Did you change it yourself or have the dealer do it? Was it easy if you did it?

 

 

Just had my rear diff and transfer case changed. The guy could not get to my front for some reason or the other. Said something about needing a certain tool. I dont know what he is talking about so i will try to do it myself this weekend. Transfer case oil looked good but the rear was pretty dirty. I have 20,000 miles.

 

seems like you must have been doing a lot of offroading, to this point, that your diff was so dirty? or ,,fill me in. guess i need to read the owner manual see what it says to change it at.

 

I was thinking along the same lines. Sounds like the rear diff. has problems but changing the oil definitely should buy it some time. Now you got me paranoid because mine is an early production number and I've read here that the ring and pinion weren't harden as later models are. The Royal Purple gear lube is doing me no good still sitting on the shelf. :bananahump-slvrathl

 

If you do any off-roading in mud or water especially if your FJ doesn't have the rear diff vent mod, you should change your diff fluid right away. The first time I changed mine the fluid was like chocolate milk. I changed it out and then did it again 3k miles later just to make sure all the dirt got out. The tranny(6MT) and transfer case was very clean and so was the front diff. As many rear diffs that are breaking on this forum I would do the first change at 5 or 6k even if you don't go off road.

 

so this royal purple is good stuff? how much does the dif take? talked me into it. looks like it has a drain so this would be an easy change to do..

 

From what I've read it's good stuff. 3 qrts. should do you. Bought it online for a good price Royal Purple "Max Gear" 75W90 Gear Oil (1 Quart)

 

what about the front diff?

 

owners manual does say every 15 thousand miles so it is time for me. just curious how hard to change front diff fluid myself.rear looks easy enough..surely there is a pdf on how to change front diff fluid..

 

I changed the diff and transfer case fluids at 3000 miles. The front diff and transfer case oil looked good but the rear diff oil was already dark black with lots of small shavings and some pretty big chunks of swarf (those bits of metal you get when you drill holes).

I have a later model FJ. I'd recommend changing the rear diff oil (at least) almost immediately to flush out the junk that a lot of people seem to find in there.

I refilled with Redline... there are a lot of "how to" threads and info on oils if you do a search.

 

...I replaced it with Valvoline 75-140 synthetic and hope it will help with any premature failure...

Thank you for the helpful reminder. The owner's manual (pg. 318) recommends 75W90 oil viscosity for front, center, and rear differentials.

 

is there a drain plug for the front diff to drain it and how hard is it to refill it, the rear looks easy enough.. I am planning either to take it in let them do it, but i would like to do this and save a little on it..

 

I changed mine at 1,600 km or 1,000 mi. Like others have commented, my rear axle fluid was jet black already. The drain plug magnet already had heavy fuzz buildup, no actual gear pieces though

The rear axle and transfer case are very easy. If you buy quart/litre bottles of gear oil, they already have a nipple you cut off and just refill. The front axle is a different matter

From the driver side, if you shine a flashlight at the front axle you can see the recessed hex head drain and fill plugs. It's easier if you take the rearmost factory skid plate off. If you have the Toyota aluminum optional front skidplate, you will need to remove that first, then the rear skidplate

I had one hell of a time getting my recessed hex head fill plug off. There really isn't a lot of room to work in so I managed to scrape my knuckles and ape arms a few times

I use Mobil Delvac Synthetic Gear Oil 75W-90, which is a heavy duty gear oil intended for severe operating conditions in road transport, logging, and mining operations. Got a 20 litre pail, on a per litre basis worked out to $6.50

Mobil Delvac Synthetic Gear Oil 75W-90, 80W-140

I have a pail pump, so refilling the axles is very easy for me. I can do the front axle, transfer case, and rear axle in 25 minutes

NOTE: when you do decide to change your gear oil, ALWAYS take the fill plug off first! If for any reason the fill plug is cross threaded or otherwise fubar'd, you sure don't want to find out after you've taken the drain plug out

 

I'm glad to see such an active bunch of guys. I changed mine myself as it is very easy. A 15/16 wrench or socket is all you need. Drain and fill to the level of the check bolt. I should have clarified that the problem lies in the rear diff. only. My front diff. and transfer case look like new still. The only hard part is squirting the oil into the hole. Some oils come with a pump dispenser, most come with a lid that has a tapered tip. Just turn it sideways and squeeze. Take what is left and put in the next bottle. In the end there will be some left over, but oh well...
As far as checking the front diff. goes, it should be the same as the rear. You have to remove the skid plate though.

