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Car has ~ 35,000 miles; did annual oil and filter change as well as first ATF fluid drain and refill.

The ATF fluid change did wonders to alleviate what I call my 2 step EV take off mode. This is where when you launch from a stop with low to moderate acceleration, you will feel a slight "bump". I believe this is when the car switches from Motor A (smaller) to Motor B (larger) via clutches in the planetary gear set. The phenomenon is non consistent, depends on fluid temperature, and pedal demand. But it's definitely there. With the ATF fluid change, it's totally gone.

The torque transfer from the electric motor (in EV mode) through the planetary gear set and clutches seems more immediate, whereas before with the older ATF fluid, there is a slight rubber band effect. Makes the car a little more sprightly now.

Lastly, while I do not have severe "chuggle", I did feel sometimes the effect of the clutching in and out between planetary gearsets with the old ATF fluid, it's much smoother now when transitioning between the 3 different modes in CS (engine on) mode.

I highly encourage changing ATF fluid if you having either of these 2 symptoms. Drain and fill of ATF fluid (for my case) is 5 QT. Drain plug on transmission is accessible after removing driver's side aero shield.

FWIW I'm using Amsoil Signature Series ATF and engine oil (5W-20) with AC Delco PF64 oil filter.
 

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Gen 2 I assume?
Amsoil makes very good synthetic products....been using them for years on all of my automotive and marine products.
 

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Don't see how changing ATF at that age would affect it but low ATF would and an oil change would fix it. Are you sure the ATF wasn't low to begin with?
 

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If he consistently drives it hard like a normal car and doesn't hypermile like most here seem to then its absolutely feasible. The pressure additives and friction modifiers in ATF breakdown (yes even at 30k miles) so replacing the fluid renews the friction modifiers and can alleviate internal clutch issues.
 

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Just as a side note, effective 4/27/18 only #19353429 trans fluid is approved for the Gen 2 Volt, the Bolt, Spark EV and CT6 Plug-in. Originally, Dexron VI was the fluid approved for the drive, but GM changed that to the above number.
 

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Changing the transmission fluid is a great idea, especially if you plan on keeping your Volt for the long term. You'd be surprised what a couple electric motors and clutches submerged in ATF fluid can do to contaminate and break down the fluid. The high mileage Prius guys figured this out quite a while ago.
 

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Where is the danf
Car has ~ 35,000 miles; did annual oil and filter change as well as first ATF fluid drain and refill.

The ATF fluid change did wonders to alleviate what I call my 2 step EV take off mode. This is where when you launch from a stop with low to moderate acceleration, you will feel a slight "bump". I believe this is when the car switches from Motor A (smaller) to Motor B (larger) via clutches in the planetary gear set. The phenomenon is non consistent, depends on fluid temperature, and pedal demand. But it's definitely there. With the ATF fluid change, it's totally gone.

The torque transfer from the electric motor (in EV mode) through the planetary gear set and clutches seems more immediate, whereas before with the older ATF fluid, there is a slight rubber band effect. Makes the car a little more sprightly now.

Lastly, while I do not have severe "chuggle", I did feel sometimes the effect of the clutching in and out between planetary gearsets with the old ATF fluid, it's much smoother now when transitioning between the 3 different modes in CS (engine on) mode.

I highly encourage changing ATF fluid if you having either of these 2 symptoms. Drain and fill of ATF fluid (for my case) is 5 QT. Drain plug on transmission is accessible after removing driver's side aero shield.

FWIW I'm using Amsoil Signature Series ATF and engine oil (5W-20) with AC Delco PF64 oil filter.
[/QUOTE
Car has ~ 35,000 miles; did annual oil and filter change as well as first ATF fluid drain and refill.

The ATF fluid change did wonders to alleviate what I call my 2 step EV take off mode. This is where when you launch from a stop with low to moderate acceleration, you will feel a slight "bump". I believe this is when the car switches from Motor A (smaller) to Motor B (larger) via clutches in the planetary gear set. The phenomenon is non consistent, depends on fluid temperature, and pedal demand. But it's definitely there. With the ATF fluid change, it's totally gone.

The torque transfer from the electric motor (in EV mode) through the planetary gear set and clutches seems more immediate, whereas before with the older ATF fluid, there is a slight rubber band effect. Makes the car a little more sprightly now.

Lastly, while I do not have severe "chuggle", I did feel sometimes the effect of the clutching in and out between planetary gearsets with the old ATF fluid, it's much smoother now when transitioning between the 3 different modes in CS (engine on) mode.

I highly encourage changing ATF fluid if you having either of these 2 symptoms. Drain and fill of ATF fluid (for my case) is 5 QT. Drain plug on transmission is accessible after removing driver's side aero shield.

