Wifes 07 Limited is coming up on 30k, was gonna do the gear oil switch and fluid changes. Does anyone know the correct weight ? I plan on using synthetic....any imput ???

 

80/90 GL5 in front transfer and rear differential.

 

Read you Owners Manual. NOTHING is to be replaced (trans or diff) for 110K. This is just the dealers looking for $$$ saying Ha, ha, ha to the bank.
Have them show you in the owners manual were it states that.
I had a "talking to" with my former service manual. He finally relented that these are for "severe use" (towing a trailer all the time, speeds above 80mph all the time (troopers)).
Hyundai dealers can be just as despicable as Ford.
Then you wonder why the auto industry collapsed !
I would call a lawyer and go for a class action suite. For the former manager to suggest this could affect my warranty. bull !

 

Sorry but "severe use" is more than just towing. City driving and driving on salt covered roads in the winter place you in "severe service".

Like I said 14 months ago when you complained about this exact same topic (https://www.hyundaiforum.com/forum/s...ead.php?t=6308) 90% of the cars on the road today drive under "severe service"conditions.

The trans fluid should be replaced every 30K miles.

 

i don't have experience with the santa fe, but my wrx's rear diff was not due for a fluid change until 30k. i drained it anyway at 5k and was not really surprised to a build up of shavings.

gear oil is cheap. if you can do it yourself (always remember to loosen the "fill" plug first), why not spend the little bit of time, money and effort. and while you're at it, do the front diff as well.

:-)

maybe i'm just crazy, but simply service items like this are actually rather therapeutic for me.

 

There are no drain plugs, only fill plugs. That usually indicates a non replenish system. Now Subaru has a fill and drain, but again. After 80K or so.
If it were a standard item.. it would be in the owners manuals.. if you want to pay.. go ahead... the dealers always welcome to take your money.