96 Leg OB overfilled transmission damaged?

[paulivan]

Did I damage my 2.5L, Leg-OB auto transmission by putting in about 1-gallon too much fluid and driving a couple hundred miles?

 

I drained fluid by removing pan plug then put full fluid amount specified in Chilton manual (10 quarts!) following process described which said nothing about only getting partial drainage of fluid.

 

Later I found a small amount of fluid leaking around passenger side upper transmission case. I removed about 4 qts of fluid to get the dip stick to read correctly.

 

Will this overfilling have damaged my transmission? Should I look out for any signs of trouble now? I drove around a bit and the leakage seems to have stopped. Am I OK to drive without worry or is my tranny about to blow any day now?

 

I understand the correct procedure now, just hoping for advice on what to expect as far ans any permanent damage.

 

Thanks,

 

PT

[nipper]

1 GALLON!

 

I think you may get the award for most overfilled.

 

NOrmally i would say no, but i've never seen one so over filled and be driveable. Usually it screws up the shifting.

 

I think you would be ok, as Auto Trannies die slow deaths and will give you warnings. If your not slipping when the car shifts your fine.

 

nipper

[crash321]

:eek:HOLY CRAP:eek:

[98obster]

:eek:HOLY CRAP:eek:

 

yep, stole my line (insert pic of peter boyle here). did you get the AT light? check radiator cooling lines-that's a lot of pressure on the system with, what like 15 qts?

 

Also, I just want to say how much I love this site, where you can admit a misake and not fear constant flaming

[nipper]

:eek:HOLY CRAP:eek:

 

i was trying to be nice, but OK i will second that

 

nipper

[kingbobdole]

If it's not slipping or binding, you're fine... Man that's a LOT of fluid over filled... Didn't push anything out the vent? Didn't foam it up? Amazing!

[crash321]

i was trying to be nice, but OK i will second that

 

nipper

 

you know, holy crap, in a kind, pat you on the back way. Not flame broiling. (Believe me I've done a lot worse! (No, I don't know how that shipment of s-10s all got smushed together like that. Me, back into them with a ford tuarus with no brakes! What!)

[paulivan]

Thanks for the gentle flame broiling of my mechanical ego!

 

I'll post again if any trouble arises so others can learn from my experience.

 

For now all seems to be going OK. I did not notice any symptoms or change in performance while it was overfilled, just the leak coming from trans housing.

 

There is a cylindrical shaped part of trans housing, passenger side, vertically oriented, about 10" long and 1" diam, with what seem to be two rubberized seals, top and bottom. The leak seemed to be coming from these seals. It is not a separate part, just part of the bell housing mold. Does anyone know what this is?

 

PT

[johnceggleston]

what color was the fluid you drained?

 

where did you pour in the new fluid? passenger or driver side?

[EVOthis]

yeah...wow im kind of surprised that you didnt see any fluid coming out of the filler tube or anything...especially if you only drained the pan...

[paulivan]

The drained fluid was red.

 

Filled ATF through long dipstick tube on driver side that goes to pan, not the tube on passenger side with a short dipstick and gear oil in it . I'm sure I got that part right.

 

I saw no no leakage anywhere except the passenger side of tranny case, around rubber seals on housing which has now stopped.

 

I guess my tranny has lots of room for extra fluid...or it leaked out of tube and I just didn't see it.

 

PT

[johnceggleston]

because of my very limited knowledge, i would never base the correct fluid level on a cold trans; everyone knows you check it when it's hot. but, it can be difficult to read when hot. so i would always check the fluid level when cold after a drain and refill, just ot see if i'm in the right ball park. then fine tune after a test drive with the fluid hot.

 

there are some tricks to reading the dip stick when hot if you want to search for them.

[mountaingoatgruff]

i think the two seals you're talking about are the 1" - 1.25" plugs with circlips locking them in place - top one's horizontal on top pass front of trans case, the other is vertical about 6" directly below.

 

those are simple plugs, there's nothing held in by them and they're just locked in place with the clips. get the clip out with lockring pliers, tap one side to turn it, grab and yank with pliers (just be damn sure you don't gouge the aluminum bore). should be able to get the seals for a couple bucks, the bear will be getting tools in there. pull the torque strut and rear driveline out then just unbolt the rear crossmember and lower it all down with a jack under the rear of the trans.

 

of course, if they seem to have quit leaking now that the atf is at the proper level you can just keep an eye on them to make sure they don't continue leaking slowly and if they're legit just leave them.

 

with enough pressure to spring external leaks i'd also keep a close eye on the front pinion seals! check the front diff oil for atf contamination regularly.

 

other than that you said its not slipping so if anything, running the extra 5qts of atf probably just cleaned the snot outta that trans!

[paulivan]

Just to follow up with one more question now that all seems to be OK with the leak after overfilling.

 

Since I put so much fluid in there (8qts new fluid went in then about 4 qts were drained off to get the proper level) did I put in enough new fluid to make this a complete or adequate fluid change?

 

should I continue to drain/fill a couple more times or just leave until time for another change?

 

Thanks,

 

PT

[nipper]

Leave it alone, why bother tempting the automotive gods.

