Need transfer case diagnosis

Joined
Sep 1, 2004
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302
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austin, tx
I was driving around a ranch on the gulf coast this weekend and got caught up in some mud. I went full lockers and low range, and naturally made it out easily. It was a full throttle out of the mud and up the embankment, so I would describe it as a high torque situation. Nothing the LC can't handle, right? Well I shifted back into high and turned off my center differential lock, reversed, then attempted to move forward on a slight incline. Wasn't working, so I figured I was not all the way in hi, so I jacked with it, and began to move. At the top of the rpm range for 1st gear, instead of shifting, the t-case seems to have just gone out. The rpms redlined, just as they would have if I was in neutral. I stopped and the car would not move in either hi or low range. The engine would rev, and the car would remain stationary, in all configurations. When I would shift from drive to park sitting there trying to remedy the problem, there were awful clanking sounds going on. The transmission sound busted. When I looked under the car, only the front drive shaft was spinning when in drive. So I decided to lock the center differential, and the car moved. My conclusion was that something was going on in the t-case with the differential, so I opted to remove the front drive shaft and go with a locked center diff(my only option basically besides being towed). Well I made it back to Austin, 180 miles of high way driving just fine. Now I need to figure out what the hell is going on, so let me know what you think please. Thanks a lot for taking the time to read this.
 

bjowett

 
 
 
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Oct 28, 2002
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Probably a broken CV Joint or ring and pinion gear. Pull your fill plug on the front diff and check the fluid, if it's clean, you probably toasted a CV. If it is metalic paste... well....
 

sleeoffroad

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Mar 27, 2003
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Yup, busted something somewhere in the front. When the truck moves, does it turn? Either way don't drive it otherwise your knuckles will be a big old metal blender and trash everything inside there.
 
Joined
Sep 1, 2004
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austin, tx
sleeoffroad said:
Yup, busted something somewhere in the front. When the truck moves, does it turn? Either way don't drive it otherwise your knuckles will be a big old metal blender and trash everything inside there.
Good god... I just drove it 180 miles... and I did a complete knuckle/birf job a few months ago... :flipoff2: me
 

sleeoffroad

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Well, it depends on what is broken. Did you pull the front drive shaft and drive plates?
 

Tools R Us

 
 
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Chandler, AZ
Drive plates are the covers on the hubs held on by 6 nuts and cone washers. Most of the time a broken birf will affect steering, randomly locking it up and with the drive plates on they will still turn making lots of noise even with the driveshaft out. Jack up the front and spin the wheels to find the affected side, may just be a stripped drive plate.
 

IdahoDoug

 
 
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Aug 9, 2003
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I'm going to speculate that you at some point were in reverse in low range and trying to get unstuck? If so, I'm going with the front diff ring/pinion, NOT a knuckle. Loosen the front diff fill plug, then open the front diff drain plug. My guess is you'll get some metal chunks. Then call Cdan for a surprisingly reasonable price on a new Toyota front diff gearset all ready to bolt in.

DougM
 
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Mar 13, 2003
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North Front Range, CO
If you can turn the front drivshaft without the CAR moving, you should be able to here where the brake is. Lock the front diff and turn the drive shaft by hand with it up on jacks. Do both wheels turn? Can you turn either front wheel by hand.
The one that turns freely is the one that is broken.
 

Cruiserdrew

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If this was the front diff, wouldn't the long drive home have been extrememly noisy and/or impossible. I like the idea of the drive plate splines going out. If so, the problem can be fixed for $60 or so. Any other problem is going to be expensive and messy. Good luck, and post a follow up.
 

IdahoDoug

 
 
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With a broken front diff (ring or pinion), the clanking was likely the missing teeth, broken parts bashing past each other as the transfer fluid coupler let the front shaft spin but no power to the rear shaft (or very little). At higher RPMs he described, it would move as then the coupler will transfer more power to the rear to move the truck. By locking the center diff for the drive home, the front ring/pinion were essentially spinning at the same speed rather than clashing.

If it had been a blown birfield, he would have heard clashing all the way home on turns, etc.

So, my money's on the front differential failing from backing up under high power and something hooking up.

DougM
 
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