New (to me) truck question.

I just bought a 1990 full size Chevy, 1/2 ton 2WD with 68,000 miles on it. It's the first automatic transmission I've owned in 30 years, hence the question.

It's been softly driven and spent most of the last two years sitting in a shed, I want to change the oil and tranny fluids but someone is trying to convince me that messing with the transmission will just open up a can of worms. It it ain't broke, don't fix it! I understand the logic, but I see a fluid and filter change as routine maintenece.

What do you say?

Dan

Could go either way, but wouldn't you rather know? Crack her open... Metaphorically.

I see a fluid and filter change as routine maintenece.

This^.

I'll post pictures once I get all the mung off it.

The can of worms thought comes from the people who wait till the trans acts funny to service it then blame the fluid change for breaking it. It is regular maint.

I would say "if it ain't broke...." would only apply if you had been driving this truck for a few weeks or months and you JUST wanted to change the fluid/filter because....? When a vehicle has been sitting awhile, changing a fluid couldn't/shouldn't hurt and in fact could forestall damage.

Change it. Might be good idea to do a complete change. Since dropping the pan changes only a part of the fluid.

Don't bother dropping the pan, have a shop do a hot power flush where they get all the fluid in the tranny, converter, lines and cooler. After one of those you'll be fine.

jimbob_racing wrote: Don't bother dropping the pan, have a shop do a hot power flush where they get all the fluid in the tranny, converter, lines and cooler. After one of those you'll be fine.

Agreed.

Whether I do it or a shop, any opinions on Lucas products?

There's an old school of thought that if the auto tranny fluid is skanky, but the tranny is working, changing the fluid will immediately destroy the transmission.

I'm not old enough to know where this theory comes from, for it's an old theory. But I don't agree with it.

DIY full tranny flush is easy, although sometimes messy. Disconnec the line to the cooler/radiator, start it up. Pour in new fluid as the old pumps out. Takes 2-3 gallons.

FWIW: a bit long, but, Wouldn't it be a good idea to drive it for, oh, 100 miles or so, to get all the seals "resealed", and get all the gunk that may have settled in the cooler, nooks and crannies in the tansmission into suspension, and then do the flush?.

A really well respected, trans shop--one that does not have to advertise, recently doubled in size, and is always busy- and I have personally used, does not recommend changing the fluid on older vehicles when there's a problem. I had an escort's auto trans act up, and after they partially changed the fluid, it got worse. They put the old fluid in (following their own policy, they saved the old stuff) and the trans came back to it's cantacerous, but working self. I got another 840 miles out of it before I could sell it. Maybe luck, maybe a one-off occurance, but, it kinda goes with the if it's not broke don't touch it thinking.

I would, however, pull the dipstick and look really closely for signs of pitting/rust on the dip stick. If it was stored in a damp area or one with large heat cycles, then I'd change the fluid for a period-correct fluids; do check for potential compatability problems. I know on some manuals, where there can be huge compatability problems with current, new fluids and older trannys. Something to think about. Continue debating.

I know people who use Lucas religiously, and can point to having nothing wrong with the vehicle. At the very least it won't mess anything up, I suppose.

jimbob_racing wrote: Don't bother dropping the pan, have a shop do a hot power flush where they get all the fluid in the tranny, converter, lines and cooler. After one of those you'll be fine.

this is where i see the "if it aint broke dont fix it" theory comes from. on a new vehicle doing the flushes on a regular basis is great, but i personally have seen problems form flushing trannys that had poor maintenance. a standard fluid and filter change should cover all you need .

on a side note, i have a 1990 silverado with a 5 speed if you want to trade trannys to have a manual again. lol.

I'm still trying to get the "sitting in a barn in Georgia" smell out of it and the mung, moss, fungii looking E36 M3 growing in the corners, but yeah I plan on driving it before perfoming any maintenence or changes.

Thank you for the imput.

Dan

Are you a squatter at my house I don't know about? I have an e36 m3 too. Lol and I bought my truck from a guy just south or Georgia.

I would recommend a regular change of fluid and filter - not a flush.

chandlerGTi wrote: The can of worms thought comes from the people who wait till the trans acts funny to service it then blame the fluid change for breaking it. It is regular maint.

+100million.

Theses are the same people who think a Shift kit is a rebuild kit...

I change the fluid on any auto trans vehicle as soon as I get it, once or twice it has led to an issue but in most cases the auto has gone another 100 to 150K without trans problems.

These are usually 100K+ vehicles which do a lot of miles for the next few years until worn out.

YMMV