artemyk

Today while driving on the highway, I noticed a strong vibration at > 45 mph, especially when I took my foot off the brake. If I had known then what I know now, I would have realized that it was the drive shaft and inspected it. In any case, I did not realize this, and pushed the truck a bit in order to get home.

So, going about 50mph, the rear drive shaft (real propeller shaft?) disconnected from the transfer case. You can imagine that it sounded and felt horrible. I pulled over immediately and saw what happened (see pictures).

The truck is an 1987 4runner, 22re, ~320k miles, 33 inch tires, probably ~4" lift.

The strangest thing is that the place where the transfer case attached had one bolt sheared, and it looked like the other 3 bolts were just not there in the first place. Could they have come undone from regular vibration?

Anyhow, do you think I could just replace my u-joints and be fine? Will the rear drive shaft also likely need to be replaced? Also, is it possible that the force of the events could have damaged the rear differential (I attach a picture of it also, seems to be leaking a bit of fluid) or the transfer case?

I've heard that I could maybe unscrew the back end of the rear drive shaft from the differential and drive home on the front wheels using 4WD. Would this work / is this a terrible idea?

Finally, if I get my ujoints and/or driveshaft replaced at transmission shop, roughly how much should I expected to pay?

Thanks greatly

millball

You can remove the rear shaft and drive on the front wheel propulsion.

Looks like that flange was bent when it dug into the road. The shaft might have been bent too.

The coupling bolts likely fell out, one at a time.

Best thing would be to have the shaft looked at by a shop that is equipped to balance them.

It's a perfect time to put a new pinion seal in that differential, and maybe a seal in the transfer output also

Let us know how you do. These trucks are tough, but after 325,000 miles it could use some TLC.

wyoming9

iTrader: (1)

I gotta wonder if those bolts on the transfer case flange were the wrong ones.

I made the mistake of just putting off the shelf bolts in that very same place .

My results were the same but I caught the problem before they fell out completely .

A very scary lesson to learn

I have seen the carnage where the drive shaft digs into the black top lifting the back end of the vehicle

artemyk

Thanks for all the tips, guys. Went out there today, disconnected the drive shaft from the diff, put it in 4hi and drove it home. Only tricky part was getting the hubs to catch (I forgot to roll it forward, so ended up disassembling hubs by side of road ,etc.). So far so good.

1) The drive shaft I will take to get inspected/balanced. The u-joints seem fairly decent, but the flange is slightly bent (as can be seen from the pictures). I suspect I might have to replace the drive shaft. Is it a bad idea to get one from a junk yard? New ones are ~ 300 bucks :-/

2) The pinion and tcase seals seem to have slight leaks. I will replace those using the FSM. Grease inside the seal, and then RTV inside the flange, correct? Is there any tricky parts? I saw a video where it said it's important not to overtighten the center bolt when putting the flanged back on the differential ... is this a real risk?

3) Is it possible the pinion gears or something else is damaged? Is there a way to check?

4) Most importantly --- I forgot to mark the orientation of the drive shaft w/r/t the diff (and w/r/t the tcase -- that just flew off , so who knows what the orientation was). How do I align it properly without having these marks?

Thanks again

millball

A junkyard shaft might be fine, but its balance should be checked as well.

The transfer flange tightening spec is 95 foot pounds. The diff flange can be tightened this tight or a little tighter.

I have tightened them to 130-140 foot pounds without changing the bearing preload any.

As for damage to the diff, there's probably none. Just drive it and listen for new noises. There's nothing to lose.

As for any previous alignment marks, forget it. all is out the window with a different, or repaired shaft Just install it..

RJR

I don't see anything in the FSM about RTV inside the flange, although I suppose it wouldn't hurt. I just lube up the seal and the inside of the flange and tighten it to spec. Most important thing is staking the nut so it stays on. Get a new nut if you can.

I would probably jack up one rear wheel and spin it, and listen for any strange clicks or catches in the diff. You might also want to drain it and check for bits of metal. If neither of those tests reveal anything, then just fill it up and run it.

I wouldn't be too worried about this. Toyota doesn't align the drive shaft to the flanges in any special way at the factory - they're balanced separately and assembled however they come out of the box. It's the only sane way a manufacturing process can work. Plus, as @Wyoming9 says, if you get a different shaft you won't have any marks to go on anyway. I've had my drive shaft off at least 4 times and never experienced vibration when reassembling it in a random orientation.

dropzone

iTrader: (6)

you realize how lucky you were?
We had that happen to a truck at a former job I had and it was totaled.

Vole

I just caught this same thing on my truck. Just in time, too. All week during my commute I noticed a new vibration that was getting progressively worse. Finally, after work on Friday, I decided to crawl underneath and see what I could see. All 8 of my driveshaft bolts (4 on each end) had worked themselves loose so there was about a 1/2 inch gap between the drive shaft flange and differential/transfer case.

flg8r22

iTrader: (1)

This happened on my 86 at 50mph. The front of the driveshaft fell and lodged itself in an expansion joint in the concrete on the interstate. The entire truck endo'd and it sent the bed into the back of the cab which creased it and blew out the windows. Sad to see her go.

