feel the transmission dropping into gear when I experience the clunk.

I understand some think it's a driveline issue but I truly believe it's just a situation where the transmission hasn't dropped into the lowest gear yet. The lowest gear on these automatic transmissions is pretty darn low. I detect it shifting up into second at around 10mph. That means when it's downshifting, it's not going to drop into that gear until you slow back down to around 10 mph. If you come to a complete stop quickly, I just think the transmission didn't have a chance to shift into the lowest gear yet. Taking the foot off the brake and rolling forward allows the transmission to finally drop in.

I've never experienced this with an automatic transmission and it possibly means that maybe we both might be having to do a transmission rebuild or replacement at some point. My transmission has no problems shifting or downshifting and I don't detect it slipping at all. It's just that weird clunk I feel rolling from a stop sometimes. As long as the transmission isn't slipping, I'm not too concerned about it but it would be nice to get a definitive answer what exactly is causing this. Since my 4runner had very low miles for it's age, I think most of it's miles were around town and the transmission probably got a lot more shifting through the gears than one that was driven on the highway mostly.

Does anyone else have any theories on what we're experiencing?

Another common cause and what happened to my 2000 4R Ltd was the rear brakes grabbing. The clunk is the brakes releasing.

hard to imagine this would be it and I fought this explaination tooth and nail but it seems when Toyota wheel cylinders start to go the sort of freeze in the out position. Weird.

A test is to at a stop, idling, see if you roll forward by just letting your foot of the brake pedal. Also after a few miles feel the drum, it should be rather cool, not hot. If hot….. If so don't fight it; replace the wheel cylinder, springs and shoes. Less than $100 at NAPA for good quality. Turn them drums too! Makes no sense I know but the only cure IF brake grab.

it could also be the yoke as well. That requires lubrication and kind of tricky. If it is semi "frozen" you'll have to really pack a lot of grease in there. Mine was expanding the drive line instead of getting in the splines. You have to pack it and see if you are expanding. The slack gets taken up in the transmission and I don't think that's good. What I did was pack it tight, drive just 1/4 miles, then use a pin on the zerk fitting to allow the excess grease to be forced out. Careful! It can come screaming out! Wear googles!!!!! Took about 3 tries to get it smooth.

HTH

UTeP

 

[StreetCreeper]

I also experience this exact issue. Right down to it only happening when I come to sudden stops. I recently greased the driveline and it had no effect at all. It never occured to me that it might be a transmission issue as the feeling/sound always seemed like it came more from the rear of the vehicle.

I had been suspecting that it is a sticking rear brake since I think I have a leaky wheel cylinder that has contaminated the drum. I haven't yet had a chance to get in there yet though.

Now I'll be paying more attention to it. While it's kind of annoying to just have something "clunk" under your truck, I too have not noticed any performance issues related to it.

 

[StreetCreeper]

Another common cause and what happened to my 2000 4R Ltd was the rear brakes grabbing. The clunk is the brakes releasing.

hard to imagine this would be it and I fought this explaination tooth and nail but it seems when Toyota wheel cylinders start to go the sort of freeze in the out position. Weird.

A test is to at a stop, idling, see if you roll forward by just letting your foot of the brake pedal. Also after a few miles feel the drum, it should be rather cool, not hot. If hot….. If so don't fight it; replace the wheel cylinder, springs and shoes. Less than $100 at NAPA for good quality. Turn them drums too! Makes no sense I know but the only cure IF brake grab.

it could also be the yoke as well. That requires lubrication and kind of tricky. If it is semi "frozen" you'll have to really pack a lot of grease in there. Mine was expanding the drive line instead of getting in the splines. You have to pack it and see if you are expanding. The slack gets taken up in the transmission and I don't think that's good. What I did was pack it tight, drive just 1/4 miles, then use a pin on the zerk fitting to allow the excess grease to be forced out. Careful! It can come screaming out! Wear googles!!!!! Took about 3 tries to get it smooth.

HTH

UTeP

I see you beat me to it.

 

[mtbtim]

Another common cause and what happened to my 2000 4R Ltd was the rear brakes grabbing. The clunk is the brakes releasing.

hard to imagine this would be it and I fought this explaination tooth and nail but it seems when Toyota wheel cylinders start to go the sort of freeze in the out position. Weird.

