Did I ruin my t-case? (1 Viewer)

[805surfwagon]

Hey folks, I went up to the mountains this weekend and took my 1999 LX470 with 250k miles up a worn dirt fire road. Considering the trail is pretty dusty, I decided to do it on 4 low at low speed (likely my first mistake). Slowly going up the hill, my wheels get stuck and when I gave it more gas, it gave a loud and expensive-sounding grinding. Seemed to come from under the front end, and had a burnt smell to it.

After this oh-s*** moment, I popped it in neutral, took it from 4 low to 4 high, and let gravity take me back down the hill in neutral & 4 high. Noticed that the center diff lock light lit up on my dashboard, but when I pressed the button for the cdl it doesn't go away in 4 low. When in 4 high, the light goes away and the truck works like normal. I'm grateful that we were able to get down off the mountain and even drive up to highway speeds back, albeit very gentle on the road.

I'll try to attach a video where you can hear it happen, but I got nothing else. The transmission fluid seems to be normal red color with no burn smell. Haven't checked the diff fluid nor the t-case yet, just curious if anyone had this issue or can shoot me some advice. Otherwise I'm going to see if my mechanic can diagnose it at the minimum. Thanks!

 

[805surfwagon]

Here's a link to the video

 

[MongooseGA]

If I'm not mistaken, didn't the '99s have a CDL that came on automatically when the transfer case was in 4-Lo?

In any case it sounds to me like something in the transfer low range blew up. If you were able to drive it home in high range, that'll rule out the diffs and transmission.

What happened after the loud expensive bang? Did it move at all after that in low range or did you immediately put it into high range at that point?

 

[805surfwagon]

If I'm not mistaken, didn't the '99s have a CDL that came on automatically when the transfer case was in 4-Lo?

In any case it sounds to me like something in the transfer low range blew up. If you were able to drive it home in high range, that'll rule out the diffs and transmission.

What happened after the loud expensive bang? Did it move at all after that in low range or did you immediately put it into high range at that point?

I actually never noticed the cdl would activate on 4 low normally, but I certainly do notice that now. The cdl seems to actuate just fine in 4 high as well.

After hearing that noise I immediately put it back into 4 high and haven't drove it in 4low since, I'd be worried about making the issue worse. 4 low does seem to be engaging when I have the vehicle stopped, where it jolts when shifting into drive and reverse.

 

[Patassa]

That seems like an incredibly rare failure. Tells us more about getting stuck and giving it more gas.

 

[elhombre]

I can't tell from you video, but the first thing I would take a good look at is a front drive flanges. One may have started stripping out under the heavy load. Pop the dust cap off each side of the front wheel hubs and remove the snap ring. See if you have a bunch of metal shavings in one of them. I can not imagine you did anything to the transfer case if the video contains the actual moment the failure happened. Not impossible, but unlikely. The only thing I could think of is that you did not have the transfer case fully shifted into Low, and it popped out of gear if the transfer case is making the noise.

If a flange is stripped out, it is a bad idea to drive it around in all wheel drive. Use the diff lock switch if you have to drive it so that you are in true 4 wheel drive to save wear on the center diff assembly in the transfer case.

 

[excessive]

my bet is stripped drive flanges. i think the Tcase in the 100 series is virtually bulletpoof

 

[JOSHD]

I have a 99 LX as well and CDL does come on automagically when in 4Lo unless the PIN 7 mod has been done.
Also, my bet is on a stripped hub flange or couple of stripped teeth in the front diff.

 

[krice118]

Following for the education. Unless you have altered it, 98-99 models have CDL lock automatically when in 4Low. Search Pin 7 Mod to be able to select CDL when in 4Low. Great Mod to do

7 pin mod - 1999 100 Series

I have done the cdl mod. Now the question is this, does the 7 pin mod need to be done on the '99 100 series? Any insight would be greatly appreciated. UZJ100

forum.ih8mud.com

 

[nissanh]

Perhaps you blew the front diff as it got 1 pinion diff.

Try draining the fluid and see you see large metal particles.

 

[MongooseGA]

Perhaps you blew the front diff as it got 1 pinion diff.

Try draining the fluid and see you see large metal particles.

I thought this too, until he mentioned that he drove him with no issues in high-range. The diff would have been effed in high-range as well as low, so I would think it safe to rule it out.

 

[Patassa]

I thought this too, until he mentioned that he drove him with no issues in high-range. The diff would have been effed in high-range as well as low, so I would think it safe to rule it out.

Yeah seems like high speed on the way home would have totally wrecked the front diff. Money is also on stripped splines or not fully in low or something. I can't see the video so I'm missing some info though.

 

[awesomeissquid]

I’m going to go with not fully in low gear.

If the splines were stripped wouldn’t the CDL need to be engaged to move anywhere? Didn’t sound like that was the case.

 

[prwillard2]

my bet is stripped drive flanges. i think the Tcase in the 100 series is virtually bulletpoof

I blew mine out trying to pull out a 2500 Ram stuck in mud. I also used a steel chain and tried to yank it out. So totally my fault.

Shredded my low range gears.

 

[awesomeissquid]

I blew mine out trying to pull out a 2500 Ram stuck in mud. I also used a steel chain and tried to yank it out. So totally my fault.

Shredded my low range gears.

View attachment 3143040

When that happened could you still drive in high range? I would assume not since aren't the broken gears then floating around in there, but maybe they are separated?

 

[805surfwagon]

I blew mine out trying to pull out a 2500 Ram stuck in mud. I also used a steel chain and tried to yank it out. So totally my fault.

Shredded my low range gears.

View attachment 3143040

Yikes, that probably wasn't a good time for you. How did it go repairing the damage?

 

[prwillard2]

When that happened could you still drive in high range? I would assume not since aren't the broken gears then floating around in there, but maybe they are separated?

My truck shifted into neutral when the gears shredded. Thought for sure I had done something really bad. Didn't realize it had gone into neutral and got towed out by another vehicle.

Was able to shift into 4H and able to drive as normal. Had noise when turning, thought it was my CV flanges, they turned out to be perfectly fine.

Yikes, that probably wasn't a good time for you. How did it go repairing the damage?

Had a shop swap in a used T-Case (the whole shebang, didn't open anything) into my truck. Fixed everything.

The shop I used then let me have my old T-Case and I opened it up to determine what the problem was.

 

[trdcorolla]

I was told in the 4WD class I took that backing up from a hill backwards should always be in reverse for safety.

 

[BnvS]

I blew mine out trying to pull out a 2500 Ram stuck in mud. I also used a steel chain and tried to yank it out. So totally my fault.

Shredded my low range gears.

View attachment 3143040

So @prwillard2 the T-case blew up b/c you were trying to pull more than what was advertised i.e. 6500-7000 lbs. I take it that the Ram truck was a lot bigger so it screwed up the T-case..? TIA.

 

[krice118]

So @prwillard2 the T-case blew up b/c you were trying to pull more than what was advertised i.e. 6500-7000 lbs. I take it that the Ram truck was a lot bigger so it screwed up the T-case..? TIA.

I think the sudden shock of yanking on a chain with such heavy load versus using a kinetic strap is partially to blame.