[SOLVED] Front (4wd) Axle Spewing Grease - Also Scraping Sound

[West 1]

I just replaced both driver and passenger CV boots a couple weeks ago. The Strut does need to come out to remove the CV shafts. I cleaned my OEM shafts up and installed new grease and boots. At 147,000 miles both are quiet and smooth. The OEM shaft is better quality than the NEW shafts available. Replacing the boots is pretty easy just takes some time.

If your existing shaft has been run without grease too long it may have self destructed but you would feel a rough rotation of the outer joint if that is the case when you remove it.

Just watched your video, that is not a CV noise for sure.

If it is a flex plate noise it should also do that if you Power Brake the car, put it in gear, hold brake firm and rev the engine enough to put a good load on that flex plate.

I have read but never seen a starter can fail in these models and make a noise similar to the flex plate failure.

 

[Doubeleive]

I just replaced both driver and passenger CV boots a couple weeks ago. The Strut does need to come out to remove the CV shafts. I cleaned my OEM shafts up and installed new grease and boots. At 147,000 miles both are quiet and smooth. The OEM shaft is better quality than the NEW shafts available. Replacing the boots is pretty easy just takes some time.

If your existing shaft has been run without grease too long it may have self destructed but you would feel a rough rotation of the outer joint if that is the case when you remove it.

Just watched your video, that is not a CV noise for sure.

If it is a flex plate noise it should also do that if you Power Brake the car, put it in gear, hold brake firm and rev the engine enough to put a good load on that flex plate.

I have read but never seen a starter can fail in these models and make a noise similar to the flex plate failure.

strut does not need to come out, I have pulled these axles more than a couple times changing hubs (axle end has to come out to unbolt hub), at worst you may have to remove the 2 bottom bolts and the sway bar end links for a little more free wiggle room.
once the front end is off the ground the strut is fully extended. once the axle bolt is off you may even need to lift the lower control arm for more room, just use a jack under the spindle
the axle pivots out from behind the hub, it pivots to just about 60-65deg (roughly)
that being said it's only 5 bolts I have never had to pull the strut though

 

[West 1]

I was not able to wiggle it out, I had the sway bar off already since I had pulled the tranny out and could not get the CV shaft out so I pulled the strut, 5 bolts, 10 minutes work and had plenty of room to remove the CV and to re install after new boots were installed.
On the driver side I also replaced the lower control arm so the strut had to be unbolted on the bottom for that job so it was just easy to go ahead and get the strut out of the way.

On the older body Tahoe, 2003 the shaft came out easy with struts in place.

 

[EddieC]

Good tips, thanks.
Following the leads of a few of the recent suggestions:

Cold start this morning, power brake in both forward and reverse on level driveway caused the noise. Based on that the noise appears to not be related to moving.

Drove around a bit and the most noticeable thing was going back up our steep hill.
The noise is prominent and constant both moving up the hill and stopped, both in drive and in neutral.

Cruising down the road the noise is noticible but if shifted into neutral it seems to subside, but this one is less conclusive because at the time I didn't differentiate on the grade of the road and there is tire noise that can be a mask. This one needs more time to make it more conclusive.

 

[EddieC]

I just replaced both driver and passenger CV boots a couple weeks ago. The Strut does need to come out to remove the CV shafts. I cleaned my OEM shafts up and installed new grease and boots. At 147,000 miles both are quiet and smooth. The OEM shaft is better quality than the NEW shafts available. Replacing the boots is pretty easy just takes some time.

If your existing shaft has been run without grease too long it may have self destructed but you would feel a rough rotation of the outer joint if that is the case when you remove it.

Just watched your video, that is not a CV noise for sure.

If it is a flex plate noise it should also do that if you Power Brake the car, put it in gear, hold brake firm and rev the engine enough to put a good load on that flex plate.

I have read but never seen a starter can fail in these models and make a noise similar to the flex plate failure.

Agreed on "not a cv noise" after a bit more driveway testing. I posted recent tests.
So, what goes wrong with the flex plate? The truck starts without obvious trouble and the tranny functions well as it always has.
It seems like the starter might be a least effort thing to tackle. Are rebuilds for for that part?
I recently noted that I see the most persistent noise with the truck's nose pointed up a steep hill.

 

[fredcook]

I could be wrong but I swore I had to unbolt either the strut or the sway bar link to get clearance to remove the half shaft.

Yup! Well, maybe. There's enough clearance to get the half shafts out of our LTZ. But not our Z71. The larger spring on the Z71 make it tough to get the shafts out. I've found the easiest way with least amount of wrestling and frustration is to just disconnect the upper ball joint and let the assembly drop down enough using a floor jack. No need to pull out the shock/spring assembly. Both Tahoe's are 4x4 GMT900s. But as mentioned, one is an LTZ, the other Z71.

 

[mikez71]

Issue with starter is gear doesn't retract fully and is loose, so it can slide out and touch the flexplate.
Issue with flexplate, is it can crack, and the flexing/looseness makes clanking noises apparently.

Take a quick look at the flexplate through the inspection hole first..
If nothing, removing starter is easy, then you can see if the gear is loose. (doesn't stay retracted with spring tension)
You'll have a bigger hole to inspect the flex plate through at that point if not the starter.

Yup! Well, maybe. There's enough clearance to get the half shafts out of our LTZ. But not our Z71. The larger spring on the Z71 make it tough to get the shafts out. I've found the easiest way with least amount of wrestling and frustration is to just disconnect the upper ball joint and let the assembly drop down enough using a floor jack. No need to pull out the shock/spring assembly. Both Tahoe's are 4x4 GMT900s. But as mentioned, one is an LTZ, the other Z71.

