Synthetic Differential fluid ?

bokmeipai

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Normal differential fluid is 75w 90 . what viscosity gear oil should be used when switching to synthetic oil? I went to my local jiffy lube and they quoted me $65 for each differential change so front, rear & center would cost $195 for synthetic. Is this a good price?
 
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Thats funny I just searched this topic like 5 minutes ago.. I am considering the switch to synthetic also, but the shop I went to quoted me 75 a piece. So I think yours is a good price.. I just don't know if it's worth switching to synthetic.
 
IMO, very worth it. Some have reported an increase in gas mileage after the switch too (only ~1 mpg, but still nice). I went with Mobil1 75W-90 in all 3, smooth as silk.

To be honest, don't use a garage (especially Jiffy Lube), do it yourself. It's one of the easiest jobs in the world. If you can use a socket wrench, you can do this job. There's even a how-to in the maintenance section. If you must have a garage do it, at least buy the fluid yourself and save on the ridiculous markups that shops will charge for using their gear oil. Should only be about a half hour in labor.

FWIW, I spent about $75 total on gear oil and about an hour of time in my garage.
 
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IMO, very worth it. Some have reported an increase in gas mileage after the switch too (only ~1 mpg, but still nice). I went with Mobil1 75W-90 in all 3, smooth as silk.

To be honest, don't use a garage (especially Jiffy Lube), do it yourself. It's one of the easiest jobs in the world. If you can use a socket wrench, you can do this job. There's even a how-to in the maintenance section. If you must have a garage do it, at least buy the fluid yourself and save on the ridiculous markups that shops will charge for using their gear oil. Should only be about a half hour in labor.

FWIW, I spent about $75 total on gear oil and about an hour of time in my garage.

x 2!!! Relatively easy do-it-yourself! Slight mpg increase as well.
 
Running mobil-1 75-90 in all 3 diffs and its a little smoother. Yes, the job is easy to do yourself but is by far the MESSIEST maintenance item Ive done, even with a little bottle pump and a lift its pretty messy.
 
Running mobil-1 75-90 in all 3 diffs and its a little smoother. Yes, the job is easy to do yourself but is by far the MESSIEST maintenance item Ive done, even with a little bottle pump and a lift its pretty messy.

Where it was tight I attached a clear hose to the bottle with a small hose clamp and squeezed the bottle like a tube of toothpaste.

Minimal mess! :trophy:
 
75w140 is syn, maybe $80 in oil, and they prolly use cheap oil, I would do it your self, or at least bring in your own oil
 
I'm glad others who have tried this job themselves found it so easy. My experience has been mixed. The toughest part was getting the old plugs out. The fill plug was frozen on the rear diff and only numerous soaks with Kroil finally got it lose. The transfer case was indeed easy (aluminum), but now I'm having a devil of a time with the front diff drain plug. It takes a special 10mm hex bit that can round off the plug if not used carefully. I've just brushed on a 50-50 mix of acetone and transmission fluid I read about somewhere else with hopes that will work.

Just a thought: if you have a shop do the job, insist that they torque the plugs per spec and don't overtighten them. I had mine done at a shop a couple of years ago (paid way too much 'cause I didn't know better), and my hunch is they put the plugs on too tight and that's why I'm having problems now. Which is why I prefer to do the job myself from now on.
 
so regular gear oil is 75W90 and if synthetic it should be 75w140?

Synthetic gear oils are available in both 75W-90 and 75W-140. Either can be used in your 4Runner depending on your needs and local climate. If you tow frequently and live down south where it is warmer, for example, I would recommend using 75W-140. If you do not tow and live in the Northeast like me, I would recommend using 75W-90. If you are still unsure, use what is spec'd in the Owner's Manual (regardless of the fact that it's synthetic), which I believe is 75W-90.

In terms of selecting which brand of synthetic to use, check out this link which tests the performance of various brands using standard ASTM testing methods: http://www.synthetic-oil-tech.com/Gear%20Lube%20White%20Paper.pdf

Based on the analysis in that link, I would recommend using Amsoil Severe Gear 75W-90, although the study was performed and published by Amsoil so who knows .:bash:
 
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Differential change

This site has been more than helpful to me thanks. I am about to embark on doing more DIY on my 03 v6 4runner with 124,000. At what interval should the differentials be drained and filled? maybe with the trans fluid change? any help is greatly apprecited, thanks.
 
Kroil is good stuff for freeing fasteners, but I only have a regular can and it is hard to get into some areas or overhead.

PB Blast smells horrible but works ok.

The Sea Foam penetrating oil works ok and does not smell too bad.

I have found that an electric heat gun can really help free stuck fasteners and is safer than getting in there with a propane torch.

Wear gloves and give it some heat in cycles. Try it slow for awhile rotating between the heat, trying to get it undone, and swearing.

Then finally get pissed and give it "too much" force and it generally breaks free, or you break something else....
 
This site has been more than helpful to me thanks. I am about to embark on doing more DIY on my 03 v6 4runner with 124,000. At what interval should the differentials be drained and filled? maybe with the trans fluid change? any help is greatly apprecited, thanks.

30k for diffs.
60-100k for tranny.

There are many opinions on this so search if you need more.
 
This site has been more than helpful to me thanks. I am about to embark on doing more DIY on my 03 v6 4runner with 124,000. At what interval should the differentials be drained and filled? maybe with the trans fluid change? any help is greatly apprecited, thanks.

I would change all 3 diffs, and a series of drain and fills on the trans. Be a good time to do the brake and PS fluid too.
 
Best stuff in town....had very good success with it. Go to www.amsoil.com and plug in year, make and model. It not only tells you what fluids to use for everything, it tells you all the capacities for your truck too. VERY easy and much more affordable than the retail shops IMHO
amsoil.jpg
 

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Word to the wise would be to acquire a 10mm hex key socket for the fill and drain plugs on the front diff.

Also, go to your dealer and get the appropriate replacement crush washers for every differential.

Don't forget to torque things back to specification.
 
Word to the wise would be to acquire a 10mm hex key socket for the fill and drain plugs on the front diff.

Also, go to your dealer and get the appropriate replacement crush washers for every differential.

Don't forget to torque things back to specification.

Best advice yet.

The hex key socket was like $6 and I was only able to obtain 4 / 6 new washers, the other 2 I reused. For people buying a used vehicle its probably safest to just assume that the previous owner / dealer only ever changed the oil and sold the truck when the tires wore out. The diff area (front, middle, and rear) is easily overlooked by most owners of any vehicle, let alone the 4runner. Anything you can do to refresh a higher mileage vehicle, especially something as inexpensive as a fluid swap, should be done on principle alone.
 
Best advice yet.

The hex key socket was like $6 and I was only able to obtain 4 / 6 new washers, the other 2 I reused. For people buying a used vehicle its probably safest to just assume that the previous owner / dealer only ever changed the oil and sold the truck when the tires wore out. The diff area (front, middle, and rear) is easily overlooked by most owners of any vehicle, let alone the 4runner. Anything you can do to refresh a higher mileage vehicle, especially something as inexpensive as a fluid swap, should be done on principle alone.

So many people don't understand why fluid changes are so important! People think I'm weird because I am so anal when it comes to changing my fluids. It's like hydration for your body, except for you vehicle. You have to treat it and take care of it the way you would like for it to treat you and take care of you.
 

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