trans buzz in reverse

[flyinlow]

I have  a 518 trans in my 73  . On the first start after sitting a few day trans makes a buzzing sound in reverse. Backs up OK. no noise after driven.

Sounds like a power steering pump with air bubbles.

Fluid is bright red and trans is full.

[tricky lugnuts]

Can't speak to the 518, but my small block 727 used to buzz like that first thing in the morning, and slip a little in both reverse and forward gears. I'd put the transmission in neutral while car was running and it would then disappear after a few seconds of that.

Everybody told me back then that it was the pump buzzing.

[John_Kunkel]

The buzzing is caused by a rapidly cycling pressure regulator valve, this has been a problem in the 727/904 since day one. It's more of an annoyance than a real problem, the factory recommended fix is to replace the valve body.

On the later RE units they came up with a replacement valve to cure the buzz:

http://dodgeram.info/tsb/1999/21-08-99.htm

[The70RT]

I have an 01 Ram and it was buzzing like that. I ignored and later on I had a check engine light come on. I have a warranty still and they ended up rebuilding the transmission, My overdrive unit was toast. That was earlier in the year. I know the buzzing had nothing to do with that but since it is colder now I can hear the buzzing again. I guess I better get it in again before my warranty runs out in 6 months if it could be the valve body.

[flyinlow]

Thanks for the refference John.

It only makes the noise when cold and has not been driven for a few days.

For now I will turn up the radio .

I put a Trans Go Kit in last spring and I did make some preasure changes.

This winter I will pull the pan and check the filter. I have been thinking about up grading the clutches and OD direct spring.

Will decide after I see the inside of the Pan.

I put about 5000 miles on the 518 this year . So far it has worked great.