So hey guys, I haven't been on this site in at least 5 years, last time I was I had the fj40, a wife, two dogs and a dead end job hahaha, my things have changed. I guess that goes to show how dependable these toyota's are. Anyways, I've had just minor issues that have been straight forward and easy to fix, but today I think I ran into a doozy and just need some experienced answers since I don't have a proper workspace and have to get this thing fixed right the first time.
First, the set-up

1985 toy sr5 ex cab pick-up
4 cyl FI
200,600 miles
solid front and rear axles

The front and rear axles have 4.88s (rear has LSD) in them and have been working flawlessly since I got them 5 years ago. Today as I was driving, I started to get thunking out of the back end, as if my tire was rubbing cause it was intermittent BUT constant (I believe the catalyst was a sharp fast turn I took at speed because the thunking started right after, but its the type of turn I've done 1000 times before)....I checked u-joints (solid), checked for anything out of the ordinary and came up with nothing. So I deduced it's coming from the rear axle. I pulled the rear drive shaft and have been driving in front wheel to limp around. When I was driving with the rear shaft IN, when I coasted I only got some rattling...but when I was on the throttle, it became definetly more violent and louder clanking. Now that the rear shaft has been removed and I'm driving in FWD, there is some minor rattling coming from the rear.
I'm guessing some part of my pinion or third has sheared some teeth and thats the noise? Would pulling the rear cover be of any service, or should I just pull the shafts and take out the third itself? Also is that year the 8" or 7.5" rear?
I am working on tracking down a 4.88 rear (man they are hard to find) but I have to get this thing sorted ASAP as I depend on my rig for work, and I have installed a third member before (although I had a garage at the time) so the work doesnt bother me, I just want to make sure I'm on the right track, I have to have the job started and finished in one go (can't leave it opened up overnight)
Thanx!!!
Joe

1. You have to pull the third to check it, there is no cover to remove.

2. It is an 8".

3. "can't leave it opened up overnight" Why, it is not going to hurt anything. I once drove from the Hammers to Roseville without a third in my front housing.

Factory 4:88's are out there but you really do not want them IMHO, they take OEM gears only and are pricey.

If you get the third pulled and cannot find any broken gears or bad bearings in the third, check the axle bearings, when they go out they can make some strange noises.

Ditto on OOPS
- But added question... Can the rear diff be pulled and driven? Wouldnt the axel shafts bang around since diff isnt in there - front I can see as hubs bear the weight vs 4 bolts???
** 4.88's are hard to find and $$$ - may wanna look at just the gears (Yukon etc)
OR if really needing the rig - could swap front to rear...

I stripped the entire ring on mine and it banged and clanked like a drive shaft u-joint... Could drain the fluid and see if teeth fall out or metal particles....

[quote] - But added question... Can the rear diff be pulled and driven? [quote]

No, because it is not a full floater.

http://www.sky-manufacturing.com/new/detaproduct.php?id=217

Sky Mfg is offering dropin open thirds for $499. If you call and ask for Sky personally, he also has some brand new 4.88 thirds (housing, bearings, everything) for $550.

Thanx so much for the advice so far. Here is a quick update.
Today I began the process of pulling the rear axle apart. My plan was to get it apart, take a look at the axle shafts and third, see where the problem was and go from there. Problem is I only had part of the day to do so, and I was having a HELL of a time getting the drums off, so after pounding on them for an hour, I decided I have to put it back togethor and wait for another day. (I have to work). I did drain the fluid and there was a real nice shimmery hue to the oil and metal shavings on the magnetic plug....so thats great. I re-attached the rear driveshaft with the rear tires in the air to see if i could get a pattern out of the clunking, and there is a definite pattern ...something like clunk clunk....clunk.........clunk clunk...clunk. So anyways I pulled the rear DS again and will limp around in FWD for the next few days (I figure the damage is already done in the rear, can it really get much worse?) and hopefully one day next week I can get a day off and put the 4.10 third I have as a spare in.
I heard somewhere, and maybe I am wrong, that the front and rear thirds are interchangeable? If this is the case would it be better to have the 4.88 in the rear or the 4.10 in the rear? Ideally im going to find another 4.88, but for short term I just need to get the thing driving normally in 2WD as soon as possible.

Yes, the front and rear are identical, you have a good idea there w/ temporarily switching them so you can get around in 2wd.

you said you have an LSD in the rear also? which type, Tru Trac?
It's also possible something has let go on that unit.
Also those LSDs have some value so I wouldn't be quick to give up on hat you have.

You don't need to pull the drums off to remove the axles. Just remove the brake line into the wheel cylinder, parking brake pins, 4 nuts that attach the axle to the housing.
Slide axles out, drop diff. You can swap front to rear. It is a lot of work though, getting the front diff out.

[email]DANG@!![/email] I guess I did it the hard way the first time then. I will do it that way next day off I get. If it's that "easy" I'll prob just put in the spare 4.10 i have laying around. Man that made my day, I don't think those drum casings will ever budge.

Not sure what kind... when I have it out, how can I identify what kind it is, other then something obvious like it written on it in bold letters.

Oh I have another question...what is more likely, sheering teeth off my pinion or gears, or shearing teeth off the axle stems?