Transmission Oil

[89Vette]

My flush at the Isuzu dealer was 13 years ago (18K miles). So the fluid is old now. I hear you when you say that it doesn't get "old" but it has been a long time. I know the filter was never changed so I thought at 55K, now would be a good time.

I actually didn't say it never gets old. It does. But it tends to "stabilize" after a period of time (after opening/use). It breaks down a bit (upon initial use) then settles at a longterm weight. But I am talking about normal use.

You make a good point about maintenance schedules. Manufacturers don't make maintenance schedules with collectors in mind. Driving 1k/yr isn't something they normally have in mind. In fact, I would venture to say most vehicles are designed for a 10-20yr lifespan. For example, manufacturer's documentation on the design of the C4 Corvette's FRAME talks about designing it for a 20-yr-lifespan!!! They don't consider you'll keep it for 50+ years....just to look at it.

Owning a collector car (OK two of them) gives me a bit more perspective. Even at my low use level, I don't treat fluids as lasting forever. Somewhere between 5-10yrs would be the maximum I'd let a fluid remain in my car. I think most collectors would lean toward the lower end (5yrs) as a reasonable flush/change interval. I wouldn't disagree. Items exposed to the outdoors visually degrade after 5yrs. OTOH, when sealed/protected, items last much longer. (I'm speaking about cellular decay.)

You should consider changing ALL fluids every few years including brake fluid -- which many never consider. On my 89 Corvette, the manufacturer's guide doesn't list an interval for diff fuild change. Dealers would say never change it. With a 20-yr "shelf life" and/or 200k miles, they might not be wrong. I wouldn't bet on it though....especially when fluid is cheaper than a component overhaul.

Here, the question is about trans fluid. I would categorize our transmissions as sealed since they don't even have a dipstick. As such, I would consider transmission fluid safe for a longer period of time -- but not 13 years. Plus, you wouldn't be spending excessive money on maintenance to swap fluids every 5-10 years! LOL Seriously, lubricants can/do separate/congeal under extreme circumstance. Driving keeps them "mixed". Sitting for long periods does the opposite. With lack of use, lubricants separate and gaskets dry out. Letting a vehicle sit really isn't good for it. Start and drive it every week or two....is something else I recommend you do.

And, what the heck, change fluids every ten years or so -- whether they need it or not! LOL

[Maddawg]

Hi all. I came in to post a thread regarding how to check fluid level on the Isuzu VX and found this thread instead. Very informative. Unfortunately for me there is no mention of the correct procedure to check fluid level. Is there a thread already available? If so can someone give me a link?

I watched the two YouTube vids that were posted above related to that subject but they only discuss GM and Toyota transmissions. So basically I am asking if there is a "straw"/tube or standpipe in the Isuzu pan as the vids show and is temp as critical as the vid suggested? Is the Isuzu fluid checked engine running, engine running in PARK, engine running in NEUTRAL? Any help would be very much appreciated, thank you.