Leaking Auto Gearbox Oil

[Graham Whitehead]

Hi all, I had to go and recover my son's lexus IS250 yesterday, the Donut hit a post, while avoiding an animal, car now written off, animal safe and well !!!!!

Anyway I had a recon gearbox put in a few months ago, ( P reg Auto 3 Ltr Colorado) had to use the old torque converter, as I could not get another one for love or money.

Car had been running like a dream no problems until yesterday, had to go from Bath to Wells to recover the car, (with police permission as it was a hazard), got there no problem, all loaded up and off we go.

Anyone who may know this area, will know Bristol hill. there is a long steep hill going out of well, got up there no problem, pulled like a train.

Got back to my Unit, and there is gearbox oil all over the front of the trailer, all over the Front Of The Lexus and all over the back of my cruiser


Got it over the pit and gearbox oil all over the lower part of the engine from mid engine to gear box strut at mid way, cleaned as much as I could get to, started the engine, son putting it in and out of gear, not a leak in sight.

Topped up with 1 Ltr of oil .......

All steamed off last thing last night and clean as a whistle.

Now as I am an NHS volunteer I do a bit of legal miles most days, get back tonight, not a drop of oil anywhere, none on engine none on the gearbox or on the floor, its as if it never happened ???

Can any one explain this as I totally flummoxed

G

 

[AdventureWagon]

Hi mate exactly the same happened to me last year. Did hundreds of miles round town no issues. Towed my camper trailer (1000kg) for the first time on a long trip, ATF all over trailer when I got there.

Took to a mechanic near my campsite and he said the oil pan bolts were half loose, left that way by the guy I got to service it all when I bought the truck.

Overfilling can also be a cause, as the ATF can expand when hot and leak out of the breather.

The ATF will get a lot hotter and thinner when under a higher load like a trailer causing these things to happen.

Seal failure or transmission to radiator plumbing can also be a cause though I'd expect you would notice this with or without a trailer, maybe not if marginal maybe.

 

[Graham Whitehead]

Thanks, where would the ATF Breather be, I did have to put another 1 Ltr in to bring it up to the hot level after a run to warm it all up, but still no leaking

Will check the sump bolts, but surly they would of been leaking anyway ?

Was going to buy a caravan for the summer, ?? so got to get this fixed

G

 

[jibberjabber]

Thanks, where would the ATF Breather be, I did have to put another 1 Ltr in to bring it up to the hot level after a run to warm it all up, but still no leaking

Will check the sump bolts, but surly they would of been leaking anyway ?

Was going to buy a caravan for the summer, ?? so got to get this fixed

G

Just out of intrest as I don't have a 90, Iv'e got a 100, do you check the Auto GB with the engine running and the GB warm? Also my guess would be the ATF coming out of the vent/breather, just as AW said.

Sounds like you or someone else may have over filled it in the past.

Found this on another LC site, just for ref.

Checking Automatic Transmission Fluid

Question
How do I check my vehicle's Automatic Transmission Fluid?

Answer
CHECKING AUTOMATIC TRANSMISSION FLUID LEVEL


TOOLS AND SUPPLIES:

Automatic Transmission fluid
Rag or paper towels
Funnel

INSTRUCTIONS:


Check the fluid level when the transmission is hot (normal operating temperature).
If the vehicle has been driven over 10 miles or 16 km (15 miles or 24 km in frigid temperatures) and the fluid temperature is 160-175 degrees F, 70-80 degrees C, the transmission is hot.

If the vehicle has just been driven for a long time at high speed or in city traffic in hot weather, or if the vehicle has been pulling a trailer, an accurate fluid level cannot be obtained. Check the level after the fluid has cooled down (about 30 minutes).
You may check the level when the transmission is cold. If the vehicle has not been driven for over five hours and the fluid is about room temperature 70-85 degrees F, 20-30 degrees C, the transmission is cold. However, checking a cold transmission is to be used for your reference only and the transmission must be checked again for correct level at normal operating temperature.

Step-by-step procedures.
With the vehicle level, first set the parking brake and then start the engine.
While the engine is idling, depress the brake pedal and shift the selector lever into each range from "P" to "L" and return to "P".
With the engine still idling, check the fluid level and condition on the automatic transmission fluid dipstick.
Pull out the dipstick and wipe it clean with a rag (be careful, fluid is hot).
Reinsert the dipstick -- push it in as far as it will go.
Pull the dipstick out and look at the fluid level. If the transmission is hot, the fluid level should be in the "HOT" range on the dipstick. Similarly, if it is cold, the level should be in the "COOL" range.
While checking the fluid level, also check the condition. If the fluid is black or if it smells burnt, have it changed.
CAUTION: Moving parts like the fan blade and drive belts, as well as extreme heat in the engine compartment or from the exhaust system, can result in serious injury.

Approach with caution and care.
Never take short cuts.
Improper servicing may damage your Toyota and lead to personal injury.
Unless you have the proper knowledge, equipment and tools, have your local Toyota dealership perform the repairs and maintenance.
If the level is low, add the appropriate automatic transmission fluid for your vehicle.

If the level is at the low side of either range, add the appropriate automatic transmission fluid for your vehicle to bring the level within the range. (Fluid is added through the dipstick tube, using a funnel.)


NOTE: Avoid overfilling, or the transmission could be damaged.

 

[AdventureWagon]

Breather is in top of the transmission, quite hard to get to. Just use the official torque rating on the pan bolts, don't be tempted to go tighter as this can distort the pan and cause leaks.

In your case as JJ says it was likely overfilled especially if nothing else side from the leak went wrong.

When you do check the dipstick remember the transmission has to be hot and this can take much longer than the engine. Weber Auto YouTube did a video about this a while ago and it took over 80 mins of idling to bring a tranny up to temperature.

Don't be put off about the caravan. I tow my 1000kg trailer without issue now and I would not hesitate to go to 1500kg if I had the money for a new one! If your in doubt take to a transmission shop for diagnosis.

There's also other ammo to use here like transmission coolers which are fairly easy to fit.

 

[AdventureWagon]

This is the video IIRC