Low gear set from A999 installed into 904. Anyone experience gear noise?

[JoePole1]

Hey All. Like the title says. I pulled a low gear set from an A999 and gave it to my local builder to install into my 904 during a rebuild. I had read that the low gear set can be "noisy". Yes it is noisy. Odd thing is that it didn't start until I had a couple hundred miles on it. Has anyone experienced this and can you describe the sound for me? TIA.

 

[moparlvr166]

Does it make noise in 1st, 2nd, 3rd and rev? I'm assuming just 1st & 2nd.

 

[JoePole1]

Not sure about reverse but all forward gears. Goes away in neutral.

 

[George Jets]

Just like a rear end ring and pinion when they get worn and the factory backlash specs go out of whack, they make noise.

New carrier bearings and races moved the ring gear back into spec and the noise of the rear end goes away. 2 full trips back and forth to Florida and is still rolling fine > no noise.

Same with your transmission, you have 2 different generations of parts that you are trying to match up. Gears are cut in different machine shops and different years and are off just enough to make noise.

Tear it open and get in there with the Yellow gear backlash paint to see the wear pattern mating surface of old parts to new.

Bet you see the Heal Toe contact patterns are off to an other than ideal position.


☆☆☆☆☆

 

[JoePole1]

Makes sense. Just odd that it took a few hundred miles before it started making noise.
Any thoughts on longevity? I can live with the noise for now. I have a 42RH waiting in the wings but it might be a year out.

 

[moparlvr166]

If it's making noise in 3rd gear, it's not from the gearset because the unit turns as an assembly,
it can be from a bearing inside the trans or t/converter or possible rear end.