Differential

[russmedina]

Should I use synthetic gear oil in my differential ? I can only find 75-90wt gear oil is this ok to use. The dealership said that I will not need a gasket. That I should use red silicone. How much oil is needed? Thanks for your help.

[1UZ-FE]

i believe it is also a LSD so i think theres a limited slip additive to add too.

[jzz30]

the LS doesnt have LSD right? or did it start from 92? well mine doesnt.

i cant tell you off hand which oil to use but i can tell you how much to add. you have added enough once the oil starts to dribble out of the hole you are adding it in.

[99lsguy]

Should I use synthetic gear oil in my differential ? I can only find 75-90wt gear oil is this ok to use. The dealership said that I will not need a gasket. That I should use red silicone. How much oil is needed? Thanks for your help.

my 99 is 1.43 quart capacity.......

by two quarts and your good to go - stop adding when it runs out the fill hole.

[thels400guy]

russ, I did this yesterday on my 93. I needed a 10mm hexbit for the drain and fill plugs. I plan on switching to M1, Amsoil or Redline after I do more research but for now I just purchased some WalMart Supertech and plan of doing several drain fills.

When draining the fluid yesterday it was a very dark color, not brown but a very dark amber. Bits of metal came out also. So thats why I will do another or several drain fills to check and clean out any more metal particles. There was also some thick oily, grey sludge material on the end of the drain plug.

Its just my opinion but it might be a waste of time to fill with synthetic if there are bits of metal floating around the differential that can be cleaned out with a few drain fills and maybe an AutoRX application.

[92Lex]

how do i go about doing a drain and fill on the differential? can anyone walk me through it?

[99lsguy]

russ, I did this yesterday on my 93. I needed a 10mm hexbit for the drain and fill plugs. I plan on switching to M1, Amsoil or Redline after I do more research but for now I just purchased some WalMart Supertech and plan of doing several drain fills.

When draining the fluid yesterday it was a very dark color, not brown but a very dark amber. Bits of metal came out also. So thats why I will do another or several drain fills to check and clean out any more metal particles. There was also some thick oily, grey sludge material on the end of the drain plug.

Its just my opinion but it might be a waste of time to fill with synthetic if there are bits of metal floating around the differential that can be cleaned out with a few drain fills and maybe an AutoRX application.

I think it's a good Idea to flush 2-3 times

[99lsguy]

how do i go about doing a drain and fill on the differential? can anyone walk me through it?

Here ya go 92 Lex:

DIFFERENTIAL FLUID CHANGE – LS 400

What you’ll need:

2 New washers for the Drain / Fill Plugs

2 quarts GL-5 Gear Lube, 80-90W for cooler climates, or 90W

Torque wrench (3/8”) and 10 mm hex socket

Gear Lube pump (preferred) or 3/8” clear plastic tubing

Oil pan and rags

SPECS: LS Differential Case holds 1.43 quarts of GL-5 gear lube. I used Castrol Synthetic 75-90W since winter was coming on in KC. Manual suggest 80-90W for temps below 0 degrees and straight 90W for temps above zero. I will re-drain this summer and use 80-90W Amsoil Synthetic Gear Oil.

A)

The Procedure is simple and straightforward – but can be a little messy.

The tricky part may be in finding a way to crawl under the LS when you don’t have a lift... I backed my rear wheels to the edge of our garage – just before the 1 ½ inch drop where the garage doors comes down. (The area where the door fits into and keeps water from entering your garage). This additional area gave me a little more room to maneuver.

Keep car level. Put in Park. Put ON EMERGENCY BRAKE. USE BLOCKS BEHIND TIRES!!!

Let car cool down for 1-2 hours if Hot. The exhaust pipes are in close proximity and the fluid could be too hot. Be Careful!!

B)

Put Drain Pan under Diff., and loosen THE TOP/FILL PLUG FIRST. You need to know you can fill it up, lest you drain it first and can’t loosen…..a bad situation!

Second, loosen Drain Plug and carefully remove.

THE LOWER DRAIN PLUG HAS A BUILT IN MAGNET – to catch metal shavings. Clean it off thoroughly.

Take top Fill Plug out and clean.

Once the Oil has come to a small drip, REPLACE LOWER DRAIN PLUG W/ NEW WASHER. I actually did not have the washers the first time I did this. The photos you see are from afterwards with NO WASHER! There have been no leaks, so perhaps new washers aren’t necessary time – but I will replace the washer for sure on the next drain.

TORQUE DRAIN PLUG TO 39 FT. LBS.

Now for the messy part…

Take the gear lube pump and screw it down over the first bottle. Hopefully, you can “pump” all the gear lube up and into the TOP FILL HOLE. Once done, repeat with the second bottle until the gear lube just gets to the top edge OR starts to flow out. If it does flow out of top, let it go until it stops, it will then be level with the top fill hole.

Specs say to fill to top edge or within 0.5mm of top!

This is why car needs to be LEVEL!!!

C)

I haven’t actually used this pump- but it has got to be better that the first time I changed the Gear lube. Because of the limited room under the car, I was unable to “tip the quart” of gear lube UP enough to fill the case. I used a 6 foot long piece of clear tubing, snaking it along the RR driveshaft and up over the RR tire. Then, I squeezed the lube in through the clear tube and into the diffy case. I had to make sure there were no “LOW SPOTS” along the tube line, and also make sure it was going in properly (up & down, up & down)!!!

Then, more fluid will spill because you’re behind the tire and can’t see….a dilemma for sure. That’s why the pump should be good to go!!

