RTH.....what do you guys think it is? (1 Viewer)

[flintknapper]

1999 LX470:

Wife left for work this morning, drove the 15 miles into town just fine, but when making a turn said she heard a popping sound followed by a grinding sound from under the vehicle and that forward movement had slowed. She pulled over immediately.

When I got there I started the engine and checked for codes (none). Engine runs fine. But when the transmission is put in gear there is loud grinding sound. Nothing in Park or Neutral, just when put in 'gear'.

Then I noticed that the vehicle would roll backwards in PARK if the parking brake was not on.

What I did:
1. Checked to make sure Transfercase was fully engaged (tried both low and high range) no problem. Grinding still present when trans engaged.
2. Locked center diff and immediately got movement and all grinding ceased.

So.....?

Drive flange stripped?

Had the vehicle towed back to my house and getting ready to inspect, just wondering what you guys think I should look at first or test?

Thank You in advance.

Flint.

 

[DirtDawg]

Something is stripped in your driveline. Fingers crossed it’s the drive flanges. I’ve got a 100 sitting in my yard that had the same symptoms and the front diff is gone . You can lock the CDL and drive home if home is close.

 

[medtro]

When I got there I started the engine and checked for codes (none). Engine runs fine. But when the transmission is put in gear there is loud grinding sound. Nothing in Park or Neutral, just when put in 'gear'.

Is this noise coming from drive flange?

 

[flintknapper]

Something is stripped in your driveline. Fingers crossed it’s the drive flanges. I’ve got a 100 sitting in my yard that had the same symptoms and the front diff is gone . You can lock the CDL and drive home if home is close.

Had it towed (15 miles) on a roll back. Works fine with center diff locked, no noises that I can hear at all, but the grinding sound (when I am in the vehicle) sounds like it is coming right at the front of the transmission and not off to one side. But noises are tricky.

 

[flintknapper]

Is this noise coming from drive flange?

Can't really tell. Just got home with it. No one here right now to put it in gear while I am outside to listen. Need to pull the dust covers on both front hubs and have the Wifey put it in gear to see if the CV shafts are spinning in the drive flanges.

 

[Trunk Monkey]

Sounds like the c-clip's maybe popped off the end of the axle. You may be able to visually tell by looking at the back of the hub and seeing if it looks like it's pulled away from the spindle a little. Also easy to tell by popping the dust caps off and seeing if there's a c-clip in there.

 

[flintknapper]

Sounds like the c-clip's maybe popped off the end of the axle. You may be able to visually tell by looking at the back of the hub and seeing if it looks like it's pulled away from the spindle a little. Also easy to tell by popping the dust caps off and seeing if there's a c-clip in there.

Will check for that.

Wondering if the fact the vehicle would roll backwards (engine off, trans in park) is a significant clue to anything?

Would a stripped drive flange allow that to happen?

I can understand when the engine is on and the transmission placed in gear, the grinding noise and no forward movement since all power is likely biasing to that wheel.

 

[ramangain]

Sounds to me like you have an issue with the park(ing) pawls in the guts of your tranny

 

[flintknapper]

Sounds to me like you have an issue with the park(ing) pawls in the guts of your tranny

No, don't think that it is it. It holds when the center diff is locked. I know the 'clicking' sound a parking pawl makes when over-ridden, this very different. I have a grinding (rotating) sound.

 

[flintknapper]

Sounds like the c-clip's maybe popped off the end of the axle. You may be able to visually tell by looking at the back of the hub and seeing if it looks like it's pulled away from the spindle a little. Also easy to tell by popping the dust caps off and seeing if there's a c-clip in there.

Well not the c-clip/snap rings.

They are both there and look fine. Doesn't mean one (or both) of the drive flanges aren't stripped though. Will just have to wait until this evening when the Wifey gets home. I can have her put it in gear (center diff unlocked) and watch both sides to see if the axles are turning inside the drive flanges or if it's something more serious.

 

[medtro]

Or you can capture video of both sides with you in the driver seat.

 

[flintknapper]

Or you can capture video of both sides with you in the driver seat.

Could.

But going to make the Wife earn her keep. (so long as she doesn't see this).

 

[medtro]

Make her hold the camcorder or phone

 

[Couvi]

Sorry to hear that. I had the same exact symptoms a few years ago. My snap ring had popped off on passenger side and allowed the axle to slip out and strip the drive flange. I was able to drive home with the CDL engaged – had to replace the axle, flange and repack bearings. Maybe it popped out of the diff?

 

[flintknapper]

Make her hold the camcorder or phone

Hah.

Yeah, and maybe my beer.

Then have her chop some firewood, cook me up some bacon and some beans.

 

[flintknapper]

Sorry to hear that. I had the same exact symptoms a few years ago. My snap ring had popped off on passenger side and allowed the axle to slip out and strip the drive flange. I was able to drive home with the CDL engaged – had to replace the axle, flange and repack bearings. Maybe it popped out of the diff?

Snap rings are both in place...so neither axle went inboard. Both joints are intact so I'm not sure the axle could move outboard away from the diff.

I have new Axles, Flanges, Wheel Bearings, Steering Rack, Tie Rod Ends, Ball Joints, Bushings, Brake parts all sitting here. Just didn't want to put them on until it cooled off a bit.

Hoping just to find a stripped drive flange, but who knows. Perplexed as to why the vehicle would roll back (Trans in park) without the center diff locked.

 

[OwnerCS]

You don't want to know what happened to one of my cars when I heard a grinding noise from the transmission area.

The cure was a LevelTen. Level 10 TRANSMISSION

 

[flintknapper]

You don't want to know what happened to one of my cars when I heard a grinding noise from the transmission area.

The cure was a LevelTen. Level 10 TRANSMISSION

Yeah, hoping not transmission related....since it has given me Zero problems in the past, has always been serviced regularly and no previous indications of a problem. Surely they can fail suddenly and without warning....I am aware of that... but it seems to work fine with the Center Diff locked....so I'm not anticipating a problem there.

 

[AimCOtaco]

Sure sounds like a front diff to me.
Look at the CV boots and see if one is twisted, you could have a blown/broken CV joint but not super likely.
Sorry about the diff.

 

[flintknapper]

Sure sounds like a front diff to me.
Look at the CV boots and see if one is twisted, you could have a blown/broken CV joint but not super likely.
Sorry about the diff.

If the front diff, why would it not 'grind' (or stop grinding) when the center diff is locked?

Symptoms:

A. When transmission is put into gear (forward or reverse) I have a loud grinding sound from somewhere underneath the vehicle and there is no forward or rearward movement.

B. When the center diff is locked there is NO grinding sound and I have both forward and rearward movement of the vehicle.

Not trying to challenge the idea (since I am soliciting possible issues) but I am not able to reconcile why a blown front diff wouldn't make noise all the time?

Having trouble thinking that the front diff would have suffered a failure on a daily driver that wasn't under any abnormal loads?