I blew up my front differential

https://www.youtube.com/shorts/KYodo6bfDl0

So let me just start off by saying I know that with open diffs, I should not have been giving it throttle after losing momentum. Someone told me I should try that because they thought that would help me get over the obstacle. Not sure what their logic was but I thought maybe they saw something I didn't.

So anyway, here's what happens when you do that!

In the video I obliterated one of the gears inside my differential. I pulled teeth and chunks of metal out of the differential with a magnet. I am not sure exactly which gear got messed up yet. In the video, you see my passenger side front wheel is planted as I'm rolling back. What you can't see is the driver's side wheel spinning with the engine at 3-4k rpm. Eventually, while spinning, the driver's side wheel hits the ground and gains traction (as indicated by rocks flying at my friend's head). This is the point where the gears engaged and I guess the engine was spinning with so much momentum that it sheered the teeth off of one of the gears.

I'll post pics of the carnage later. I thought this would be a good post because in searching for "Toyota front differential failure" or "first gen tundra front differential failure" I actually couldn't find any posts or videos like it. Maybe I didn't look hard enough. But here's what happened, how it happened, and what it sounds like when it happens.

Thankfully yards local to me have diffs for $250 so I'm not too upset. Hopefully they're good...

 

That sucks man. Good time for a regear. Pull some diffs from a truck or tree with a better ratio. 4.10s or 4.30s.

 

The money shots



This is what I saw when I drained the fluid.



It was at this point, he knew he had fucked up.


These are all of the metal chunks I pulled out from the fluid and with a magnet inside the differential.


The drain plug itself got chewed up a bit. It was hard to get it out.





Some more close up shots

 

Maximum carnage

 

Excellent contribution, sorry that this happened to you though! The front differential is an example of a part that was originally designed and used for the Tacoma/4Runner, and our trucks have a V8, so...

I second trying to spring for 4.10 diffs at the junk yard if you don't want a full regear. Your truck will be happier in that sort of wheeling. I have a stock front and rear with 4.10s I can part with if you're close to SoCal.

 

I always love any time this emoticon can be used:



On the upside, with failures comes a great opportunity to upgrade!

 

I have a wyoming trip coming up in 3 weeks so I'm throwing a 3.91 diff back in. Now that I know I can find diffs this cheap, I will be on the lookout for 4.10 gears near me.

I know for sure after this I will be getting an arb rear air locker and compressor. Pretty clear that it's the best bang for my buck in terms of opening up doors on where I can go with my truck.

 

Anyone know if the inboard or outboard cv’s would take the brunt of that force? Something to think about while grabbing diffs.

 

Outboards are usually the issue in my case, but those are the ones that don't come off the shaft easy. If the outboard goes completely and the shaft is dangling, you can pull the shaft off the inboard CV and just continue along in 2WD (I did this for 2,000 miles).

 

I can tell you that after this happened, my CVs seem to be totally fine. I am getting zero bad CV joint noises. I am curious to see if the inboard shafts will happily come out of the diff though. Haven't tried that yet. They may have got bent.

 

Best of luck.

 

Pickle fork works okay to get them out in my experience, I take the outboard out first. To get the outboard out, put a screwdriver/ punch in the rotor holes that will catch on either the ground or the caliper. 35mm socket for the axle nut. I usually remove the four LBJ bolts so I can move the steering knuckle around and easily push the axle stub out of it.

 

You probably just shattered a spider. I think they are sintered.

 

YIKES!

Just that little bit caused the front diff to shatter? Wow. OK.

 

Low range? Aired down?

 

I saw you post this on FB a week ago and get pummeled by a bunch of stupid asses with few actually giving advice. Shit happens. I see you're in TX. If you're not busy on the 3rd weekend of October you can came up to Amarillo and hang out with the TX boys(and Sid) at Merus.

https://www.tundras.com/threads/merustober-part-2-electric-boogaloo.159310/

 

Painful but educational. Thanks for sharing.

 

I was surprised but also not surprised. You can hear the revs were pretty high when both wheels got locked up. I guess I found the limit of the diff lol

I was in low range at 20psi, i had to air down more to around 13psi to get out.

Dude thank you for the invite! That actually sounds like it would be a lot of fun. I'm in San Antonio. I've been to hidden falls and palo duro canyon but I didn't know that place existed. Looking at pics on google it seems awesome. I'm definitely down but I just need to see if I'll have enough PTO.

 

This is why Facebook is garbage, and the smarter folks always end up over here, versus hanging around in that cesspool. So much bad advice, usually delivered in confidently incorrect fashion, and too many fucking morons/trolls. 99.9% of the folks in this community act like adults. Sometimes barely-18 adults, but ... adults.

 

I think it's a Tacoma diff on the first gens... someone will correct me otherwise. 7.5"? It's not a Dana 44. Cast housing, mickey mouse CV's with virtually ungreasable u-joints on the front drive shaft. I don't assume they are very robust.

 

CV joints are common on high horsepower rear engine sand cars and the like, I don't think it's fair to call them Mickey Mouse. U-joints are stronger, but only to a certain angle. The CV stands for constant velocity, CV joints usually don't bind until higher angles. Over certain angles, u-joints will bind and lose velocity. In drive shafts and solid axle rigs, the u-joints should see less severe angles than a CV joint than on an IFS suspension.

 

The ourboard CV bearing is the weak one. The inboard has three huge rollers in it, the ouboard has a cage with I think six balls in it, that cage breaks long before the inboard does. The inner should be just about indestructible the way it's made.

 

3.91 1gt diffs are shared between first gen tacomas and 3rd gen 4runners so yes you are correct. Maybe not all of them, but when I was looking on car-part for mine they had interchangibility within at least some years.

 

Correct. I have a 2002 4Runner front differential in my truck. Only difference is it came with 3.91 gears, but I changed them out for 4.88s. Externally, this differential is the same as the one that came stock.