03 Envoy rattling in 2HI over 40mph

[lschafroth]

My 2003 Envoy SLT has 188,000 miles. I noticed it is now rattling or ticking when going over 40mph in 2HI. If you shift it to A4WD or 4HI it is quiet and works as normal. 4 wheel is engaged and works.

It only makes the rattling sound in 2 Wheel drive and once you get over 40mph.

Sadly, no I have never changed the front differential fluid, nor the transfer case fluids. I've seen the axle disconnect part and the actuator motor. I've also read about the encoder motor on the transfer case. Which one would be the culprit? Could it just be low fluid?

It is in A4WD at the moment and not being driven. Is there a way to manually put it in 2HI until I can find the problem?

 

[lschafroth]

If I posted this in the wrong spot, please move it! I also wanted to add that once in a while the red "N" on the shifter dial would come on once in a while after using 4WD or putting it back into 2HI. We put the truck in Neutral and it would go off.

 

[IllogicTC]

My 2003 Envoy SLT has 188,000 miles. I noticed it is now rattling or ticking when going over 40mph in 2HI. If you shift it to A4WD or 4HI it is quiet and works as normal. 4 wheel is engaged and works.

It only makes the rattling sound in 2 Wheel drive and once you get over 40mph.

Sadly, no I have never changed the front differential fluid, nor the transfer case fluids. I've seen the axle disconnect part and the actuator motor. I've also read about the encoder motor on the transfer case. Which one would be the culprit? Could it just be low fluid?

It is in A4WD at the moment and not being driven. Is there a way to manually put it in 2HI until I can find the problem?

I've got a couple ideas in mind. They may not be 100% accurate, someone more intimate with the system will probably come along and give a better idea on what to check.

1. Incomplete disengagement of the front axle disconnect, or a part that is loose but seems to snug up when the disconnect is engaged. It's trivial to check the disconnect, just put it in 2HI, jack up the front passenger side, and give the tire a whirl. If it doesn't move, it's probably an incomplete disengagement. It it does but begins making that rattling noise (maybe it's just softer when it's less than 40MPH? Could try spinning the tire fast) then you know your problem spot.

2. Intermediate shaft, though you said 4x4 seems to be working well so I don't see how the intermediate shaft would be an issue. Just never know though. One way to check would be to jack up the front driver tire and give it a good spin. If you get the rattle, it may be the intermediate shaft (again, doubt it if 4x4 appears to work correctly) or maybe the front differential, though that would be expected to make noise full-time. I point to the intermediate shaft as a suspect as it's been the cause of rattle for other folks, and who knows, maybe you've been using 3-wheel drive the whole time? It seems odd, but yes this part turns the entire time, even in 2HI. It'd just turn in the opposite direction the driver's side tire is going.

Maybe I'm onto something, maybe I've smoked my breakfast today these are just suggestions to ruminate on while the cavalry takes its time to arrive. As in, while I replace the bulb in the RoadieSignal floodlight.

Welcome, by the way! Why does it seem that since moving away suddenly everyone in Iowa with a TB/Envoy gets on here?

UPDATE: Just saw the post on the "N" showing up. Teaches me to take forever typing now that makes me curious, however this may be part of the problem or it could be a symptom of an entirely different problem. And you did post this in the right spot.

 

[lschafroth]

Thanks for the things to try. It will finally be above -20 here in Iowa so I should be able to do it tomorrow. 45 degrees! shorts weather!
I will test each one of the steps you listed and report back.
Thanks for the quick reply. I came over from Trailvoy.com and I already see more responses to all questions here.

Thanks!!

Lannie

 

[lschafroth]

I wanted to add the rattling is very faint. You dont hear it very well unless it is quiet while driving.

 

[The_Roadie]

Sadly, no I have never changed the front differential fluid, nor the transfer case fluids.

Welcome! Trailvoy is effectively dead after the community started THIS site in Dec 2011 due to abuse by greedy new corporate owners of Trailvoy. They bought the site, but not our hearts, and WE were what made Trailvoy great.

Until you check the fluid level and quality, and change them, anything we say won't mean much. Like a dentist scolding you to floss, all we can say about regular required maintenance is not going to motivate you as much as having to replace a transfer case. The TC fluid is a specific GM item, 2 liters of Auto Trak II, and it NEEDS changing every 50K even if you don't use the 4WD modes.

Let us know how much drains out of the diffs and TC, and what it looks like, then we can advise better.

 

[lschafroth]

Let us know how much drains out of the diffs and TC, and what it looks like, then we can advise better.

