gear oil change interval?

[cluster lizard]

At 12K miles I changed diff. oil from the factory fill to RL 80w-90 (?). Now that I'm close to 36K, is it time to change it, or am I ok for a while with RL?. BTW, it is Jeep with Dana-30 and Dana-44 axles.

 

[MolaKule]

If you don't do used oil analysis on the diffy lube I recommend changing every 30,000 miles, especially if you do off-roading.

 

[y_p_w]

Some manufacturers don't recommend any regular changes, with ordinary API GL-5 rated gear oil as factory fill. My 2004 Subaru Impreza WRX comes with a Torx T70 transmission drain bolt which seems to be an attempt to prevent the DIYer from messing with it. Here's a pic:

Here's the socket I used to remove it (next to a quarter for size comparison):

 

[nel]

Service intervals vary widely by manufacturer. GMC recommends every 30K miles but does not require synthetic gear lube. BMW used to recommend every 30K miles also, assuming non-synthetic. On the newer BMW models, synthetic gear lube is replaced every second Inspection II, which can be as much as 80K miles apart.

To be on the safe side, I've been replacing synthetic gear lube at 50K miles.

 

[cluster lizard]

So it sounds like I am fine for the next 6K miles or so...

 

[y_p_w]

quote:

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Originally posted by nel:
Service intervals vary widely by manufacturer. GMC recommends every 30K miles but does not require synthetic gear lube. BMW used to recommend every 30K miles also, assuming non-synthetic. On the newer BMW models, synthetic gear lube is replaced every second Inspection II, which can be as much as 80K miles apart.

To be on the safe side, I've been replacing synthetic gear lube at 50K miles.

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Don't some BMW manual transmissions come with an allegedly "lifetime" synthetic fluid?

As for my Subaru, I tried swapping out the factory fluid for Red Line 75W90NS at under 4K miles. I wasn't happy with how it shifted into 1st or 2nd, so I tried Motul Gear 300 (75W90). It seems to be slightly better, but the syncros don't seem to come up as fast.

 

[Flimflam]

quote:

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Originally posted by y_p_w:

Originally posted by nel:


As for my Subaru, I tried swapping out the factory fluid for Red Line 75W90NS at under 4K miles. I wasn't happy with how it shifted into 1st or 2nd, so I tried Motul Gear 300 (75W90). It seems to be slightly better, but the syncros don't seem to come up as fast.

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I tried Redline MT-90 in my Suzuki 4WD, but used neat (unmixed with aftermarket additives), performance was unimpressive. Notchy. Then tried same Redline with Schaeffer 267 E.P. additive. Much better. But still, I think there is room for improvement. I bought Motul Gear 300 75w-90, GL-4 last Thursday. I want to try Motul now. Do you think it will be better or worse than Redline?

 

[Greaser]

Did my new (at the time) 2001 TJ,and my 99 XJ at 3000km then at 10,000km and again at 23,000km all with-in the first year.Now I do it every two years or around 45,000km.There's a good write-up somewhere about breaking in a ring & pinion set I think on the Richmond Gear website.Change out ALL lubes the first year to get rid of break-in material and manufacturing residue..then go easy after that

 

[bheinz57]

quote:

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Originally posted by y_p_w:
Some manufacturers don't recommend any regular changes, with ordinary API GL-5 rated gear oil as factory fill. My 2004 Subaru Impreza WRX comes with a Torx T70 transmission drain bolt which seems to be an attempt to prevent the DIYer from messing with it. Here's a pic:

Here's the socket I used to remove it (next to a quarter for size comparison):

---

That is for the Auto transmission, right? I have a regular drain plug/bolt on my manual Subaru transmission. Brian

 

[Bror Jace]

Bravo to you y_p_w for your drive to do what needs to be done ... yourself.

As for as I'm concerned, there's no such thing as "lifetime fill."

--- Bror Jace