Differential oil and additive for LSD

[Slip_Angle]

And apparently it's the purely mechanical one, so no electronic actuation. An LSD can increase over-steer when applying power on turns, so the electronic type can be better in instances like that, where it reverts to open if needed. But if it's going to be a purely mechanical LSD, I'd much prefer a Torsen type, which never wears out, and it's as reliable as an open one. My 2.0T is much better off with an open one, since it doesn't have the power to need an LSD.

Yep. I had a torsen diff in my civic back in the day. It was great. One drawback is there is no ability to adjust it's operation, where a clutch type can be adjusted to suit your driving conditions.. track, snow etc.. My 2019 G70 had the open diff with AWD and honestly, it was great. My 2023 is AWD with the LSD. I suppose as the clutch plates wear, the diff will become open... but I expect under normal operation that would take a long time. Makes me think I can tune the operation of the LSD by varyingt the amount of friction modifier. @Volfy - What are your thoughts on that?

 

[Volfy]

Even though the amount of FM in the oil no doubt does have an effect on how the LSD operates, I suspension how the clutch plates engages and disengages might not vary linearly with the amount of FM added. It might be that under a certain amount of FM added, the LSD action is none, poor, unpredictable, or vary with speed and other conditions. Then, above a certain threshold amount makes the whole thing work as intended. From there, it might take a lot more FM added before the friction becomes so modified, the LSD regresses into an open diff.

Frankly, I dunno. And as much as like to tinker, I'm not sure I want to go down that rabbit hole.

 

[Slip_Angle]

Dealer replaced my diff today. That's 2 replacements. I'm going to get 4oz of friction modifier and get it added asap. I'm not going to wait to hear any noise!

 

[Slip_Angle]

Just wanted to give an update for the thread. The noise came back ever so slightly, so I decided to change out the oil completely. I used Amsoil 75w90 synthetic and a tube of Amsoil Slip Lock. Now the diff is silent. In fact, it feels very smooth.

Not sure if the 4oz of ATP 210 wasn't quite right or if it wasn't enough but the Amsoil did the trick. (Well so far anyways)

 

[tompass]

No issues with RedLine fluid in rear.

 

[ejguillot]

Changed mine out at 34k miles with Amsoil Severe Gear 75W-90 fully synthetic. Diff feels great so far.

Breaking the fill plug loose was very difficult, may have been over torqued from the factory.

 

[Alta23G70]

Just wanted to give an update for the thread. The noise came back ever so slightly, so I decided to change out the oil completely. I used Amsoil 75w90 synthetic and a tube of Amsoil Slip Lock. Now the diff is silent. In fact, it feels very smooth.

Not sure if the 4oz of ATP 210 wasn't quite right or if it wasn't enough but the Amsoil did the trick. (Well so far anyways)

Reviving this thread as I am at a loss and on my 3rd diff replacement... howling, chattering and shuddering is what I am dealing with... think I will follow what you did... did you go with the
AMSOIL SEVERE GEAR® 75W-90 100% SYNTHETIC GEAR LUBE

or

AMSOIL 75W-90 LONG LIFE 100% SYNTHETIC GEAR LUBE?

Is your diff still quiet?

 

[Slip_Angle]

Reviving this thread as I am at a loss and on my 3rd diff replacement... howling, chattering and shuddering is what I am dealing with... think I will follow what you did... did you go with the
AMSOIL SEVERE GEAR® 75W-90 100% SYNTHETIC GEAR LUBE
or

AMSOIL 75W-90 LONG LIFE 100% SYNTHETIC GEAR LUBE?

Is your diff still quiet?

The severe gear plus add a 4oz container of their slip lock.

My diff is completely silent

 

[Alta23G70]

The severe gear plus add a 4oz container of their slip lock.

My diff is completely silent

Awesome! Thank you for the response! Much appreciated!

 

[pulsar]

Awesome! Thank you for the response! Much appreciated!

So you have gone thru 3 differential changes or 3 fluid changes? How many miles did you get on each before they crapped out? Been following along on this thread as an observer and always wondered if the noises from the diff were that noticeable or if you had to strain to listen to it? Best I can tell my 2020 3.3 sport doesn’t make noises but I do hear what I always thought was normal tire road noise from the sport pilots? I only have 19k on my 2020 for it’s not my only car.

______________________________

Help support this site so it can continue supporting you!

 

[CVDH-TN]

After messing up with the Kia Fluid and an addition of a 4oz Friction Modifier, the chatter came back. I just purchased the AMSOIL Severe Gear and a tube of slip lock and had my local shop flush the diff with i. So far, it is silent and smooth, but let us see how it holds over time. I will make sure to report here.

 

[Volfy]

FWIW, we just changed our the original gear oil in our '21 G70 6MT, which has the same LSD, with straight Amsoil 75w90 Severe Gear. No additional Slip Lock.

No noise before. No noise after.

Too little FM might be bad, but too much FM could negate the whole purpose for having the clutch pack... reducing the LSD into an open diff.

