What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Charlie207]

Changed my oil - Miles =270995
One thing I noticed was a bit of oil dripping down the side all the way down to the oil pan. Never had a leak before but I think it may be time for some new valve cover gaskets. Maybe even new valve covers.
Has anyone replaced them? Any tips or tricks on the process?

Out with the old and in with the new Now I need to find some parts to repair my door. This was kind of a pain in the butt haha.

Valve covers & gaskets are fairly straightforward, and not too difficult. If start by blowing or spraying the top of the engine down to remove the dust and dirt chunks.

Pull the engine cover & unbolt the loom plate from the top of the intake manifold to provide some slack in the loom.

Unplug the plug wires from the coils.

Unscrew the coil mounting plates from the valve covers. (I start on the driver's side because there's less heater core hoses to deal with.)

Slide the coils & plate out from the loom, and have a beer while you inspect for leaks. Maybe reach back behind the intake manifold and feel for oil seeping out if the oil pressure sensor boss. (Mimics leaking valve cover gaskets).

Wipe down the area around the valve cover gaskets, and then loosen, but don't fully remove, the valve cover bolts. Pull the valve cover out the same way you finagled the coil & coil mount.

Now you can replace the gaskets for the valve cover and the mounting bolts. If it were me I'd reuse the covers because they are probably fine, and you can't see them buried under all the other stuff bolted in top of the engine, unless you are upgrading to the newer PCV upgraded style.

The valve cover gaskets seems to always be too big to fit into the groove, but just pick a center point on both cover and gasket, and alternate sides as you squish the new gasket back home.

Installation is reverse of removal. And, I'd do both sides before reinstalling the coils & brackets, so you have extra space to run an in.-lb. torque wrench around the intake manifold bolts. Those almost always loosen over time, and I'd bet there's at least one loose. Tightening diagram here.

The passenger side is a little more fiddly with the heater hoses laying over the top of everything, but it's fine, just an excuse to sip that beer while you ponder if you really want to replace the gaskets that isn't leaking.

If you have broken exhaust manifold bolts, now is the time to install that Dorman clamp on the driver's side, and boy is it fun!

I'm almost certainly forgetting some crucial step, but I imagine you can overcome the obstacles.

 

[LSCALADE]

How do those wheels ride?

I'm thinking about grabbing a set.. except they have firestone..

These are going to be my forever wheels, they are made of thick steel, stupid strong, and not as heavy as I thought, about the same weight as the aluminum 18" wheels I had on there at least by feel when you lift them. As for exact weight im sure they are a few lb heavier but they ride very nice and I got Hankook Dynapro AT2 tires to go on them next. The offset is spot on with the fender flares. The size I am going with is 275 60 20 vs the 275 55 20 on there at the moment. When you overlay the two tires the 60 are about 1/4" larger or 32.8" vs the others at 32.1"

 

[mikez71]

the fender flares. The size I am going with is 275 60 20 vs the 275 55 20 on there at the moment.

Nice! I was thinking I would want a taller tire.. that sounds about perfect.
The set I'm looking at has new tires, so I'd have to get my money/miles outta them first..

BTW, I think you should black-out your window trim, roof rack, and steps.

 

[Charlie207]

These are going to be my forever wheels, they are made of thick steel, stupid strong, and not as heavy as I thought, about the same weight as the aluminum 18" wheels I had on there at least by feel when you lift them. As for exact weight im sure they are a few lb heavier but they ride very nice and I got Hankook Dynapro AT2 tires to go on them next. The offset is spot on with the fender flares. The size I am going with is 275 60 20 vs the 275 55 20 on there at the moment. When you overlay the two tires the 60 are about 1/4" larger or 32.8" vs the others at 32.1"

275/60R20 = 33"

I run those on my rig, but you'll want/need spacers to avoid rubbing with GM OEM wheels. Or, go with aftermarket wheels.

 

[992dr]

Valve covers & gaskets are fairly straightforward, and not too difficult. If start by blowing or spraying the top of the engine down to remove the dust and dirt chunks.

Pull the engine cover & unbolt the loom plate from the top of the intake manifold to provide some slack in the loom.

Unplug the plug wires from the coils.

Unscrew the coil mounting plates from the valve covers. (I start on the driver's side because there's less heater core hoses to deal with.)

Slide the coils & plate out from the loom, and have a beer while you inspect for leaks. Maybe reach back behind the intake manifold and feel for oil seeping out if the oil pressure sensor boss. (Mimics leaking valve cover gaskets).

Wipe down the area around the valve cover gaskets, and then loosen, but don't fully remove, the valve cover bolts. Pull the valve cover out the same way you finagled the coil & coil mount.