A test is to at a stop, idling, see if you roll forward by just letting your foot of the brake pedal. Also after a few miles feel the drum, it should be rather cool, not hot. If hot….. If so don't fight it; replace the wheel cylinder, springs and shoes. Less than $100 at NAPA for good quality. Turn them drums too! Makes no sense I know but the only cure IF brake grab.

it could also be the yoke as well. That requires lubrication and kind of tricky. If it is semi "frozen" you'll have to really pack a lot of grease in there. Mine was expanding the drive line instead of getting in the splines. You have to pack it and see if you are expanding. The slack gets taken up in the transmission and I don't think that's good. What I did was pack it tight, drive just 1/4 miles, then use a pin on the zerk fitting to allow the excess grease to be forced out. Careful! It can come screaming out! Wear googles!!!!! Took about 3 tries to get it smooth.

HTH

UTeP

I recently had the rear brakes done due to a leaking rear axle seal so I don't think the brakes are the issue. The truck rolls fine from a stop. The clunk definitely feels like it's either coming from the transmission or driveshaft.

I heard it's not good to pack too much grease into the slip yoke so I didn't think to even try that.

 

[UTEP]

I recently had the rear brakes done due to a leaking rear axle seal so I don't think the brakes are the issue. The truck rolls fine from a stop. The clunk definitely feels like it's either coming from the transmission or driveshaft.

I heard it's not good to pack too much grease into the slip yoke so I didn't think to even try that.

Thing is about brakes is replacing just shoes wont do it. My wheel cylinders were not leaking a drop but sticking open! also there is a sharp corner on the shoes than can dig into the backing plate, creating a ratchet effect in my case, and I filed that and smoothed out the plate. Coupled with old springs and the WC's a similar issue as you have.

What I'm saying is, one could look at and do the brakes and still have this issue! I fought it for a month as I never saw wheel cylinders fail in this fashion. Usually they leak right? I still don't get it….

But again mine stuck at a stop, no forward motion and hot drums...

As per slip yoke, you should do that any way so make sure you release the pressure as it compresses in the transmission. eventually it loosens up but again I had to try this 3 times before I was getting the slip free and not putting strain on the differential or transmission.

Good luck,

Utep

 

[mtbtim]

Thing is about brakes is replacing just shoes wont do it. My wheel cylinders were not leaking a drop but sticking open! also there is a sharp corner on the shoes than can dig into the backing plate, creating a ratchet effect in my case, and I filed that and smoothed out the plate. Coupled with old springs and the WC's a similar issue as you have.

What I'm saying is, one could look at and do the brakes and still have this issue! I fought it for a month as I never saw wheel cylinders fail in this fashion. Usually they leak right? I still don't get it….

But again mine stuck at a stop, no forward motion and hot drums...

As per slip yoke, you should do that any way so make sure you release the pressure as it compresses in the transmission. eventually it loosens up but again I had to try this 3 times before I was getting the slip free and not putting strain on the differential or transmission.

Good luck,

Utep

I understand what you're saying about the wheel cylinders and I doubt they were replaced when the brake job was done. The truck always seems to roll fine at an idle and I haven't experienced any other tell-tale signs like smelling burning brakes which I imagine you would if the brakes were dragging a bit.

I did pump up the slip yoke until I saw some shaft movement. I pulled the zerk fitting and jumped up and down on the rear bumper to make sure I didn't overpack it. Some grease came out but not a ton. I put the fitting back in and drove it and I still feel the clunk.

One thing I forgot to mention is the shifter moves forward in conjunction with the clunk feeling. It really feels like to me the transmission is just finally making it into 1st gear. However, the slip yoke clunk is well-documented on the forums so maybe that's what I'm experiencing and I just haven't been able to get it lubricated enough yet. I might just pull the slip yoke apart and see if the splines are being properly lubricated or not. I understand I need to mark the driveshaft connections so I can put it back together in the same fashion and not screw up the balancing of the driveshaft.

 

[averyislost]

My '99 has done the same thing as described since I've gotten it, and mine is a 2wd if that makes a difference. However, I've noticed when driving my pop's '07 FJ that it will "bump" in a very similar fashion if I come to a complete stop quickly. I as well think it's transmission related where it just did not have enough time to shift into the lowest gear before stopping.
In any event, it doesn't really bother me since it doesn't occur often

 

[UTEP]

I understand what you're saying about the wheel cylinders and I doubt they were replaced when the brake job was done. The truck always seems to roll fine at an idle and I haven't experienced any other tell-tale signs like smelling burning brakes which I imagine you would if the brakes were dragging a bit.

I did pump up the slip yoke until I saw some shaft movement. I pulled the zerk fitting and jumped up and down on the rear bumper to make sure I didn't overpack it. Some grease came out but not a ton. I put the fitting back in and drove it and I still feel the clunk.

One thing I forgot to mention is the shifter moves forward in conjunction with the clunk feeling. It really feels like to me the transmission is just finally making it into 1st gear. However, the slip yoke clunk is well-documented on the forums so maybe that's what I'm experiencing and I just haven't been able to get it lubricated enough yet. I might just pull the slip yoke apart and see if the splines are being properly lubricated or not. I understand I need to mark the driveshaft connections so I can put it back together in the same fashion and not screw up the balancing of the driveshaft.