 

Keep your left over stuff! After a hard, or real wet run, take a sample of it out, and look at it. You can add the 2 oz. that you pull out back...
I put a small hose in and use a hand pump to get it out.
I guess I should add, that I don't trust any shop in my area, so I try to do all my own work. And man, does that save me a chunk of change (my hands will never be the same though)...

 

good call! going to change mine asap.

 

My rear Diff. took 3.3 Qts. (Manual says 3.1)
Anybody have the same experience?
I'm Curious because of the attention that seems to be given to the exact fill amount in the manual and elsewhere.

 

My rear Diff. took 3.3 Qts.

Even a slight angle while parked can affect the fill level. I wouldn't worry about it, only being grossly overfilled could damage the axle seals.

 

I would think that if you filled it through the drain hole or at least left the drain plug out while you filled it through the fill hole, on a level surface, you'd not have to worry about overfilling. The full level should be at the bottom lip of the drain hole, so while filling once it starts to come out the drain hole, stop filling and plug everything up.

But yes, the overfilling is a consideration depending upon when you put the two plugs back in.

As stated previously, the sequence should be:

1. Top (fill) plug out-check threads and see if goes back in easily
2. Drain plug open-with container beneath.
3. With drain plug still out, fill case by fill hole or drain hole until fluid starts coming out of drain (level surface).
4. Both plugs back in and tight.

Comments on alternative methods certainly welcome.

 

1. Top (fill) plug out-check threads and see if goes back in easily
2. Drain plug open-with container beneath.
3. With drain plug still out, fill case by fill hole or drain hole until fluid starts coming out of drain (level surface).
4. Both plugs back in and tight.

You mean plug up drain hole, then fill up at fill hole until fluid starts coming out of the fill hole, then tighten up the fill hole, right?

 

Bad news, my diff. blew up today. Some hard wheeling, locked and all of a sudden CRUNCH!!!!!!!!!! I guess the fluid change didnt help. I towed it to the dealer and we'll see what they say. I wish the best for all you fellow FJ owners. There is never a good time to have a diff. blow, but i gotta say, i wish i could have had the dealer replace this before it happened. I hope they issue a recall so ya'll dont have to suffer my same fate...

 

Sorry to hear the bad news. Do you have an early production model? From what I have read here they say early production models did not have harden gears and are prone to break. My rig was built 04/06 and now I'm wondering whether or not that's considered early.

 

Bummer! I hope you get it taken cared of. Seem too common.

 

Does it matter if I drive more/less offroad? If I'm only doing street driving right now, should I assume that this issue is still as urgent?

-Ryan

 

I changed out the fluids fairly early and I did notice that the rear differential fluid was very dirty as described by many of you. My thought is that the gears in the rear diff are wearing prematurely, causing the oil to get so dirty with so little use. What's considered "late" production? I'd love to hear from an '08 owner after about 5k miles or so to see if the "later" production diffs produce the same condition gear oil as the '07's.

 

I am changing mine this weekend have a late model 08 I will let you know.

 

Do you need a special diff oil with a locker or just the normal stuff?

 

If your replacing the oil with regular gear oil, you can put the regular gear oil in
But if you replacing it with synthetic oil you have to make sure it has friction inhibitor's in it, this goes for all the axles because they are limited slip.
I used Royal Purple in all the axles ,trans and transfer case and was please with the results.
I gained 1.5 mpg after switching and that was 6 months ago and I still get 1.5 mpg more then before

 

But if you replacing it with synthetic oil you have to make sure it has friction inhibitor's in it, this goes for all the axles because they are limited slip.

