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transmission fluid change

80K views 70 replies 41 participants last post by  LVG8GT 
#1 ·
I plan on dropping the pan to change the oil and the filter, but without a dip stick, I was wondering how to fill the transmission. I never looked at it yet, but didn't know if I need a special tool for this.
 
#37 ·
I had my tranny fluid exchange exactly @ 50k miles (not flushed) 2 weeks ago, and the tranny seems absolutely "refreshed" from it. AND it it was done at my local GM dealer for $65.00 :)
 
#38 ·
That's amazing. My filter was $15 and the 12 quarts of synthetic fluid was almost $100. I did mine at 25k, along with the addition of the Camaro pan. It made a noticeable difference.



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#45 ·
Yup with synthetic and a new Camaro pan for under 150


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#56 ·
An update to this topic, I've have the dealer change the oil on the trans about 2 years ago, and I've been putting up with an ill shifting trans until it reaches operating temp ever since, that is until a few days ago. It's been to 2 different dealerships to fix the problem, but nobody could find the problem. Nobody but me, I discovered that the trans was still low on fluid, but you never can tell because they don't put a dip stick on it. So I used an syringe with a hose to add about a quart, it now shifts normal, hopefully no damage as been done in the last 2 years with low fluid.

The point here is I can't imagine ever buying an extended warranty, or ever taking my car to the dealership for service, ever!
 
#57 ·
After I installed my stall converter I went through the process outlined in the maintenance manual - getting fluid up to temp, shifting through gears etc. then filled the trans until the fluid came out of the fill hole. Once the stream broke, put the plug back in and put another quart in. Underfilling the trans is a problem but overfilling it a bit doesn't hurt it from what I've read.
 
#61 ·
I drop the pan to change tranny fluid and filter at about 25 to 30k miles in my automatic transmission vehicles, then install a drain plug prior to replacing the pan. Then every oil change I also drain and change the transmission fluid. I also drop the pan to change the filter again at 100k miles.


JAM
 
#63 ·
I use the transmission fluid called for in the owners' manuals. Ford and GM fluids are widely available, Mazda fluid has been more difficult to source.

I mainly use quart containers, especially in the G8 GT which requires a smaller funnel where quart containers are easier to use.

JAM
 
#64 ·
Thanks for the advice. Just for completeness, here are some additional quotes. A second GM dealer said a flush with pan cleaning and new filter was $400. He said this includes about $100 in fluids and $80 for filter and gaskets, implying $220 for labor and machine time. So, Dealer A $370, Dealer B $400.

I then called a respected independent shop. They said flush only, using 'universal' fluid is $250. He recommended doing this. He said the flush uses the transmission's own pump to replace the fluids, so it does not upset any debris that is settled in the filter or on the magnets. He said to drop the pan and change the filter adds about $200, comprised of about $100 labor and $100 parts and fluid. He said he'd change the filter after the flush process (versus flushing through a new filter) so that means an additional 5-6 quarts to refill the pan. He said the 'universal' fluid is $5.20 versus GM $8.45/qt.

Kind of disillusioned (again) with these shops and their costs all over the place, so as a competent DIY-er I will take ebg8gt's advice and do the filter myself and replace what fluid comes out (with GM fluid).

Don't have exact figures but if it holds 16 quarts and 6 quarts comes out with the pan, then after one change it will be 37% new fluid. If I do it again at the next oil change (without filter), it's 61% new fluid. (A third change would take it to 76% new fluid, and a fourth to 85% new fluid). If the procedure is simple enough, I probably will just do 2-3 pan drop changes over the next year or so. Make sense?
 
#65 ·
Camaro pan, filter, and gasket are ~$80. I got mine on Amazon.

If you change to camaro pan, be sure to get the magnet out of the old pan. The new pan has the stamped spot for it, but doesn't come with one. Also add 1-2 quarts for the deeper pan.

Changing the filter... either leave the filter seal alone (reusing the old one), or be ready for a fight. :)

Regardless of camaro pan or stock pan, most will recommend doing the fill procedure, button it back up, then add another quart.
 
#66 ·
Camaro pan, filter, and gasket are ~$80. I got mine on Amazon.

If you change to camaro pan, be sure to get the magnet out of the old pan. The new pan has the stamped spot for it, but doesn't come with one. Also add 1-2 quarts for the deeper pan.

Changing the filter... either leave the filter seal alone (reusing the old one), or be ready for a fight. :)

Regardless of camaro pan or stock pan, most will recommend doing the fill procedure, button it back up, then add another quart.

