Swapped the Diff and transmission Oil by Accident

[Phantom Gett]

So... I may be mildly dislexic... Because I changed my gear and diff oil recently in my 96 240 and I accidentally swapped the oil viscosities between the two. I put 80W-90 in the Transmission and 75W-90 in the VLSD...

Will this have any short term or long term adverse effects and should I swap the oil ASAP or not worry too much about it? Just realized it (a week later) and wanted a quick (but educated) opinion.

Sorry if this seems like a stupid question, I've never changed gear or diff oil before? Only crankcase oil, so I'm not really sure. Common sense says they probably aren't too different but also that they are different for a reason... So any help would be appreciated

[AZhitman]

Nope - they're absolutely fine.

Both will perform as usual with the "wrong" fluid. Hell, you did a good thing by having clean fluid in both!

[Towncivilian]

If the 80W-90 you put in the trans is GL-5 or claims "GL-4 and GL-5 compatible", you should probably drain the transmission and fill it with a GL-4 only fluid such as Redline MT-90, Amsoil MTG, or the stock Nissan fluid. The GL-5 fluid can harm yellow metal (brass synchros), which I'm assuming your transmission has (correct me if I'm wrong!), so a GL-4 fluid is preferred and is what is specified in the maintenance section of the FSM. I think LSD additive, if present in the gear oil you picked, can also cause slippage.

As for the diff, I'm not quite sure to be honest. Hopefully someone else will chime in.

[Phantom Gett]

Thank you for the reply, it was bugging me so much I couldn't sleep <-- noob

Actually asked a dealer before buying the oils, they told me APi-GL5 was okay to run. It's got Royal Purple 75W-90 in the Diff and Vavoline Sythetic blend 80W-90 in the trans. --- but correct me if I'm wrong.

[asoomal]

GL5 is not okay to run in those transmissions.

Drain it asap man!

[Hoffman5982]

Drain the transmission and put some Penzoil synchromesh in it. I've used it on both my ka and sr and have never had a problem

[AZhitman]

If the 80W-90 you put in the trans is GL-5 or claims "GL-4 and GL-5 compatible", you should probably drain the transmission and fill it with a GL-4 only fluid such as Redline MT-90, Amsoil MTG, or the stock Nissan fluid. The GL-5 fluid can harm yellow metal (brass synchros), which I'm assuming your transmission has (correct me if I'm wrong!), so a GL-4 fluid is preferred and is what is specified in the maintenance section of the FSM. I think LSD additive, if present in the gear oil you picked, can also cause slippage.

As for the diff, I'm not quite sure to be honest. Hopefully someone else will chime in.

Ah, my bad - I forgot about Nissan transmissions and their brass synchros.

Dammit - I'm gonna go back to my cage...

[Towncivilian]

RP 75W-90 is great for the diff. Just get some good API GL-4 fluid in the trans and you'll be set.

[OutToWinPAHC]

GL-4 only.... GL-5 expands soft metals aka the brass bushings and syncros. Amsoil or reline in the trans, diff whatever you want as long as the weight is good

[ddgsxr504]

Yea it was always hard for me to find GL-4 transmission fluid in Cali unless I special order it. I used to put Valvoline Synthetic 75W-90 in the transmission and on cold morning that bastard did not want to go into second, felt like I was trying to Lat Row a 60lb weight. Been running Royal Purple ever since and with 230,000 miles it still shifts like butter.

[240sxAli4Life]

How the hell did you manage to do that??? LMAO!!!!

[PEZi]

If the 80W-90 you put in the trans is GL-5 or claims "GL-4 and GL-5 compatible", you should probably drain the transmission and fill it with a GL-4 only fluid such as Redline MT-90, Amsoil MTG, or the stock Nissan fluid. The GL-5 fluid can harm yellow metal (brass synchros), which I'm assuming your transmission has (correct me if I'm wrong!), so a GL-4 fluid is preferred and is what is specified in the maintenance section of the FSM. I think LSD additive, if present in the gear oil you picked, can also cause slippage.

As for the diff, I'm not quite sure to be honest. Hopefully someone else will chime in.

Whadda ya know... our new mod knows some shiz!

See above