Trans fluid change at 136k miles?

[CrustyOreo]

Car is a 94 LT1 C4. It has 136k miles. I have no history on if the fluid has been done before. Good idea or bad idea?

 

[Hib Halverson]

Excellent idea. Change the trans filter while you're at it.

 

[CrustyOreo]

It's an automatic.

 

[Otter]

Excellent idea. Change the trans filter while you're at it.

Hib, I have read, and been told more than once by different folks, that one would open up a huge can of worms by changing the trans fluid on a auto tranny that hasn't had one in years. Is that an old wive's tale?

 

[Hib Halverson]

Let me ask my wife about....uh...she's younger than me so she's not an "old wife".

Ok, seriously...I've heard that legend from various sources but never have seen any facts to support it.

If it were my car with 136,000 on it and I didn't know the service history, the first thing I'd do is change:
Oil and filter
Power steering fluid
Brake fluid
Trans fluid and filter
Rear axle lubricant

 

[Otter]

Let me ask my wife about....uh...she's younger than me so she's not an "old wife".

Ok, seriously...I've heard that legend from various sources but never have seen any facts to support it.

If it were my car with 136,000 on it and I didn't know the service history, the first thing I'd do is change:
Oil and filter
Power steering fluid
Brake fluid
Trans fluid and filter
Rear axle lubricant

Thanks, I appreciate the info. All of the above has been done on my 178k mileage 89, except the trans fluid/filter. Have no problems with the tranny, but had heard so many 'stories' that I didn't want to upset the apple cart by being overly diligent.

 

[hotmtrsports]

Let me ask my wife about....uh...she's younger than me so she's not an "old wife".

Ok, seriously...I've heard that legend from various sources but never have seen any facts to support it.

If it were my car with 136,000 on it and I didn't know the service history, the first thing I'd do is change:
Oil and filter
Power steering fluid
Brake fluid
Trans fluid and filter
Rear axle lubricant

Ditto ++++

Chuck M

 

[Hib Halverson]

If you've never had the fluid changed in 178,000 miles, I'm astonished. Back then, periodic transmission fluid/filter changes were required by the FSM.

Rather than just changing the fluid and filter, but take it to a trans shop and have the trans flushed. That's the only way to do a complete change.

Also, when they pull the pan to change the filter is there's more than a dime's worth of metal powder on the bottom of the pan, I'd rebuild the trans.

 

[Otter]

If you've never had the fluid changed in 178,000 miles, I'm astonished. Back then, periodic transmission fluid/filter changes were required by the FSM.

Rather than just changing the fluid and filter, but take it to a trans shop and have the trans flushed. That's the only way to do a complete change.

Also, when they pull the pan to change the filter is there's more than a dime's worth of metal powder on the bottom of the pan, I'd rebuild the trans.

Bought the car 8 yrs ago from the original owner with 166k miles, he kept up with most maintenance but never messed with changing the trans fluid/filter. He told me at this point, with the mileage, I would be better off leaving it alone. Subsequently, I have asked others (one was an owner of a trans shop), and they said if it isn't acting up, leave it be. So...the trans has been fine, no problems, thus I haven't touched it. The original owner was a close friend, an engineer at NASA, so I pretty much took his thoughts as gospel. Funny, any time the car has a hiccup or something, I immediately think, "I gotta call Bob about this"..Hard to believe he's been gone 4 yrs.

 

[JHO]

The Truth.

There's an old wives tale about changing transmission fluid causing the transmission to "go bad" There's some truth to this, although the fluid isn't really to blame.. It's gunk.

Clutch material mostly. Some metal. (Transmissions don't run as clean as engines, which is fine.) This stuff builds up like arterial plaque inside the cooler, in passages and drums.. Converter fins.. Etc.

ATF is extremely detergent. It's a very advanced fluid. It does such a good job of cleaning it can wash a glob of plaque loose and stick a transmission component, causing undesired operation or failure.

This was more common in older units which used a mechanical governor. It was on the backside of the cooler/lube circuit and it would wash glop right around and stick the governor... The transmission stops shifting, and people think it's gone "bad" You could clean the governor and the controls, of course.. But since nobody knows that, they just cursed and replaced the entire transmission.. THEN blamed the fluid change for "killing it"

Yours is a newer model, it's got electronic controls. No governor. Much, much less risk in a high mileage fluid change.

If it were mine I'd do it. Then again, I own a transmission shop and if it gave me any crap, I'd just yank it out and rebuild it.

But at least if you understand exactly what happens and why, you can make an informed decision.