Front & Rear Differential Oil

[catrains]

A quick warning to all. I did my rear diff and transfer case last weekend and had intended to the front diff. However, I stripped the front diff drain plug. It takes a hex bit and as I learned if it's difficult to get out, it's easy to strip. Throw some PB Blaster on it before you try. I have a new plug on the way, but have yet to ass around with getting the old out.

some sockets made have a tapered edge to make the socket easy to set on the fastener. I have taken the sockets to the grinder and removed this so that the socket has full contact to reduce slippage on fasteners that have a small height. like these drain plugs .

sometimes you may require a 12 pt socket so I have both 6 and 12 point sockets .

 

[1000MPH]

I've done this myself, especially for installing thin nuts.
The problem being discussed is the 10mm hex so grinding won't help much.
The only thing I can add is that you make sure the socket is clean before installing the hex. I like that info on the expensive toyota spec oil only for mpg improvements. True or not it makes me feel better.

 

[catrains]

75w90 GL5 is excellent in the diffs and transfer case. The 75W85 was developed to increase mileage, same for 75 LF. Toyota changed the AWD transfer case oil spec on my 200 Series Land Cruiser from 75W90 GL5 to 75 LF, nothing inside the case changed, most notably the Torsen T3 with its gears and clutch.

The front differential drain plug can be problematic to remove. The issue lies in the large 24mm thread size and smallish 10mm female hex required to remove it. The short of it is that it can round out, and frequently does. For those looking to get rid of the problem, Lexus installs a plug on some front diffs that has a male 14mm nut on it, so a regular 6 point socket or wrench can be utilized to remove it. The part number is 90341-24016. Toyota does not supply through their dealers.

the hex bit he used maybe some inferior china made tool. also these may also have a tapered end. I have also had some cheap bits not properly made where they were not as sized and fit too loose in the bore hole.

 

[Stangboy]

I use supertech 75w-90 because it's close enough and GL-5 is GL-5 and haters gonna hate.

I would bet a barrel of gear oil that most Toyota dealers use whatever 75w-90 or 80w-90 they can get in bulk for the cheapest. I would also bet that it is lower quality than supertech, and that doesn't matter either as long as it says GL-5 on it.

When I worked at O'Reily Auto we delivered a lot of gear lube, transmission fluid, etc. to all the dealerships in town. That was my experience anyway.

 

[ADK Explorer]

I tried to check my rear diff oil today but the fill plug will not budge. I used a 12 point 24mm socket adapted to a small 3/8" rachet. I read alot of various vehicle forums where evidently this is a notorious problem. Solutions ranged from break bars, pipe plug sockets, heat and hammers. Notably most warned against pneumatic wrenches for fear of cracking housing. I don't have the cash to buy a ton of tools right now but I really want to at least get a look at the oil. I will call the dealer Tuesday and try to get them to free the plug for free. If not I'll call a local mom & pop service station that I know is honest and get a quote from them. They may just crack it for free?! No such thing as a simple DIY project. (Truck was built last October.)

 

[Snow-Jet-MK5]

I changed mine out to synthetic at 40k and had no issues. Maybe you need to lift some heavy weights every once in a while. Lol. [emoji13] jk

Sent from my SAMSUNG-SM-G935A using Tapatalk

 

[ADK Explorer]

I changed mine out to synthetic at 40k and had no issues. Maybe you need to lift some heavy weights every once in a while. Lol. [emoji13] jk

Sent from my SAMSUNG-SM-G935A using Tapatalk

I used to be into power lifting when I was a younger lad. Trust me, I miss the that extra muscle often. (I'm just happy I can still jog 5 miles.)

 

[ADK Explorer]

Getting back on topic, the parts guy at my dealer said their bulk gear oil (80W90) can be bought for $5.50 a quart. He was as surprised as I at how inexpensive it is. Is it a substandard product or bulk price savings?

 

[NorthwoodsRunner]

I tried to check my rear diff oil today but the fill plug will not budge. I used a 12 point 24mm socket adapted to a small 3/8" rachet. I read alot of various vehicle forums where evidently this is a notorious problem. Solutions ranged from break bars, pipe plug sockets, heat and hammers. Notably most warned against pneumatic wrenches for fear of cracking housing. I don't have the cash to buy a ton of tools right now but I really want to at least get a look at the oil. I will call the dealer Tuesday and try to get them to free the plug for free. If not I'll call a local mom & pop service station that I know is honest and get a quote from them. They may just crack it for free?! No such thing as a simple DIY project. (Truck was built last October.)

