Topic: Clunking/rattling x-case? Trans? drive shaft? rear end?

[SlayTank]

1985 Toyota Truck 5-speed 4x4 380k miles. While running over 10mph I'm getting a "Clunk.... Clunk-Clunk.... Clunk...Clunk-clunk" faster I go faster it clucks. clucks harder on accel and deccel. Can almost get it to go away while coasting. u-joints look tight. the diff does have some play for sure. spines mating the driveshaft are a little loose but not too bad. But here's the thing the sound doesn't seem like it matches anything particular. Example: 30 mph "clunk, (2 secs later) clunk-clunk"

HERE IS WHAT IT MIGHT BE i'm getting a wie bit of movement from the drive flange coming out of the x-case also I have one of those drive shaft mounted e-brakes like so: http://www.lowrangeoffroad.com/toyota-mini-truck-transfer-case-e-brake.html

I installed the e-brake like 2 years ago. I know this probably threw the shaft out of balance and (maybe I'm a dumb ass of it) but I was never very concerned about it. My truck is a do everything truck so I take it on the freeway on the regular.

SO! has my complacently on the driveshaft balance finally caught up with me and has worn the Bearing (or Bushing) that holds the drive flange true out? or do you guys think it might be something else? Also is that a bearing or bushing that holds the drive flange? is a little bit of wiggle in the drive flange ok?

Also of mention i've been getting a rattling noise at coasting to a stop since i bought the truck in 2012. It sounds like a bearing going bad so I rebuilt the front wheel bearings. haven't done the rears or u-joints yet. But like i said the U-joints seem nice and tight. Maybe this plague of rattling has been my drive flange bearing the whole time? is a rebuild in the works?

Sorry Also, my pinion angle is not the greatest after my Old Man Emu lift 2 years ago. I know i know shame on me. I just ordered some shims from 4crawler (he's the man) so maybe my pinion bearing has been starving for oil and is yelling at me now. Its not a crazy bad angle just not what it should be its like 5 degrees high.

Anyway any thoughts i would be grateful for thanks i'll keep it updated to help anyone else who might have this problem

[SlayTank [OP]]

It might be as simple as the nut holding the flange on. I'll let you guys know what happens after i tighten it

[jangelfire]

Stake the flange nut after you tighten it

[Snowtoy]

You might put the rear on some jack stands, and see if you can hear the clunk w/o the load of the vehicle.

Do you have vibrations with the clunk?  If you do, and you feel them in the seat, it is generally a drive line issue.

[jssgbsn]

Just to clarify is the 'Clunk....clunk, clunk....clunk' constant while driving?  Meaning, it just does it all the time (every 2sec's or so) regardless or RPM or speed??

Agree with 'Snowtoy', put the rear on stands and strart "driving" it.  Make sure to isolate, 2WD (assuming you don;t have 4WD) and see if sound is duplicated while the rear is on stands.  If so at least you know it willbe from trans back.

Not a driveline/diff expert, but if the u-joints are tight 'enough' and you get that noise on stands then I would guess it is somewhere between "trans/case/double cardon/shaft/u-joint/3rd/diff".  I can't imagine a bad rear wheel bearing causing a 'clunk'.

Good luck dude.  I have been dealing with my own 'mysterious' driveline noises recently 

[blackdiamond]

I had a massive rear bearing failure and it did result in a bit of a clunk though not cyclical at all. It actually sounded and felt like a rock hit the floorboard under my feet. I stopped several times looking for something in the driveline but it wasn't until I pulled in the garage that I noticed the extreme heat on the axle. It was raining so it masked it. The spaces between the balls had come loose so the balls were sort of just rattling around in the bearing. Total catastrophic failure.

[SlayTank [OP]]

So i found it. it was the diff. The sound was getting louder and it started to "clunk" the whole truck, just like a rock hitting the floor board. It degraded so bad i couldn't go faster then 5mph with out it sounding like the whole 3rd member was gonna explode... Got any recommendations on 3rd members? i'm going to re-gear to 4.88 awhile I'm in there. Thanks for all the input guys

[blackdiamond]

So i found it. it was the diff. The sound was getting louder and it started to "clunk" the whole truck, just like a rock hitting the floor board. It degraded so bad i couldn't go faster then 5mph with out it sounding like the whole 3rd member was gonna explode... Got any recommendations on 3rd members? i'm going to re-gear to 4.88 awhile I'm in there. Thanks for all the input guys

How did you confirm that it's the differential?

