Oil fill instructions for drive unit Gear case

[Nixapatfan]

Doing some investigating for an out of warranty Rivian oil leak, most likely from the output seal behind the disconnect. Also this is required 100k maintenace for anyone looking to keep long term. Looking for procedure on how to change/fill oil on a Gen1 drive unit gear case. I found the TSB instructions for draining and replacing fill plug but nothing for actually refilling it.

Anyone know the type of oil the gear case requires for Gen1?
Capacity: minimum Front 1.1L Rear 1.3L what's the max or normal capacity TSB isn't really clear?
How do you fill it? Is the circled part the fill tube in the picture below? If so WTF!
I assume only way to check fill level is to drain it and measure what comes out as per the TSB procedure.

TSB's:
Drain plug:
MC-10240312-0001.pdf

Half shafts:
MC-10240310-0001.pdf

Sponsored

 

[SolartoEV]

@Riviot to the rescue

 

[Zoul]

Is the work you are needing to complete on a quad motor or a dual? If I read the tsb correct it's for quad, but you mention the 100k oil change which I thought rivian had said was only for dual motor.

What you point out in the picture looks to be a vent tube, depending on how accessible it is could be a fine fill point. I do know some manufacturers are eliminating fill plugs and filling through the drain plug.

I'd also be interested to know what fluid is specified, if it's special for the disconnect clutch.

 

[MountainBikeDude]

Is the work you are needing to complete on a quad motor or a dual? If I read the tsb correct it's for quad, but you mention the 100k oil change which I thought rivian had said was only for dual motor.

What you point out in the picture looks to be a vent tube, depending on how accessible it is could be a fine fill point. I do know some manufacturers are eliminating fill plugs and filling through the drain plug.

I'd also be interested to know what fluid is specified, if it's special for the disconnect clutch.

It's the other way around, actually. The filter on the side of the Enduro/Ascent motors means they don't need a fluid change. The Gen 1 Quad has no filter, so the fluid needs to be swapped at the 112,000mile interval.

 

[Nixapatfan]

Thank you @MountainBikeDude if I end up doing this myself I'll be sure to document the steps for future DIY folks.

 

[Nixapatfan]

Is the work you are needing to complete on a quad motor or a dual? If I read the tsb correct it's for quad, but you mention the 100k oil change which I thought rivian had said was only for dual motor.

What you point out in the picture looks to be a vent tube, depending on how accessible it is could be a fine fill point. I do know some manufacturers are eliminating fill plugs and filling through the drain plug.

I'd also be interested to know what fluid is specified, if it's special for the disconnect clutch.

It's a quad.
Confirmed the tube is a vent tube/leak testing and not a fill tube.
Fill is via plug on the side of the gear case, have to pump it in.
Fluid, all the alternatives are listed there also: RAVENOL MTF-3 SAE 75W | RAVENOL
Capacity:
Front: 1.1L - 1.3L refill (1.4L when dry)
Rear: 1.1L - 1.5L refill (1.6L when dry)

If I decide to DIY I'll document as I go.

 

[Riviot]

 

[Zoul]

It's the other way around, actually. The filter on the side of the Enduro/Ascent motors means they don't need a fluid change. The Gen 1 Quad has no filter, so the fluid needs to be swapped at the 112,000mile interval.

Ahh. Must have remembered that backwards for some reason. Good to know.

Looking through the specifications on the fluid I don't see any friction modifiers like you'd see with Limited slip or automatic transmission type clutches. I wonder if you could see any benefits of using a different weight gl4 gear oil. Higher weight could theoretically take more abuse. Lower weight could theoretically give more range/better efficiency. Although don't know if I'd toy with it while still under warranty. Does the rear axle disconnect use an electromechanical clutch, or is it applied via fluid pressure like gm uses for AWD.

Sorry to hijack a bit. Can't wait for the how to write up.

 

[Time2Roll]

I assume only way to check fill level is to drain it and measure what comes out as per the TSB procedure.

Unless the level is low from a leak.

 

[MountainBikeDude]

Ahh. Must have remembered that backwards for some reason. Good to know.

Looking through the specifications on the fluid I don't see any friction modifiers like you'd see with Limited slip or automatic transmission type clutches. I wonder if you could see any benefits of using a different weight gl4 gear oil. Higher weight could theoretically take more abuse. Lower weight could theoretically give more range/better efficiency. Although don't know if I'd toy with it while still under warranty. Does the rear axle disconnect use an electromechanical clutch, or is it applied via fluid pressure like gm uses for AWD.

Sorry to hijack a bit. Can't wait for the how to write up.

Electromechanical flip chip dog clutch of sorts.

I recommend watching the entire video, as well as another one specific to the Bosch Gen 1 Quad motors. This one starts by talking about the disconnect within the dual motor Enduro drivetrain, and then pivots to comparing it to the Bosch Gen 1 Quad motors external disconnect

 

[Nixapatfan]

Ahh. Must have remembered that backwards for some reason. Good to know.

Looking through the specifications on the fluid I don't see any friction modifiers like you'd see with Limited slip or automatic transmission type clutches. I wonder if you could see any benefits of using a different weight gl4 gear oil. Higher weight could theoretically take more abuse. Lower weight could theoretically give more range/better efficiency. Although don't know if I'd toy with it while still under warranty. Does the rear axle disconnect use an electromechanical clutch, or is it applied via fluid pressure like gm uses for AWD.

Sorry to hijack a bit. Can't wait for the how to write up.

Watching the Munro video I don't think higher weight oil would be a good choice here, at least from looking at the tiny oil passage windows on the middle support casting and being that it's a splash lubricating setup it might not actually lubricate things properly on cold mornings unless you overfill it somehow. Most diffs are filled around 50%, this setup looks to only hold oil in the bottom 25% or so.

 

[HaveBlue]

Rivian will sell you the axle seal. I thought I had the part number but no luck.

Sponsored