The plan is to go get the fluids I need today. 30 miles to get anywhere to get supplies. I'm fighting a cold as well so depends on how well I feel later on.
I will do the front diff and the transfer case all at once. Will do the rear later.

 

[IllogicTC]

The plan is to go get the fluids I need today. 30 miles to get anywhere to get supplies. I'm fighting a cold as well so depends on how well I feel later on.
I will do the front diff and the transfer case all at once. Will do the rear later.

Consider looking up user "May03LT" on YouTube. Scroll through the videos. There's videos on how to service all three of these points.

 

[lschafroth]

I replaced the front differential grease. It was a little black with a tint of biege or brown color to it. Not burnt or dirty as I was expecting. It is topped off and was very easy to do.

The transfer case was just as easy. I took the pointed tip from the diff grease and put that on the Track II quart bottle and slid a tube onto the tip. The quart bottle slid in between the drive shaft and the heat shield and I was able to squeeze every drop from both quarts. No pump of any kind needed. That fluid was a little black but you could still see some blue tint. I got this truck with 88K on it. I think the fluids had been done at least back then by the previous owner or dealer who sold it. I was expecting much worse.

Both old oils totaled to about 2.5L of fluid. The front diff was low but not bad.

I drove it around and I could not hear the rattling in the front and on the way back I started to hear it real faintly. Its still there in 2HI but nothing like it was before. The actuator motor sounds like it is moving freely and smooth. I did notice the axle shaft on that side was laying down grease all over the place on the CV joint where it goes into the diff. Would this axle shaft make a noise like that if all the internal grease has worked its way out? Maybe the A4WD puts a load on the CV and the noise goes away and the 2HI there is no load on it so it rattles? Those are pretty easy to replace. Should I replace it since its loosing all of its internal grease anyway?

Lannie

 

[The_Roadie]

I think you nailed the diagnosis with that observation. A4WD does indeed put a minor amount of torque on the CV joints. Aftermarket Cardone shafts are around $50 on Rockauto and maybe your local parts stores.

 

[lschafroth]

Whats left to replace on this thing? lol
New struts, rear shocks, all four sway bar links. Torsion bar mounts. Ball joints, hubs and brakes. Water pump, thermostat. A/C Compressor.....

Thats what happens when you drive them until they die. I will go get one today. You dont have to remove the hub assembly to replace the axle in these either. remove the bolt from the upper A-Frame, lower the assembly down enough to slide the shaft out of the hub then out of the diff.

One thing I did notice was when I grabbed the CV and tried to move it, there was some play back and forth where it goes into the axle disconnect on the diff. Is there supposed to be any play there? Would that be a bad bearing in the disconnect as well? or would that make a sound all the time?

 

[The_Roadie]

You dont have to remove the hub assembly to replace the axle in these either. remove the bolt from the upper A-Frame, lower the assembly down enough to slide the shaft out of the hub then out of the diff.

That's how we offroaders change them on the trail when we break them. Sometimes our oil pan skid plates get in the way of smacking the inner tripot joint to snap the circlip out of the splined receptacle they're in.

 

[lschafroth]

I went to take the axle out of the passenger side and noticed the way bar link on that side was disconnected. The lower bolt had come off.
The axle looks fine and the axle disconnect looks trashed. You can grab the axle and move it all around, tons of sloppy play.

I believe the grease everywhere is from the axle disconnect assembly. I suppose with the sway bar link off and we drove through that horrible ice storm in Arkansas that thrashed our suspension, the bear was destroyed with the sway bar link loose.

I cant afford one of those suckers unless someone has a used one for sale that is in good shape.

 

[lschafroth]

I bit the bullet and got the ATP one for $323 on Amazon and 2 day shipping. ouch.

We drove through Arkansas when the interstate was closed due to ice. The bumps and road was horrible. 25mph for 4 hours. We drove a parallel highway to the interstate instead and got through it. With that sway bar link dosconnected I can only imagine how the bearing in the disconnect assembly got thrashed up and down.

I will go ahead and put the new axle on anyway, who knows what it did to the old one as well.

 

[lschafroth]

Got the part from Amazon today. The item was described as 100% new. It is still dirty from being refurbished from used parts. Its not 100% new as described but hopefully it will do the job. Will put it in tonight. I will take a pic of the old one when I get it off and post it.
I thought the grease laid out on the frame was the cv but it was from the disconnect assembly the whole time!

 

[IllogicTC]

Got the part from Amazon today. The item was described as 100% new. It is still dirty from being refurbished from used parts. Its not 100% new as described but hopefully it will do the job. Will put it in tonight. I will take a pic of the old one when I get it off and post it.
I thought the grease laid out on the frame was the cv but it was from the disconnect assembly the whole time!

