Differential Fluid

[TexLexus]

Lexus Dealer says the Differential Fluid is to be changed every 15K miles along with the Tranny fluid too.

Just did a semi 90K service, they wanted 1100 bucks, I chose for them to do the hard work, Plugs and Tranny Flush along with an oil change for my free car washes. Total price of 350. I'll be doing the PCV, Air filter but the Differential fluid I may not be able to do myself.

The manual says to "inspect" according to schedule B.

Also, anyone in Texas getting bad gas? my car sputters every now and then when at idle. It may be the old PCV not helping.

They mentioned on their "inspection report on the invoice that the engine mounts and tranny mounts were "collapsed" Anyone experienced this? My car has 94K miles.

Tex

[nc211]

Tex, the differential fluid is easy if you have a couple key parts. I did mine about 5k miles ago. There are TWO alanwrench bolts on the passenger side of the differential. One on top "fill", and one on bottom "drain". You'll need a device to "inject" the new fluid into the differential with. I got something that is a cross between a caulking gun with a 12 inch rubber hose. It's used to drain oil from lawmowers and such. You can get one at any auto store. You need a drain bucket too, and that's it. It's super simple. JUST MAKE SURE you have loosened the TOP bolt FIRST! You don't want to drain the fluid and realize that you can't get the fill bolt off.

Drain the fluid, put the drain plug back in, and use the injector tool to fill it back up. I think it's like 2.3 quarts. Took me literally 20 minutes of rolling around under the car. Transmission fluid is even easier. Just undo the drain plug, let it drain it's 2 quarts, put plug back in, get narrow funnel and put in 2 new quarts through the hole in the engine. 20 minutes..tops. Do a search under my name, you should see a thread about this somewhere that has a tutorial in it.

PCV valve is a 2 minute job. Just pop out the old, put in the new. It's right there on top of the engine, by the 'Toyota V8 32 Valve" labeling on the cam cover..driver's side.

edit: here's the link to the thread: http://us.lexusownersclub.com/forums/index...topic=23033&hl=

Bad mounts.... probably true. Tranny mount is simple too. Motor mounts can be a bit of a chore as it's hard to get to the driver's side. but once they're replaced, you'll instantly notice a much smooother car.

[LexusLooker]

Hi Tex,

Yeah, 15K for the diff sounds too quick. Like you said, the manual says to inspect every 30K unless you're in the "tough conditions" category, then you actually do change it at 30K. But not 15K. What dealer?

I bought the funny pump and the fluid for the diff change, then realized that I didn't have the right hex socket for it, and THEN realized that the synthetic fluid I bought was probably too thin (a thread on somewhere here stated that synthetic fluid in the recommended 80-90W range was actually thinner than regular 80-90 fluid and would make the diff noisy...so either go 80-90W traditional or higher synthetic). So for this change, I just let the pros do it. I'll do it myself next time. It seems easy enough if you can get up in there.

Tranny fluid is a snap as nc211 stated. As someone else (Blake?) said, it's easier than changing the oil. Just be sure to use the right fluid.

Intersting that you asked about bad gas. I filled up in Dallas last Saturday and the car hasn't run very well since. Kind of coarse at idle. I filled up this morning at a different place, so I'll see how it drives.

[91ls400]

I have the problem that when I hit the gas quick to get around someone....already going 60mph... the back end shakes a little bit and the engine hesitates for about 3 seconds, the engine doesnt speed up or anything and then all of the sudden it just goes like there wasnt any problem. Could this be the diff causing me probelms....its not an issue all the time, just annoying at times. Also do you have to jack up the car to change the diff oil?

**The problem is with the 1991 LS**

[prix]

dont' quote me, but someone told me recently that engine mounts were not a huge repair .. a few hundred i think he said. if that's what it is..

Lexus Dealer says the Differential Fluid is to be changed every 15K miles along with the Tranny fluid too.