Upper balljoint is what I've done to get the struts out also..
I find hammering it from the centerline of truck outwards works best..
When I bang on it frontside or backside, it doesn't seem to pop out as easily..

 

[mikez71]

I recently noted that I see the most persistent noise with the truck's nose pointed up a steep hill.

Either way they can make noise not moving, but that's a good sign it's hopefully just the starter.

I've told this story before, but...

I had an old Toyota sequoia, it had an intermittent light tinkling sound, usually accelerating, sometimes idling as well.
One day I went to start it and CLANG! CLANG! BANG! CLANG! nonstop. Loudest engine noise I've ever heard. Sounded like metal chairs and tables tumbling around..

The starter gear had popped completely out, and was bouncing around the bellhousing and flexplate.
That incident, plus feeling just how loose my 200k Tahoe starter was, is why I frequently call out the starter for intermittent engine noises..

 

[EddieC]

Either way they can make noise not moving, but that's a good sign it's hopefully just the starter.

I've told this story before, but...

I had an old Toyota sequoia, it had an intermittent light tinkling sound, usually accelerating, sometimes idling as well.
One day I went to start it and CLANG! CLANG! BANG! CLANG! nonstop. Loudest engine noise I've ever heard. Sounded like metal chairs and tables tumbling around..

The starter gear had popped completely out, and was bouncing around the bellhousing and flexplate.
That incident, plus feeling just how loose my 200k Tahoe starter was, is why I frequently call out the starter for intermittent engine noises..

Any thoughts on new Delco Gold or Bosch starters? The oem GMs are remanufactured and twice the cost plus a hefty core charge. At the rate we're going I'm not sure if we'll outlive the truck or the other way around; either way economizing is part of life now.

 

[mikez71]

I bought a delco gold after the remy starter I bought wouldn't bolt in. (bolt hole spacing was slightly off!)
Rockauto photo shows the Delco Gold with a delco remy casing, and that's why I tried remy initially.

Delco gold 3371200, 6.2 starter.. No noticeable difference. (bigger, heavier, 2.0kW?, 11 tooth)
It had NO markings except a number ink stamped on it, and at the time it looked exactly like the wai global brand.
(ACDelco box made in Tenessee, ACDelco sticker says Michigan, starter made in China. 66% made in the USA!)

I could have saved $55-$90 without the brand box and sticker..

And since the starter is easy to replace, and commonly available.. I would go ahead and save money there if I could do it all over again..

 

[EddieC]

I bought a delco gold after the remy starter I bought wouldn't bolt in. (bolt hole spacing was slightly off!)
Rockauto photo shows the Delco Gold with a delco remy casing, and that's why I tried remy initially.

Delco gold 3371200, 6.2 starter.. No noticeable difference. (bigger, heavier, 2.0kW?, 11 tooth)
It had NO markings except a number ink stamped on it, and at the time it looked exactly like the wai global brand.
(ACDelco box made in Tenessee, ACDelco sticker says Michigan, starter made in China. 66% made in the USA!)

I could have saved $55-$90 without the brand box and sticker..

And since the starter is easy to replace, and commonly available.. I would go ahead and save money there if I could do it all over again..

So the Remy NG and the Gold ok?

 

[mikez71]

In my very limited experience, yes.

 

[EddieC]

Starter?

Accelerating pulls the starter gear back into flexplate..

Should be worse going uphill, better downhill. Might suddenly stop if you slam on the brakes..

Seems like I call starter everytime there's a noise, so grain of salt...

BINGO!
Floppy starter gear. Lucked out and thanks for the heads up.

Went with a RA AC Delco Gold and it came in a AC Delco box and was marked accordingly with both AC Delco and GM part numbers.

For just 2 bolts, a screw and 2 wire connections it took half a day of my life.
Another reason that I don't have a positive opinion about automotive Engineers.
And AI on the internet that thinks the wheel doesn't need to come off ought to tell the programmer to pick up a wrench and give it a try.

 

[j91z28d1]

BINGO!
Floppy starter gear. Lucked out and thanks for the heads up.

Went with a RA AC Delco Gold and it came in a AC Delco box and was marked accordingly with both AC Delco and GM part numbers.

For just 2 bolts, a screw and 2 wire connections it took half a day of my life.
Another reason that I don't have a positive opinion about automotive Engineers.
And AI on the internet that thinks the wheel doesn't need to come off ought to tell the programmer to pick up a wrench and give it a try.

Ai had ruined Google. you can't find anything but slop put together from 7 different car types made into. one.

 

[EddieC]

So back to the original issue but related question.

Related, one of the seals at the axle stub out (hub?) at the passenger side end of front differential housing where the cv axle mates to it is slowly weeping differential fluid. Is that a tough replacement?

 

[EddieC]

Sounds like the CV (half shaft), which can be replaced without removing the hub & brakes. Pic?

If it's the half shaft, see video below.

How to Replace Front CV Axle 2007-17 Chevy Silverado

Check out this video to learn how to replace a broken or bent front axle on your 07-17 Chevy Silverado. The part is available here at 1AAuto.com!

www.1aauto.com

Are the replacements that simple as the A-1 video?
I have seen videos where some take out the struts, others disconnect suspension parts.

 

[Fless]

Are the replacements that simple as the A-1 video?
I have seen videos where some take out the struts, others disconnect suspension parts.

Maybe. Some other posters with experience have indicated it could be more difficult with things in the way.