Hey everyone, I have been searching and searching on how to flush my differential out.

Car has 82k miles and is a 1999

I found articles for a C6 but nothing for a C5

can someone point me in the right direction?

also, how would I know when it is "full"

thank you all, lp

 

Wow. Its really simple. Theres a drain plug on the bottom of the diff. Its on the passengers bottom side. Its right above the rear spring. Theres a fill plug on the side.

Open the drain, the old stuff will come out. When you first pull the drain plug, you will or should hear a slight vacuum relief. Our differentials have a check valve on the top that allows pressure OUT but no air back in. It helps control seal leakage.

Reinstall the drain plug & the washer. The washer usually sticks to the diff case and falls into the old fluid when your not looking.. Make sure that you find it and put it back on the drain plug.

What Diff fluid are you planning on using? I used DTE's fluid and have been very happy. It comes premixed with the correct limited slip addative. What ever you use, make sure that you get the required limited slip addative in the fill.

If you jack the car up and put it on four jack stands make sure that it level. Fill the case until the fluid runs out of the fill hole.

While it in the air, make sure that you change the tranny fluid. If you get new tranny fluid, I recommend the AMSOIL synthetic ATF tranny fluid if you have a six speed! Made a world of difference in the way my 98 shifted. The AMSOIL ATF is compatable with your paper blocker rings. Contact SUBDRIVER if your interested.

BC

 

im planning on doing this tommorrow. im thinking about using the royal purple gearmax.
But what fluid is recommended for an automatic?

 

Yes I have a automatic, thanks BC are there any photos online and what tools are needed? how many bottles or fluid is needed in there?

 

AUTOMATIC!! Man that drain/refill procedure is a bitch. You have to have the car up on a lift (or stands) and fill the tranny "while the engine is running" to get the correct level in the pan!!!! Get and follow the procedure to the LETTER!

Cant even tell you how much fluid that trans takes. Don't have access to my service manuals.

As for tools to drain fill the diff. All you need are some Allen wrenches. I have Allen sockets and that makes life a LOT easier. You will also need to find some way to pump the fluid into the fill port. Its really tough to get that bottle in that small space and not make a mess.

I use to have a giant IV bag that you put the fluid in and once the hose is in the hole, you squeeze the bag and in goes the fluid. That bag worked excellent but the fluids caused it to get brittle over time and it started cracking.
Now I have a pump like you find on large bottles of hand cleaner. I just attach a piece of vinyl tubing to the spout and pump in the fluid.

BC

BC

 

Whenever draining a differential, I always remove the FILL plug first, then the drain plug. If for some unknown, (God only knows what reason), the fill plug proves difficult to remove - you could end up with an empty differential with no way to fill it.

Many cars & trucks do not have a separate drain plug, in which case the fluid is sucked out with an inexpensive suction gun. This can be done on the C5 if the drain plug doesn’t want to come out.

You should have no trouble, but REMOVE the FILL plug FIRST.

P.S. -

Best to drain the fluid while it is warm - immediately after driving the car.

By driving the car to warm the fluid immediately before draining, an additional benefit will be that any solid contaminates will be suspended in the fluid and drained out with the fluid.

 

A little less than 5 qts. is needed to refill, if you're just dropping the pan and replacing the filter.

(I'm assuming that you're asking about the transmission here.)

 

For 6 bucks at Harbor Freight- you can buy a hand held pump to add or remove any fluid-even comes with a very small hose to pump out the PS reservoir.
Ralph down at the Shell station liked it so much better than his Snap-On tool, I told him he could keep it.

Steve

 

Thanks for the information, is there anything else to know about?

 

Like Bill Curlee suggested, follow the shop manual procedure to the LETTER! The transmission fluid temperature is VERY important for the final fluid level check.