D)

Since I did all this without a lift, it was tight conditions to say the least. But the job is very do-able and vital. Not hard, just make sure the exhaust is cool enough that you don’t get burned.

WIPE UP EXCESS GEAR LUBE. CLEAN UP AND TAKE FOR TEST DRIVE.

YOUR LS WILL BE RUNNING BETTER THAN EVER!!!!

[thels400guy]

great instructions 99!

I backed my 93 up on some ramps so the diff was very accesible but on an incline :(

Getting the diferential plugs to move was another story. Both were extemely tight and it is an excellent idea to see if you can uncork the top lug before trying the bottom.

My 93 did not have crush washers.

[99lsguy]

Yea,,,,,,,

Those bolts are on pretty tight, add a 1" diameter iron bar over the socket wrench to get more leverage (of course, there's not much room to crank it , as it will hit the garage floor........

At least it might "break it free"....

[thels400guy]

92, just as an FYI, I purchased Supertech GL5 80W90, 1qt for less than $2 and also a 1 gallon container of the same for around $6.

I will change the fluid out again next weekend so even if its the cheap stuff its good enough as a drain fill before using a good synthetic.

The 10mm hexbit was $3.97 at Advanced Auto, so it should cost you less than $20 easy to do this.

[thels400guy]

Yea,,,,,,,

Those bolts are on pretty tight, add a 1" diameter iron bar over the socket wrench to get more leverage (of course, there's not much room to crank it , as it will hit the garage floor........

At least it might "break it free"....

I put my foot on the wrench and braced my hands against a part of the car. My made in China wrench didn't break and neither did my back!

I don't know the torque spec but I went with hand tight.

[92Lex]

thanks, all that info is real helpful. im gonna tackle it tomorrow...but where do i find the right washers for it? also, whats the best/recommended brand of gear oil for my car? i live in california so i should go with 90w right? thanks.

[92Lex]

oh, thanks for reminding me about the hex socket...i wasnt paying too much attention and thought you said 10mm socket.

[99lsguy]

92 lex,

yes on the socket........ a 3/8" drive 10 mm . I bought one @ sears, but you can get Stanley (I think) from Wal-mart cheaper. The washers will have to come from Lexus (or Toyota). Have Lexus get a part number & price, See if Toyota dealer has similar - they'll be less.

[92Lex]

so im going to need a hex socket, not a regular socket right? is it completely necessary to replace the old washers with new ones? cant i just reuse them? thanks for the patience.

[99lsguy]

so im going to need a hex socket, not a regular socket right? is it completely necessary to replace the old washers with new ones? cant i just reuse them? thanks for the patience.

you will need the hex socket for sure.

I didn't replace the washers though. Actually forgot to get new ones the first time, so I was stuck with using the old ones - no problems.

Hey, if it did leak, it would be very little so I would have eventually gone to get some and reflush/replace again. But I check under the diffy several times for a month or so and there was no leaks. Dry as can be..........so you should be ok without new washers.

[92Lex]

thanks for the info...i was able to finish the job in about 30 mins. the bolts wasnt all too bad to remove..i sprayed a little wd40 to get it loose.

clearance wasnt all too bad either...at first glance i thought "how the f@$! am i supposed to fit under there?". im probally going to drain it everytime i change my motor oil. thanks, real helpful.

[99lsguy]

thanks for the info...i was able to finish the job in about 30 mins. the bolts wasnt all too bad to remove..i sprayed a little wd40 to get it loose.

clearance wasnt all too bad either...at first glance i thought "how the f@$! am i supposed to fit under there?". im probally going to drain it everytime i change my motor oil. thanks, real helpful.

Well done!!! Not a bad idea to flush it out with clean stuff for a few times....

I've got Castrol 75-90 synthetic; - filled in Oct /03. I've got two quarts of Amsoil 80-90 W syn sitting in the garage, So I'll drain and refill this October again.

I think it a good idea to get fresh gear lube once a year!

[LinuxFan]

Very interesting.

But what does the manul suggests for this? I will check when I get next to my manual -- but for now, is anyone aware?

Did I miss the part where this does not affect the 91LS and as such removes the need to do it?

I am on a roll this month -- so if it is needed I will do it. Just did the Oil, the pwr steering, the tranny. So if the diffy needs to be done, then what the heck -- right? Then I can just do them at oil change since I have found it to be so easy now.

[silvermate]

great tutorial Agent ;)

very thorough

you out to have management put that in the workshop.

[Smokey]

I know this is an old post but i need to do some work on my 98 ls400 before winter comes and the diff is included.

so there is no LSD additive correct? if so I will just use some sythentic gl5 gear lube. I tried talking to the lexus service dept and a) no one knew or B) they kept telling me to talk to so n so. after about 5 people i decided to jump online.

[30585]

instead of buying the hex socket i hav used the actual ratchet head, if u have one bit enough, i cant remember if it was a3/8's or a 1/2 inch, but it work and you can save yourself some money.

[98 LS]

What timing ........ ?

I'm just getting around to doing this particular maintenance and this thread has been very helpful in getting prepared .............. lots of good info ......... great job guys ...... it helps to know there are folks out there with the exact same questions and such ......... and answers too.

Long live the LEX

[99lsguy]

What timing ........ ?

I'm just getting around to doing this particular maintenance and this thread has been very helpful in getting prepared .............. lots of good info ......... great job guys ...... it helps to know there are folks out there with the exact same questions and such ......... and answers too.

Long live the LEX   

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Good luck 98LS............