[Darth G-F]

I'm switching my tranny oil to MT90.

I used to change the diff oil at the same time in my previous cars. What oil should I use in the diff? Any suggestion?

I have an open diff btw.

 

[Westrock]

As far as I know in a transverse engine setup, the differential shares the same lubrication that the rest of transmission uses, since they are in the same housing.

 

[Darth G-F]

As far as I know in a transverse engine setup, the differential shares the same lubrication that the rest of transmission uses, since they are in the same housing.

Really?
I never owned a car with such a set up before... That's probably why I couldn't find anything about this...

 

[MaineLotus]

Yup - the differential is part of the gearbox and shares the gearbox oil. Most front wheel drive and rear engine cars are like this.

 

[apk919]

For those of you that have changed the diff oil...

Do you warm up the transmission, and then drop the drain plug, or do you use a fluid extractor to remove the oil through the level/filler plug?

Oh, in case anyone was interested, the sealing washer is the same for both plugs... Toyota part #90430-18008, $1.62/each.

 

[apk919]

bump

 

[tommyc]

I did not warm the engine. I just removed the fill plug first then the drain and let it drain out for 10 minutes or so. The dino gear lube is thick and smelly. I then put the drain plug in and used a pump to pump in the MT90. Had the pump from my boat used to change outdrive oil. Good tool, and the MT 90 is great stuff. Tommy

 

[TimMullen]

On any car, I drive the car to warm up the engine and trans/diff oil. Then I do the engine oil change, and the trans and/or diff oil. Warm oil flows better and carries the contaminants out of the housing better. Cold oil flows slower (takes longer to drain/doesn't drain completey). "Junk" in the oil tends to cling to the bottom better with cold oil. Warm oil has been mixed up and the "junk" tends to be mixed in with the oil and dranis out with the oil.

And always make sure that you loosen the fill plug on the trans/diff before you remove the drain plug. You would be surprized by the number of people that have drained the oil and couldn't get the fill pulg lose. Then you have a major problem as you can't drive the car somewhere to get it fixed, and yo ucan't fill it back up... :shrug:

 

[apk919]

I did not warm the engine. I just removed the fill plug first then the drain and let it drain out for 10 minutes or so. The dino gear lube is thick and smelly. I then put the drain plug in and used a pump to pump in the MT90. Had the pump from my boat used to change outdrive oil. Good tool, and the MT 90 is great stuff. Tommy

On any car, I drive the car to warm up the engine and trans/diff oil. Then I do the engine oil change, and the trans and/or diff oil. Warm oil flows better and carries the contaminants out of the housing better. Cold oil flows slower (takes longer to drain/doesn't drain completey). "Junk" in the oil tends to cling to the bottom better with cold oil. Warm oil has been mixed up and the "junk" tends to be mixed in with the oil and dranis out with the oil.

And always make sure that you loosen the fill plug on the trans/diff before you remove the drain plug. You would be surprized by the number of people that have drained the oil and couldn't get the fill pulg lose. Then you have a major problem as you can't drive the car somewhere to get it fixed, and yo ucan't fill it back up... :shrug:

Thanks guys. I was considering cutting down on the number of plugs to remove/replace by just vacuuming out the oil through the filler plug... just wondering if the tubing from the extractor can find its way to the bottom of the transmission housing. I couldn't find MT90 locally, so I'm going to use <a href=http://group5motorsport.com/motul/motul_gear_fluid_gear_300/g-52546.aspx>Motul Gear 300 75W90</a> instead.

Yeah Tim, I agree... I always get the engine to operating temp before doing an oil change (and will do the same for diff oil change)... and good tip on removing the filler plug first...

 

[TimMullen]

I was considering cutting down on the number of plugs to remove/replace by just vacuuming out the oil through the filler plug... just wondering if the tubing from the extractor can find its way to the bottom of the transmission housing.

I wouldn't expect it to. Engine oil dipsticks usually have a straight path to the bottom of the oil pan. Every transmission I've opened up has always been packed with gears with very littl extra space. Every fill plug I've ever pulled has had gears there when I pike my finger in the fill hole. I always poke the finger in, and bend the finger at the first joint to get a "feel" for how far down the gear oil is (by how much gets on my otherwise clean dry finger). If I stick it straight in, I can feel the gears. :shrug:

 

[apk919]

I wouldn't expect it to. Engine oil dipsticks usually have a straight path to the bottom of the oil pan. Every transmission I've opened up has always been packed with gears with very littl extra space. Every fill plug I've ever pulled has had gears there when I pike my finger in the fill hole. I always poke the finger in, and bend the finger at the first joint to get a "feel" for how far down the gear oil is (by how much gets on my otherwise clean dry finger). If I stick it straight in, I can feel the gears. :shrug:

Yep... oh well... just thought I might be able to save a couple of steps. Probably not worth it in the long run.

EDIT:

No way that the tubing from an extractor was going to get to the bottom of the diff case from the fill hole. Fairly easy job anyway, just be prepared to catch 2L of really foul smelling gear oil when you pull the drain plug... it's inconveniently close to the subframe (and therefore close to where you'd put a jackstand). Instead of using a pump to refill, I used 3/8" ID clear plastic tubing (fits perfectly over the nipple of Motul's oil containers) and used gravity to gave the car a 75W90 I.V.