Now you can replace the gaskets for the valve cover and the mounting bolts. If it were me I'd reuse the covers because they are probably fine, and you can't see them buried under all the other stuff bolted in top of the engine, unless you are upgrading to the newer PCV upgraded style.

The valve cover gaskets seems to always be too big to fit into the groove, but just pick a center point on both cover and gasket, and alternate sides as you squish the new gasket back home.

Installation is reverse of removal. And, I'd do both sides before reinstalling the coils & brackets, so you have extra space to run an in.-lb. torque wrench around the intake manifold bolts. Those almost always loosen over time, and I'd bet there's at least one loose. Tightening diagram here.

The passenger side is a little more fiddly with the heater hoses laying over the top of everything, but it's fine, just an excuse to sip that beer while you ponder if you really want to replace the gaskets that isn't leaking.

If you have broken exhaust manifold bolts, now is the time to install that Dorman clamp on the driver's side, and boy is it fun!

I'm almost certainly forgetting some crucial step, but I imagine you can overcome the obstacles.

Thanks Charlie, I appreciate you taking the time and writing that out.

I was inquiring about new ones for that reason. I'm not sure if I have the updated PCV style. I'd like to find out before hand, How would I know if I have them?

I'll have to go over the manifold bolts as well and my intake bolts.

Thanks again

 

[Charlie207]

Thanks Charlie, I appreciate you taking the time and writing that out.

I was inquiring about new ones for that reason. I'm not sure if I have the updated PCV style. I'd like to find out before hand, How would I know if I have them?

I'll have to go over the manifold bolts as well and my intake bolts.

Thanks again

IIRC, if you have a MY 2011 or newer, it should have the update from the factory.

https://static.nhtsa.gov/odi/tsbs/2014/MC-10114272-9999.pdf

 

[mikeyss]

I used it this past weekend for this :

65" OLED TV. If I had gotten anything bigger, I would have needed a Suburban!

 

[Rocket Man]

How low are we going?

I think it’s around 4/6 like someone said. That’s just the free travel mod, it was hitting metal to metal with the springs I put in, and the new ones were 1” shorter so it would have been hitting more.

 

[992dr]

IIRC, if you have a MY 2011 or newer, it should have the update from the factory.

https://static.nhtsa.gov/odi/tsbs/2014/MC-10114272-9999.pdf

Thanks again Charlie, looks like I'll be ordering a new one along with some rocker arm covers.
edit: my valve cover gaskets were just dropped off, what a kawinkydink

 

[Rocket Man]

Free travel mod. This is on my list to do this winter. I'm not very good with a side grinder, and don't have a plasma cutter. Has anyone tried an oscillating tool with a bimetal blade to do this? That gas tank is awfully close!

I’ve used one to cut thin metal with and even then they’re slow. This metal is about 1/8” thick. It would take forever and tons of blades I think.

What plasma cutter is that?

YESWELDER CUT-55DS Plasma Cutter,... https://www.amazon.com/dp/B083GPXF8Y?ref=ppx_pop_mob_ap_share

I had to run it on 120v 20 amps and it couldn’t cut that thick of metal well. I like it though and am keeping it.

That sounds like a friggen nightmare to me.

It’s a nightmare if you look at the whole thing. I looked at it in sections and cut parts off it out with the angle grinder first and then just cut pieces off as I went. It was kind of a crazy job to me, so many little challenges. Like I said, I just did it in parts. Some of that backside by the tank, I put that piece of metal in there to protect it and then cut from the front with the angle grinder after removing the front parts so I could access it that way. The sawzall cut a lot of the backside after cutting the front with the grinder and prying it open a bit for blade clearance. Nightmare? Nah lol.

 

[j91z28d1]

got a new remote fob off Amazon. had to pull out the tech 2 to program.


was easier than expected

 

[Rocket Man]

In the last few days I replaced the rear control arms, upper and lower. The left lower bushings fell out of it when I removed it, if that says anything about the condition of them. And it looked like someone jacked the truck up by the lower arms, they were badly bent. Also installed a set of Nolathane sway bars. I used Energy Suspension bushings and clamps on the fronts, the ones with zerk fittings. I ordered new Energy Suspension front end links, the shortest they have. I feel the road with the long ones on there. I should have ordered ahead of time. Oh, and an adjustable panhard bar, cheap knockoff. Got the rear wheels centered left to right.
Edit: forgot one thing. I ordered a new damn driveway. 24’ x 38’ exposed aggregate, way wider and most importantly- new. Im tired of this old crumbly thing. I signed a contract yesterday.

 

[the_tool_man]

I’ve used one to cut thin metal with and even then they’re slow. This metal is about 1/8” thick. It would take forever and tons of blades I think.