 

Now if you really rteally want to do this regularly, every other oil change do a drain and fill.

 

Hydraulic fluid, unlike other fluids, get refreshed when new fluid is added.

 

nipper

[forester2002s]

Hydraulic fluid, unlike other fluids, get refreshed when new fluid is added.

 

Can you elaborate on this? I've never heard of this phenomenon before.

[nipper]

Lets look at the fluids under the hood;

 

Antifreeze - in an ideal world can last for the life of the car if it is pure antfreeze. In modern antifreeze you have lubricants and anti corrison chemicals that wear out. These chemicals also make sure there is no electro-chemical reactions between all the differnt materials in the cars cooling system and to keep from eroding parts from physical friction. The coolant is exposed to (for an engine) fairly moderate temperitures.

 

Engine oil - Exposed to hell. It is exposed to extreemly high temperitures as well as low tempertiures. It sees very high pressure (not from the pump, but by acting as the cushion in the bearings. It is desgned to capture dirt and hold it in suspension untill it goes through the filter. It is also exposed to gasoline and its additives which will thin it out over time.

 

Brake fluid - Exposed to high temperatures (can be as high as 650 degrees). Every time the Master Cylinder is opened it absorbs water from the atmosphere. It also protects against corrosion.

 

Now transmission (hydraulic fluid) - used in the transmission and power steering. In comparision it has a rather charmed life and unlimited shelf life. Hyd fluid primary job is to transmit force, its secondary job is to cool and lubricate. Since automotive transmissions have thier oils dictated by the mfg, the viscosity is not a worry (yes hydraulic fluid does have viscosity specs). They all have anti corrosion aditives ( a minor problems as I have yet to see the insides of sealed transmission corroded), antifoaming (critical). Tranmsissions are basically sealed, but other properties are the ability to seperate water out of the oil (more important in construction equipment). Every wonder why modern cars seem to have sealed transmissions (those sticks can be a PITA to get out sometimes), its to keep the enviorment out. BMW has gone as far as sealing thier transmissions. There are some detergents, but since the fluid lives a charmed life they are not that important. Once a transmission starts to make sludge and the things dtergents protect against, its generally a mechanical fault or lack of maint then a failure of the fluid.Transmission lubricant generally does not operate at high enough temps to cause varnish (as long as you dont do heavy duty driving or the clutches dont slip).

 

Interesting factoid, every 18 degrees over 140 F you can cut the life of your tranny fluid in half. Rule of thumb with a tranny/hydraulic fluid temp gauge is that the oil should not exceed more then 100 degrees hotter then the air temp. Over 140 the additives start to break down.

 

Dirt is not a problem in transmissions (this is why i hate transmission shops). All trannies will shed material. This material will collect in the bottom of the pan because that what it is supposed to do. Engine oil will hold particulates in suspension and let the filter take out the dirt. transmissions are the opposite. i can sell a trannny job to almost any unsuspecting person that walks in off the street if i wanted to.

 

When you add fresh fluid, that fluid gets mixed in with the old fluid. You are adding fresh additives at this time. Depending upon your math, you are replacing 20-25% of the fluid on a drain and fill. The new fluid mixes with the old fluid (assuming the fluid is not burnt). Also since the fluid lives a charmed life it doesnt take much to give it what it needs. Its not contaminated like antifreeze/oil/brake fluids can get.

 

You may have noticed that soobys shift hard. The harder a tranny shifts, usually the longer it will last. Soft shifts mean the clutches are slipping. SLipping clutches under load can easily make high spot temps for the fluid. The synching of the shifts with engine torque reduction at that split second of engagement, have trippled the life of a transmission, along with better clutch material and seals.

 

I dont think i am explaining this well, as i hate NYE (long story).

 

Does that help?

[iflyifr]

Thanks Nipper. That was one of the best bunch of data and information I've ever read on fluid and will be very useful to me. Now I'm glad I didn't let the Subaru dealer sell me a tran flush when getting only a drain and refill. He said it was necesary to get all the old fluid out.

Well written....

Jim

[nipper]

i use synthetic engine oil. Every 7,500 miles i change the oil as i do lots of short trips. Every oil change I do a drain and fill. This always keeps some fresh fluid in there, and saves me alot of work (as i am already under the car).

 

 

But thats just me.

 

Oddly i left out blinker fluid....

 

 

nipper

[paulivan]

Thanks everyone, I learned a lot more than I thought I would from that mistake!

 

USMB Rocks!

 

PT

[nipper]

Thanks Nipper. That was one of the best bunch of data and information I've ever read on fluid and will be very useful to me. Now I'm glad I didn't let the Subaru dealer sell me a tran flush when getting only a drain and refill. He said it was necesary to get all the old fluid out.

Well written....

Jim

 

Well you have to do drain and fills at regular intervals. If you want to let your fluid goo 3/36,000 miles then you have to do the 4x drain and fill to get clean fluid in there, then you can start doing drain and fills.

 

If at any time your fluid smells burned, looks brown, or you have an AWD issue then you need to do a full change, but even that can be done in your driveway.