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*UPDATED* 2002 GMC Yukon Denali 141000 miles...I have so many questions related and unrelated

Im sorry guys i left out a bunch of info

mileage 141000
engine 6.0L
Transmission 4L65E…Flush 80,000

Hi guys my Nali is in excellent shape for its age and I am really in love with it…but…I come from a family that usually runs foreign cars that usually go to 300,000 miles without a major problem. My main question today is SHOULD I KEEP THIS DENALI??? The issues I have had so far include 1 water pump and a radiator at around 80,000 miles. Also at that time since transmission cooling line in the radiator busted and coolant was getting into the tranny they had to do a full flush. I am now receiving my truck from my mechanic after another radiator replacement and leaky oil pan gasket. This time I requested the AC Delco radiator vs the aftermarket one they used last time in hopes of getting more life out of it. Last time they replaced the radiator they flushed the system and replaced it with dex cool, this time I had them use the normal yellow stuff.

Even tho the system got flushed will the yellow stuff hurt any components in the system that may be used to the dex cool?
Is it normal for aftermarket radiators to not last as long?
For all the people with the third rows do y’all have as many rattles in the cabin as I have? Is there a way to correct them to make the ride seem more solid?
Its almost time to replace suspension, is it worth it to swap my auto leveling suspension with standard struts? Is there a ride difference? (I know there is a price difference)
Provided I repair EVERYTHING on my truck at FIRST SIGN of WEAR like I do, how long will this transmission last? I hear such bad news about these transmissions. And if it get it replaced is it hard to stick in the 5 speed instead?

I’m forgetting like half the questions I want to ask but they must not be all that important to me so forget it…

Thanks in advance

How many miles on it? And since you’re concerned about the transmission life, have you done regular fluid/filter changes at the recommended intervals?


Have you been servicing the trans fluid and filter every 30K?

Do NOT flush the trans

Some of those aftermarket radiators are visibly inferior to the factory parts. As such, I wouldn’t really expect them to do as well. I suppose you get what you pay for

You’ll be fine with the yellow coolant . . . can I assume it’s a universal type? One word of caution, though. Do a drain and refill every 3 years. The dexcool was good for 5 years. However, universal coolants are often only good for 3 years.

As for the suspension, if money is an issue, I would consider retrofitting a standard suspension.
There are some companies out there that specialize in this kind of thing.

Have you replaced the plugs yet?

“I hear such bad things about these transmissions” What trans do you have?

What engine do you have?

4.8 liter V8
5.3 liter V8
6.0 liter V8

What wheelbase?
Regular (as in Tahoe)
Long (as in Suburban)


The 4L60E had a few issues, but can lead a long life, if maintained correctly
The 4L60E is more of a heavy duty transmission, and pretty sturdy. You might have this one, if you have the long wheelbase

The engines are generally unproblematic, in the mechanical sense, except for a few leaks

What’s the mileage?

If anything goes wrong with the transmission, it’ll probably be because of a failed reaction sun gear shell. And no matter how often the fluid is exchanged the shell fails from it’s poor design.

You can go on Youtube and enter in their search engine, “4L60E reaction sun gear shell”, and see an example of the failure.