Yea, could be…


Like I said it took a few times before I could get clean grease to extrude from the yoke. I used a good Lincoln grease gun that provides enough pressure to force it through.

Taking it apart is the best approach if you have the skill.

HTH

Utep

 

[jeremyc74]

I understand what you're saying about the wheel cylinders and I doubt they were replaced when the brake job was done. The truck always seems to roll fine at an idle and I haven't experienced any other tell-tale signs like smelling burning brakes which I imagine you would if the brakes were dragging a bit.

I did pump up the slip yoke until I saw some shaft movement. I pulled the zerk fitting and jumped up and down on the rear bumper to make sure I didn't overpack it. Some grease came out but not a ton. I put the fitting back in and drove it and I still feel the clunk.

One thing I forgot to mention is the shifter moves forward in conjunction with the clunk feeling. It really feels like to me the transmission is just finally making it into 1st gear. However, the slip yoke clunk is well-documented on the forums so maybe that's what I'm experiencing and I just haven't been able to get it lubricated enough yet. I might just pull the slip yoke apart and see if the splines are being properly lubricated or not. I understand I need to mark the driveshaft connections so I can put it back together in the same fashion and not screw up the balancing of the driveshaft.

Mine did this exact same thing from the time I bought it until just recently when I greased it for the third time. Now it doesn't do it at all. I suspect that once they get really dry it takes a long time to get the grease back to all the friction points. You might just give it a few weeks and grease it again before you start tearing the driveshaft out.

 

[mtbtim]

Thanks Everyone so far for the responses. I'm going to pursue the slip yoke disassembly to make sure it's getting greased properly. It looks pretty easy to take apart. I just have to make sure I make marks on the u-joint differential connection and on the slip yoke propeller shaft connection to make sure I don't mess up the balancing.

It would be awesome if I can get rid of the clunk. I'll report back with the results when I get the chance to do it.

 

[LittleCaesar]

The bearings in your U joint may be too far gone (14+ years) for any amount of grease to work well enough to eradicate the clunk completely. The only real solution would be to remove and take the drive shaft to a shop to have new U joints pressed in.

It is similar to those who have leaking valve cover gaskets. Retightening the bolts may stop the leak and one is good to go but if the leak(s) continue then nothing but new gaskets and more will solve the problem.

 

[mtbtim]

The bearings in your U joint may be too far gone (14+ years) for any amount of grease to work well enough to eradicate the clunk completely. The only real solution would be to remove and take the drive shaft to a shop to have new U joints pressed in.

It is similar to those who have leaking valve cover gaskets. Retightening the bolts may stop the leak and one is good to go but if the leak(s) continue then nothing but new gaskets and more will solve the problem.

If it were a u joint issue, I thought the symptoms would be different than the clunk I'm experiencing. I had a u joint go bad once on a 68 Bronco and I remember it made a constant noise. I thought the clunk was mainly an issue with the slip yoke binding from a stop and than releasing after you let off the brake and roll forward. Will bad u joints give you the same symptoms?

 

[64rat]

I had a similar issue, it ended up being the transmission mount.

 

[mtbtim]

I had a similar issue, it ended up being the transmission mount.

The transmission mount was the very first thing I checked when I was trying to diagnose the clunk feeling when I bought the truck last September. The mount looked fine to me but maybe I'm missing something. The rubber bumpers look good and I don't see any obvious cracks in the mount. How did you determine the mount was bad?

 

[64rat]

The rubber on mine was falling apart, i could see it. I would try power braking it to see if you can reproduce the noise or slide a jack underneath it and see how much the transmission moves.

 

[mtbtim]

The rubber on mine was falling apart, i could see it. I would try power braking it to see if you can reproduce the noise or slide a jack underneath it and see how much the transmission moves.

I'm going to take a better look at that transmission mount. I have a GoPro camera and I was thinking it would be cool to somehow mount it under the truck to see how much the transmission is moving while driving and during a hard stop. I could also point it at the rear propeller shaft and see if the the slip yoke is binding and then releasing causing the clunk.

 

[Joshv4runner]

I'm having the same exact issue but I'm having to accelerate from a complete stop to 1300 rpms to get going. This all happened about two days ago and just this morning I noticed the clunk. For a second I thought it was my tranny that was about to grenade then reading this gave me some relief. LOL

I will have to grease the the driveline tonight and see if that works if not, I'll have to check if my rear brakes are sticking or if it is time to change out the u-joints like previously posted. Is anyone having to accelerate a bit more from a complete stop to go?