[SlayTank [OP]]

I put it on jack stands and ran it up to 40 mph on the speedo. I chalked the front wheels and crawled super carefully from the rear so if it fell off it wouldn't run me over. Narrowed the light clunking to the diff. I then went hunting in it, while I was climbing up the side of a gullie loud bang  with shake. a few more loud bangs and shakes as moving a few more yards. Stopped went rabbit hunting came back removed rear drive shaft. crawled out in front wheel drive... good thing I got that winch installed and wired... and good thing telephone poles were there.  :lowdown: got back to main dirt road and couldn't go over 5mph without loud bangs and shakes. had my buddys in the back and they said it felt and sounded like it was coming from the diff. left "Jimmny" (thats my trucks name) and in the morning came back and put it on a u-haul 2 wheel dolly towed it to my brothers to wait to be fixed.

[SlayTank [OP]]

Quick question didn't really find a solid answer yet, Can I just switch the front and rear diffs? and I just won't use 4 wheel till I get some money saved up? that way i can still drive the truck as normal. I'm a broke college student as of now so scraping the bottom of the barrel right now.

[Dingman.]

Yes you can swap front and rear diffs on your 85'.

As far as recommendations on 3rd members, i know the feeling of being low on funds due to being in school.  Check out your local pick and pull yards.  A lot of 3.0l v6 2nd gen runners came with 4.56 gears And the automatics that came with 31" tires had 4.88 gears factory.  The 4.56 diff will make some difference over your 4.10s.  If you go with the factory 4.88 diffs, you need to know they are special in the fact that you cannot regear those diffs later due to the housing being more offset i believe.  You might get lucky and find a couple 4runners with the same gear ratios. With that said, around here at the local junkyard i believe you could get each diff for like $80ish. If you can find two 4runners at the same time That is a pretty cost effective regear.

[SlayTank [OP]]

Thanks Dingman. Good looking out. I'll check the local yards

[Snowtoy]

....................A lot of 3.0l v6 2nd gen runners came with 4.56 gears And the automatics that came with 31" tires had 4.88 gears factory....................

Along w/2nd gen Runners, the 4.56 and 4.87gear sets were also available in the 3rd gen trucks.  Since a lot of people run bigger tires, just looking at the equipment wont likely help you that much in the wrecking yard, so you will need to check the door jam plate/sticker code.  Also, don't look for the tire size on the sticker either, the tire size was left the same, only the gear code was changed.  The gear code for the 4.56 gear set is G25(4 or 2), and the code for the 4.87's is G14(4 or 2). 


The "G" is for the 8" diff., the next two #'s are the gear size, the (4 or 2) is for the number of pinion gears, the 4cyls. have two, the V6 had 4.

[SlayTank [OP]]

Great Info Snow thanks!

[SlayTank [OP]]

Hey guys, I would have reserched this more but I have class till 10pm tonight and will be heading to a junk yard tomorrow moring. I need a diff. I found one. the 4runner has 291,000 miles. its a v6 with 4.88 gears. My diff blew the r&p gears at 380,000. so how should I go about telling the condition of this junk diff? I rocked the runner back and forth while in park today and it seems like it has a large amount of play with a little bit of clanking. I know all diffs have play but where do you draw the line between a good diff and a bad diff? or is there such a thing? any pointers will help as in 12-15 hours ill be pulling/buying this diff and dont want to pull it again in 10,000 miles.

THANKS GUYS!

[Tjcarter]

I'd take it to a mechanic and have him measure the backlash before installing the diff. It'll take them 10 minutes to do and is worth checking before you find that you need to shim it more or just leave it... just my 

[SlayTank [OP]]

Ya i took both the diffs i got up to ZUK in phoenix and he went through them. Real good dude check his website if anyone ever needs diff work. http://www.gearinstalls.com

[OVRAROK]

since the diff is coming from the junkyard, you cant test drive, so you can drain diff oil, bring a telescopic magnet and stir in old oil, also you have a visual, check wear pattern on gears, then just 

[SlayTank [OP]]

ya after having Zuk check them out they are good to go. I only need them to last 50,000 or so miles before I get enough cash to go in a do it the way i want for the last/long time with an ARB and 4.88s