Are rear diff service and trans fluid exchange both easy for a beginner?

[lawless97]

I have a 2016 SR5 2WD with 72000 miles and the dealer said I need both of these services. I am a novice and have recently completed brake fluid exchange, power steering flush, drive belt replacement, and coolant exchange. I just watched T4R Garage's video on differential service and it looks super easy. Is there any reason I shouldn't try this one myself as well or should I have my mechanic do it for $75?

For the transmission, T4R's video talks about a "drain and fill," but says if you want a full change of your fluid, you should take it to Toyota. Do I need a full change or should I just do the drain and fill? I plan to keep this car for another ten years at least. Toyota wants $400 to do this and my local mechanic quoted me $280. I'm guessing I can't do a full flush myself, and I've seen posts from people saying not to mess with the transmission.

 

[RRosco]

Rear Diff is easy. Make sure you check to make sure the upper plug (fill plug) is able to be loosened before draining.

Transmission fluid is a little more complicated. I use a Scangauge II to monitor my temps when doing it. You do not have a filter, just a screen so pan drop is not necessary. The drain and fill requires you to monitor the fluid temp for servicing. Plenty of threads and video's online. There are also excellent threads on a complete flush. Your choice.

It may be worth it for you to have it done if you know a experienced Toyota mechanic who can do it. Even if someone did it for me, I would still have to double check their servicing.

 

[Chumly]

As mentioned, Diff is super easy. The Transmission fluid drain and fill only slightly more complicated. I did the transmission using the “jumper” method instead of a Scan Gauge. All you need is some old wire for that. Plenty of tutorials on how to do on YouTube. Not really complex, just as long as you understand the min and max temps needed for fill. I found there is enough time from when trans fluid hits proper minimum temp till it is too warm to allow completion of this without rushing. Fluid and Washers & such are not terribly expensive.

 

[Humble Leader]

in theory diff, transmission and transfer case drain and fills are not difficult on the DIY scale. however, one stripped drain or fill plug increases the order of difficulty exponentially

I've had the transmission flushed by the toyota dealer, they use some sort of exchanger to flush the system. in fact, I get the diffs, transfer case, transmission all serviced at the same time. costs more yes, but it's convenient just having everything done in a span of a couple hours. sometimes it's worth it to pay for the convenience factor. a good toyota dealer can do these services easily with low risk of collateral damage to your vehicle lol

 

[jdm-v35]

At the prices you listed, It would be worth it to just have them do it for convenience and to reduce risk. If you don't have all the proper tools you will need to buy those too. I only do it myself because I already have the tools and experience.

 

[lawless97]

I have all the tools for the rear diff, so I think I may try that on my own and then have the transmission service done by a mechanic. Any reason to have Toyota do that over my local mechanic? Toyota is $120 more than what my mechanic charges for it, but if they have any special tools for it that likely would only be at a dealership, or if it's more complicated, maybe it's worth the extra amount for it to be done by them.

 

[jdm-v35]

I have all the tools for the rear diff, so I think I may try that on my own and then have the transmission service done by a mechanic. Any reason to have Toyota do that over my local mechanic? Toyota is $120 more than what my mechanic charges for it, but if they have any special tools for it that likely would only be at a dealership, or if it's more complicated, maybe it's worth the extra amount for it to be done by them.

No special tools, but I personally prefer and would want to make sure they are using the OEM toyota fluids and not off-brand.

 

[Hungryhawk]

Local mechanics are an unknown . You can ruin a $5000 tranny doing it wrong either under fill or overfill. Dealer is safest but an untrained tech can mess it up too.
Read several or more write ups about DIY tranny service. Then phone around-must use Toyota Fluid (WS)- at least 2 dealers and only Japanese specializing or 4runner specializing independent shops.
All shops will say "no problem, can do" but remember its your tranny is they mess up.

 

[Bmnorm2]

You definitely don’t have to use Toyota fluids for any of it. I don’t use Toyota in the diffs or transfer case. I did use Toyota WS for transmission. However, CutthroatSlim uses non Toyota in transmission and has 300k miles.

Make sure your mechanic knows how to check transmission fluid level after exchange.

Diffs are super easy.

 

[Ezlife45]

I do mine myself, the only thing i would have done differently is to measure how much trans fluid is drained from the transmission and shoot to replace the exact amount. I had seen several different volumes of fluid for a dump and fill.
Its pretty simple and easy to do.

 

[SOSHeloPilot]

I do mine myself, the only thing i would have done differently is to measure how much trans fluid is drained from the transmission and shoot to replace the exact amount. I had seen several different volumes of fluid for a dump and fill.
Its pretty simple and easy to do.

.
...^^^... These are my thoughts too as a novice DIY'er on service.

IF you put back EXACTLY WHAT YOU DRAIN ... why is it necessary to check do the temp check ??

Especially if cold transmission is drained and cold transmission fluid is filled with the exact same amount as drained ?

This is just a curious question ??

 

[RRosco]

.
...^^^... These are my thoughts too as a novice DIY'er on service.

IF you put back EXACTLY WHAT YOU DRAIN ... why is it necessary to check do the temp check ??