Just did a semi 90K service, they wanted 1100 bucks, I chose for them to do the hard work, Plugs and Tranny Flush along with an oil change for my free car washes. Total price of 350. I'll be doing the PCV, Air filter but the Differential fluid I may not be able to do myself.

The manual says to "inspect" according to schedule B.

Also, anyone in Texas getting bad gas? my car sputters every now and then when at idle. It may be the old PCV not helping.

They mentioned on their "inspection report on the invoice that the engine mounts and tranny mounts were "collapsed" Anyone experienced this? My car has 94K miles.

Tex

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[nc211]

On which one? 91 or the 99? "you lucky dog!"

I have the problem that when I hit the gas quick to get around someone....already going 60mph... the back end shakes a little bit and the engine hesitates for about 3 seconds, the engine doesnt speed up or anything and then all of the sudden it just goes like there wasnt any problem.  Could this be the diff causing me probelms....its not an issue all the time, just annoying at times.  Also do you have to jack up the car to change the diff oil?

←

[nc211]

Prix...I will quote you on that....because you're right. ;)

It's not that bad to change those two mounts. I HIGHLY recommend buying them online and taking them to a mechanic. My first indi mechanic at the exxon station installed mine for $120. Driver's side nearly broke his left hand.

[91ls400]

Im still not used to having both cars around....the problem is with the 91

[TexLexus]

nc211,

Looks like a job that's easier to do. Smart about the upper plug getting it out first, very smart. Great advice!

LexusLooker,

I have been putting gas at QT QuickTrip in 121 at Lewisville, they claim their gas is "Guaranteed" for what that's worth. I noticed that if I fill up at Costco the sputter is gone. It would't surprise me that some gas stations mixed their fuel a bit to get some winnings at the end of Katrina and Rita.

I service the cars at Park Place Lexus in Grapevine. Nice folks out there, plus it's 5 minutes from work, so I really take advantage at least 3 times a week of the free ole' car wash, or so they claim.

Tex

[lexluxury]

my motor mounts were changed WAY before 94K.

Lexus Dealer says the Differential Fluid is to be changed every 15K miles along with the Tranny fluid too.

Just did a semi 90K service, they wanted 1100 bucks, I chose for them to do the hard work, Plugs and Tranny Flush along with an oil change for my free car washes. Total price of 350. I'll be doing the PCV, Air filter but the Differential fluid I may not be able to do myself.

The manual says to "inspect" according to schedule B.

Also, anyone in Texas getting bad gas? my car sputters every now and then when at idle. It may be the old PCV not helping.

They mentioned on their "inspection report on the invoice that the engine mounts and tranny mounts were "collapsed" Anyone experienced this? My car has 94K miles.

Tex

←

[LexusLooker]

Thanks for the reply, Tex. I had that one bad tank, but all seems OK now. I may give PP Lexus a try for the big stuff that I can't do - it's 5 minutes from my work too. I'm kind of partial to Sewell, but my coworkers swear by Park Place. I may see you in line at the car wash!

James

[lexus400]

I changed mine for the first time at 125k and it looked brand new. I wouldn't bother at less than a 100k. It's just a bunch of gears and when is the last time you heard of a rear diff going ? ALL other fluids in the car I go overboard with.

Bob

[Mike Hobbs]

I'm well passed the point when the maintenance book recommends that my '98 LS400's differential oil be changed and since I don't know whether the dealer actually did change it at 90K (yes, I don't trust them), I thought I'd do it myself (non-limited slip model). Then my search for the required GL-5 90w began. Our cars share that requirement with several other makes. I contacted Lexus of North America to see whether there was an approved substitute. They said "no". That left me with the successor product from Lubrication Engineers, LE 1605. Searching more, however, I found that Miller's in England still makes 90w GL-5. It is carried by an Amazon merchant.

The price is about 1/2 of that of the LE product.