YESWELDER CUT-55DS Plasma Cutter,... https://www.amazon.com/dp/B083GPXF8Y?ref=ppx_pop_mob_ap_share

I had to run it on 120v 20 amps and it couldn’t cut that thick of metal well. I like it though and am keeping it.

It’s a nightmare if you look at the whole thing. I looked at it in sections and cut parts off it out with the angle grinder first and then just cut pieces off as I went. It was kind of a crazy job to me, so many little challenges. Like I said, I just did it in parts. Some of that backside by the tank, I put that piece of metal in there to protect it and then cut from the front with the angle grinder after removing the front parts so I could access it that way. The sawzall cut a lot of the backside after cutting the front with the grinder and prying it open a bit for blade clearance. Nightmare? Nah lol.

I kinda figured the oscillating tool was a bad idea. FWIW, I got to practice using a cutoff wheel on my grinder the other day. I had to cut a 28"x28" square of 1/4" thick steel out of a larger piece. 1/8" thick steel frame should be a little easier, lol.

 

[Charlie207]

In the last few days I replaced the rear control arms, upper and lower. The left lower bushings fell out of it when I removed it, if that says anything about the condition of them. And it looked like someone jacked the truck up by the lower arms, they were badly bent. Also installed a set of Nolathane sway bars. I used Energy Suspension bushings and clamps on the fronts, the ones with zerk fittings. I ordered new Energy Suspension front end links, the shortest they have. I feel the road with the long ones on there. I should have ordered ahead of time. Oh, and an adjustable panhard bar, cheap knockoff. Got the rear wheels centered left to right.
Edit: forgot one thing. I ordered a new damn driveway. 24’ x 38’ exposed aggregate, way wider and most importantly- new. Im tired of this old crumbly thing. I signed a contract yesterday.
View attachment 469519View attachment 469520View attachment 469521View attachment 469522

How did those rear links twist like that?

 

[CMoore711]

In the last few days I replaced the rear control arms, upper and lower. The left lower bushings fell out of it when I removed it, if that says anything about the condition of them. And it looked like someone jacked the truck up by the lower arms, they were badly bent. Also installed a set of Nolathane sway bars. I used Energy Suspension bushings and clamps on the fronts, the ones with zerk fittings. I ordered new Energy Suspension front end links, the shortest they have. I feel the road with the long ones on there. I should have ordered ahead of time. Oh, and an adjustable panhard bar, cheap knockoff. Got the rear wheels centered left to right.
Edit: forgot one thing. I ordered a new damn driveway. 24’ x 38’ exposed aggregate, way wider and most importantly- new. Im tired of this old crumbly thing. I signed a contract yesterday.
View attachment 469519View attachment 469520View attachment 469521View attachment 469522

Nice work @Rocket Man .
You need some shorter sway bar end links for the front.

Lowering Control Arm Sway Bar Endlink with a 1.75 inch Spacer

djmsuspension.com

 

[mikeyss]

I've been having a weird issue lately. I'll remote start the Tahoe, then when I get in and turn the key on, I get a 'service charging system' message. I turn the Tahoe off and restart it with the key and the error goes away. This issue only happens when I use the remote start but of course, not every time. I have a 250amp Mechman alt, new battery, and really expensive cables. The Tahoe also will drain the battery if it sits more than 3 days. Have any of you guys ever heard of this?

 

[mikez71]

I'm guessing the message is there from when you remote started it, charge was low.
By the time you put the key in and restart it, you've already charged it up long enough.

Probably have something draining the battery? Or is the battery old?

 

[j91z28d1]

a variable displacement ls oil pump.

fins inside instead of gears, and I don't see any pressure bypass. how it changes displacement, I have no idea. I'll have to take the cover off the old one.

 

[j91z28d1]

I've been having a weird issue lately. I'll remote start the Tahoe, then when I get in and turn the key on, I get a 'service charging system' message. I turn the Tahoe off and restart it with the key and the error goes away. This issue only happens when I use the remote start but of course, not every time. I have a 250amp Mechman alt, new battery, and really expensive cables. The Tahoe also will drain the battery if it sits more than 3 days. Have any of you guys ever heard of this?

if you can, check for a amp draw on the alt charge wire while it's off. if you don't have amp clamp, you can try taking the wire off the alt before you park it for 3 days and see if the battery is still dead.


I've seen a few alternators themselves be battery drain over the years.

 

[mikez71]

a variable displacement ls oil pump.

fins inside instead of gears, and I don't see any pressure bypass. how it changes displacement, I have no idea. I'll have to take the cover off the old one.

What's it from?