Exeter

So a few months ago I replaced both U-Joints on the rear drive shaft. A few weeks ago I started to notice the sound/feel of how they were BEFORE I changed them out. Checked them periodically and all visually seemed well.

Fast forward to today, about an hour ago. Merging on the interstate @ ~60mph (which is good for my 3.slow while still on the on ramp) into traffic and click the button to hop into O/D. (Have it turned off to keep the RPM's up while trying to merge.) Let off the gas after it shifts to O/D, and holy crap my teeth were about jarred out of my face, me and the girlfriend kinda look at eachother and can tell something is up. Look at the gauges out of habit when i sense car trouble, (I know, I know vibration + gauges = ) but anyway, whilst looking, theres a single loud BANG.

Costing off the the shoulder over the "wake up drunk guy" / "ripple strip" on the edge of the interstate, I see the drive shaft getting smaller and smaller in my rearview. That's right, it completely fell off the pumpkin side and xfer case side as well.

So I get out, asses the situation, hop across a lane of traffic after watching a few 18wheelers roll over my drive shaft, and lug the beast back to the 4runner, and crawl under to see WTF happened.

This is what I saw: (Sorry, cell phone is only camera handy)





Questions? Comments? Concerns?
Let's hear it.

YotaJunky

ouch! what part of the shaft other than the u joint broke off? I'm trying to get my brain around what broke off other than just the u joint.

Exeter

going to take more pics now. just wanted to get the thread posted so i could take the G/f home. will elaborate more shortly.

Exeter

So after hobbling home with the front hubs locked and in 4Hi, I started posting the original post.

More pics:

Pumpkin Side

Pumpkin Side

Pumpkin Side

Xfer case side

Xfer case side

Xfer case side

So all 4 (four) bolts on the xfer case side were sheared off i guess, and for all i know are still rolling around on the interstate.

So, were the fronts loose, causing the vibes and the back just came off because the front was FUBAR.

Or was the back ujoint gone again, and the back came off first and sheared the front bolts?

Nobody was hurt and the truck didn't seem to suffer and physical damage other than drive line related. (i.e. the shaft didn't rotate under the truck ripping the exhaust/xfer case out)

superjoe83

are you sure those front bolts were tight?

Exeter

bout 99% sure, yep. they were about a week ago, which was last time i put a socket on 'em. I've looked at it since them but not had a socket/wrench on it.

ADH8796

Go get you some Grade eight bolts and new U-joints then make sure you put everything together tight. After that take it for a spin around the block (loosen things up a little) and then crank it all down one more time and I doubt you will have any problems with it again.

YotaJunky

You may also consider using some loctite just to make sure they don't back out again (if that's what happened).

Cargun

More than likely the t-case end was loose and when the shaft dropped the diff end broke.

Make sure the making surfaces are clear of debris so the flange and yoke sit true. Do not grease the bolts, use them dry or loctite them. I've never looked up d-shaft bolt torque specs, but it would be worthwhile just to get a feel for how tight they should be. Make sure the threads are good and that all of your torque is going into stretching the bolt, not overcoming messed up threads.

Theoretically you could have had a u-joint going bad and the vibration worked the bolts loose... but I'd say 99% that the bolted joint itself was bad. At least it wasn't a major suspension/steering component.

Exeter

Thanks for the info.

I ran up to the dealer today, got a quote for 2 new yokes, 2 new ujoints. He pointed me to a guy in lowell called Larry's D-shaft and he quoted me about 50 bucks less for beefier parts, assy., and balancing. So needless to say the shaft is in lowell awaiting parts.

Oh, and I found the results of the "bang" today... was too dark last night but it pierced the floor and i can feel the carpet/insulation through the hole. At this point i've given up on keeping it pretty, so as long as i can get it welded shut/sealed i'll be happy.

CJM

Your sure the angle of the shaft wasnt partially to blame?

After its all said and done, try and see if you can mount a camera back there facing the pinion and watch for it to jump around when on the gas.

colsoncj

Id agree with hans that the t-case side was loose... i've periodically found myself missing bolts. If ya need any parts, i'm sure i have a whole driveline for your truck in my back yard.

Napoleon047

Make sure Larry's D-shaft is giving you toyota joints and yokes not Spicer with adapter yokes.

Exeter

He measured quite a few places and referred to a book many a time, other than that i have no idea... you have a similar experience or something?

bigt

what size bolts are a good replacment i have both my driveshafts out as we speak and should replace with nice new grade 8 hardware