[Ser1clymb]

This seems like the thing we all would love to know, and obviously it's hard to know all the information, but could be a good indication for a potential purchase, or help decide if it's worth it poring money into a rig or finding a new one.
My situation is I bought a truck that I've already poured a good bit of money, sweat, and curse into and gotten to the point where I'm not sure if I should continue upgrading/maintaining it or leave as is and drive into the ground or sell.

So, what are some ways to test or diagnose some of the major headaches and components on a truck so you can know if a transmission will fail, a head gasket will blow, or your frame is rotting from the inside, etc...?

[spartacus]

Compression test of the motor will give you a good idea as to the health of'the motor. drop the transmission oil pan and see how much of the transmission material is in the pan replace the filter. Use a borescope with a light and check for rust, use por15. Preventative maintenance is what keeps these truck running good even though they are two decades old. Other then that Drive it and don't worry about it. It will get you there and back.

[jross20]

You can check the flex Plate and also the main crank timing cog.
Those are two things on my list

[brillo_76]

Basically, Toyotas thrive on maintenance. That's why its always good to follow the maintenance schedule. Check things.

For example:

In the rust belt we have to watch for rusting rot issues. Our 3rd member back plate can pin hole and loose gear grease. Run it low on grease or out you destroy the 3rd member.


Change your differential fluid, and your transmission fluid or gear grease if manual.

Sadly most PO do nothing but the basic maintenance.

So your antifreeze, transmission fluids and differential greases dont get checked and exchanged.

Also keep an eye on your front lower ball joints and upper ones. We have a design flaw that makes the lower joints have a higher failure rate

Most users only use OEM lower joints and change them out on a schedule. Especially if lifts and oversized tires are in use.


Along with what the other users have suggested as well..


The 3rd gens are very solid. They will last a very long time considering if they are maintained. It's one of the reasons they are very popular.

Sent from my SM-J337V using Tapatalk

[Ser1clymb]

Luckily I'm not in the rust belt, but I think at one time my rig was, because I do/did have a pinhole in the rear diff, that hopefully is all taken care of now.

I have not done a compression test yet, but I really would like to. I also haven't changed the pan on the transmission yet, but I've flushed the fluid and it wasn't as bad as I expected. I've done a hell of a lot of maintenance for sure.
I've mostly decided to go all-in on this truck and am contemplating painting it and a few other things, but I don't want to do any of that if the transmission is going to shit the bed next year, or if my engine is about to call it quits. Thanks for the suggestions, and I'll go with the tried and true method of "test and hope for the best."

[jross20]

Some other tasks I personally recommend:

- Replace the transmission filter (people have different opinions but I see no harm)

- Replace the front lower ball joints (critical)

- Bypass the radiator and install a stand alone transmission cooler. (Optional, add a magnefine filter)

- Flush transmission and use a fluid that is as close to dex III as possible. (I spent collective hours reading about these and went with the blue bottle dex/Merc. Its' viscosities are very close to dex III.)

- Flush power steering system with the same dex III fluid as used above.

- Flush the radiator, or replace if she leaks, replace upper and lower hoses.

- Change all hoses and gaskets for the oil cooler.

- Change the fuel filter

- Change the spark plugs

- Replace any worn brake parts (or upgrade to tundra brakes if your wheels are large enough.)

- Clean and paint any rust spots, check for compromised steel and weld in new pieces if absolutely required.

- Change the front, rear diff fluids and the transfer case fluids.

- Change all diff/transmission/transfer case breathers. Move them higher if you plan on crossing water.

- Have the 4runner professionally washed, claybared and waxed. Have the seats and fabric steam cleaned.

Also, only use Japanese OEM parts. (Personal belief)

This should give you a super refreshed 4runner that should be good for a while