Ok, I only ask this on here because of time constraints.

Changing differential fluid. Got a FULL 2 quarts out. Only bought 2 quarts to go back in. I am filling with Redline 75w/140 and I spilled about 70 CC of it!! I have put all that I had left and it's still not running out the fill hole.

Do I:
a) Drive a half hour each way and buy another bottle?
b) Use the Redline 75w/90 I have on the shelf for another car?

I suspect the small mix would be harmless, but I don't want to take any chances with this car.

Thanks.

 

Ok, so...time constraints dictated I make a decision. Silly really, when you think about it, but my reflex was to question it. It took all of 40 to 50 cc of the 75w/90 to finish filling the differential, an inconsequential amount really.

Heck, it could have easily been the case that I couldn't get all of the old fluid out and there would have been a significant mix of fluids anyway! I'm sure it happens all the time.

 

Can you tell me how you got to the drain/fill? i wasnt able to get to it easily when i was under the car last.

 

I think the Redline 75w/90 was one of the recommended fluids on the forums here for diff oil. If I remember right you need some kind of a suction device to pull the old fluid out thru the fill hole, then put new fluid in.

 

I have used the Redline 75w/90 in my previous 2001 XJ8 and 2003 XJR vehicles but many forum members claim the 75w/140 Redline product is a good modern fluid to use in our X308s. I used the Redline 75w/140 in my wife's X350 because that's what it actually called for. I'm not sure how much the differentials changed from 2003 to 2004, but my theory is that they just decided the 75w/140 was a better choice. Some of the other members claim it protects over a broader temperature range. I don't know and frankly now that it's in there I don't care. haha The last thing I intended to do was start a viscosity debate. I think both are probably fine, I was just a bit worried about mixing them.

I pulled the old fluid out with a vacuum pump and used a large syringe to re-fill.

For accessing the fill hole, I use the socket holder out of a busted 1/2 inch torque wrench (threw the rest of the wrench away). I slide a ratcheting wrench up in front of the fill hole and then put the 1/2 inch piece through the ratcheting wrench and into the fill plug. Then, I just ratchet the wrench until it's loose. I posted pictures of the tool and the process in another thread a year or two ago, so it's out there somewhere.