FWIW I'm using Amsoil Signature Series ATF and engine oil (5W-20) with AC Delco PF64 oil filter.
Where is the dang drain plug on the trans axle??
I can't find it.
I am just going to drain the fluid and just put back however much drained out.
I will just buy the fulid from the dealer, I paranoid about messing with transaxle.
Done.
 

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CeeW,

There is a post on that:


Stephen
 

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CeeW,

There is a post on that:


Stephen
I've seen that one, but I guess there is no drain plug?
Just a fill-level hole for the trans?
 

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Nice!
Finally! This is what I have been looking for with no success.
You can download the service manual?! Sweet!
I will try to find it.
 

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Welp, I can't find a service manual to download......I thought I knew how to use the internet! arg!
Where can I find it??
 

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Don't see how changing ATF at that age would affect it but low ATF would and an oil change would fix it. Are you sure the ATF wasn't low to begin with?
GM is known for underfilling the ATF fluid at the factory on other cars so I can see them doing this with the Volt.
 

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Anybody know if there is a gasket to replace on the drain-plug on the transmission?
 

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No gasket. Just did my 2017 at 88K. Fluid was black but didn’t smell burnt. I did not use the level check port because I couldn’t find a reference to the fluid temp needed. Used the measure and replace method. Couldn’t really find a good Gen 2 video or method but here is what I did.

2017 Volt Electric Drive Unit Fluid Change
  1. Drive front end up on ramps
  2. Remove drivers side belly pan
  3. Position catch pan
  4. Remove fill cap in engine bay. Cover hole with clean cloth
  5. Remove 11 mm tapered bolt from bottom of EDU
  6. Drain until stopped
  7. Jack up rear end on both sides until level
  8. Continue draining until stopped
  9. Lower driver’s side rear end part way
  10. Continue draining
  11. Lower rear end completely
  12. Replace tapered drain plug (I reused old one. Supposedly single use but couldn’t find one)
  13. Mark exact position of fluid on new 4 quart container
  14. Pour entire 4 quart container into fill port
  15. Fill empty container with used fluid to mark
  16. Measure remaining drained fluid (mine was 850 mL)
  17. Add same amount through fill port in engine bay
  18. Replace fill cap
  19. Replace belly pan
  20. Start engine with hood up and cycle through gears a few times.
 

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Good info Sdeck, thanks, few questions:

So it is about 5 quarts that drains out?
Wondering cuz I need to know how much new fluid to buy.
The manual says the capacity is 7.13 qt, so it would mean about 2 qt stays in.

How did you go about jackin up both side of the rear?
Just have 2 jacks? Or use jack stands?

So does the drain bolt just not have a gasket?
Is it just a regular bolt?

What fluid did you use?

Final thought, I wonder if temperature matters and if cycling through the gears is necessary as it is a CVT transmission?
As they don't have regular gears like a traditional A/T....
I'm not sure, but I am sure it does not hurt to do so regardless.
 

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Good info Sdeck, thanks, few questions:

So it is about 5 quarts that drains out?
Wondering cuz I need to know how much new fluid to buy.
The manual says the capacity is 7.13 qt, so it would mean about 2 qt stays in.

How did you go about jackin up both side of the rear?
Just have 2 jacks? Or use jack stands?

So does the drain bolt just not have a gasket?
Is it just a regular bolt?

What fluid did you use?

Final thought, I wonder if temperature matters and if cycling through the gears is necessary as it is a CVT transmission?
As they don't have regular gears like a traditional A/T....
I'm not sure, but I am sure it does not hurt to do so regardless.
Yes, about 5 Q came out. I had 2 jacks for the rear. The drain bolt is a tapered pipe thread plug-type bolt. Don’t overtighten as I expect the trans case isn’t steel. I used AC Delco dexron VI. I figure when in doubt, use the manufacturer brand. Yeah, cycling thru gears is probably pointless, just force of habit.
FYI, not really noticing a huge difference in drivability or range but our temps dropped a lot day after I did it and I’ve been stuck at home the past week. I do think it is a bit quieter.
 

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Yes, about 5 Q came out. I had 2 jacks for the rear. The drain bolt is a tapered pipe thread plug-type bolt. Don’t overtighten as I expect the trans case isn’t steel. I used AC Delco dexron VI. I figure when in doubt, use the manufacturer brand. Yeah, cycling thru gears is probably pointless, just force of habit.
FYI, not really noticing a huge difference in drivability or range but our temps dropped a lot day after I did it and I’ve been stuck at home the past week. I do think it is a bit quieter.
Just had random solution to an issue of mine......
I don't have enough jacks to raise up the front and rear of the car at same time.
Solution?

Just lower the front of the car when the drain bolt is out, and you have a level car to drain the trans!
(making sure the pan is shallow enough to fit under car)

then jack back up, replace plug, and refill with same amount that came out.

(insert thoughts of how nice it would be to have a car-lift here)
 

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old trans fluid on the left, new on the right.

oldandnewtransfluid.jpg
 
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