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Guest Message by DevFuse

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changing tranny/LSD gear oil

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7 replies to this topic

#1 avatar382


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Posted 21 December 2005 - 03:59 PM

I know there's a thread on this somewhere, I just can't find it with search, and can't find the instructions in the FSM! Feel free to smack me upside the head...

Anyway, got some simple questions about changing gear/LSD oil. (Got some Redline NS gear oil for the tranny and non-NS gear oil for the diff)

Looking at the drain plug on the tranny, the largest wrench/socket I have is too small at 18mm. What is the size of the plug? Looks like 20mm, but I want to know for sure before I go out there and buy a socket just to learn it doesn't fit.

Also, the drain on the diff looks like a square recessed into the plug. What tool is needed to take that out? Seems like my socket wrench minus a socket on the end will fit in the hole, but it just doesn't seem right to me.

Lastly, tranmission gear oil is poured in through where the dipstick is right? I bought this pump thingy, just want to make sure the oil goes in through the right hole :)

Oh, I have the RX FT4WD D/R 5spd and LSD.


#2 NorthWet


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Posted 21 December 2005 - 05:45 PM

The diff drain and fill plugs are pretty much 1/2" socket sized. I think someone makes a special tool, but I just use the business end of a breaker bar. Heat, penetrant oil, and patience is also useful.

Suggestion: Make sure that you loosen the fill plug first. Goodyear Service did an oil change on my Datsun's R160, and removed the drain first... then spent 6 hours trying to remove the fill plug. (I couldn't budge my fill plug, which is why I let professionals have a whack at it.) Better to have old oil than no oil.

#3 Caboobaroo


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Posted 21 December 2005 - 06:28 PM

yes, IIRC, the drain plug on the tranny is a 20mm but I'm not quite for certain. I can run out and look later today if you'd like since mine is up on jacks right now.

#4 NuclearBacon


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Posted 21 December 2005 - 10:54 PM

I can run out and look later today if you'd like since mine is up on jacks right now.

yes please :) this is EXACTLY what i'm going to do in the next week...

...with the same redline oil...

#5 idosubaru


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Posted 21 December 2005 - 11:11 PM

it's not a 20mm.
22mm i believe. (small chance of 19...but i think that's just the oil pan).

#6 ballitch


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Posted 21 December 2005 - 11:44 PM

19 is oil pan and 22 im almost positive is the tranny drain plug. as for the rear diff, buy a short 1/2'' extension for your 1/2'' socket wrench. if you dont have a 1/2'' socket wrench, buy a 3/8''-1/2'' socket adapter and your good to go. the drain and fill plug are the 1/2'' male end of the socket extension........that reminds me...i need to change rear diff oil soon.


#7 rallyruss


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Posted 22 December 2005 - 03:21 AM

trans drain plug is a 21mm on my new RX. I just went out there to verify. 7/8" will work in a pinch.(sometimes cars have aftermarket drain plugs of different sizes too)

rear end plug will work fine with a 1/2 rathet or breaker bar.

a trick to help with the rear end plug if it gives you a hard time.
install a breaker bar in plug socket kicked out to the right side of the car. then put a jack under it and pump. use the weight of the car and the jack bar to help break it loose. this is helpfull if you have bad shoulders like me of just like to do things the easy way.

fill with a skinny long funnel thru the dip stick. pour slowly or it may give you some trouble.

I just put the 75/90NS in the gl10 wagon this week. it works great.

#8 carfreak85


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Posted 22 December 2005 - 12:53 PM

I think that you should put the NS oil in your transmission and the regular Redline oil in the diff. Do a search for redline oil in the old gen forum and I'm pretty sure thats what you'll come up with.

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