1st time rear diff oil change

My '07 PreRunner just turned 30k recently and Im going to R&R the rear gear oil. Ive searched on here and my results are inconclusive. I want to use a synthetic oil(Amsoil severe gear) but read that some guys had problems with synthetic oil in the rear diff. Has anyone here had problems with the Amsoil stuff or should I just stick with regular gear oil. Thanks

 

I wouldn't suggest it being that there are different viscousities--but if your ARE going to, at least stick Royal Purple---pricey but worth it. The only reason is that full syn might be tooo thin. And cause a diff leak.

 

At 30K, I to went to full synthetic as well. Not sure if your Prerunner has a LSD, there are additives needed here many times. But no problems running synthetics. Some with manual trannys have reported issues with notchy shifting using GL-5 rated synthetics.
I went with Amsoil Severe Gear

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 in the diff, and I went with Amsoil Manual transmission & transaxle gear lube, 75W-90 API GL-4 in my manual tranny. So far so good. Good luck.

 

What truck do you have? It's an 07 Automatic.... we need more info. Sport? Offroad?

Do you have the LSD (mechanical)? Look at your rear diff....do you have one of these?
http://t1.gstatic.com/images?q=tbn:ANd9GcQD3Uq68smODqsy6m3MPJ3DxHktIwO5tNZ0TAQUE3Lb5TrAKB0a5XjjKtHR

You can safely use synthetic oils in your diffs - just make sure you get the proper weight/type.

IF YOU HAVE AN LSD .........You need friction modifier. I've used Amsoil severe gear in our corvette. The Severe Gear already has friction modifier in it....HOWEVER - You may need to add more friction modifier depending on the results. I have an LSD....and I use Mobile 1 75W-90 with 2 bottles of XL3 (FORD) friction modifier. If you use the Amsoil, do a lot of tight 8 circles, drive around for a couple days and if your rear diff chatters and groans....I would add a bottle of friction modifier (when using the Severe Gear). Or...with any other synthetic....try it with one bottle first and if you have problems, add a 2nd bottle.

There's an entire thread dedicated to this topic - although LENGTHY, you can read thru it and make your own decisions of what you want to use. http://www.tacomaworld.com/forum/technical-chat/24545-changing-differential-fluid-step-step-how.html

If you don't have the LSD....synthetics work great!! Amsoil is a great product......other than, having to find someone to buy it from.

 

i just did this. second time for me during owning this truck.

i used Redline last time and did it again this time. i have an offroad, no limited slip.

full synthetic 75-90. i might rethink synthetics..i keep up with the fluid changes. 30 - 35k miles. i bet regular cheaper gear oil would do fine.

 

In my research on the subject I concluded that synthetics in an LSD diff are no good. One member here tried about every brand and combination synthetic with friction modifier and nothing worked. They all made the rear end clunk.

So my advise is:

If you have the TRD sport then you have a mech LSD and you should use regular 80w90 gear oil with 4oz of friction modifier, aka LSD additive.

 

^^This^^ x 1000

 

Synthetic is the best choice. Any quality 75-90 will be fine unless you use your truck for hauling, towing, hard off road, or climbing grades. If you do then I would use Redline 75-140. I chose Redline over a long list of others based on the lower temperatures it generates when working hard. The additive package also stands up to higher temps better that most. If you have an LSD, then you may need friction modifier per Janster's post.

 

Don't waste your money with synthetic for ring and pinion applications. Just use dino oil.

 

I just realized someone bumped this thread from April . The OP is long gone. Without knowing how he is using the truck, there is no right answer.

Dino oil will work fine if it's changed regularly and is not used for towing or hauling, especially if grades are also in the equation. Synthetic does lower operating temperatures in those extreme applications. The fact that it runs cooler is a pretty good indication that it produces less wear, but it probably doesn't become critical at lower temps and loads.

 

I tried using Royal Purple 75w90 with NAPA additive on my TRD Sport rear and I got the groans.

I switched it out for Valvoline 80w90 dino with Motorcraft additive from Ford and zero issues.

 

I ended up using Amsoil "Severe Gear"

$29 75W-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75W-90 and a 4oz. tube of Amsoil "Slip Lock" friction modifier. I did some figure 8's in a nearby parking lot and all is well. No problems at all. I also did the "breather mod" at the same time.
BTW, the diff has the LSD sticker on it.

 

BG Ultra-Guard

$29 75w-90 Synthetic Gear Lube - 1 Quart (Pack of 2)

75w-90 and BG LSII limited slip additive. No issues with chatter thus far.

 

dino for lsd plus a tube of transx....been ok for 30k miles...have purchased another tube for next change coming up..mobil 1 synthetic in transfer case and front differential...

2008 trd sport 4x4 lwb 1gr w/trd sc and lsd..

 

anyone know it this gear oil is ok? No lsd. we use all the time in mining equpment, gear box ,planatary gear. seems to work good for that

 

Does it say GL-5 anywhere?

 

I wouldn't use that for the truck. It's for industrial usage. We probably have that stuff at work for our machinery/gearboxes.
http://www.lubricants.com/BuyersGuide/GearOil/Industrial/ExxonMobilSHC632.php

 

my dino oil of choice cost as much as synthetics...i use Swepco 201 in my 911 tranny..and i have put leftover gallons into my neighbor's tacoma rear diff. he sold it shortly afterwards, so no long term evaluations.

nice way to get rid of all my stockpile of Swepco..and saved him some $$. Swepco is navy blue in color, so it is shocking when it gets dumped.