Differential Fluid Issue; How Often to Change in This Circumstance
 

I have a 1989 Camry with an automatic transmission. I have never had problems with the differential, ie no whining or howling when I turn.

I bought the car in 2014 with 143k miles and poor maintenance history (eg tranny fluid was brown). At 143k miles, I changed the differential fluid and found it dark brown and had metal shavings on the drain plug. I replaced the differential with Valvoline synthetic Mercon. When I recycled the oil, the employee commented that he had never seen transaxle fluid that dark.

Today, at 160k miles, I decided to change the differential fluid to see the condition of the differential fluid. It was dark brown/black and had about 2 cc of metal shavings. Again, I replaced the differential with Valvoline synthetic.

I checked the transmission fluid and it looks pink (at 143k miles, I dropped the pan and flushed the dark brown transmission fluid).

Does this mean anything?

How often should I change my differential fluid?

I found it hard to put fluid into the differential. Has anyone used pumps, like this:




Thanks!

Are you doing the work yourself or a shop?

Typically the differential fluid is changed at the same time as the trans fluid. Differential fluid will last longer then trans fluid because its functioning only as a gear oil. The color will darken over time.

Pink trans and differential fluid is good.

Use of a pump is very common. The alternative is funnel having long snout such as at the link below:


More concerned about the shavings.

Thanks for your reply.

My driver's side CV shaft broke and needed replacement at 149.9k. Is the differential issue related?

Yes, I'm doing all the work myself.

The shavings were black and sliver-like in shape.

Given the fact that the differential was poorly maintained and that after only 17k miles, I had lots of shavings and dark fluid drain, at how many miles should I make my next differential fluid change?

On the differential body, I noticed fins, like those on the old VW Beetle engines. The case and fill plug were hot, my doing the differential service right after driving. Is that normal?

Is the drain plug magnetic? If not use a magnet to determine if the debris is ferrous or non-ferrous.

The differential case will get at least as hot as the engine block its bolted to. The case fins are for cooling.

Hot fluid flows better then cold. For the differential this also allows a better flushing of any debris.

If concerned about debris, suggest changing the differential fluid (hot) after a few hundred miles. Determine if more debris is present or that it was removed at the last change. If OK at this change, do it again when changing the oil. If OK, change it when changing the trans fluid.

Thanks.

I didn't check the magnet, but I believe it's magnetic due to my moving it sideways when exiting the underside of the car.

At 143k miles, I changed the differential fluid when the differential was cold, so that could explain why I didn't get a complete cleansing.

https://cimg0.ibsrv.net/gimg/www.cam...deeef1bdf9.jpg
https://cimg1.ibsrv.net/gimg/www.cam...30cd7d5444.jpg

Follow up: after 332 miles, I drained and changed the differential fluid. As shown above, the fluid was off-pink. On the drain plug was about 1 ml of a dark muddy substance. There was metal shavings at the base of the drain plug, not not on top of the magnet. However, they might have been from the last drain, because I don't think that I removed them.

Your thoughts about the condition of the differential?

When should I change the differential fluid next?

Thanks

The concern of course is the metal debris.

The diff has a removable cover (finned cover with fill port). It may be possible to remove this cover in car and inspect the diff.

Could try flushing out the differential only (NOT trans!) with kerosene. Remove both fill and drain plug. Pour it in using a long nosed funnel and see what debris comes out the bottom.

The trans fluid will last a long time. The issue is the metal debris.

thanks
 

thank you