Thread: High mileage transmission, change fluid or not?

Transmission pan magnets?

I just did a pan drop/transgo. My fluid was bad 134k and i dont think it had been done befor. It took 7.5 of DEXIII one lucus drives and shifts great threw a cooler in while I was at it. Put 5 hundos on it rechecked fluid lvl and pan bolts no leaks and im off to the races.

My .02 is to just do a basic pan drop and shift kit. Auto parts store ask for trans magnet. Button it up and let er rip.

Originally Posted by wowitsfast

I just did a pan drop/transgo. My fluid was bad 134k and i dont think it had been done befor. It took 7.5 of DEXIII one lucus drives and shifts great threw a cooler in while I was at it. Put 5 hundos on it rechecked fluid lvl and pan bolts no leaks and im off to the races.

My .02 is to just do a basic pan drop and shift kit. Auto parts store ask for trans magnet. Button it up and let er rip.

So, you also used Dexron III. Any particular brand?
Did you have Lucas Transmission Fix in the trans before?
And, because of the high mileage on the old fluid, did you take off the return line and start the engine to force out more old fluid?

im running travelers brand dex 3 sold at tractor supply, they got 2 gallon jugs. its the same fluid as walmarts dex3, made by the same co. been on it for 5 years now, the tranny im running was used, but also flushed out a few times before i got it and was bone dry. i got two 2 gallon jugs cause i was told the tc i was using was also drained.

the tc only took about a gallon and the trans took the whole other 2 gallon jug. im not exactly a light foot and she holding up still with like 150,000 on it now.

Originally Posted by NotEnoughGPs

What kind of magnets are available for use in the transmission pan?

http://www.grandprixforums.net/threa...=1#post1392701

Bronco Boy, you deliver! I need to spend more time reading GrandPrixForums! Don't know how I missed that thread you listed

There are a lot of threads that should be linked to in a sticky on top of the different sections of the forums.

Sent from a galaxy far far away.

Originally Posted by NotEnoughGPs

So, you also used Dexron III. Any particular brand?
Did you have Lucas Transmission Fix in the trans before?
And, because of the high mileage on the old fluid, did you take off the return line and start the engine to force out more old fluid?

I used Valvoline
I dont know if there was lucas in there before but that stuff is thick
no i didnt do anything else I will do it again in the spring car doesnt get out much during the wet months

Originally Posted by Slick2500

There are a lot of threads that should be linked to in a sticky on top of the different sections of the forums.

Sent from a galaxy far far away.

Well, anyone who visits this forum regularly (or everyday like I do) would surely like to see stickies listed at top.
The search function works so well on here, but as other's have stated, you have to spend some time sorting through numerous threads to find a thread with the info you are looking for. Of course, the title of each thread can be misleading.
Even better, I need to kick myself to remember to just use everyone's best friend: Google
I typed in "magnet placement in a 4T65E transmission pan in a Pontiac Grand Prix", and that's where I found http://www.grandprixforums.net/threa...D-Transmission
Well, as has happened in the past, I didn't have this info when I installed the transmission pan last night on my GP. I put some extra flat magnets (like the stockers) in the pan, but due to getting more new info on the round magnets, I dropped the pan and gonna add them. I agree that those smallish flat magnets can get overloaded fast with metal particles. I don't need any problems after letting the fluid change go for 241,000 miles!
In addition, I wanted to see the condition of the Dex III fluid. I drove the car easily for 60 miles today (and Intense shift kit worked quite well) I was surprised that the fluid looked only slightly darker than the pinkish new color. After only 60 miles, I presume that the old dirty fluid has not had time to mix with the new fluid.

my tranny just blew up lol looks like the tc took a crap all at once.

Originally Posted by NotEnoughGPs

Bronco Boy, you deliver! I need to spend more time reading GrandPrixForums! Don't know how I missed that thread you listed

Glad to help. The search function here sucks; I know I've seen things, but try and find them. I bookmarked that trans rebuild so I can find it easily.

Neglecting to change out the transmission fluid and filter for so long is a bad on my part, especially on this '02 GP that I have owned for 12 years, and enjoyed driving it every single day! The comfort, performance and reliability of this car is amazing even at 241,000 miles. It pays to keep up on maintenance which I do with engine oil, coolant, power steering, etc. as well as some parts. But just don't know why I never bothered with the transmission which is so critical. I have changed out the trans fluid on other GP's I have owned and that helped them also last a long time.

Anyways, with this 40th Anniv GT, I also installed the Intense Performance Shift Pak (shift kit). I had no issues with the install as Intense goes above and beyond in the products they sell, and they provided great instructions. The one comment I got to make is that this is a HUGE improvement. The trans really woke up. It was stupid of me to not install this shift kit many many years ago. Now, this car, even with the inflated amount of miles, is so enjoyable to drive. I highly recommend the Intense shift kit to everyone. I mean, I am at a point that I love to drive the car because of the way it shifts now, and even on the expressway on the way home this morning, it seems to move out 100 times better than before.

