Transmission Fluid Change

[rdnkcpa]

Well all, I read up on the various forums on how to change the fluid on my truck. I bought 13 Qqts of Dexron 6, a transmission cooler line fitting, 10 feet of clear hose, small hose clamp, and a filter kit.

 

I popped the return line off the radiator no problem. Put the transmission fitting and clear 3/8" ID tubing into the radiator, started the truck and pumped out the pan. Fluid was very dark. (135K on the truck, first fluid change). Next step is to drop the pan. I read up on how do to it, several posts called for a TORX40 to loosen the shift linkage bracket. I tried that method but the engineers at GM thought it was a good idea to put the bolts for the bracket in an almost impossible to get at position. I consulted the internet again to make sure I was not missing anything. I came across a few posts that recommended bending the bracket out of the way. I decided to go with this method. I tried with a pair of chanelox pliers, no dice. i could not move it far enough with the pliers. Fired up the googles again, found some good info on bending the bracket. Turns out, if your rig is a 4X4, it makes things easier if you drop the front drive shaft. Be sure and mark the yoke and drive shaft. I used a piece of my kids driveway chalk. Got the front drive shaft unbolted from the front differential and pushed to the side. I did not remove the drive shaft from the transfer case. I then got a 12" screw driver and pried on the bracket and was able to move it just enough to get the pan out.

 

Inside of the pan was dirty, I sprayed it out with parts cleaner and got all the junk out of the pan. The filter came right out. I thought about pulling the plastic seal out, tried for a few minutes but I did not want to scar up the inside of the transmission trying to pull it out. Put the new filter in, snapped right in. Getting the pan back on took a little wrestling, especially trying to keep the gasket lined up. It took a few tries but got it lined up. Bent the bracket back.

 

Bolts for the pan torqued to 97 inch pounds, drive shaft hooked back up, torqued to 18 foot pounds. (Per my GM shop manual). Put 5 qts in, started it and pumped about 5 more qts back out. 5 more qts in, started and pumped about another 3 qts out. Topped off.

 

I'm not a mechanic by any means, but if I were to do this again I would drop the drive shaft first, bend the bracket, drop the pan.

 

The test drive went better than expected. The fresh Dexron 6 makes the truck shift like butter. Much improved.

 

I found Castrol Dex6 for about $7.95US a quart (local Western Auto) and Walmart Supertech Dex6 for $4.97 qt.

 

if you have a 4x4, just resign yourself to bending the bracket. If I would have dropped the drive shaft first then bent the bracket, this job would have taken a lot less time. Live and learn. Next project is the differentials and transfer case.

 

Oh yea, the dealer wanted $62 for the filter kit. Amazon has it for ~$35.

 

 

[CapitalTruck]

Look up Delcoline Parts. They are all over Maryland and Virginia. GM OEM parts for way cheaper than dealer. I go there for all my stuff.

[Rocko973]

Thanks for sharing that info. Just curious... did your GM shop manual recommend flushing through the cooler return line the way you did? I am about to do mine, maybe tomorrow, but I was just planning on draining, dropping pan, swap out filter, replace pan, refill. My 2003 1500 HD is just a 4X2, so I don't have the front drive shaft to worry about. Also, it looks like that once I remove the pan bolts, I can just tilt the pan a little and move it away and around the shift linkage bracket. I feel pretty confident I don't need to remove or bend the bracket.

 

Thanks!

[8.1HD/ALLISON]

Glad to hear you did things youself, but I would NEVER recommend taking a line off the transmission cooler and starting. Thats a good way to trash the pump. There is a reason that all dealers have a nice expensive tranny flush machine. Otherwise they would do it this way. JMO

[Black02Silverado]

Did you find this thread on any of your Google searches?

[rdnkcpa]

Shop manual says nothing about flushing through the cooler line, it just says to drop the pan. Flushing through the radiator is the way to go. The shop manual does not differentiate between 2 wheel and 4 wheel drive, it just says to loosen the bracket. Just be ready to put up with the bracket.

 

Have a good time. You will suprised how much better your truck will shift, I know I was.

[MTPoleKat]

Just some advice take it if you want but scince it was 135K miles with the orgina fluidl. In 5k miles I would drop the pan and change the filter and fluid again. Reason being with that long the old fluid tarnished all the parts inside the tranny the new fluid will take that tarnish off, clog the filter and burn out the tranny. I change my tranny fluid every 25K miles but I do some towing. Fluidl is cheap trannies are not.

[Rocko973]

Just an update: I changed out the transmission fluid yesterday on my 2003 1500 HD with 112K miles. It was the first time it's been changed, but the fluid was still pretty clean and red. However, there was a little bit of metal on the magnet and also what looked like little bit of gray sediment at the bottom. The actual filter inside was black. I cleaned everything out with some acetone and brake cleaner. Looks brand new!

 

I did NOT have to do anything with the shift linkage bracket. I just unbolted the heat shield bracket and pushed it up and away from the pan and tethered it to a screw with a wire. Once I removed the pan bolts, I just tilted it and slid away from the bracket and out. It was just as easy going back in as well. The hardest thing about this job was getting out that little metal fitting that goes into the housing for the filter. That was a pain! But I got it out by straightening out the lip and bending inward, spraying just a tad bit of lubricant in there, then I grabbed the lip with some channle locks and pulled like hell on it. It finally came off. You have to be VERY careful in there....

 

Next time I am NOT going to remove that little fitting and just re-use the same old one. Has anyone here done that? I imagine that that's what they would do at the dealership... but please correct me if I am wrong.

 

I put in 5 QTS, then I tonight I will start it up, drive a little bit, then top off...

[gmtech4]

Glad to hear you did things youself, but I would NEVER recommend taking a line off the transmission cooler and starting. Thats a good way to trash the pump. There is a reason that all dealers have a nice expensive tranny flush machine. Otherwise they would do it this way. JMO

dealers have a machine alright but it only flushes the cooler and it also measures the flow thru the cooler ,,,,,if a dealer wants to buy a machine to flush the tranny they can ,not all have them ....

 

the filter seal can be reused

[8.1HD/ALLISON]

Dealer I worked at had a fluid exchanger that hooked into cooler line and replaced quart for quart. It was pretty nice, but I know what you mean Rob, all dealers are different.