Transmission Failing on my Silverado

[NYEngineer]

Here's what I can tell you about my long term relationship with a 4L60E in my 98 Yukon. The first failure I had with it was around 100,000 miles. I took it to a trans shop I had a long history with. They always did the transmissions in my fleet of vans. Anyway, they completely rebuilt and updated my 4L60E and it was perfect... Until in lost 3rd and 4th. No noises, just no 3rd or 4th gears.
They went through it, found nothing else wrong, repaired it for free and all was well until it happened again while on my way to Florida from NY. Thankfully, I was only in NJ and was able to limp home in second gear. Back to the trans shop... They rebuilt it and this time, replaced the computer. Turns out, the computer sends a signal to the trans to increase line pressure to engage the 3-4 plates. Without that pressure, they slip and burn up. So.. New computer and trans harness and now the truck belongs to my brother and has 260,000 miles on it. this last repair took place at about 225,000. Now, I'm the proud owner of an 09 Suburban with a 6L80E.

 

[bigmike]

My wife and I decided after this mess we'll just be taking the Honda on our out of town trips. I also purchased AAA so I don't have to call my parents to bail me out again, even though they would, as I'd rather be independent.

I hope it doesn't become an ongoing issue. I've had enough of those in vehicles prior to owning this truck, which has been very reliable.

Luckily, it happened while under warranty. I feel blessed in that aspect.

 

[TooManyWheels]

When they are updated correctly, these transmissions become reliable. The aftermarket makes a heavy duty sun shell called The Beast, which most rebuilders install. GM made very significant updates into the later model 4l65E, but it is looking like they only install the 4L65E into certain vehicles that would have otherwise had the 4L60E.

 

[440Magnum]

The 4L60E is based heavily on the non-computer-controlled 700R4. That particular transmission family has had a long, long history of running upgrades and improvements, and never seems to quite get all the way to "bulletproof" in the sense that the old TH400 was. But with the right updates, it should be plenty reliable... Given that yours was a mechanical breakage, not a burnout or computer glitch, I'd be willing to bet it was a small fabrication flaw that was there all the time and just finally let go. Its not likely to happen again. If I were you I'd trust it a whole lot more than a Honda automatic on long road trips :-/

 

[bigmike]

Truck finally is repaired. I'm supposed to go pick it up today.

They flushed the cooler, lines, etc, and installed a GM reman AT. It came with a 3 year, 100k mile warranty.

Any recommendations on keeping the Magnefine filter? I'm guessing I should keep it since it's on the return side of the cooler. Hard to tell what might be left in the cooler and break free later.

When should I drop the pan and change the internal filter?

 

[440Magnum]

Originally Posted By: bigmike

When should I drop the pan and change the internal filter?


I've debated with folks on here before about whether the magnefine (or other) in-line filter keeps the internal filter clean. My argument is that it DOESN'T, so the internal filter still needs to be changed according to your usual schedule, OR should be deleted entirely.

Here's my reasoning, you decide what you want to do:

The general oil flow for an automatic transmission is:

1) sitting in pan
2) sucked up through internal filter
3) pump distributes it to pressure system
3a) some goes to torque convertor, through external filter, then to cooler, then lubricates the clutches, bearings, etc. and returns to pan.
3b) some goes to valve body then clutches/actuators, then returns to pan
4) back in the pan waiting to start over

Some automatics differ in whether the convertor is in the loop all the time (some bypass it when the TC clutch is locked) and others differ on the order of flow of cooler relative to , but the key is that whatever part of the oil flow that gets used for lubrication (which is where clutch "dust" and metal wear particles are picked up by the oil) always dumps right back into the pan, and therefore the INTERNAL filter is always the first thing in the oil flow/filtration path to see dusty oil and it will always be the first thing to clog. The external filter will only catch whatever gets through the internal filter.

That's my reasoning- feel free to explain how I'm wrong, I'm open to being corrected

 

[GMBoy]

I don't like any extra stuff plumbed in my vehicle - including external filters. Just adds more places for leaks to develop. What 440magnum says about the most of the gunk being caught by the internal pan filter makes sense.

 

[SteveSRT8]

Since the filters vary I can't comment on much other than GMC products I work on every day.

But the filters in our vehicles are very thorough and catch absolutely anything that could harm the pump or the trans.

No need for anything else. You just created another failure point when you added the magnet.

 

[bigmike]

Well, since we have the heaven's light shining down on this GM filter, I feel like I should play devil's advocate. I wish the transmission was as good as the filter supposedly is!

The magnefine is, based upon where I put it is at the very least, easy to see if it is leaking, easy to change, easy to open up and observe. I can't say the same on the internal filter.

I'm personally glad it is on there as I feel the cooler probably should have been replaced due to the "hand grenade" (tech's term, not mine) that went off in the AT. At least I have filtering on the return line to prevent debris from going back to the AT.

I've read quite a bit on here and many people here recommend using it. I'm trying to weigh the pro/con obviously.

Additionally, I'll probably drop the pan and change the filter alot sooner than I normally would. This is, for all intents and purposes, a "new" transmission.

Maybe I should ask this in a different way, considering that:

When would you recommend to drop the pan and change the filter on a new transmission?

 

[mechanicx]

Quote:
When would you recommend to drop the pan and change the filter on a new transmission?



Assuming they flushed the cooler/lines or it was clean anyway and used Dex VI you should be able to go at least 50-60K. You could do it sooner like at 30K of course for peace of mind but since you have the warranty for 3 years, I wouldn't touch it till just before the warranty is about to run out.

 

[bigmike]

mechanicx, good point on the warranty.

I replaced the magnefine filter that was originally on it when the failure happened. I did open it up and found little to no debris and very little metallic dust on the magnet. I plan on taking pictures and posting them.

Truck shifts pretty much the same as the old one, but firmer. I'm sure that's due to it being new.

Tech stated that it'll take a bit for the computer to learn and that my shift points will be off a bit until then. I didn't really notice.

 

[Vizzy]

Originally Posted By: bigmike

Tech stated that it'll take a bit for the computer to learn and that my shift points will be off a bit until then. I didn't really notice.

He is correct about that. The computer module for the transmission has a "default" program mode after anything is reset or the battery has been disconnected for a period of time. The transmission computer can learn your driving habits so that the truck will respond a little more smoothly especially on upshifts, improve fuel economy a bit, and actually improve the life of the transmission as well.

 

[Jim Spahr]

I would normally rec. changing the filter which I refer to as a s screen and the fluid in the pan every 12-15k. If towing or hauling heavy loads, more often. Be sure to get a new pan gasket and filter seal. BTW the old filter seal is hard to remove and be very careful not to scratch the alum. tube that holds the seal. You will have problems if the old seal stays in and the new seal is installed! Do a complete flush evry 30k or 60k. If you do this, the trans should last 200-300k. Oh yes, be aware of any foreign objects on the screen and in the bottom of the pan. Get a sample to your trusted AT mechanic immediately , if any appears. Take the old filter to him. My 4L60E now has 270k on it and it is just starting to flair a little on shifts.

 

[pavelow]

Did they replace your converter too? If not, I hope they at least thoroughly cleaned the old one out.

I personally wouldn't use the external filter, but that's just me.

Change the fluid and filter the dealer installed after you put 500 miles on it. You may want to put a deep pan on it at that time...that'll allow you to run more fluid for lower fluid temps. Change the fluid and filter every 30K-40K after that.