Yes, more gear oil talk..

Ok, ok, I know this topic as been beaten to death so I thought I'd post a quick summary of what I read for the past week with a few extra questions. I'm most concerned with the LSD on the Sport because that is what I have. I was going to get what the dealer put in but they only had it in a barrel not a quart. This led me to the long frustrating search on gear oil for the LSD.

***PLEASE correct me if I'm wrong here as I have only read many threads and have not preformed this oil change yet.

Tacomas 2005-2009 Off-Road
FRONT
-Any synthetic gear oil for front & t-case will work fine.
REAR (has locker)
-Any synthetic gear oil for rear locker will work fine.

Tacomas 2005-2008 Sports (2009 has electronic LSD):
FRONT
-Any synthetic gear oil for front & t-case will work fine.
REAR (Mechanical LSD)
-Mobil 1 synthetic

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90: problems with chattering. Some LSD ok with 2 bottles of LSD friction modifier.
-Redline synthetic 75W-90: Ok??
-Royal Purple synthetic 75W-90 - Ok at first, but will chatter eventually
-Blend of synthetic/conventional 80w-90- Ok??
-Any conventional (dino) 80W-90 - Haven't read any issues.

Questions:
1) For those that have had used conventional oil, did you have to add a friction modifier even if the gear oil said it was ok with conventional and limited slip differentials?
2) What is the best conventional oil for the LSD. I've read Castrol Hypoy C is pretty good.
3) If you did you an additive and have had success, which additive did you add?

Thanks for reading! I'd like to have all my gear oils soon since I'm at 35k

 

This is the same info that I gathered, and other forum members were taking there trucks into the stealership for the rear mech-LSD. I would get the rear LSD gear oil from the dealership just to be on the safe side.

What is everyone using for 2009 that have electronic-LSD? I know that its a lighter weight than previous years.

 

I have same the truck, run syn everywhere but LSD. Have used cheap off the shelf dino and also synblend 80w-90 that was for LSD applications. No modifier. NO problems with either.

 

I'm using Amsoil Severe Gear 75w90 in Diffs and transfer case.
No extra friction modifier need with the elec LSD.
No issues.

 

I use Castrol 80/90 Hypoy C / API spec GL-5 with a small bottle of friction additive from Carquest.
Been working just fine with zero chatter.

 

What was the reason for adding the friction additive to this gear oil? Dosen't the Castrol bottle say it can be used for limitied slip without any additional additives?

 

Sometimes you still have to add friction modifier.
Can't hurt to add a bottle anyway.

 

Exactly

 

Thanks for the replies!

Has anyone had success with RedLine synthetic

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 for the LSD? If so, did you use the additive too?

 

Ross,
I used Redline 75W90 in both diffs. for my 07 4X4 Sport.. No friction mod. needed as the Redline comes with it mixed in. I did not have any issues with rear end chattering. I put Redline MTS in my 6-Speed tranny as well. I did have a problem with 3rd gear not going in smoothly and the MTS fixed that. Overall very happy with Redline..

 

Gerry, how many miles have you put on since the diffs were changed with Redline?

 

Ross,
I have put on 460 miles since changing all fluids.. I have not had any chattering at all. Like I said earlier I am very pleased with the way the Redline MTS has smoothed out 3rd gear. I did notice an improvement in mpg. Was getting 13-14 mpg and now I am getting 15-16.. I have 17600 miles on the truck..

 

Thanks for the reply. The reason I ask is because one person on this site said that the chattering showed up 20k miles after the synthetic change. I suppose it's getting close to change the diff by that time anyways.

 

I wouldn't get too upset after 20K... Like you said it's gettin close to change again anyhoo..

 

Well, I finally changed my rear/front diff & t-case this weekend. Thanks for all the input. Here's what I put in and some suggestions for others doing this oil change.

Front Diff: Mobile 1

$30 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90
T-Case: Mobile 1 75W-90
Rear Diff: Valvoline 80w-90 + 7 oz. tube of Friction modifier

I couldn’t believe it was about $12 for new washers! You might be able to reuse the front diff drain copper washer and the drain/fill t-case washers since they’re not really ‘crush’ washers like the others. I picked up a hand pump too but the tube didn’t reach the bottom of the oil bottle. Plus, the pump had an inch or so of travel so it took FOREVER to fill the rear. I must have picked up the wrong type of pump.

Rear Diff: I added the LSD friction modifier because I think even though the bottle says “for conventional and limited slip” it doesn’t mean it has the friction additives like RP and others has on the bottle. The magnet on the drain plug did have a lot of goo/metal shavings. I had only picked up 3 qts of Valvoline, but couldn’t pump the entire 3qts in since the pump tube was too short. I added a few pumps of the mobile 1 to top it off. Should be fine. After I changed this I did the 8 right/8 left tight turns in a parking lot to mix it up. Nice and smooth.

Front Diff: Probably the hardest due to the tight space under there. Drain plug also had a lot of goo/metal shavings attached to the magnet. Why didn’t Toyota use the same 24mm socket for these plugs??

T-Case: Oil looked pretty good. I’ve heard this oil doesn’t get that dirty anyways.

Next time:
Reuse some of the washers that weren’t crush washers, get more oil than I need and get another drain pan so I can drain both front and rear to save time.

 

The dealer told me:

LSD you should use synthetic.

No LSD use dino.

 

dealers will tell ya anything man.

i have synthetic in my rear(locker) and front diff's and transfer case..........shifts into 4 wheel drive alot smoother.

 

I've been thru this in detail @ nausium recently. Glad I did. Gear oil is one of the most vital but yet misunderstood and misrepresented auto subjects. I'm not brand loyal nessarily. Knowing why GL4 and GL5 are different is vital to application. True GL4 is tough to find. If the brand claims both GL4/GL5, generally has to much yellow metal eating properties

GL4 = yellow metal friendly, (reduced corrosive additive for sycro related life).

GL4 is not recommended for a hypiod use, GL5 is

According to Redline, GL4 will help shifting quality, GL5 will hurt, due to slickness makeup

My takeaway

MANUAL TRANSMISSION
*Redline MT90 (75W90) Synthetic ... GL4!... BETTER shifts/synchro friendly/runs cooler than petroleum based

LIMITED SLIP DIFFERENTIAL
*Redline 75W90 or (75W140 tuwing) synthetic ... GL5...
Modifier NOT needed/hypoid rated/runs cooler than petroleum based