For the longest while there's been "kachunk" coming from the rearend of my '86 4rnr...4cyl. (I even started a thread about it, then.) Couldn't trace it down, and for a short period recently it stopped altogether. Well, today after hauling 'bout 800lbs of animal food the issue finally revealed itself.

I began hearing a intermittent rotating, metal scraping sound a couple days ago and thought it must be some small rocks having made it's way passed the rust holes in the rear backing plates. (Wrong!) The sound got a lot worse on my way home tonight, and I felt a distinct vibration/rumble in the drivetrain like something was about to give way....and just a mile from my house. Nothing was visibly apparent, so I crossed my fingers 'til I got home to jack it up. I've yet to pull it apart to puke at what damage there may be, but the spline shaft mated to the flange on the t-case is all crunchy where it slips into the driveline. I know it ain't good, and I know I'm not going to drive it as is. I'll go out in a minute to view what's going on, but I wanted to post for input right away as I already have an idea for a solution and hope it works 'cause I have to get to work tomorrow.

Please say it'll work!...
I have a '92 4rnr (well, my wife does) that's up on stands at the moment, so I figured I'd borrow the driveline from it until I could get mine repaired. However, it's about 1in longer. Enggh! What I'm wondering (and sincerely hoping) is that the spline shaft will just slide in bit further to the slip joint and still work getting me where I need to go without hurting anything. But, since I've never had my driveline apart and don't know much about it, I figured I'd better ask someone who actually knew. In the event it doesn't work, I do have options, but it's kinda tricky. That vehicle has developed a running issue in the past week that I've been unable to address. It might make it....it might not. So, I hope I can get the 4rnr going.

 

I'd do it. I ran one that was an inch too short for awhile once, 'till I found the right one for my truck.

As long as it's got like an inch or two to further compress when you get it on there it should work.

Same engine? I ask because they'll probably have different bolt patterns if not. Which'll mean having to swap the companion flanges too. Kind of a hassle, but doable none-the-less.

 

Okay, thanks for the reply, Mudhippy.

I just got in from taking the driveline down and everything appears to be just fine with the driveshaft and slip joint. The problem APPEARS to be in the transfer case output shaft....and I suppose just "traveling" or "reverberating" into the driveshaft. It's had play in it for a while (you and I have discussed this before) but I hadn't gotten around to tightening it with my oh so busy life. I figured it could wait. That may have been a mistake. I hope to hell the t-case isn't y'ucked up and that's where that nastly metal scraping sound is coming from. I can't duplicate the noise by hand, so it's hard to tell. All I can say is there is a lot of slack, gear oil came dripping out (once the driveline came loose at the flange, but then stopped), and when I crank the flange back and forth by hand it kinda feels chunky...like gear teeth when they're slipping.

So, what do you think? Is it screwed or would retightening the nut help at all? I know...over the net it's hard to say, but I though I'd ask anyway.

Speaking of the nut/retainer..
How would that thing come loose and need retightening? The shaft it screws on to has a groove in it and the nut is staked to it. Is it even that it comes loose or that play just develops from the internals wearing and then retightening remedies that....or does it?

The '86 is a 4cyl and the '92 is a V6....btw.

 

So, I'm going to retighten the nut and see if that works at all. What's the best way to unstake that nut and restake it? What tools, method...you know?

 

From what you've described, it sounds like you may have a bad U-Joint.

 

I'll check that in the morning. Thanks!

 

thook, i use a small flat screw driver that i ground the tip really flat, then use a slightly bigger one to push it the rest of the way up. i just rebuilt my t-case a couple of weeks ago with a few tools from H\F. i had the same problem as you are describing, but my bearing was way beyond trash. i had to make, out of angle iron and two bolts, a lever to hold the flange. there is a video over on pirate in the truck/4runner forum that covers the rebuild, kinda, it's for the 4:71
gear install........and marlin has a pretty good how to with pics you can print out. if you were closer i would come help ya rebuild it. are you going to Rocktoberfest in Cass?

 

Cass? As in Cass, AR? I didn't know about a Rocktoberfest. I'd have to say "no" to that, though. I'm in the middle of reroofing the house and, when that's done, reinsulating. Needless to say, I'm in a time crunch with Mother Nature and I'm not getting around much until it's done. Who's going to be there? Are you going?

Thanks for the offer. I'd take you up on that, too. But, I don't quite know anything definitive, yet. I just woke up and am retrieving whatever portions of myself that didn't get completely destroyed when that truck ran over me last night. Ugh...I feel like hell. Two nights in a row with less than four hours of sleep. And two cigars in one day didn't help, either. Ah well, coffee shall clear the fog. Then, I shall commence tackling my driveline. I'll post my findings when I get to work later.

 

Okay guys....I'm down to the wire. I gotta go to work in less than two hours. Pretty please...

It's a seized u-joint at the t-case end. Don't know how I overlooked it, but...

