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2005 GP GTP Tranny

lawadm1

New member
I'm trying to figure out what transmission the 2005 GTP has. Is it the 4T65-E or the 4T65-E-HD/MN7?

I'm wanting to drop the pan and replace the filter, but I'm not sure if there's a difference between the Base/GT and GTP transmission filter.

Also, if I drop the pan, should I count on at least 7 quarts to refill?
 


same tranny inside, the hd diff is the only real difference.

and if you have a supercharger installed from the factory, you have the HD tranny.
 
So I was checking the transmission fluid after writing this thread, and it appears to be a little brown for my liking. No pink tint whatsoever. The car is 12+ years old, and I have 101,000 miles on it. Just broke 100,000 this year. I had a trans cooler line replaced by the dealership about 5 years ago, but I have never done a drain and filter change on the car. Is that normal for that age/mileage?

I plan on doing the pan drop and filter change this weekend.
 
Your about 2 changes behind for long tranny life. 50k is a good rule of thumb.


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Roger that.

Do you guys go with the Dexron VI? Or do you look for the Dexron III? I did see the AC Delco Dexron III for $5.49/qt on Amazon, but now it's back to $9.54. Damn.
 


If it says dex IV use dex IV otherwise dex III. Unless IV is cheaper for some strange reason. Just don't put dex III in a DEX IV tranny. My opinion.


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The manual for the 2005 GTP says use Dexron III type H, but the manual for the 2007 Base says use Dexron VI.

Napa has both Dexron III and Dexron VI, so I'll probably go with the Dexron III for the 2005 GTP. It's Napa brand, but it has to be better than the brown stuff that's in there now.
 


Got it. I was actually able to get some Castrol Dexron III - H for pretty cheap.

Does anyone use a fluid extractor to pull as much tranny fluid out as possible from the dipstick, before dropping the pan? Or is the transmission shower the recommended way?
 
if you have an extractor use it, why not......if you dont we put a pan under the trans pan, loosen up lowest looking corner and let it drain in a controlled manner.
 
I used dex VI because that's all I could find locally, and I needed it now rather than later.

But I did add about 3 bottles of Lucas to it...

My method is not recommended. Lol. :rolleyes:
 
Im impatient so I usually end up with the shower method. Add an extra magnet to the filter if you can.


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Thanks for the extra magnet tip. I'm actually getting two new donut shaped ones based on another thread, which says to put one in the factory location, and one on the bottom side of the filter.
 


Well, the transmission oil was completely brown, and the bottom of the pan and magnet were nothing but brown sludge. I upgraded the magnet, and added an additional magnet, and the fluid is now pink on the dipstick. I ended up adding about 8.25 qt before it was all said and done.

Putting the car into "R" and "D" sounds much quieter, and the shifting between gears seems much smoother. I won't be letting this happen again.
 
My dipstick says to use III and I used VI. Maybe why my transmission is shifting hard on occassion. Or my transmission is dying. Going to drop the ole pan again and put III in I guess. Thanks thread!
 
id just let it ride. not a huge deal. lots of guys use IV.

in my mind tho, if you have a old tranny with high miles, use the dex 3 cause its thicker.

yours is all mixed together already, save your money. try some trans medix stuff if its acting up.
 
If it helps you can get some Castrol DexIII on Amazon for $14.99/gal. I got two but needed more, so I grabbed 1 qt of Dexron III from the local NAPA.
 
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