Transmission flush

I bought a used 4Runner a few months ago and it just hit 100k miles.

I have no idea if the transmission has ever been serviced and I’m afraid to do a full drain since the mileage is on the high side. Car care nut recommends not doing a full flush unless it has always been done at regular intervals of 60,000

has anybody done their first flush after 100k with no issues?

I did see there is a thread covering this topic, but nobody mention when they first drained the fluid

 

You must have missed the other 4,572 threads on this topic.

 

Since this is his 1st post....yeah. I am sure you made him feel very welcome.

OP This link may help.
https://www.4runners.com/threads/should-i-change-my-transmission-fluid.30350/#post-430066

 

If that were mine, I would just drain it and refill it. I wouldn't be afraid to flush if you trust the person doing it, if that's what you want. Ford Explorer? Different story...

 

It has less to do with the person doing the flush, but the junk in the transmission that can loosen up and kill it. I did flushes on vehicles for a few years. If a vehicle came in and needed a flush with high miles and no history of one getting done, we had to read them the riot act about what can happen to their transmission and would not be held liable for any damage caused. I agree with you on a drain and fill only.

I've seen both ends of what can or can't happen. Vehicles ( with no flushes ever done ) with high miles ( 100-200K + ) flush fine with no issues, to transmissions with under 100k miles crap out 3 days after the service.

 

I understand all that and very valid points. Have you seen a flush kill a 5th gen 4Runner with 100k?

 

Drain and refill for me.

 

No, but I'm not saying it can't happen either. Retired and have not worked on a car in almost 20 years.

 

More like a ford exploder

 

I guess it’s just safer to drain and refill. I want to prolong the life of the transmission but I don’t want to ruin it either. Too bad we can’t manual swap these things

 

I suppose a drain and refill is better than doing nothing

 

Well, I was trying to play nice..

 

If it were mine, drain and fill only.

 

I gotta hand it to Ford though… their 90’s trucks are decent. I had a 96 van with 410k miles and a 99 F150 with 288k.

 

Thanks for the link

 

Welcome. Drain and fill is the route I would take.

 

OP. I did the "drain the pan, refill the pan, pump out the old fluid, refill, repeat" at 90k miles on my Tacoma. Fluid was absolutely black. after the drain and refill it was dark cherry red. After that was done, I installed a Purolater P1320 inline transmission filter on the trans return line from the radiator. I've now changed the filter twice at 30K miles intervals. Fluid is back to the proper red color. I'm not going to worry about the pan "filter" as it's more of a screen than a filter. Besides, it's much easier to change the inline filter than clean the pan screen.

 

The Ford 300 straight six was a beast of a motor. An army buddy of mine had one. He just couldn't kill it.

 

.

 

Lol

 

The 4runner is transmission fluid and the filter ,pan cleaned it around 80K-100K miles ...the towing is 40-60K miles fluid changed it ....the plug of the fluid level 110F transmission temp.....I was the scan tool of the temp fluid ...

I did the GM transmissions dexron III fluid and it updated it dexron VI ... I did the 40K miles fluid ...

 

My brother owned a 77 Ford pickup with that same 300 inline six and a manual 4-speed. Couldn't destroy it. In the 60's they also made a 352 V-8 with similar longevity. I believe Ford originally built both as truck engines.

 

Just drain and fill. All my cars that lasted I only did a drain and fill or nothing at all.

 

I have done both and never had transmission issues. My 2003 Tacoma has a dipstick and will do a drain and fill every couple oil changes. Still bright cherry red with 200k miles. My Lexus LS430 I did several flushes starting at 60k and again every 30k. Fresh fluid is cheap insurance for me on not causing transmission to fail.