View Full Version : Filling the IRS differential - Solved
maclonchas
05-23-2023, 01:10 PM
Folks,
The simplest tasks seem to give me the most trouble. The picture below shows what I believe is the fill location for the differential. I have a funnel and tube that fits into the hole and I began to pour in the first bottle of oil. Before I even finish this bottle I am getting fluid run off from the opening. I put the bolt back in and waited five minutes, but I still get fluid running out. My chassis is level. What can I be doing wrong. The IRS differential was from Factory Five and came in a packing from Ford Racing. Any help in trouble shooting this problem would be appreciated.
184819
Thanks
Bill;)
Hoooper
05-23-2023, 01:13 PM
Thats the drain, the fill is on the right side of the rear cover
BradCraig
05-23-2023, 01:29 PM
Yep. Don't forget the friction modifier as well and make sure to get plenty of it on your hands then go into the kitchen and wipe it off on your wife's hand towels. :-) They love that.
maclonchas
05-23-2023, 01:31 PM
My bad with the picture as I tried to get this question up quickly. Here is the right picture
184820
The right side still just letting out fluid
flyboyjy
05-23-2023, 01:34 PM
So I did this two weeks ago. I drained out what I thought was shipping oil because I have never seen a part manufacturer send a part other than a stock hydraulic clutch on a Dodge Ram full of oil ready to go. I got about 2 quarts of fluid out of the IRS and it may have been the right stuff. But I refilled it with known friction modifier and Ford 75w90 gear oil as required. I used a device that attaches directly to the quart bottle and just pumped it in. When filling, when the fluid starts coming back out of the fill plug is when you know you have the right level.
184821 This is the Slippery Pete, got it off of Amazon. Has one end with a gripper on it to hold onto the sides of the hole so both hands can be used to pump out of the container. As a side note I also used it to fill the transmission. It fits neatly between the passenger aluminum and park brake.
If oil is running out of the fill port, it's full.
maclonchas
05-23-2023, 01:48 PM
flyboyjy,
You hit the nail on the head. I just pulled the drain plug and the unit was packed with fluid. I guess I need one more quart of the 75W90. Thanks for the quick assist.
Bill
Folks,
The simplest tasks seem to give me the most trouble. The picture below shows what I believe is the fill location for the differential. I have a funnel and tube that fits into the hole and I began to pour in the first bottle of oil. Before I even finish this bottle I am getting fluid run off from the opening. I put the bolt back in and waited five minutes, but I still get fluid running out. My chassis is level. What can I be doing wrong. The IRS differential was from Factory Five and came in a packing from Ford Racing. Any help in trouble shooting this problem would be appreciated.
184819
Thanks
Bill;)
On my 2020 IRS diff I was told by FFR that the diff comes with friction modifier already installed along with fluid in the diff. You should only have to top off.