Here are some suggestions that will help to extend the life and increase the durability of your automatic transmission.

These things are especially important for severe duty applications, but are also applicable to almost all vehicles.

1) Check your fluid level regularly- although fairly obvious, many people neglect to do this- or do this wrong.

Consult the vehicle's owner's manual if you are unsure as to how to do this correctly, as it can vary between different vehicles.

If you need to add fluid, it is always indicative of a leak. Unlike motor oil, your transmission fluid level can only go down if you are losing it somehow.

2) Service your transmission regularly- transmission fluid breaks down in the same way that motor oil does, but this is a step in preventive maintenance that is often ignored.

I've rebuilt countless transmissions over the years that clearly were never properly maintained- many of them had never had a single fluid and filter change.

Many manufacturers have different recommendations on the service intervals, but I recommend that this be done once a year or every 15- 20,000 miles.

3) Install an external transmission cooler- you've all heard the cliché that heat is the number one cause of transmission failure, well it's true.

A reduction of 40 degrees in your transmission fluid temperature can double the life of the unit.

When shopping for a cooler, a stacked plate design is far superior to a "tube and fin" type. If you're going to go through the trouble of installing one, you may as well put on the best kind.

On this same subject, it is also always a good idea to insure that your vehicle's cooling system is in optimum condition- most automatics utilize a fluid to antifreeze heat exchanger that is built into the radiator.

4) Install a transmission temperature gauge- with a gauge you will be able to tell when your trans is getting hot before it's too late.

5) Add a friction modifier- there are a few excellent products that can be added to your automatic trans that will significantly increase the life of the transmission. I recommend the products that are made by LubeGard.

On the same subject, avoid at all costs the auto parts store "mechanic in a can" and "stop leak" type products- they are mostly seal swelling agents and will usually harm the trans rather than help it.

6) Install an in line cooler filter- most automatics have some type of filter, however, there is always room for improvement.

Factory filters vary in effectiveness; many transmissions use something that isn't much better than pouring the fluid through a screen door.

The idea is to eliminate contaminants such as small metal particles and loose debris as effectively as possible.

In line filters are inexpensive, easy to install, and are highly effective in removing damaging contaminants from the transmission fluid.

I recommend the ones made by Magnafine and Filtran- in addition to their filter element, both of these products have a bypass valve in case they become clogged and also an internal magnet to further aid in trapping ferrous debris.

7) Use a synthetic based fluid- automatic transmission fluid serves many functions. It provides cooling and lubrication, it is the hydraulic fluid that applies the clutches and bands, and it even "drives" the car through the fluidic coupling that occurs in the torque converter.

It stands to reason that a synthetic fluid is much less susceptible to breakdown, a better lubricant, reduces friction and also has the capability of reducing operating temperatures.

More importantly, in cases of extreme cold and extreme heat, fluid made with a synthetic base stock is much more stable from a viscosity standpoint. If you don't believe me, try to pour "dinosaur" oil out of a container at -10 Fahrenheit- it's not exactly going to serve very well as a lubricant when it's the consistency of Jell-O.

8) Check transmission problems promptly- most transmission problems start out small and will get worse over time. Often times, major repairs can be avoided by taking care of a problem early on.

If you see a warning light on the dash, see a few drops of fluid in the driveway or even just have a feeling that something isn't quite right, there is no better time than the present to get it checked out.

9) Install a shift kit or modified valve body- while normally thought of as a "high performance" modification, almost any vehicle will benefit from shortening the shift time, reducing overlap and "cleaning up" the shift quality. This in turn reduces heat and also reduces wear on the clutches and bands.

Many of these modifications also address certain factory design shortcomings and eliminate common drivability complaints.

Most of the better engineered products have shift quality settings that are adjustable to achieve a result that is appropriate for the intended usage. The person with an 11 second rocket will have different needs than the person who occasionally tows a trailer with his SUV.

I hope that I didn't bore anyone with this long post.


-John

 

Great post! Losts of helpful hints. I'll see you in a few months, john

 

Ditto!!!!!!

Very helpful info for us all.

 

I'd love to have a ˟˟˟˟-kit of some sort, but I have been looking and looking for one for an 02 Tundra, v6, 2wd. I'm easy on the throttles and occasionaly tow lighter trailers. Generally 2-3 times a month, the bed is full of goodies. Any ideas where I can find a kit for my truck??

--Adam

 

While there are no commercially available shift kits for any of the Toyota rear wheel drive and four wheel drive transmissions, the valve body can be modified to provide high performance / heavy duty transmission operation.

Normally, the valve body is removed from the vehicle and sent out for this modification service.

These modifications were originally developed for Supras but are applicable to all variations of the Toyota A340 series of transmissions and are very popular among the people who have supercharged 4Runners and Tacomas.

-John

 

Very helpful since I just had a rebuild done! Thanks!

 

I'd be happy to help you void your warranty

-John

 

How hard is it to install a transmission cooler and a shift kit on a 97 2.7L.Is it hard to install a transmission temp gauge ?

 

Again, there are no shift kits available, just modified valve bodies.

If people are interested, perhaps I could find a way to put the instruction sheet for removal and replacement of the valve body assembly up on my website.

Installing a cooler and temp gauge isn't too terrible, I say it's a 2 hour job for the do it yourselfer.

-John

 

Hey John, great thread! Where would I mount one of these in-line filters ideally? I've still go to change over to the stacked plate model for my cooler, but I just haven't had any time.

Chris

 

Hi Chris,

The filters can be mounted easily anywhere in the rubber cooler line, they are directional- so the only consideration is that they face the right way.

I'm glad to see that you are changing to a stacked plate style, I think that tube and fin coolers are not the way to go.

Do you have the new cooler yet? Let me know.

-John

 

Nope, don't have it yet! Any recommendations?

Chris

 

Yes, I recommend that you give me a call

-John

 

I'll do it!

Chris

 

I got a question too, in changing your fluid, like say on a 1991 Camry (going to do this tonight), can you disconnect the return line off the radiator and stick it in a quart of fresh tranny fluid, while the inlet pours out into a tray for disposal? Or is that bad? Otherwise, I am just gonna do a simple drain and refill from the pan (drain out is only 2.6 and the entire tranny takes 5.9 liters), but I do it now every 5000 miles.

 

John, What brand of synthetic trans fluid do you recomend? Another question, I have 03 Tacoma with 100 shot of nitrous. Sometime its shift hard from first to second. I bought a trans cooler, will it help?? That would be great if you could put the "how to" on a modifed valve body!
Thanks,
NX Tacoma

 

Any of the major brands of synthetic ATF are about the same in quality as far as I can tell.

The hard shift can be caused by a number of things, fluid temp isn't usually one of them. A cooler is a good thing to have, but really wont help your problem.

As far as a how to on modified valve bodies- that's kind of top secret stuff

-John

 

You may be better off disconnecting the return line, putting it over a drain pan and pouring new fluid down the dipstick tube while the car is running.

-John

 

That wouldn't do any damage would it? I thought the vane body (or whatever it is called) needs a constant flow of the tranny fluid or otherwise won't it stall? I don't know anything about trannys...yet.

I looked at the fluid at the dipstick again this morning and it is still somewhat dark (like black like) no not burnt as there is no smell of it being burnt, but it needs a flush since it really hasn't been maintained in a quite a while. I might have to redo or flush tonight...if I can get the damn car from my "miss thang" sister!!!

 

By adding fluid as it is coming out of the return, you will have a constant flow. You will not damage anything like that.

-John