[Exhaustgases]

Just like you would use multi vis stuff in the engine, it will also work just fine using 80W-90 in the differential as long as its GL5, that ensures it has the EP lube for hypoid gear sets.

[billydpowell]

Just like you would use multi vis stuff in the engine, it will also work just fine using 80W-90 in the differential as long as its GL5, that ensures it has the EP lube for hypoid gear sets.

listen to Bob, he is right on ....

[Mike Hobbs]

Just like you would use multi vis stuff in the engine, it will also work just fine using 80W-90 in the differential as long as its GL5, that ensures it has the EP lube for hypoid gear sets.

Thanks, you're probably right. But I decided to go with the product I mentioned for 2 reasons:

1) Lexus said that there are no "approved" substitutes for my car.

2) When I checked the Mobil web site for their hypoid gear oil, I also noted their instructions for changing the oil. They flatly stated that, if your car requires GL-5 90w, that's what you should use, nothing else.

https://mobiloil.com/en/article/car-maintenance/car-maintenance-archive/six-steps-to-changing-rear-differential-fluid

[Exhaustgases]

It would be nice to know what the dealer uses. And also all the independents around the country. Since it seems no one has SAE 90 on the shelf anymore then I would bet many are not using it. Besides it could be substituted and you would not know the difference unless you had some lab equipment to check it.

If your a multimillion dollar outfit, and you said anything other than use what the manufacture says to use, then you open yourself up to big problems. If inventors and aftermarket manufactures just did what the manufacture suggested there would be no alternative auto parts manufacturing and aftermarket. Yes its best to do what the manufacture says, but then when they make something like 80W-90 or 75W-90 as the only oil on the self whats that tell you? When it is the only choice what can you do? And why would they make that oil so prevalent if they don't recommend using it? It is obvious by the statement to use the straight 90 weight that they know some cars and trucks need that, then why is it so hard to come by? The logic just doesn't add up. They obviously meant the multi grade to substitute for the straight grade. And besides the only thing the lower gradient will do that isn't good is leak easier at low temps, if there is a place to leak. The lube quality will be the same as the 90 weight if we are to believe what the additives do for viscosity at higher temps, because at the starting out temps the lube quality will be as same as straight 90 would be when its warmed up, and when warmed up supposedly the viscosity is exactly at what straight 90 would be at that operating temp.

So that makes the multi grade the exact same as straight 90, only not so thick when cold. It will lube exactly the same as 90 but flow better in real cool conditions and that is better for the roller bearings. So that is likely the main reason for them substituting multi grade gear oil for differentials.

[Mike Hobbs]

[billydpowell]

SO? if you dont want any advice, and you are going to do what you want to do, why all the posting?

just curious?? we went thru this 10 years ago

[Mike Hobbs]

SO? if you dont want any advice, and you are going to do what you want to do, why all the posting?

just curious?? we went thru this 10 years ago

The reason I posted my comments was to let others know that differential oil meeting the exact specifications indicated for our cars was still available. It took an email from Lexus of North America to motivate me to continue the search. I though I might be able to help someone else who was also experiencing difficulty obtaining it.

[Exhaustgases]

http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3903933#Post3903933

So I posted this question. I agree about the multi vis engine oil deal. If you want to used straight 90 in the diff then you also need to use straight 30 in your engine. You need to look through this linked site. And you really need to try to learn what multi viscosity oil is all about. I agree there are cases where straight viscosity is needed, that is old radial aircraft engines, and 2 cycle Detroit diesel engines. And some large industrial engines too. A Lexus rear end does not need it. What do they spec now for lexus cars?

The gears are made the same as the older models, nothing is going to change with gears and materials.

If the newer higher loaded gear sets can use multi viscosity so can the older one. Just call the oil company and ask an engineer.

And look here for what Amsoil specs.

http://www.amsoil.com/mygarage/vehiclelookuppage.aspx?url2=1999+LEXUS+LS400+B