So, can I take the yoke/spline shaft from the '92 and mate it to the '86 driveshaft? Will the splines mate? Otherwise, it's the complete driveline swap....provided the flanges will mate, of course...which I'm going to check on now.

Back to check for replies shortly...

Thank you

BTW, the "crunchy" noise I was hearing...it was just the lube in the slip joint being all sticky and making that sticky noise when I applied pressure back and forth against the mated assembly checking for play.

 

Hey, sorry I didn't get your message.. I guess I logged off right before you sent it. Your truck's a 5 speed, right? If so you have a gear driven t-case and there should be very little play. An impact is extremely helpful in changing out that flange. It really does sound like a t-case problem. However, look over your driveshaft well (u-joints, etc), jack up the rear tires and spin the differential to see if there is any noise there. You may be better off finding a spare t-case and swapping it out.. I bought a spare t-case and tranny for $100 yesterday. Keep us posted on anything else you find.

 

T'anks, guy...I'm right here...waiting...ideas?

 

Another thing I thought of.. When you're driving does it make the same sound in all gears? My trans has been whining/grinding for several months (hence why I bought the spare) and it's loud as crap in every gear except 4th.. Quiet as a mouse in there. So, if it's only making noise in certain gears that narrows it down to the trans.

Also, dare I ask that you've checked to make sure all the fluids are full?

 

Oh, I missed your post about the u-joint. I don't know if that other shaft will mate up. You're probably just going to have to try it.

 

It's the u-joint, mate. (Funny how all that noise reverberates. Had me looking at everything else but that.)

Got any input on the spline shaft/driveline ass'y swap? I just hate to waste my time tearing the '92 apart to find it won't work.

 

Gotcha. Okay, I'm outta here to find out. Thanks anyway. I'll post what happens later.

 

Just drop the rear driveshaft entirely, lock the hubs, and cruise around in 4WD. It's squirrely but it works fine. I drove around town for several weeks like that cause I couldn't find time to fix a ujoint.

 

Whatever you do, Don't put a driveshaft in your truck if it is too long. when the springs compress, the slipyoke shortens the shaft compensating for the difference in length between full drop and fully compressed, it moves more than you think. If the shaft is too long there is no room for the yoke to slide and it will jam against the output shaft of the tc. I had a friend who figured he had plenty of room after he swapped trannys in his truck, and it worked ok until he loaded the truck and trailer for a job in NJ. and headed over the G.W. bridge. He made it to the crest of the bridge, hit an expansion joint, shoved the driveshaft too far into the tranny, and imideatly stopped. Not good on a friday at 4:00, he broke the race on the output shaft, and broke the case on the transmision, not a cheap tow, and lots of pissed off people .

 

Yeah, thanks. I'd thought of doing that, but didn't want to if I didn't have to. And probably good that I didn't...I've atleast one more u-joint going out on the front DS. I just discovered it once I got to work and got under the vehicle to check things out from the trip here.

Which means....yeehaw, I made it. The slip joint/yoke from the '92 worked perfectly. There was some faint whirring noise I could hear. Not sure if it was from the slack in the t-case output or what. I'm not worried about it, though. I figure it's not imbalance in the driveshaft from using the borrowed part since there's no associated vibration. Then again, I don't really flippin know. I thought the whole time my "kachunk" noise was coming from the rear end because that's where it actually sounded like it was coming from. I'll find out anything more this week. I'm doing a thorough drivetrain exam/repair this week. Unless it's needing t-case repair, for example. That's something that would take some time.


I follow what your saying. That was my concern from the beginning. But, I could see once I got under there and pulled the driveshaft down there wasn't going to be enough travel for it to work safely. So, if the splines wouldn't mate up allowing to just use the slip joint I was up caca creek.

I suppose I could have found all this out on my own, but hey...it's easier to type than it is to wrench.

Here's something I did discover on my own...
Since I've adjusted my timing (it was retarded 2deg's), I've had this odd thing happen at times. I'd be driving a long and slightly release the throttle from a cruising speed and it would feel like I just downshifted 1/2 a gear. Didn't happen a lot or everytime, but the frequency had increased in the past couple days. So, I thought I must have adjusted the timing wrong. Well, I didn't. I can see now what I was feeling was the u-joint seizing up creating a lot of resistance. Today I've not seen any sign of that. In fact, since I almost always coast to intersections and stops, this morning I could see I was going to have to start coasting sooner or start breaking sooner. She's rolls a lot easier. Gee...maybe I'll get another a mile or two per gallon out of her...

 

what is the latest?

 

Just remember that the slip yoke will compress down quite aways onto the splined shaft, all the way 'till the yoke hit's the shaft cover. I think it'll be fine they usaully have some room to move around an 1.5"-2.5" slack either way. I've had more experience with Toyota driveshafts than I care to have had. And I would have told you "most likely" on the splines matching up too, as it's been my experience. All parts are entirely interchangeable between all 2wd and 4wd driveshafts that I've seen. Different strength components per application.

If tightening the nut on the t-case don't work you'll need to replace the output shaft bearing.