Harbor Freight sells nice breaker bars for less than $15 as well as $12 torque wrenches. I have one Mac Tools and two Snap On torque wrenches but those from Harbor Freight are very good and cost effective. Don't waste money getting Snap On or high end torque wrenches as they are no more accurate. The idea behind breaker bars is ability to get the torque you need to crack a bolt or nut loose. However, I do not recommend using a 12 point 24mm socket because of an elevated rounding risk. Craftsman is okay (if made in the USA) but those Chinese made are bit softer. I would procure either a Matco or Snap On 6-point 24mm socket in 1/2" drive. In addition, I would also procure the following: high end 10mm and 5mm hex sockets in 3/8" drive, 6-point 10mm, 12mm and 14mm sockets in 3/8" drive. You can be frugal on the drives but be careful buying cheap sockets or hex bits.

 

[ADK Explorer]

Harbor Freight ...

Thanks for the great info. I will definitely look into picking up some better hardware. I prefer to do my own wrenching and need to update my tool kit. I have read about the benefit of 6 pointed socket over 12 so will give that a try. Many people put all this hardware on them and still can't move them. Some had to have a shop drill out the plug. I will give it another go with some heavier artillery.

 

[wanderMT]

Probably like most, my metric sockets are 3/8 drive so I often use 3/8 to 1/2 adapter and use longer, stronger 1/2 ratchet or breaker. Be a little careful though, I have snapped several sockets doing this.

 

[ADK Explorer]

VICTORY ! Sprayed WD40 on it yesterday and today, tapped on it with a hammer and put a larger 1/2 " ratchet with a 6 point 15/16" socket on it. Pulled down with everything I had (and I weigh 200 lbs) but no movement. I feared rounding the bolt head so went in and had lunch. Later I tried again, more WD40 and tapping, I put the ratchet on to push up and it gave. I thought, Shit I've rounded the head but tried again and it came right out with no damage.

So put a little dropper in and sucked up some juice and as you will see, it is as black as my soul. It still feels slick but I'm guessing it ain't good if it looks like that! My truck is 6 months old with 4941 miles on it. So when the dealer is open I'll get some oil and change it out. Hopefully the drain plug will come out easier.

In the bottom pic,I'm guessing size does matter.

 

[catrains]

VICTORY ! Sprayed WD40 on it yesterday and today, tapped on it with a hammer and put a larger 1/2 " ratchet with a 6 point 15/16" socket on it. Pulled down with everything I had (and I weigh 200 lbs) but no movement. I feared rounding the bolt head so went in and had lunch. Later I tried again, more WD40 and tapping, I put the ratchet on to push up and it gave. I thought, Shit I've rounded the head but tried again and it came right out with no damage.

So put a little dropper in and sucked up some juice and as you will see, it is as black as my soul. It still feels slick but I'm guessing it ain't good if it looks like that! My truck is 6 months old with 4941 miles on it. So when the dealer is open I'll get some oil and change it out. Hopefully the drain plug will come out easier.

In the bottom pic,I'm guessing size does matter.

the gear oil being black at your mileage may mean you drove it too hard the first 500 miles and or you drove it for too long of a drive during this period. the gear teeth need about 500 or so miles to break in during this period the gear oil gets hot so short drives are recommended and also no load/towing hard driving etc.

good you checked it .. I would recheck this after a 2k miles .

 

[ADK Explorer]

the gear oil being black at your mileage may mean you drove it too hard the first 500 miles and or you drove it for too long of a drive during this period. the gear teeth need about 500 or so miles to break in during this period the gear oil gets hot so short drives are recommended and also no load/towing hard driving etc.

good you checked it .. I would recheck this after a 2k miles .

I figured this could be break in debris. I thought I took it easy but may have done some lite 4 wheeling. This and water submersions before my diff breather mod is why I checked it. I'm also leary about leaving my engine oil in until 10k. I'm old school, drive it hard but change fluids frequently. Food for thought: manufacturers tell you not to check your fluids until after the warranty expires. Hmmm ...

 

[catrains]

changing the engine oil @5K miles the first 5K miles is IMO the best way to go. this is because the engine has dirt in it . also more wear / break in . after this 5K then 10K miles with the synthetic engine oil is normal.

I have a 16 plus year old truck use mobil 1 and change the oil 7.5K miles. 170K miles on it and after this mileage it uses about 1/2 qt of oil .. also the oil is very clean. problem owners have is they have quick lube service this does not allow the time for all that old oil to come out . now with the outdated conventional oils it takes perhaps 45 min for all the oil to drain. synthetic drains faster but still takes a 30 min drain time to get it all out.

also drain oil when hot ..

