Front diff locked up while driving in 4hi

I was driving in 4hi today going about 30mph through some pretty icy and snow covered roads in mammoth when my front tires locked up and sent my truck skidding until it finally stopped. I did regear to 5.29s this year and believe maybe something failed in the diff causing the wheels to lock up. I gave it some light gas and the truck would not move so I put it in 2wd and was able to get off the road. The truck seems to drive fine in 2wd. I noticed when I got the truck home that there was gear oil splattered all over under the truck. It almost looks like the transfer case may have been damaged when this happened as well. Ill check along the top of the t-case for cracks in the morning. Taking the truck to the gear shop next week to get inspected. Just wanted to get some thoughts.

 

Same as other thread. You probably had front gear failure and the lock up took out the tcase in the process.

Installing gears in the front clamshell diff requires attention to detail. When something is done incorrectly, failure is imminent.

 

Did you check the front diff housing? That’s probably where the oil came from. I doubt the t-case broke. I had something like this happen on dry payment at 70mph and my t-case was fine. Completely exploded the front diff though.

 

Tough brake OP, I feel for you. Hopefully the shop will make it right, sounds like something was not done properly.

 

The housing on a Toyota clamshell front diff is made of really thin pot metal. If you over-torque the mounting bolts putting it back in the chassis, it can warp the housing, mess up the total preload and the differential will overheat, or worse, seize up. I found this out the hard way when I did gears and Harrop e-lockers on my Tacoma. I ended up having to do my front diff twice.

I had meticulously set them up but then when I put the front diff back in, I zapped the mounting hardware on with a 3/8" impact and thought nothing of it. Second time around I did the mounting bolts with hand tools and a torque wrench, following all OEM torque specs and checking the preload several times with a beam-style torque wrench to make sure it stayed in spec. If you had a shop do your gears for you, this is probably the step they overlooked.

 

That sticker

 

Lol great eh?

 

Ill drop my skid today and check today but it does appear to be coming from the transfer case

 

Yeah I had a pretty well known shop do it

 

Narrowed it down to the ring and pinion im pretty sure. Jacked up the front put it in 4hi and put the transmission in neutral. I am able to spin one wheel and the opposite side spins the other direction (spider gears are okay). Switched the truck to 2wd kept the trans in neutral and tried to spin the front driveshaft and im unable to turn it. It should be able to turn freely and rotate at least one of the front tires. Ring and pinion failed somehow and when the front end locked up, the transfer case still wanted to spin the driveshaft. Because of this im pretty sure the transfer case cracked. Not draining any fluids or pulling anything off until the gear shop looks at the truck next week. Hopefully they make things right since transfer cases are not cheap

 

You pretty much got it. This was also the indication when you were able to drive fine in 2wd (spiders good). Yes, when you tried to spin the front driveshaft by hand in 2wd neutral it should spin freely, but it likely won't rotate a tire when you do that (RF disconnected, more drag on LF than the disconnected RF shaft so the disconnected RF shaft is what will likely be driven to rotate when you do this).

You're also right on about the shock load going into the transfer case which could likely damage it. This is a very severe case that introduces a lot of stress to driveline components.

You either ate the R&P or completely seized a bearing. When you tried to spin the front driveshaft was it solidly locked up or did it have some backlash before it felt bound up? It is possible the driveshaft can be locked up by tcase failure, but given your gear work and historical failures that's unlikely the root failure.

 

wow that sounds catastrophic, hopefully the shop has enough insurance, resources, and moral compass to make it right. If not, hopefully you paid using a major credit card, so maybe you can recoup some monies that way.

 

Looks like the transfer case end of the driveshaft has some backlash but the diff side is completely seized. Pulled the skid off the transfer case and it looks like hopefully only the seal at the flange started leaking and there are no actual cracks

 

Yeah I dont want to name drop but I went to a very well known gear shop. Ive never heard anything bad about them and they supposedly offer 1 year warranty on parts and labor

 

Yeah I believe the damage stopped there. Call me an idiot but I drove 300+ miles to get home in 2wd and everything seemed normal

 

I will! Shops getting me in on Tuesday or Wednesday to inspect

 

Yeah definitely give em a chance to make it right before you publicly out them.
GL

 

probably dumb question; if the gear shop re geared both diffs and front diff checks out as OK and they not touch the transfer case and it is a transfer case would it still be on them?

 

No