RJR

When you reassemble the drive shaft to the flanges, make sure you (as @Wyoming9 says) use the right bolts. They are special fine thread and high strength, and you probably need to get them from Toyota (at a premium price). The ones in the tcase flange are made to be pressed in. Also, torque them fully to the spec of 54 ft-lbs. That'll seem like a lot for such small bolts, but I think that's crucial for making sure they stay tight.

The fact that 3 of the 4 tcase bolts were missing suggests that they were not press fit as they should have been, indicating that the wrong bolts were used for a previous installation, probably contributing to the failure.

artemyk

Regarding not having to make 'marks' etc.: I read that the u-joints have to 'in phase', otherwise friction and vibration will occur. This is not really true then?

I'm having a horrible time getting the 30mm nut off the tcase (the diff side was a piece of cake). It seems to be staked in a strange way, not really 'in the grove'. I've tried a center punch, a filed down center punch, a screwdriver, a filed down screwdriver, etc. I'm worried I'm actually making it worse. (see picture). At the same time, I can't seem to lock up the flange (e.g. put some bolts in and jam something there, etc.), so when I put a lot of torque on it with a breaker bar, it wants to turn the engine. Is there a trick to this?

I'm wondering if there's any possibility of putting a breaker bar in place and then using the engine to undo it (This is how the crankshaft bolt is sometimes handled on the 22re) Is this a terrible idea?

(Is an impact wrench required for this? I don't really have access to one)

@dropzone Yes, I realize it could have been much much worse. As is, the buckling and sounds felt like the truck had literally broken in half.

@wyoming9 When I removed the 4 bolts on the diff side, they were of 2 different kinds, some shorter some longer. I presume they should all be the same? I'm thinking somebody might have thrown random 14mm bolts on there.

RJR

The drive shaft u-joint phasing is a different issue than the flange match-marks. It simply means the two sets of u-joints on opposite ends of the shaft have to be in phase. THis is set by how the shaft is assembled where the two ends slide together. This is very important (google u-joint phasing for a picture of how it should be), but has nothing to do with how the shaft bolts to either the tcase flange or the diff flange.

To lock up the tcase shaft, put the transmission in first gear and the tcase in low range. That should allow your engine to hold it from turning. I had to do that to get my front flange nut off the other night. Took a 3 foot pipe on the breaker bar to break it loose.

I'm not sure what direction the shaft turns when the engine is turning, so I don't know if engine (actually starter) power would tighten or loosen it. I'd want to think long and hard before I tried that.

millball

Yes, the joints have to be in phase but this pertains to how the splined pieces of the shaft fit together.

Doesn't have anything to do with bolting the shaft up to the flanges.

Best way to get that nut off would be to use an impact wrench.

To address what RJR said about the pressed in bolts on the transfer flange:: While the pressed in bolts are found on some later models, all the first gen 4Runners I have ever seen do not have that setup.

The bolts found on the transfer output flanges are identical to the bolts found on the differential flanges.

artemyk

Alright -- 4-lo + 1st + some under-the-car acrobats did the trick! (silly me, I was trying to do in 4-hi)

Thanks for the clarifications regarding u-joint phasing.

wyoming9

iTrader: (1)

Yes all the older trucks and 4Runners did not have the pressed in bolts

You need to get the drive shaft and flanges out of a 22RE vehicle the 3.0 and 22RTEC have different flanges which can cause interesting things

artemyk

I was going to take the drive shaft to a shop today.... however, they said it could be an hour of labor just to check it out, so I inspected it myself and realized there is a dent in the shaft (pix). Is it worth paying to have it checked out / possibly balanced --- or should I just assume this DS is hosed and get a new one?

Also, does anyone have experience w. the Dorman 936-765 rear drive shaft? Does it come from the factory pre-balanced?

millball

Your old shaft is probably toast. Not worth the hours labor for them just to check it.

Any brand new shaft should already be balanced and ready to go.

artemyk

Ugggg, replaced the pinion and t-case seals (with RTV), replaced the gear oil, and put in a new rear drive shaft. However, I noticed that the pinion seemed to have some play, side to side and back and forth. Now it's possible (just drove it once) the pinion seal might be leaking and I think there might be a 'tumbling' sound when I let my foot off the gas.
Is the rear differential toast?
Is it difficult to replace?
Is it dangerous to drive with a bad rear diff? (was planning on taking a weekend road trip w. this car)

Thanks as always

millball

How tight did you retighten the pinion flange?? Did the play exist before you took it apart to replace the seal?

artemyk

I tightened to 90 ft/lbs. I didn't test extensively, but the pinion did seem to have some play before I removed the seal.