And, as far as the transmission fluid change as a whole, it went well EXCEPT for the problem I had with the transmission fluid return line (that goes from the radiator to the trans) I had detached this line so that I could run the engine in short intervals of 4-5 seconds, so the the new transmission fluid would displace the old fluid contained in the transmission. I hooked up a clear hose on the return line fitting and ran the hose into a clear jug. As I started the engine, I could see the old trans fluid draining out. After about 2 quarts of old fluid, I could see the new trans fluid that I added started to drain out. At this point, I stopped running the engine and moved to reattach the return line. Well, I had a problem getting the threads to start turning. I cleaned the threads and added a small amount of white grease, but still could not get the threads to start. I had a tap which I inserted and turned lightly into the threaded hole in the trans. And I removed a bolt that held down the return line to the front of the transmission. This enabled me to finally get the line in place and tightened down. That took 2 hours! I was not prepared for that struggle, but just wanted to make everyone aware that lying under the car and trying to get this line connected was a little difficult, but all is good now.

Lastly, I want to point out that I am continuing to add transmission fluid to bring the level up the hashed area on the dipstick. I am only adding a pint of fluid at a time, as I don't want to overfill the transmission. So, I keep adding, and then driving, and then checking the level of fluid on the dipstick, and it is still below the hashed area. I still have some fluid in one of the gallon jugs that I am going to add later on today.

And, I continue to hope that I don't experience any slipping of the trans. So far, after 60 miles of driving, there has been no problem. I have not gotten into the throttle a whole lot. I am going to give is some time before I do any fast accelerations. And for this weekend, I have a trip planned. So by Monday, with 1000 miles on the new fluid, any problems will be revealed.

Thanks to everyone for the advice given to help me out during this maintenance!

he bought the car new

UPDATE: New Valvoline Dexron III trans fluid, new trans fluid filter, 24 oz of Lucas transmission fix fluid, Intense Shift kit were all added to my 40th anniv. last week. I also followed the procedure in which I filled the transmission, then disconnected the return line (from radiator to the transmission) and started the engine and let it run in 3 second intervals, thus running the transmission pump and pushing out more of the old black transmission fluid. I did this until about 1 gallon of old transmission fluid poured out.
Since I performed this work, I have driven 1500 miles, and I'm happy to report that there have been no issues whatsoever.
The L32 engine has only an HV3 installed.
Total mileage sits at 242,600 miles.
Right after topping off the transmission with fluid, I checked for leaks at the pan and detected none (I installed a brand new GM pan gasket)
The first 200 miles or so, I drove easily not getting into the throttle.
Then, on a 1000 trip over the weekend, I drove the car like I always had done before.
I had never intended to let the transmission fluid go that long before changing. I was not too optimistic that the trans would shift well.
The performance of the transmission is better than it has ever been. The 1-2 shift had been slow before, and under heavy throttle there was a shudder. Now, when I push it hard, it shifts with no shudder, and I don't have to let up on the gas to let it shift. The 2-3 shift had been slightly jerky before, but now it is silky smooth. 3-4 shift is unchanged.
What truly amazes me is how the down shifts are so much quicker. On the open highway which was the bulk of the miles I drove at 55mph or more, I would hold steady pressure on the accelerator pedal. Then when I pushed quickly on the pedal, and the transmission would downshift very quick, and upon holding the pedal down, it would stay in 3rd gear and speed would increase pretty dramatically, where I could go from 55mph to 70mph or more in a short time. Previously, that process was difficult at best.
Driving it now seems like a totally different car. The benefits of the new fluid and the shift kit has made for a overwhelming driving experience. I obviously know how this car preforms because I have driven it most of the miles on the odometer (it has mostly sat during winter seasons since 2004) but I got to admit, I didn't expect it to run this good!
I would highly recommend to everyone to replace the transmission fluid at the advised intervals (don't let it go as long as I did) and to purchase and install the Intense shift kit.
I also recommend the Grand Prix and any w-body car to anyone looking for a well built car that can easily last beyond 200,000 miles. I have always been a believer in these cars, and now I believe that even more.
The next step is I want to drain the fluid again, and install another filter, and install the differential lube tube retainer clamp (Sonnax 8453201K) to hold the differential fluid line in place.
Also, I would like to get a shift kit with springs to upgrade the 3-4 accumulator.

Originally Posted by jbamonte

Excellent! I have 195,000 miles on my 01 GP and Had a hard shift condition when the fluid got hot at 88K. Previously to the 88K hard shift I changed the fluid/filter at 40,000 miles (I have owned the car since brand new) and at 62k. At 90k I added (2) 18,000 GVW double stack Long/Dana tranny coolers in the grill and disconnected the in radiator trans cooling lines (the 2 Long coolers do all the cooling), and added a Transgo shift kit (not the Intense kit which firms up the shifts but the Trango eliminates the long shift duration) along with Dexron VI/new filter. I have changed the fluid with Dexron VI/new Filter every 20k miles since then and now have 195,000 miles on the tranny with zero issues with shifting/ hard shift condition, etc. Add the Biggest Dana/Long double stack cooler in the grill and let it do all the cooling and you hopefully can hit 300K miles on that Tranny....

All good advice man, Thanx.
I am not a fan of trans coolers unless I am running lots of engine mods. In this particular GP of mine, I plan to change the fluid at least once a year going forward, which will be around 20,000 miles or so. Hopefully the trans will continue to hold up as I hope to keep this daily driver running as long as I can.