tranny woes

[rpjn59]

Hi gents, new to the forum. I just recently purchased a 2004 astro 2wd, 123K. The tranny's doing a couple of things that I have never experienced before in transmissions.

1) the tranny (I assume) groans when the van is in drive and the brake is depressed, like at a stop light, heck it shakes the whole vehicle. The groaning stops as soon as I release the brake pedal and vehicle starts to move. Would this indicate an issue with the torque convertor?

2) when driving at speed in overdrive, ~sixty and I mash on the gas pedal to kick it down to the passing gear, which would now be third gear, it whines pretty obviously while in third.The whining stops when the van up shifts back to overdrive. It also seems like it takes a lot to get it to kick down also, that's why I said "mash" the pedal, more so than on any other vehicle I have every owned.

Outside these two issues the tranny shifts fine.

I'd appreciate any feed back, thanks, Ray

[Astrophysics]

Hi,

The transmission is the highly rated 4L60E.

It has a very good service reputation. The E stands for electrically controlled.

The 4L60E is so good that many old Jeep folks put it in old Cherokees And TJ's etc.

Check fluid of coarse and see if it is burnt smell.

Go to "You Tube GM 4L60E rough in 3rd gear" and read about it.

Then get trust worthy shop to help you diagnose.'

Go easy on the vehicle until you get tranny fixed.

AP

[rpjn59]

Astrophysics, thanks for responding. Several things that I have continued to diagnose is that the overdrive to third gear whine appears to be my power steering pump, which of course increases with rpm and becomes most apparent with the high rpms in that situation.

The "mashing" of the throttle to get the passing gear seems to be a characteristic of the tranny. The manual states that the throttle needs to be fully depressed to get it to kick down. So that brings me back only to the potential torque convertor issue. I checked the fluid and it is clean and the level is o.k. I didn't smell it though, da, I cant believe I overlooked that, will do this afternoon.

Finding a reputable, confident, trustworthy shop for an opinion on the tranny, seems almost impossible. I have had so many bad experiences with tranny shops over the years, even with full rebuilds its depressing, but ya gotta do what you gotta do.

How many miles are these trannies normal good for, mine has 123K and are there maintenance periods? I remember years ago, that bringing your tranny in for servicing ever couple of years was a good thing. Not only a fluid and filter change but they would "adjust your bands" does this still apply and or for this tranny in referencing "the band adjustment"?

[Astrophysics]

Hi Everyone,

Sounds like you are making progress in sorting out the noises. Yes, on steep hills in hot weather, the Astro 3.42 axle or 3.08 axle does not make hill climbing easy.
The cooling fan noise and power steering noise to make it loud.

Have you tried just shifting the tranny into 3rd gear for hills?

Remember, 3rd gear is 1 :1 ratio.
4th gear is about 0.8:1 overdrive.

Often in hills I just set tranny to 3 Rd gear.

Also, you could try engaging the tow/haul mode switch.
This should let engine rev higher before shifting.

The latest ideas I have heard are to avoid flushing tranny, since it can loosen up debris and causes problems.

You may want to install Hayden or equivalent, Aux tranny cooler which will help lower temps.

Our Astros with more than 100,000 miles need to be driven a bit slower in my opinion in hot weather up hills.

I want my 32003 AWD to last a long time. I stay in slow lane and avoid passing. I have 131,000 miles.

AP

[rpjn59]

Hey, I did a little more snooping around. A thought hit me the other day the heavy gyrating I am hearing may be the exhaust system. Sure enough, that's what it is. I can't figure out what exactly is vibrating but if I put pressure on the tail pipe it stops. I still have suspicion that something may be going on with the torque convertor though. Taking off thru 1st and 2nd gear seems like it has dull heavy sound and feel to it, more so than any other vehicle I have every owned. Also, I did finally smell the fluid at the dip stick, it does NOT have a 'burnt' smell, but it does have a 'cooked' smell. Kind of like cookies baking in the oven???

Ray