This took some planning; FOLLOW The Factory Service Manual: (Do see a lot of stupid **** posted in these forums)...used Royal Purple 75-90 in the trans and RP Synchromax in the differential carrier. Go online and order the 13mm drain plug socket (for recessed plugs) and STOP the neanderthal practice of using a 1/2 " drive...IT'S CRAP to do it that way! These cars are not made for IDIOTS to "work on"!...Jack the car up to ramps in the front and stands in the rear, totally level. Take out the fill plugs FIRST(see manual drawings) to equalize pressure, then the drains. (You may have to go to a shop / lift to break these loose, almost impossible to do it while lying on your back). The trans took 2 full quarts, the diff took 1 and 1/2 quarts (again, see manual); using a $10.00 plastic gear oil pump to fill both. After all are COMPLETELY drained, FOLLOW the torque ft / lbs specified in the manual; DO NOT over tighten these plugs, otherwise you will go back to a shop / lift next time. This beats the $175.00 shop labor estimate to do this task. (The You Tube videos I have seen so far are worthless when it comes to this year / model).....

 

Nice douchey post. The 1/2" drive works just fine. It's extremely close to 13mm, and most people have that in their toolbox.

 

Suit yourself, these plugs had already been partially wallowed out by a "1/2" drive" and had been overtightened at a shop...(to get return work)...the metal in the plugs and the trans / diff case are not equivalent so differential heating and cooling occurs..they "freeze up" over time. The 13mm socket (made in Japan) broke them free as DESIGNED to do...

 

Hey, why dont you go change the trans fluid on a Audi A4. Then come back and post about it. I cant wait to hear that one!!

 

Thank you for sharing this. I am new here and needed the info you posted big time. I was going to attempt it myself, having done it on other cars, but as you know, my '86 z31 is not 'just a car.'
Are there any links to diagrams of engine and undercarriage? I have had terrible luck in finding anything.

 

XenonZ31 Reference

 

I did, links are no good, '404'.

 

not to poke the wolf, but why couldn't i just use a 1/2 drive with a shim wrapped around to make it 13mm? i can pick up fluids locally, that drain drive, 2 wks unless i pay 30$ shipping...

I'll be shimming personally...

 

kudos on getting the exact tool for the job .... i guess if it comes out easily though the 1/2 is ok .
I never liked Royal Purple though ,,, saw it destroy more than a few of the 90's performance trans Getrag , mitsu .
It did not flow well when cold (20-50 degrees) most 5 gears need the oil to flow across the plactic track oiler piece to lube
and theres the fiber insert brass ring sycro issue
also older trans usually want a thinner fluid for the speed gear tapers that are glazed or ribbed from normal wear ,thick fluid prevents the brass ring from grabbing the gear effectively , as a pure race fluid ... it could be super duper though .

how come you put Sycromax in the diff L S ?

 

I have noticed on this forum, that there are several people who forget that at a previous point in their existence, they did not know any more than the people they criticize. These individuals should want the younger generation to follow, in our footsteps and carry on the love of automobiles and give them our knowledge and wisdom, without the harsh comments. I have also noticed, that several new members have not returned to this forum after being made to look like fools and that is so sad.
Helping others with the accumulated knowledge, I have gained over my many years as a Mechanical Engineer, working in the paper industry designing, installing and maintaining that equipment and working on, repairing and restoring cars and motorcycles (since I was 19 and I will be 67 in October this year), has given me the wisdom to want to give back to others. This is supposed to be a fun site to give and get information. Let's treat each other with respect please. Thanks Bob

 

what fluids do you use? I'm looking at doing these (trans & diff fluid change) soon as well

 

I would like this post or give it a thumbs up if that was an option..

 

Bobs 84 300ZX......U are entirely correct!....Not everybody is gifted with the same abilities, so will ask the pardon of others.
My biggest gripe is with shoddy shop work and not having the correct tools for these cars.
Have not been here for a good while, hopefully some have been helped by my experiences.

 

Hey, whatever works for you....my comments are not meant to be harsh, have been around Nissan Masters for too long.....by all means shim away!!