 

[ADK Explorer]

Now to choose an oil. The Toyota parts guy said they have 80W90 for $5.50 a quart but that must be regular oil. Do 5th gens come with syn from the factory? Is it ok to switch between the two? If I am going to run it 2k more and then change it out again could I put in regular now and then put in a good syn oil at that time and leave it be for another 40k? Will call dealer tomorrow to get their take. (Decisions, decisions, decisions)

 

[NorthwoodsRunner]

Now to choose an oil. The Toyota parts guy said they have 80W90 for $5.50 a quart but that must be regular oil. Do 5th gens come with syn from the factory? Is it ok to switch between the two? If I am going to run it 2k more and then change it out again could I put in regular now and then put in a good syn oil at that time and leave it be for another 40k? Will call dealer tomorrow to get their take. (Decisions, decisions, decisions)

Just replace it with Mobil 1 75W-90 LS and forget about it. You will need to buy 4 quarts. If you want to do the front differential then you will need another 2 qts. I would just go with Mobil 1 and nothing else.

 

[Woz1976-MT]

Now to choose an oil. The Toyota parts guy said they have 80W90 for $5.50 a quart but that must be regular oil. Do 5th gens come with syn from the factory? Is it ok to switch between the two? If I am going to run it 2k more and then change it out again could I put in regular now and then put in a good syn oil at that time and leave it be for another 40k? Will call dealer tomorrow to get their take. (Decisions, decisions, decisions)

I just changed my differentials and transfer case to Royal Purple (got it from Amazon, but it was still pricey). I was at about 1100 miles when I did it, and I was surprised at the amount of metal particles on the rear differential's magnetic drain bolt. I followed the proper break-in for a differential, too. There wasn't a lot (as I've seen in other pics), but for only 1100 miles it seemed like a good amount. The front differential and transfer case drained almost clear fluid, but they are regularly under stress like the rear diff.

I wasted a little RP after each was drained to flush out any lingering remnants of the factory fluid. I wound-up using about 5.25 qts of RP Max Gear 75W-90 and almost 2 qts of RP Synchromax.

I know there are quite a few members here who will say I'm crazy for doing this so early, and that RP is expensive overkill. But since I tend to keep my vehicles for 10+ years I like to treat them as well as possible -- plus it helps settle my OCD for vehicle maintenance.

I would say if you want to do it right, now, Mobil 1 75W-90 would be a good choice, and it's cheaper too (you could probably change your differentials twice for the same price I paid for the RP). I've used Mobil 1 75W-90 in my old Tundra (2008) and it seemed quite good -- plus it's readily available.

 

[NorthwoodsRunner]

I just changed my differentials and transfer case to Royal Purple (got it from Amazon, but it was still pricey). I was at about 1100 miles when I did it, and I was surprised at the amount of metal particles on the rear differential's magnetic drain bolt. I followed the proper break-in for a differential, too. There wasn't a lot (as I've seen in other pics), but for only 1100 miles it seemed like a good amount. The front differential and transfer case drained almost clear fluid, but they are regularly under stress like the rear diff.

I wasted a little RP after each was drained to flush out any lingering remnants of the factory fluid. I wound-up using about 5.25 qts of RP Max Gear 75W-90 and almost 2 qts of RP Synchromax.

I know there are quite a few members here who will say I'm crazy for doing this so early, and that RP is expensive overkill. But since I tend to keep my vehicles for 10+ years I like to treat them as well as possible -- plus it helps settle my OCD for vehicle maintenance.

I would say if you want to do it right, now, Mobil 1 75W-90 would be a good choice, and it's cheaper too (you could probably change your differentials twice for the same price I paid for the RP). I've used Mobil 1 75W-90 in my old Tundra (2008) and it seemed quite good -- plus it's readily available.

The Toyota factory differential oil seems to go bad after a few thousand miles. I used Mobil 1 and will stick with Mobil 1 after reading this article: http://www.goodsenseoil.com/G2457-GearOilWhitePaper.pdf

It basically says RP is not very good for being so expensive but Amoil is the best. I think you get the colored story. However, Mobil 1 is considered very good value.

 

[ADK Explorer]

The Toyota factory differential oil seems to go bad after a few thousand miles. I used Mobil 1 and will stick with Mobil 1 after reading this article: http://www.goodsenseoil.com/G2457-GearOilWhitePaper.pdf

It basically says RP is not very good for being so expensive but Amoil is the best. I think you get the colored story. However, Mobil 1 is considered very good value.

Interesting paper. Thanks for posting it. Food for thought. We spend hundreds of dollars buying armor to protect the outside of our vehicles but cheap out on internal protection. Out of sight, out of mind. Considering I spent 45 grand on the truck I guess I could cough up 45 bucks to protect it's gears.