Weird "Think" noise with initial movement

So pulling into home depot yesterday I realized my truck is making a weird "tink" noise. It only happens when you give the truck gas causing the truck to kind of jerk back a bit, and then again when you let off the gas pedal and it jerks forward. Real easy to get it to make the noise in 1st and 2nd. Acceleration is usually smoother once you get past those, so I didn't really hear it past 3rd. It's not a constant noise, just an instant Tink, then silence, then again if you recreate a jerky movement.

Truck: 1998 Access Cab. 2.7. 5spd. 4x4. manual hubs

Any ideas?


Thanks
-Josh

 

Lube the driveshaft U-joints.

 

I'll check them.
I greased them real well about 500 miles ago, which is why I think it's something else. It does resemble the driveshaft thunk you can get when your ujoints are shot or need grease in that it happens at the same time. It's not the same sound though, and you can't feel it through the floor boards like when you have that thunk.
This is just a light "Tink". About the volume of when you have a rock in your treads.

 

Wild-ass-guesses:
u-bolts.
skid plate
motor mount
clutch slave

Where does the 'tink' appear to be coming from?
Rear, front, left, right?

 

Also could be axle wrap.

 

Sounds like it's coming from the front half of truck. Not sure if it's more to one side or the other.

 

Ok, went and drove around, and it seems to be coming from right under the seat area of the truck. I also think it is definitely coming from the drive train. I tried to mimic the jerk forward action by smashing the brakes and it didn't do it. Only when I press the gas at low speeds, and also when I let off the gas causing the truck to lunge forward.

 

Hmm... Maybe something's up with where the front drive-shaft meets the trans or t-case?

 

Do the RPM's change at the same time?

 

The RPMs change, but that's due to me giving it gas or letting of the gas. It's not a constant tink, just with the initial jerk forward of giving it gas, then the lunge forward when letting off the gas. Seems like it only does it in the lower gears 1-3 since it's not as smooth with driving and shifting.

 

Maybe something where the driveshaft leaves the Tcase?

 

When mine does this the slip joint on the rear driveshaft is dry, Grease the slip joint, it goes away.

 

I was about to say the exact same thing.

 

If the motor mounts are weak, then the shift lever could be contacting the metal side of the console 'hole' with every change in torque. Do the levers move quite a bit with the initial 'take off' from a stop?

 

My '98 3.4L does the same thing as well

 

SpeedoJosh,
Did you ever figure out the problem? My '99 just started doing the same thing a few days ago and I've been unable to diagnose.

Thanks

 

This is funny (odd funny, not haha funny), mine began doing this too, and I cannot replicate the sound at will. It generally seems associated with initial movement or a change in speed, but it is totally unpredictable and does not seem specific to braking or acceleration. And this is on pavement with normal granny driving, 5 speed.

I just finished lubing the entire driveline (including slip yoke) and it did not change it. It does sound like it is roughly around the middle of the truck under the cab, but hard to tell when inside, which is the only time it happens.

Just had a thought: Would the carrier bearing do this if going bad?

I've not checked the U bolts in quite some time, and I do have a small lift, but that does not seem a likely culprit. I check them next, anyway.

 

I've actually had mine make the noise while coasting around the neighborhood (while trying to find out what's causing it). 99% of the time it's associated with acceleration. The other 1% is during constant velocity. We're going to check the u-joints, just replaced the carrier bearing 6 months ago.

 

Just about any slop in the driveline can cause a "tink" and it can be telegraphed from one end to the other.
Here is a "tink" (solved) thread that might be worth a read. The solution starts at post #14.

 

Ah jeez. Great links and info, but if that is the cause, I'm more likely to live with it than dive into that unless I have leaking seals, too.