Especially if cold transmission is drained and cold transmission fluid is filled with the exact same amount as drained ?

This is just a curious question ??

If it is your only option it will work. Due to residual fluid hanging on to the sides of the container it is never exact unless you want to wait overnight. It will work for 1-2 times, but after that it will be off.

I do a drain and fill every 20k with just 2 quarts (container is marked) and I put the drain plug back in while fluid is still running. I then let the trans temp get to 105, open the overflow and let it drip until 110 degrees. I do this just to save a little time since its done every 20k. I personally use Amsoil or Idemitsu for synthetic.

I also do not trust factory fills. It could already be low/high from the start.

It is very easy to monitor the temps. I personally have a scangauge II installed to monitor everything while driving. I have noticed my temps drop after using synthetic for my drain and fill.

Just one mans opinion.

 

[Hungryhawk]

Lots of great replies here . My two contributions are:
1) do not forget to grease the propeller/drive shaft zerk fittings-pay special attention to not overgrease the sliding yoke zerk.
2) both Honda and Toyota recommend drain and refill the tranny fluid. There are lots of discussions posted everywhere about pros & cons. I suggest do a drain and refill first, and yes it only refreshes the fluid. But, you can assess the fluid you drain out if you collect it in a clean container! A lot can be learned by a careful exam of this used fluid.
Plus you can always do a second drain and refill after a short drive!
I would save dropping the pan and cleaning out its collected sediment if this first drain and refill is especially dirty or gritty.
Personally I would stay away from the tranny power flush process for all the published arguments and especially that both big Japanese manufacturers do not recommend it.

 

[STEVE'S40TH]

If I can do it, you can too! The rear diff is probably the easiest thing to do. As a big guy, I recommend dropping the spare to give yourself more room. Also, the valvoline bag gear oil makes this job easier! I follow "Vikings Garage" on YouTube. That guy knows his stuff! My personal theory is that I'd rather try and mess up, then bring it to a shop. I just can't find a mechanic I trust. Plus I enjoy doing the work and it's a nice feeling when it's done. Best of luck!

 

[CutthroatSlam]

On the transmission, the difference between cold fill level and warm fill level is about 8 oz of ATF. That amount is not going to cause physical damage to the transmission. Most likely it will leak out the rear seal of the transmission until the correct level is reached. It will create a mess with the ATF fluid blowing back on the transfer case and fuel tank.

 

[Ezlife45]

People can say what they want about factory fill. I followed the procedure but can't be certain I replaced the same amount of fluid. My runner is not a DD so I don't remember. I replaced with Toyota WS. When my vehicle sits for more than a week, it's like the torque converter doesn't grab until a few seconds. I put the car in drive, and it slowly starts moving, after 5 seconds it works normally.

 

[CutthroatSlam]

People can say what they want about factory fill. I followed the procedure but can't be certain I replaced the same amount of fluid. My runner is not a DD so I don't remember. I replaced with Toyota WS. When my vehicle sits for more than a week, it's like the torque converter doesn't grab until a few seconds. I put the car in drive, and it slowly starts moving, after 5 seconds it works normally.

That is called delayed engagement. You are not getting sufficient hydraulic pressure. This could be caused by a number of reason, including low fluid, burnt fluid, clogged filter, worn pump. How many miles on this transmission?

Just a moment...

 

[tollarja]

Differentials are easy. Any brand fluid will do.

Transfer case is easy, the Toyota fluid is really expensive and a substitute 75W is difficult to find. I don't know if it matters, but the two fluids I found that are compatible are Royal Purple Synchromax and RAVENOL J1C1003 MTF-3 SAE 75W Full Synthetic Gear Oil. There's a possibility of some brass gears that normal gear lube may not be compatible with, I didn't have a problem when I used 75W-90, but I prefer not to take the chance.

Transmission is easy if you are mechanically inclined. My 2021 doesn't have a wire to jump, so the jumper doesn't do anything, but I basically did the same shifter trick (link below) to get my car to show the transmission reached temp to drain. I don't really remember, but you can probably ask your local Toyota Parts department to print the instructions.

https://www.youtube.com/watch?v=eRxSu4-4ojo

 

[Adamus]

I always disregarded the advice to loosen the fill plug first, paid the price when I couldn't get it off my S2000 after draining and had to walk a few miles to the parts store.

 

[Franken4Runner]

The rear differential fluid is very easy to change, its basically idiot proof. Just get two 12157-10010 crush washers and 3 bags of your choice of synthetic 75W90, I used Valvoline Advanced. Took less than a half hour with most of that waiting for the old fluid to stop dripping out.

Compared to other vehicles I have had where you have to remove the rear cover, scrape off a gasket and/or RTV, put the cover back on with a gasket and/or RTV, torque on a bunch of bolts, let it set for a few and fill using a pump this is insanely easy.

Steps:
Remove fill plug, then remove drain plug with a drain pan under the hole.

Clean the magnet on the drain plug.

When the fluid is done draining out install the drain plug with a new crush washer and torque to 36 ft/lbs.

Squeeze the fluid in the fill hole until it starts to run out (mine took almost 3 bags) install the fill plug with a new crush washer and torque to 36 ft/lbs.