The front axle is "open" in that a wheel in the air will spin, the wheel on the ground will remain motionless. Unless A-TRAC is active and the brake is used on the spinning wheel. There are no clutch plates in the front differential

The rear axle on FJ's is a true mechanical locker. When you push the diff lock button, an electric actuator moves a shift fork to pull/push a splined collar back and forth. There are no clutch plates involved. Please see the attached pdf

I use Mobil Delvac Synthetic Gear Oil 75W-90 in mine, as it is intended for heavy duty OTR and industrial applications. I know for a fact this product does *not* have LS additives, and should never be used in LS differentials. Otherwise the clutch plates will slip/chatter and eventually glaze

Conventional LS differentials have clutch plates that are lightly "preloaded" with bias springs. If you want more torque transfer, you need to put in stronger bias springs. Doing so tends to make the rear end chatter and hop going around tight corners

Howstuffworks "Clutch-type Limited Slip Differential"

Posi LSD - Eaton.com

A conventional mechanical locking rear end is usually engaged all the time. I put a PowerTrax LockRight in my 1984 Ford plow truck at my hobby farm. This rear end only disengages when in a tight turn, and it makes a "click click click" noise while doing so. Very simple to install, very reliable, but I sure wouldn't want to do a lot of city driving with such a unit

POWERTRAX® LOCK-RIGHT LOCKER BY RICHMOND

This fact tends to trip up a lot of GM owners. Their pickups and SUV's have the RPO G80 option code, which GM calls a "locking" differential. It actually has a centrifugal weight assembly to force the clutch packs together.

Eaton Locker

When they claim that no additives are required, they assume you're using the GM dealer synthetic 75W-90, which has the additive already blended in. Try to use a HD synthetic that does *not* have the additive, and it will slip and chatter like crazy. I know from experience, I used to have a 2000 GMC Sierra 4x4 and the first gear oil change, I used a HD gear oil

Most regular and consumer synthetic gear oils claim to already have the LS additive blended in. Especially conventional 80W-90 gear oils, they have the additive. The following is commonly used as a bulk service fill at garages

http://www.esso.ca/Canada-English/Files/Products_Lubes/IOCAENCVLESEsso_GO_LS80w90.pdf

Mobil claims their Mobil 1 gear oil has the additive

Mobil 1 Synthetic Gear Lube LS 75W-90

A gear lube with LS additives should never be used in a HD truck axle, such as the Eaton RoadRanger series with extended 750,000 mile warranty. They claim there will be tooth wear and spalling

 

I also let some fresh oil drain out before plugging the drain hole just to flush out any debris the normal drain may have left. Not a bad policy.

 

I just changed my 07 (purchased 01/07) at ~13,000 miles and the rear diff fluid did not look bad at all, normal wear color and particles but not bad. Hardly anything on the magnet. I do off road so I was expecting the worst.

I read somewhere on this forum that the rig and pinions on FJ's produced before something like 06/07 may have gears that were not properly heat treated by the manufacturer and Toyota knows about it. They are more brittle then spec'd and fail catastrophically.

DEWFPO

 

I read somewhere on this forum that the rig and pinions on FJ's produced before something like 06/07 may have gears that were not properly heat treated by the manufacturer and Toyota knows about it. They are more brittle then spec'd and fail catastrophically.

DEWFPO

The one thing about gear oil changes - and this applies to motors as well - if there is a hidden manufacturing defect, all the oil changes in the world will do very little to prevent the failure

Even if frequent gear oil changes buy you some time, what happens if they buy *just* enough time to get you out of warranty before the failure? If the person is unaware of the failure history, and the dealership is a real scumbag, the standard response is "TFB you're SOL"

I'm hoping that Toyota will do the same thing they did with their motors prone to sludge: dramatically extend the warranty on the rear axle

 

Any updates on your diff? Was it repaired under warranty?

 

The dealer is going to replace it under warranty. The new one is ordered and will get installed in the middle of the week. They are also replacing the e-locker. And they will check for other damage to the axle housing when it's apart. My only issue is that they don't know about the production date of the replacement part. That concerns me, but there's nothing I can do about it. I'll let you know when I get it back.

 

The dealer is going to replace it under warranty. <snip> My only issue is that they don't know about the production date of the replacement part.

It does appear to be a problem that Toyota is aware of. I'd be very surprised if they choose to ignore it in the future. Remember all those early 1990 Toyota 4Runner V6 that got free head gaskets? I had a 1990 4Runner and they put in new headgaskets in 1999 when it had over 300,000 km on it.

 

So someone PM please. What is the bottom line. I'm gonna change my rear diff fluid on Dec. 24. I have 2wd with locker. I'm gonna run synth oil. How much do I need. weigt, and I'm thinking of royal purple or Mobile one. Anything else I need to know. Thanks in advance. Cheers.

 

1911 had a good post about this here. Mobil 1 75w-90 would be what I'd use.