Pulsating/frog-like sound

[laurentgascon]

Hi,
I have a strange pulsating/frog-like sound coming from (I think) the transmission around 1500-2500rpm. I hear it when stationary in P or N, and especially when accelerating in all gears and R. It’s like some rotational chaffing sound at a rate of 2 per second or something in that range.

I recently rebuild my Disco 2 2001 v8 4.0L engine. I started it up and everything was fine (what a relief!). I then immediately did a transmission oil & filter change. I feel like this is when the noise started. I used Castrol Transmax fully synthetic. I followed the fill/run engine/fill/cycle through gears/fill to a constant drip... I’m pretty sure the qty is correct (probably 5 or 6L went in)

I’m about 15km into my new engine and trans oil change. Should I drive it a little more and see if it settles? What could the pulsing sound be???

 

[Toran]

Does it sound like its coming from under the hood or under the truck?

 

[laurentgascon]

When listening in the engine bay - I can't hear it from the passenger side. Driver side it's low. when I crawl under the car and put my ear against the transmission oil pan (at idle) I can hear a faint intermittent scratching. but it's hard to tell - the sound could be travelling from elsewhere too i guess... from inside the car, it's coming from the floor - so all signs pointing to tranny i guess... but i'm wondering how/if the oil change created this problem.

 

[laurentgascon]

I did drive the truck for 4-5km after the engine rebuild (before the transmission oil change). I know the transmission oil had been leaking and this is why I changed it... I hope it wasn't too low and I could have fried something :S
but other than the sound - it drives great, shifts fine and accelerates fine.

 

[Toran]

My thought was also on the fluid level.
I never agreed with the engineers that thought it was a good idea to remove the transmission dipstick for quick checking.

 

[laurentgascon]

My thought was also on the fluid level.
I never agreed with the engineers that thought it was a good idea to remove the transmission dipstick for quick checking.

I know right! i mean I drove it around the other day and pulled the fill plug and it immediately started dripping out, so i think the fluid level is good.

 

[discostew]

The vehicle should be running at idle in park when you check the trans fluid level.

 

[laurentgascon]

The vehicle should be running at idle in park when you check the trans fluid level.

yes, that's how i've been checking it.

 

[Swedjen2]

You must live next to a creek.

 

[discostew]

I wonder if the torque converter is all the way in the front pump of your trans. That or a broken flex plate makes a warble sound. Is it worse in drive than it is while it’s in nuetral

 

[bri]

" pulsating/frog-like sound "

LMFAO