 

[pulsar]

FWIW, we just changed our the original gear oil in our '21 G70 6MT, which has the same LSD, with straight Amsoil 75w90 Severe Gear. No additional Slip Lock.

No noise before. No noise after.

Too little FM might be bad, but too much FM could negate the whole purpose for having the clutch pack... reducing the LSD into an open diff.

Did you change due to mileage recommendations or did you just want to be extra preventative since you had no issues? I’ve got just under 20k miles on my 2020 presently with factory diff fluid still.

 

[Volfy]

Did you change due to mileage recommendations or did you just want to be extra preventative since you had no issues? I’ve got just under 20k miles on my 2020 presently with factory diff fluid still.

In this case, it was because the car is approaching the 36,000 mile schedule for LSD oil change (fore severe driving conditions). Ours is still under 30k miles, but we've done AutoX and track days with it, so I'd rather err on the side of caution.

We also changed out the manual transmission oil at the same time, even though the schedule says 72k miles. The Amsoil 75w90 MT gear oil made the shifting - especial first 2 gears - noticeably smoother. Probably should've done way earlier.

 

[TheBeginning]

If you don't want to have to add Trans-X, then for sure Amsoil is the way to go. Valvoline and Mobil1 LS just do not have enough FM for these Stinger/G70 LSDs. Not all LSDs require as much FM. My GMC Savana has GM's G80 Eaton LSD, and Valvoline works just fine as is, without adding FM.

How can you tell if a certain fluid works and has enough FM? Is it the noise?

If you know, what hardware differences between the G70 LSD and your Savana’s LSD drive the need for friction modifiers?

 

[Volfy]

How can you tell if a certain fluid works and has enough FM? Is it the noise?

If you know, what hardware differences between the G70 LSD and your Savana’s LSD drive the need for friction modifiers?

Not all LSD's are built the same. Even if they are the same clutchpack type, their oil requirements might still vary. I just did a bit of googling on GM G80 Eaton Positraction LSD, and most folks say it runs fine on regular synthetic hypoid gear oil. I don't doubt most of those gear oils probably have a bit of FM in them. Both the Valvoline and Mobil 1 gear oils I bought are labeled "LS", so they likely have some amount of FM added. Maybe just not as much as Amsoil.

The G70 LSD might be built a bit differently, with a different clutch-pack spring tension... such that it requires a bit more FM to have just the right amount of slippage in the clutch pack. Do I know for sure? Nope. I just go by the fact that mine runs fine - without the whirlling noise on tight turns - with either Amsoil Severe Gear 75w90, or Valvoline/Mobil1 75w90 LS with a few Oz. of FM added.

 

[Genesisgirl86]

I am also looking to change my LSD gear oil for my 19 3.3 RWD soon. Did you add other "additive" to this gear oil? or does it already have that additive?

Which oil would a 2021 G70 2.0 RWD Elite? I can't seem to find that anywhere !

 

[joegr]

Which oil would a 2021 G70 2.0 RWD Elite? I can't seem to find that anywhere !

2021 G70 Owner's manual...

 

[TheBeginning]

Which oil would a 2021 G70 2.0 RWD Elite? I can't seem to find that anywhere !

Do you have a limited slip differential? If you don’t know, the best place to look is the window sticker which came with the car. Otherwise search google for equipment which came on your year and trim level. Just be careful of the country. Different markets receive different equipment.

If you have the limited slip, this thread details what fluid to use.

Just had the fluid flushed and replaced on my ‘20 G70 3.3T AWD Sport which has the limited slip differential in the rear. This was for the 36,000 mile service specified in the manual. Used the OEM Genesis multipurpose gear oil (for limited slip applications) and some AMS Trans-X. No issues before the flush or in the 1000 miles after.

 

[Volfy]

Which oil would a 2021 G70 2.0 RWD Elite? I can't seem to find that anywhere !

If you're in US or Canada, and your 2.0T has an 8sp auto, then you DO NOT have an LSD. For North America, the only G70 2.0T trim that came with LSD is the 6MT. So... for non-LSD, going by the chart posted above, any GL-5 hypoid gear oil 75w85 would work. Go with a full synthetic for good measures. And unless you live - and drive - up in the extreme norther tundra, 75w90 should work as well. In fact, for some of us having to put up with hotter-than-Hades Texas Summers, I actually prefer 75w90.

Just had the fluid flushed and replaced on my ‘20 G70 3.3T AWD Sport which has the limited slip differential in the rear. This was for the 36,000 mile service specified in the manual. Used the OEM Genesis multipurpose gear oil (for limited slip applications) and some AMS Trans-X. No issues before the flush or in the 1000 miles after.

Glad that worked out well for you. It boggles my mind why Genesis can't seem to figure out how to fix such a simple issue. Kia already has a TSB on this issue for G70's sister car Stinger, back in 2018.

LSD Service Bulletin - Oil Update

Why Genesis would change out some folks' whining LSD 3-times over - instead of squirting in a few Oz. of FM - is beyond me.