2004 8.1 Yukon

RedF

Adventurer
Just did a "shock upgrade" on mine. I have had good luck with bilstein shocks. Good customer service.
That's a much bigger upgrade than I'll likely ever do!

As an aside, I didn't mention in my last post how disgusting under the front seats is! I sure got a good view while replacing that mode door actuator. I'll have to pull the front seats to do a decent job of cleaning under there. That said, it has made a significant difference cleaning out the majority of the dog hair, and using the oxidizing spray. I don't think I'll have to pull the carpet.
 

Buddha.

None of this matters
Rock auto order was placed on Sunday, and delivered on Wednesday, and that was with the cheapest shipping option!

New AC belt and tensioner done; easy! There's still a little belt noise though - I suspect it's the idler pulley.

The HVAC mode door actuator was quite the miserable little project, but it too is done and it even works now! It took a bit over an hour, but most of that was trying to contort myself in a way that I could both see what I was doing, and perform the task. I don't know the last time I had scratches and scrapes like this from working on a vehicle. It didn't take much for tools but it sure took some patience and perseverance. I opened up the old part and it looks to be intact. I believe it had been changed previously, as it had some goofy brand name on it, so maybe it was just an inferior part.

The hydroboost hoses can wait for another day. I'll have to order those shocks soon, too.
When I had to do the HVAC repair on my s10 I found it easiest to flip around upside down with my feet over the head rests and my head under the dash. I got some looks from the neighbor lady who was trying to figure out what I was doing, lol.
 

RedF

Adventurer
Hydroboost pressure hoses are done. That was a painful process too! I imagine doing it with a hoist wouldn't have been so bad, but I don't have that luxury. Getting the fitting lined up on the back of the pump was awful! Nearly 4 hours to replace the two hoses and do an oil change; not my best performance.

Flushed the hydroboost the next evening. The fluid wasn't as bad as I was expecting, perhaps it had been done previously. The oil in the transfer case and rear diff appear good, so I'm not going to change them, not yet anyway.

Did the 4-hi headlight mod. Amazon delivered a pair of Husky liners for the front - and just in time for the first snowfall of the year.

5100's are on en route, should be in tomorrow.
 

jeep-N-montero

Expedition Leader
Not much to speak of lately, just been putting on some miles - going to the beach, camping, Costco runs (fold up the back seat and just keep pushing groceries in!). We may take it for a long drive to southern BC; not sure if we're going to fly, or drive. I like driving, but not as much with an infant and a toddler.

It did get it's new windshield. The hydroboost pressure lines are leaking, so I'll work that in sometime. I'll have to put in that Rock Auto order soon. It sounds like it has a cold exhaust leak too.

The "Service Ride Control" message came on today, so it looks like it's time to defeat the Autoride, and install some new shocks. What's do you guys recommend? A couple of you have suggested 5100s; what valving?

Sadly, this brute averages better mileage than my 6.0 Silverado - albeit still terrible!
How much better is the mpg? I am looking at replacing the Yukon with a 2500hd with the 8.1, found a one owner with 61k miles I may look at.
 

vintageracer

To Infinity and Beyond!
Every 4x4 8.1 PU I have ever driven or trucks friends have owned got 10 MPG no matter how ya drove it or what ya pulled with it.

For some reason and I don't know why my 8.1 4WD van gets a solid 12-13 MPG.
 

rayra

Expedition Leader
That's a much bigger upgrade than I'll likely ever do!

As an aside, I didn't mention in my last post how disgusting under the front seats is! I sure got a good view while replacing that mode door actuator. I'll have to pull the front seats to do a decent job of cleaning under there. That said, it has made a significant difference cleaning out the majority of the dog hair, and using the oxidizing spray. I don't think I'll have to pull the carpet.
You have to pull the seats to remove the carpeting, anyway. They're bolted thru the carpeting sections. There's a front and rear half, which overlap under the second row seats. If you want to remove the carpets and thoroughly shampoo / wash them out, you basically have to remove the seats and the rear cargo area interior trim panels, which trap the carpet.
 

rayra

Expedition Leader
And I didn't see mention, which transmission do you have, 4L60-E or 4L80-E. If it's the 60 I strongly recommend an aftermarket trans cooler, as the factory external cooler included with the Tow option is tiny and very poorly placed. And the 60 seems prone to sudden death if it is overheated during towing, especialyl on protracted grades. 275F seems to be the cutoff point and it's kept around 200F already by the in-radiator-tank loop that GM uses (ironically as a pre-warmer for the trans, NOT as a cooler). With that big motor you'll be tempted to tow heavy. Get teh trans cooler upgrade FIRST.

Too, GM doesn't consider oil pressure to be 'low' on the Vortec motors until it hits single digits. These motors can go past 200k mi readily with proper maintenance. But you'll eventually need a new oil pump (front of the motor) and replacement of the o-ring on the oil pickup tube (drop front axle and pan to get the pickup loose)
 

Jacobm

Member
I don't think GM put the 60e in any of the 3/4 tons, mine's a 6.0 and it has the 4l80e. Probably still worth looking into better cooling for longevity though.
 

jeep-N-montero

Expedition Leader
You have to pull the seats to remove the carpeting, anyway. They're bolted thru the carpeting sections. There's a front and rear half, which overlap under the second row seats. If you want to remove the carpets and thoroughly shampoo / wash them out, you basically have to remove the seats and the rear cargo area interior trim panels, which trap the carpet.
Removing the seats is a good idea anyway if the rig had kids in it dropping candy and crumbs everywhere.
 

NewGuard84

New member
Nice Yukon! This is very close to the '04 2500 Suburban I picked up in Edmonton area in August. Mine is the 6.0L with 130KM on it now.

Enjoying this discussion, as you asked some of the things I was thinking.
 

lilkia

Active member
And I didn't see mention, which transmission do you have, 4L60-E or 4L80-E. If it's the 60 I strongly recommend an aftermarket trans cooler, as the factory external cooler included with the Tow option is tiny and very poorly placed. And the 60 seems prone to sudden death if it is overheated during towing, especialyl on protracted grades. 275F seems to be the cutoff point and it's kept around 200F already by the in-radiator-tank loop that GM uses (ironically as a pre-warmer for the trans, NOT as a cooler). With that big motor you'll be tempted to tow heavy. Get teh trans cooler upgrade FIRST.

Too, GM doesn't consider oil pressure to be 'low' on the Vortec motors until it hits single digits. These motors can go past 200k mi readily with proper maintenance. But you'll eventually need a new oil pump (front of the motor) and replacement of the o-ring on the oil pickup tube (drop front axle and pan to get the pickup loose)
This a different animal than the 1500 youre used to. His yukon is a 2004 2500 with the 8.1ltr. Being a 2004 2500 it has the upgraded 4l85e transmission. The 4l85e is a 5 planetary trans rated for vehicles up to 16,000lbs. It doesnt have the vulnerabilities that a 4l60e has. Plus the 2500 suburban already comes with a much larger tranny cooler than the 1500. The 2500 8.1 burbs and yukons are specially built to tow with heavier frames, better brakes, bigger radiators, oil and tranny cooling, and Full Float rear axles. The 8.1s have a tow rating of over 10,000lbs. These arent designed like mommy's 1500 to take the team to soccer practice. Theyre made for dad to take the football team to the game and haul the equipment AND band trailer behind it.

And for the record the 8.1ltr is nothing like the 5.3 or the 6.0 for that matter. They arent really an LS motor. Its more of a redesigned stroked 7.4 with better heads and different intake and coil system. 300k miles is not uncommon with the 8.1s just keep checking the oil they tend to use a bit.
 
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