How low is too low (tranny fluid)

[98gpgt]

98 GP GT. Changed my radiator. Like a fool I forgot to tighten the coolant line nuts. I went to bed, said I'd worry about it tomorrow. Well it's tomorrow. I had to take all kinds of crap off just to get to the lower line. I decided to break for breakfast. I ran it around maybe as much as 10 miles last night, all the while fluid spilling out. Mostly 30 mph or so, a couple of times i got it up to 50+, with ample acceleration, for 1/4 mile or so. Yes there were a few hiccups. Fluid is about 1/8" below bottom of hash pattern (cold). Going to tighten up bottom fitting and put up to whatever I have sitting in the trunk, maybe a quart and a half left of Castrol.

 Should I expect a catastrophe when I get it on the road? About 144k, fluid is slightly orange. Never any tranny problems, a couple of burps/skips/misses over the 2 years I've been driving it, don't even know if that was tranny related. Even if everything seems ok, should I change the fluid (and inspect the pan)? Is fluid color a more or less an absolute gauge of whatever shape your tranny is in? Does a little bit of metal, and I don't mean a dusting, which is normal, at the bottom of the pan mean heartache is coming?

Edited August 21, 2018 by 98gpgt

[vipmiller803]

You'll be fine. Top it off and drive it. As long as you weren't in it while it was slipping for minutes at a time, low fluid will make itself known but won't kill the trans in thatt big of a hurry.

When you checked the level, was the car running?

When you say you didn't tighten the cooler lines, were they attached, just not tightened? Or were they spraying wildly?

[98gpgt]

They were attched, but when I pulled up and popped the hood, the top fitting at least was eh gushing? pretty good. I tightened everything up. I may have another coolant leak LOL. The belt was spitting at me, thought it might be the water pump. But it stopped. We'll see.

 

Car was cool when I checked the level this morning. Added about a quart so far. Was making noise when I manually sshifted to first (see I'm nervous). A little also in neutral, but that seemed to go away.

 

I think there might be a trail of tranny juice wherever I went.

 

Thanks manster! It makes me feel real fine hearing that. Still got to take it out though. Got to shower the crud and ooze off myself first.

Edited August 21, 2018 by 98gpgt

[vipmiller803]

Coolant leaks that do not get repaired right away often reveal other leaks when they are finally repaired.

I understand it was cool. When you're checking the trans fluid, is the engine running?

[98gpgt]

No, car off. Just wanted an idea of where it was. Once running I added about a quart. Probably need to add more, but don'-t want to overfill

[vipmiller803]

Trans fluid level is checked while car is running. The dipstick level means very little with the car off. If it's making noise, then you are starving it for oil.

If you're seeing low fluid with the car off, then you're probably 2-3 quarts low.

Edited August 21, 2018 by vipmiller803

[98gpgt]

I know that, but it has to be checked when warm. I didn't want to keep running it around low on fluid. I was contemplating taking the bus to buy more.

 

How far would you drive, according tonyour estimate, .5 - 1.5 quarts low? I put a quart in, half 1/2 left over. I'll probably just dump that in before I leave. Or run it ab while and check it?

 

I'm not trying to be a pain. I just really don't know what the effects of running 1, 2, 3 quarts low would be.

[digitaloutsider]

If it's barely showing up on the dipstick when off, I wouldn't drive it man.. 

[98gpgt]

It was showing up. The morning after I sprinkled the town candy apple red (nearly) it was a bit below the low hash mark. Car was off and cold. Since then i've added a quart.

[98gpgt]

Ok well car is good. I drove 6.5 miles to whalemart, bought valvoline dex/merc in a jug. It took about 1.5 quarts. So I guess I sprinkled about 3 quarts around town. Rides smooth though. And my radiator hose burst. Alls well that ends well.

 

Thanks for all the help.

Edited August 21, 2018 by 98gpgt

[Schurkey]

If you already know that the trans fluid is discolored and the vehicle has 144K miles on it, why not drop the pan, change the filter, and then re-fill with fresh fluid?

I'd have done that before dumping 3 quarts of fluid into it.

[Imp558]

I'm on the fence with that one. 

Proper maintenance is a good idea but sometimes fresh fluid will kill a transmission quickly. 

