Bent/crooked drive shaft? Repercussions?

2021 4x4 long bed here.

Shaft is most definitely not in-line, fades 1.5-2 inches(edited) to the right rear side after the U joint(looking at it from where the rear tire sits of course)

Truck was definitely in an accident. Drives great since.

Trying to figure out if there is an offset from factory...apparently not.

Thanks for any input.

 

I've got a 2021 4x4 long bed as well, and I can confirm that the drive shaft should be straight from the factory. If yours is fading 3-4 inches to the right after the U joint, it's definitely not normal. Sounds like the accident may have bent the drive shaft or caused some other misalignment.

 

I expected as much

I just rechecked it
It is actually only 1.5 to 2" off in my estimation. But it is certainly not in-line.


What issues will this cause down the line?

Truck has 22K miles on it total and 7K since the date of the accident.

 

U-joints wearing out, maybe pinion bearing on the diff and tcase output bearing. If it's just used for slow speed stuff and not a lot of miles it'd be fine, if you're gonna take it down the highway I would swap it out. It'll probably vibrate like a mofo.

 

Thank you for outlining possible issues that will come.

I have had it at 70-85 mph on freeway and gone on 400mile trips on interstate, zero vibration. Still drives really smooth. 7K miles and zero issues since it got rear ended at a dead stop. Towing 3-4K every day at up to 70 MPH.

I feel like the frame is bent and the Drive shaft is just accommodating it. So in other words the rear diff center is "back and to the right".

Frame had/has minor buckles and was totaled because new long bed frame + unseen further damages exceeded 70% cost of vehicle. I chose to retain vehicle instead of send it to auction.

Swapping it for a factory shaft will probably still end up with the same angle due to the frame being the issue.

I just now saw some slow seep at the rear diff seal where rear diff meets drive shaft, just enough seep to let me know it's there.

 

To better explain...the two individual parts of the shaft actually appear straight themselves, but the driveshaft as a whole is "kinked" for lack of a better term. The two part shaft is not exactly in-line, which is evident due to the slight angle of the U Joint.

 

Bed is so long it’s just the curvature of the earth.

 

https://www.youtube.com/watch?v=zdjvchXL1lM

 

I like the earth curvature answer better.

 

NO WAY.

The earth is flat....

 

Oh maybe I'm misunderstanding. If the shaft itself is straight and the diff is just offset, then that's fine. I thought you meant you got under the truck and spun the driveshaft and if you put your finger on the shaft it would touch your finger then move 2" away then come back so the shaft itself was curved.

If the differential is just offset from the tcase then there shouldn't be any issues. If you can't feel a vibration then I wouldn't be worried. What's happening is no different from the axle cycling up and down when driving, except it's offset to one side.

 

Thank you so much, I didn't sleep well last night after as I pondered whether I would have to sell her to avoid issues down the line. I looked at the rear diff front from the other side and yep, it is offset about 2 inches. Your video makes me feel a lot better about retaining the truck, I bought it back for 19,500 USD after they totaled it and valued it at 42K. Truck looks in mint condition unless you have a keen eye and can see the small frame buckle.

No way I could spin that thing, it is massive. Thanks for your input.

It is very Loong and I didn't account for curvature

 

What about this weeping/seeping on the Rear Diff seal? Normal or not?

You can also see the 2 inch offset in one of the images below that the Toyota tech talks about in that video posted above.





This is a really great forum, Thanks Folks

 

That leak is not normal and should be fixed. There was a recent thread of someone else having the same issue

https://www.tundras.com/threads/rear-differential-leak.143834/#post-3628124

 

Thanks
I will address it

 

You'd know if the u-joints aren't canceling. There would be some seriously annoying vibrations going on. Tacomas are famous for it, at least they were on the 2nd gens. Move the center bearing over 1/16" and it shakes at different vehicle speeds.

It's also a reason for the massive rubber ring around the center bearing. The axle can move up and down and rotate with torque so it is always screwing up the quest for a perfect angle cancellation.

 

If it were me I'd not mess with that slight weep other than to snug up the bolts on the off chance that takes care of it unless or until there is a solid reason to open things up, or you get really bored one day. Unless it is leaking a lot more than it looks like it is (and that can be easily determined with a fluid level check) that itty bity weep falls solidly under my "Don't fix what ain't broke" rule which avoids the potential for self induced headaches for little to no gain.

 

Yeah, another vote for leave it alone if it isn't dripping.

 

If the offset of the rear diff is not stock, such that the axle is off to one side, then the tires will not track properly. The front alignment could be adjusted to compensate, such that all four wheels are pointing in the same direction, but the rear wheels will be offset to one side. You can see this if you drive straight on a dirt road. The tire tracks from the rear tires will not align with the tracks from the front tires, they will be off to one side. The body of the truck will not be perfectly parallel with the road when driving. A frame shop should be able to check if the frame is bent without spending a lot.

 

I wouldn't touch the bolts until it has a drip.

OP, thats a nothing burger.

 

I’m bumping this tread to hopefully gather some more knowledge about the subject.
I get a driveline vibration at takeoff up to about 20 mph. I’ve experimented with different carrier bearing drops to cure it with no success. My truck was also rear ended and repaired.

I put a string on the zerks, so centered on the driveshaft and mine is out about 5/8”. I moved the carrier bearing mount over as much as possible but is still 1/2” out.

Can anyone take a pic of a Crewmax rear driveshaft to measure the correct straightness?

 

The rear axle favors one side on these trucks making it hard to determine what the center line should be. I just measured with a straight edge off of my tire sidewalls to the bedside and my rear axle sits a full 3/4” further to the passenger side. There’s no changing that. I just wanted to mention that in case you guys are noticing that based on the angle it causes the driveshaft to point. Here’s a photo of mine also which looks similar to @ZPhilip and mine has also never been in an accident.

 

What’s even more odd is that my tires are equally flush with the fenders on drivers and passenger sides. I’m guessing the bedsides were aligned this way when the body shop was repairing my bed (passenger side had entire outer bedside replaced).

 

Yes that is possible that they were able to correct the bedsides in relation to the axle, but I guess if the axle is actually off centered in relation to the frame than it doesn’t change anything in regards to the driveshaft angle.

 

I did a fluid level check today. I could reach the fluid with my pinky finger(only finger that fit) barely into the fill hole. So not really low at all.

Decided to drain and fill at 21K miles.

I put this stuff in, from Walmart. Toyota dealer didn't have factory Diff Oil because..."it is too expensive so we use a generic"...lol


Torqued the nuts to 50 ft/lbs, and the drain and fill plugs to 36 ft/lbs.
Cleaned the weep/seep with brake cleaner and will monitor for further seep/weep.

Dealer said any service was still under warranty but I couldn't wait 3 weeks so I just did it myself. Not sure if I want them messing around with it or a new seal yet. Truck will be under warranty for another 18K miles. Currently has 21K on it.

Found this on the drain plug, probably been there since the start up break in period.


Should I run thicker diff oil? or is this gonna be good enough?

 

Truck rides true and straight still
Frame is within factory specs despite the small buckle

 

I feel like my driveshaft has a 1.25" or slightly more angle.
Likely due to the super long wheelbase and longer shaft.