Clunk when cold engaging drive

qwertyjjj · Post by **qwertyjjj** » 04 Nov 2020, 07:42

The head of the engine was replaced recently is (had a timing belt/water pump failure that bent all the valves so we got a used engine from the yard).
Since then, when the car is cold, there is a big clunk on engaging drive. It goes away when warm.
Any ideas what it could be?

moncureww · Post by **moncureww** » 04 Nov 2020, 12:12

Is it axle ping? Mine (2006 s60 AWD) has an intermittent axle ping on engaging drive - doesn't happen all the time, but definitely a clunk when taking it from park to drive sometimes.

qwertyjjj · Post by **qwertyjjj** » 04 Nov 2020, 12:27

Would axle ping disappear when the engine is warmed up? When warm if I go to park and then back into D there is no clunk

moncureww · Post by **moncureww** » 04 Nov 2020, 20:17

I'm not quite sure - I wouldn't think that it would be dependent on the engine "warming up," but for some reason I notice my "clunk" or axle ping more when I'm just starting out after leaving the car parked for a while.

qwertyjjj · Post by **qwertyjjj** » 06 Nov 2020, 06:40

When I rock the wheels with my foot I do get kind of a clicking sound though it's not exactly the same as the clunk when driving but that could be a speed thing.
Is it dangerous at all? It looks like a simple change, you just take a bolt out, puts new one in, and torque.
I assume if the bolt were to fail, you would just lose drive power to the car?
I'm guessing when they changed the engine, they had to take off the axle or something and the bolts are now worn

Post by **jonesg** » 06 Nov 2020, 07:20

moncureww wrote: 04 Nov 2020, 20:17 I'm not quite sure - I wouldn't think that it would be dependent on the engine "warming up," but for some reason I notice my "clunk" or axle ping more when I'm just starting out after leaving the car parked for a while.

initial shifting can be bumpy when the transmission is cold, idle might still be high too.
It may have more to do with trans temp than engine itself.

Post by **abscate** » 07 Nov 2020, 03:34

qwertyjjj wrote: 06 Nov 2020, 06:40 When I rock the wheels with my foot I do get kind of a clicking sound though it's not exactly the same as the clunk when driving but that could be a speed thing.
Is it dangerous at all? It looks like a simple change, you just take a bolt out, puts new one in, and torque.
I assume if the bolt were to fail, you would just lose drive power to the car?
I'm guessing when they changed the engine, they had to take off the axle or something and the bolts are now worn

You won’t lose drive power of that bolt gets loose. It just holds the axle shaft tight in the bearing hub. The splines transfer the drive power. If it does get lose, it can cause an ABS code caused by the tone ring not being exactly in the right place relative to the ABS SENSOR

Post by **RickHaleParker** » 07 Nov 2020, 04:07

It is not uncommon for a transmission to clunk when cold. Transmission fluid is a type of oil. Like any oil it thickens when it get cold. Also metal contracts when it gets cold tightening the tolerances. I pretty sure it not your engine warming up that makes the clunk go away. It is the transmission fluid warming up and getting circulation going that makes the clunk go away.

When it is cold letting it run for a minute or two might do the trick. Which is something you should be doing anyway, it extends the life of the engine. If it does not clunk. It pretty much confirms my guessanostic.

A transmission fluid change might do the trick. If anything don't get freaked out about the transmission clunking when its cold.

Post by **Blacklab467** » 02 Jan 2021, 19:22

I had that problem, hard clunk going into drive or reverse from park cold or hot. Changed all the motor mounts and top mount with OEM, didn’t solve the problem, changed the B-4 servo also. Problem solved when I did a Transgo shift kit and rebuilt the linear solenoids, now it’s sooooo gentle going into drive or reverse.

537playing · Post by **537playing** » 06 Jan 2021, 18:28

Blacklab467 wrote: 02 Jan 2021, 19:22 I had that problem, hard clunk going into drive or reverse from park cold or hot. Changed all the motor mounts and top mount with OEM, didn’t solve the problem, changed the B-4 servo also. Problem solved when I did a Transgo shift kit and rebuilt the linear solenoids, now it’s sooooo gentle going into drive or reverse.

You have peaked my interest in the shift kit. How was it done?