This. If you are able to do it yourself, go with the Camaro pan, widemouth filter, and slightly increased fluid capacity. Will cost you less, and you'll know what fluid and level goes back in. I would personally avoid the flushing machines. Just drop the pan, change the filter, swap the magnet into the new pan, and fill her back up with Dexron VI.
 
#67 ·
Thanks for all the help starting with my "thread revival" post #58. I chose not to have it flushed but will drop the pan and replace the filter and fluid. While easy to switch to the larger Camaro pan, I decided to keep things stock as the car is unmodified, shifts fine, and I do not track the car (I'm easy on it). I like to keep things OEM (when they prove to work well) so confirmed for my '09 G8 GT VIN that the AC Delco filter is #24252158 (and gasket #24224781). Summit Racing has these AC Delco parts ($33 and $17 respectively).

I collected the procedures and tips from both this G8board and from a Corvette forum on the 6L80 trans. I'll make the special tool found on the Corvette forum to both extract and insert the filter seal. Of course ordered Dextron VI fluid (Amazon).

So I'm ready to go once the parts arrive. But one more question where your guidance is requested. How important is it to verify proper fluid temperature when setting the fluid level? Spec says it needs to be between 86 and 122 F. Too cool, you'll overfill; too hot, you'll underfill. I'll be doing this job with ambient temps in the low 50s. Is driving the car the only way to get the trans up to this temp range? (I suspect just idling the car won't heat the trans much if at all.) I guess I can wait till next summer when ambients are 90+ F to do this job if that's advisable.

Also, I see there's a Torque Pro app ($5) that can display trans temp. Do many use that app and is it simple to use? I guess with that app I can drive and get the trans hot enough to do the job before fluid drops below 86 F. Thanks for helping this first-timer.
 
#68 ·
Also, I see there's a Torque Pro app ($5) that can display trans temp. Do many use that app and is it simple to use? I guess with that app I can drive and get the trans hot enough to do the job before fluid drops below 86 F. Thanks for helping this first-timer.
Engineering mode can show you the trans temp, if memory serves. Press and hold down left scroll wheel as you turn on key and start the car, then you can scroll through and monitor trans temp until it's where you need.
 
#70 ·
Also, you won't need to drive it. Since the trans cooler is part of the radiator, it brings the trans up to temp pretty quick.

But you should let it idle, and run it through Park, Rev, Neutral, Drive, to make sure fluid is cycled through it.

Edit: Torque Pro is awesome. $10 bluetooth ODB adapter, $5 app... you have real time monitoring, data logging, code checking, etc. If you get it, you'll have to install the additional GM pack, which includes another 50 or so parameters that you can monitor.
 
#71 · (Edited)
Job successfully completed today. Very straightforward. I'll share a few things from my procedure that might be helpful for others doing this the first time.

1. Exactly 5 quarts drained out... an 18-gallon Rubbermaid storage container is a great way to catch it all.

2. For the seal removal and installation, I made the tool found in the Corvette 6L80 forum using a 1/4-20 x 5" fully threaded hex head bolt, a thick 1" washer ground to 0.95" with a 10 degree taper affixed at one end for seal removal, and a 1.25" fender washer topped by three 1" washers affixed at the other end for pressing in the new seal. You force the 0.95" washer through the seal (the taper helps) then it's supposed to catch the top of the seal so you can yank it out. In my case, the washer pulled out without the seal. So I put a 1.00" diameter washer on, lightly hammered it up through the seal, and modified the tool with a 1.5" steel pipe cap to make a "mini slide hammer." Seal came right out. (Next time I'll use a 6" hex bolt to allow more movement for the slide hammer.)

3. Once all back together, I put in 5 quarts Dextron VI and started it up, idling while cycling through all the positions. Did an earlier test in engineering mode... found that my trans temp increases 1.25 degrees C per minute and will climb steadily through the 30-50 C range required for level check. Timed it so that I did my level check when it was at 35C. I erred on the cooler end of the range as that leads to a higher fill volume. I needed 0.5 quart additional fluid before it started coming out the level control plug.

4. I believe this trans holds 11.2 quarts and I added 5.5 quarts new fluid. So I am 50% new fluid. I may do another drain/fill later (leaving filter alone!) which will get me to 75% new fluid.

5. The AC Delco part numbers for the filter and gasket in my post #67 are correct for the stock trans pan.
 

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