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Discussion Starter · #1 ·
Folks,

I've found that the Bolt EV uses Dexron HP (Dexron High Performance, I believe) for the gearbox - about 3 quarts. And, GM makes no mention of needing to ever change it.

Would it be a good idea to put a few thousand miles on the car, then change this fluid out for a fresh fill of Dexron HP to get rid of material left in the manufacturing process?

(I'm asking because over in Priuschat, it's considered a good idea to change the transmission fluid early, and then about every 60 miles or so. I'm wondering if it applies to the Bolt too).
 

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Discussion Starter · #3 ·
Early Dexron HP change on the BOLT - Good Idea?

^ - is all about the transmission fluid for the VOLT. And, the Volt has a few clutches and a more complex transmission.

I'm asking not about the V-olt, but the BOLT. No clutches, just gears and bearings. Which is the same as the 2nd generation Prius - just gears and bearings.

Anyone have anything useful regarding the Bolt?
 

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The Bolt's Dextron serves two functions: lubricate the drive unit (motor & gears/bearings) and cool it. GM engineers even included a dedicated power-electronics/drive unit glycol cooling loop specifically to keep the Dextron cool and comfy. Pretty light duty for a transmission fluid that usually goes 50-100K miles between changes in much tougher duty - running constantly-shifting automatic transmissions on big pickups towing things, driving torque converters, etc. The Bolt EV's owner's manual doesn't even have it on the time horizon for being changed at 150K miles, which is when GM recommends changing the glycol coolants. Your call, but I sure can't see any reason to think about even checking it until at least 150K miles.

Edit: After reading the thread on the Volt drive unit service, I wonder if the Bolt's drive unit even has a drain plug on it. Seal and forget. GM probably doesn't want to tempt shade-tree mechanics or Jiffy Lube to monkey with the Bolt's drive unit in any way.

http://gm-volt.com/2016/01/19/129946/
 

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Folks,

I've found that the Bolt EV uses Dexron HP (Dexron High Performance, I believe) for the gearbox - about 3 quarts. And, GM makes no mention of needing to ever change it.

Would it be a good idea to put a few thousand miles on the car, then change this fluid out for a fresh fill of Dexron HP to get rid of material left in the manufacturing process?

(I'm asking because over in Priuschat, it's considered a good idea to change the transmission fluid early, and then about every 60 miles or so. I'm wondering if it applies to the Bolt too).
I've never heard anyone advocate that for any GM transmission. If anything large breaks loose the filter will catch it. So, I wouldn't bother. Given the lack of clutches, the fluid will probably outlast the car.

It's pretty sketchy that Toyota's manufacturing process is sloppy enough to make that a good idea in the Prius.
 

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What does your manual say? Follow what it says to preserve your warranty and have a GM dealer do the work. Many people still change full synthetic oil at 5000 miles which is just a wast of money.
 

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OK, so you think that those brilliant folks on Priuschat must be smarter than the GM engineers that designed, tested and developed the proper maintenance procedures for the Bolt? Forgive me for calling BS.

VIN # B0985
 

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Don't waste dead dino juice. RTFM

Compound that with the fact that Prius owners don't understand the 4th grade math term "greater than" - they still bought a Prius, PiP, or Prius Prime despite other cars getting better eV range and overall fuel economy. Does Toyota have a 200+ mile all electric vehicle that isn't sold only in a few select states? I'll grant that early priuses ruled the fuel economy world, but no more. Then their designers decided to make their cars (all of them, even the yaris) fugly. Geez can't do math, can't see clearly, certainly a winning combo.

I used to own a Supra, before the dark times, back when they could design a great looking car. I miss those days.
 

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No need, unless you just like wasting money for "peace of mind" predicated on nothing but somebody's feeling.
 

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Folks,
Would it be a good idea to put a few thousand miles on the car, then change this fluid out for a fresh fill of Dexron HP to get rid of material left in the manufacturing process?
That's about the craziest thing I've ever heard of. Unlike engine oil, there is no combustion or by-products to contaminate the fluid. As far as material left in the manufacturing process, I would venture to say that the inside of the Bolt EV drive unit is cleaner than the insides of your computer. Any metal shavings etc would wreak havoc, and they are not there.

Even with conventional transmissions, old-timers in the transmission business advise against early transmission fluid changes unless there is some sign of burning or degradation - again, no combustion inside. Anecdotal cases tell about transmissions that worked fine until the fluid was changed.
 

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That's about the craziest thing I've ever heard of. Unlike engine oil, there is no combustion or by-products to contaminate the fluid. As far as material left in the manufacturing process, I would venture to say that the inside of the Bolt EV drive unit is cleaner than the insides of your computer. Any metal shavings etc would wreak havoc, and they are not there.