That said I've done 2 or 3 4T65E's with no repercussion because they were new to the car.

[cheatah faheatah]

3 hours ago, Imp558 said:

I'm on the fence with that one. 

Proper maintenance is a good idea but sometimes fresh fluid will kill a transmission quickly. 

Would that be a case of the new fluid flushing out whatever gunk is holding said transmission together ?  I've been leery of changing mine [o6 GP 135k miles] because of just that. Sometimes "Let It Be" is the way to go, I think, if nothing is acting up. Thoughts ... [open to all]......

[digitaloutsider]

That is a complete myth. If the trans fluid is old, you should change it, and the filter.

[cheatah faheatah]

Just now, digitaloutsider said:

That is a complete myth. If the trans fluid is old, you should change it, and the filter.

We should start a "Poll" ?????????

[digitaloutsider]

The only time a transmission fluid and filter change MIGHT accelerate a failure is if the transmission is already fucked, and the clutches have gotten so damaged that the fluid is full of friction material. The transmission in that case is already on it's way out.

A fluid and filter change will never harm a properly functioning transmission.  All lubricants have a maximum service life, and filters get clogged with garbage.  There's no reason not to change it. It's also an opportunity to clean the magnet in the pan off, especially with the 4T65E and how quickly it gets full of gunk. 

The only thing that is not recommended, including by manufacturers, is using a solvent-based flush.  It tends to be done incorrectly, leaving lots of it behind.  A flush using normal fluid being pumped by the transmission itself should cause no ill effects.  If we're going off anecdotal evidence, which is weak at best, I've changed the fluid and filter on plenty of 200K+ mile transmissions and I have never seen a failure. Including changing the FACTORY filter from my 200K mile 1998 ZJ.  The key is that none of those transmissions were defective in the first place (well, beyond being 4T65Es which is a defect in and of itself).

[Imp558]

The theory is that the new fluid attacks the worn clutch friction material more aggressively than the worn fluid.

I've never seen it personally, my transmission builder holds to that as "The fastest way to kill an old transmission".

Realistically there has to be at least a little truth there but the fluid and filter change in an attempt to save a failing tranny would probably still result in a failed transmission because it was already CTD. So there's likely a significant failure rate right after a fluid change because most people wouldn't think to do such a thing until they see signs of trouble. 

 

[digitaloutsider]

54 minutes ago, Imp558 said:

So there's likely a significant failure rate right after a fluid change because most people wouldn't think to do such a thing until they see signs of trouble. 

That is exactly what it is.

And I'd run far, far, far away from any transmission shop that told me new fluid kills transmissions.

[vipmiller803]

I have to agree with Shaun here. If you change the fluid and the trans dies, that trans was long gone already.

In our case though, my experience tells me that fluid maintenance matters less than other platforms. Sure, you don't want fluid totally destroyed, but a serious number of failures in the 4t60/65 lineup is hard parts, which couldn't care less what state the fluid that bathes them is. If you ask me, adding a good trans cooler is far more important than doing fluid maintenance.

Edited August 24, 2018 by vipmiller803

[Schurkey]

On 8/23/2018 at 5:16 PM, digitaloutsider said:

The only time a transmission fluid and filter change MIGHT accelerate a failure is if the transmission is already fucked, and the clutches have gotten so damaged that the fluid is full of friction material. The transmission in that case is already on it's way out.

A fluid and filter change will never harm a properly functioning transmission.  All lubricants have a maximum service life, and filters get clogged with garbage.  There's no reason not to change it. It's also an opportunity to clean the magnet in the pan off, especially with the 4T65E and how quickly it gets full of gunk. 

The only thing that is not recommended, including by manufacturers, is using a solvent-based flush.  It tends to be done incorrectly, leaving lots of it behind.  A flush using normal fluid being pumped by the transmission itself should cause no ill effects.  If we're going off anecdotal evidence, which is weak at best, I've changed the fluid and filter on plenty of 200K+ mile transmissions and I have never seen a failure. Including changing the FACTORY filter from my 200K mile 1998 ZJ.  The key is that none of those transmissions were defective in the first place (well, beyond being 4T65Es which is a defect in and of itself).

Thank you.  You saved me a lot of typing.