If you're feeling intrepid you could crack her open, it could either be refurbished or it could be completely rebuilt with all-new parts on the inside, with an old shell on the outside (the shells themselves are stupidly expensive!)

 

[lschafroth]

I'm pretty much screwed now. The Axle Disconnect assembly broke in half with the rest still stuck in the diff. How the hell can I even get that out now?

 

[lschafroth]

I got the outer gear removed. There is still portions of the inside of the assembly inside. I've air hammered the sides, air chiseled and nothing. Will not budge.

maybe time to sell this thing as is and take a loss.

 

[Envoy_04]

Don't give up just yet! An old trick I learned in getting busted driven clutches off of input shafts is to use a die grinder or Dremel with a grinding wheel on the piece you want to come out and be careful not to cut into the shaft. You could try that from the inside out and see what happens.

 

[lschafroth]

I have to get the rest of the guts out of it first then maybe I can try a dremel. I dont have one so thats a problem to begin with.
I'm going to drill into the rest of the guts about every half and inch and see if I can break it out. then I will be down to just the shell left.

About ready to say F*** it and sell.

 

[jsheahawk]

I'm pretty much screwed now. The Axle Disconnect assembly broke in half with the rest still stuck in the diff. How the hell can I even get that out now?

I have to get the rest of the guts out of it first then maybe I can try a dremel. I dont have one so thats a problem to begin with.
I'm going to drill into the rest of the guts about every half and inch and see if I can break it out. then I will be down to just the shell left.

About ready to say F*** it and sell.

Sympathies, man. I have to pull my disconnect off in the near future, and now you have me worried.

Jared

 

[The_Roadie]

A dozen owners or so here and on ORTB have had housings corroded into the oil pan break upon removal. Spraying with PB Blaster helps the next step, but it almost always involves drilling and chisels and making a huge pile of aluminum chips.

Not having a Dremel is a trivial problem to solve. You might think it costs $$, but that's a lot less than the time, pain and expense of selling and buying a newer vehicle. Every possible interaction with used car salespeople is going to cost you 100-1000 Dremels.

Trading in a vehicle with a known problem has two downsides:

1) You're going to get less on a trade than it would cost you to fix, unless you get things fixed at full list price at a dealer.

2) If it's not disclosed or fixed, and you sell it privately, the next owner will come HERE for support and we don't need the hassle.

 

[lschafroth]

Its not coming out. No way in hell. I took a drill and drilled into the guts of the bearing that is left into it. Drilled every 1/8". Still cant get any of the guts to budge.
I put it all back together without an axle on that side. Will drive is in 2 wheel drive until I can find someone to pull the oil pan and diff.

Is it safe to drive that way or should I take out the driver side axle as well and seal the opening with the fancy Gatorade cap method?
It drives just fine as is.

 

[Texan]

Here is a link with pictures that may help.

Offroadtb.com Front Axle 4WD Disconnect

 

[lschafroth]

That link doesnt have anything to do with what I am dealing with. I have to say rebuilding one of those looks daunting.
I just want to know if its ok to leave the driver side axle in with the passenger one out?
We will remove the oil pan this summer and try and fix it but will have to drive it as is until then.

 

[Texan]

If you scroll down there is a picture of the oil pan with the disconnect removed.
It shows what it would look like after you removed the broken part. It also talks
about why you should not drive it, because it can damage the oil pan.
Just trying to help.

 

[IllogicTC]

It also talks
about why you should not drive it, because it can damage the oil pan.

The loose parts and the intermediate shaft sans disconnect on the other side will likely lash about. Literally the only way would be to do a temporary 2-wheel drive conversion, that is removing the propshaft, removing the CV axles and installing axle stubs in the hub assembly. Not fun and a bit much just to have to put it all back together.

 

[lschafroth]

That link doesnt have anything to do with what I am dealing with. I have to say rebuilding one of those looks daunting.
I just want to know if its ok to leave the driver side axle in with the passenger one out?
We will remove the oil pan this summer and try and fix it but will have to drive it as is until then.

We have driven it over 50K miles since without the front right axle and it still works fine. We moved to Texas and have never needed 4x4 so i havent gone back to trying to get the guts out.

 

[gmcman]

I know this is an old thread, but did you ever change the front diff fluid? What about the transfer case fluid?

 

[lschafroth]

No, I havent changed the fluid in the rear either!! 242K now. Still runs great. I do need to try and get the pieces out so I can fix 4 wheel drive. We are now back in Iowa and will need it.