Even with conventional transmissions, old-timers in the transmission business advise against early transmission fluid changes unless there is some sign of burning or degradation - again, no combustion inside. Anecdotal cases tell about transmissions that worked fine until the fluid was changed.

Totally correct! Before retiring I worked in power generation. On larger pieces of equipment, even those with sources of contamination like steam, water, wear metals, coal dust, etc., lubrication was used continuously for decades. This included large turbine generators worth millions of dollars. One station where I worked started initial operation in 1924 and will be retired this fall. It potentially still has oil placed service in 1924, though it probably is very much diluted with newer oil due to leakage losses. Lubricating oil was continuously filtered to remove contamination. In the case of a modern drive system with no contamination sources and continuous filtration, changing lubrication makes no sense.
 

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The Bolt drive has a drain and a fill plug, but it also has a filter for the fluid, so unless it's been in a flood or something, I wouldn't bother changing the fluid.

When I've changed the fluid in the Prius, it came out all nasty, but I don't think they have a filter in there.
 

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What does your manual say? Follow what it says to preserve your warranty and have a GM dealer do the work. Many people still change full synthetic oil at 5000 miles which is just a wast of money.
Yeah, what he said...
 

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I agree 100% with almost all of the posts here. The transmission fluid should not be changed unless it needs a repair, and only changed under the scheduled maintenance printed in the owner manual for all vehicles, EV or not. My 2009 Chevy Equinox still has the original transaxle fluid inside, and it runs like it was new. My previous 1995 Buick Regal never had a transaxle fluid change in 21 years of my ownership, and it is still running under a new ownership. All GM transmissions and transaxles have a filter inside that will trap and protect from any particles (metallic or not) that gets into the fluid.

Changing the fluid ahead of the schedule is a total waste of money and time. If done wrong, the transmission or transaxle can fail!
 

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Toyota WS is a non-synthetic I believe. The "nasty" appearance is not necessarily an indicator of unsuitablility for service. I changed our Camry Hybrid at 45k or so, and it was black. Since I could replace the fluid for the price of an oil analysis I changed it. It's cheap (relatively) and only takes 4 quarts. Dexron 4 or 5 (whatever is in the Volt) is a synthetic lube designed for long life, and the transmissions have an internal filter. Oil analysis results I've read indicate it will easily last to 150k miles.
 

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All of the GM auto trannies I'm familiar with do NOT have drain plugs. Reason: GM did not want people merely drain and refill the fluid - they wanted them to change the filter as well, hence if you have to drop the pan, might as well replace the filter.
 

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All of the GM auto trannies I'm familiar with do NOT have drain plugs. Reason: GM did not want people merely drain and refill the fluid - they wanted them to change the filter as well, hence if you have to drop the pan, might as well replace the filter.
A lot of GM transmissions don't even have serviceable transmission filters anymore. The transaxle had to be removed and the case split to change the filter. Not sure if the Volt is like that, but wouldn't be surprised.

It's pretty rare for transmission filters to clog anyway. If they do, then either the clutches are so warn that the unit is shot, or something big explodes and the unit is shot.
 

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A lot of GM transmissions don't even have serviceable transmission filters anymore. The transaxle had to be removed and the case split to change the filter. Not sure if the Volt is like that, but wouldn't be surprised.

It's pretty rare for transmission filters to clog anyway. If they do, then either the clutches are so warn that the unit is shot, or something big explodes and the unit is shot.
The volt doesn't have a traditional transmission between the power plant and the drive wheels. There is a simple gear that changes the overall gearing ratio. The magic is the complex cvt that balances two electric motors and the ICE to work in harmony. So this is not something we'd take to a transmission shop.
 

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A lot of GM transmissions don't even have serviceable transmission filters anymore. The transaxle had to be removed and the case split to change the filter. Not sure if the Volt is like that, but wouldn't be surprised.

It's pretty rare for transmission filters to clog anyway. If they do, then either the clutches are so warn that the unit is shot, or something big explodes and the unit is shot.
The Volt has an internal filter that you would have to split the case to get to.
 

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The volt doesn't have a traditional transmission between the power plant and the drive wheels. There is a simple gear that changes the overall gearing ratio. The magic is the complex cvt that balances two electric motors and the ICE to work in harmony. So this is not something we'd take to a transmission shop.
I realize it's not a traditional transaxle. But, its setup very similiar to one in how the engine mates to it and how the axle halfshafts are connected. It's also uses ATF and has some clutches. Agreed that a transmission shop would be unlikely to be able to rebuild it.
 
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