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motor oil in automatic??

 
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a2000m5 a2000m5
New User | Posts: 5 | Joined: 01/06
Posted: 01/21/06
05:40 PM

I was adding fluid to my transmission after draining the pan and accidentally grabbed a bottle of 5-40W motor oil which was in the same brand/color bottle and mixed in w/ my box of Dextron.

I started to pour and as soon as I did I noticed the oil was not red. I'm guessing anywhere from 1 tablespoon to maybe 1/4 cup of oil went into the tranny. My vehicle is a 98 Range Rover w/ 80k miles on it and the tranny holds nearly 12 qts of fluid.

Should I worry about this? Should I get the tranny flushed? I'm fairly confident the amount of motor oil that made it into the tranny was closer to a tablespoon than 1/4 cup.

I know a rebuilt tranny costs about $4,000 so spending the money on a flush seems like cheap insurance. A couple of friends told me not to worry about it as it was such a small amount of oil and even a flush may not get 100% of the motor oil out of the system.  

buddymyra buddymyra
New User | Posts: 32 | Joined: 12/05
Posted: 01/21/06
05:47 PM

Don't worry about it. It's not recommended but it will operate on motor oil alone.  

a2000m5 a2000m5
New User | Posts: 5 | Joined: 01/06
Posted: 01/21/06
08:48 PM

really? You could run regular motor oil in the transmission, say, in an emergency situation? I didn't know that.

Thanks.  

Rapid Robert Rapid Robert
Enthusiast | Posts: 328 | Joined: 01/06
Posted: 01/22/06
08:53 AM

If the amount you added is that small, not a problem. Oil should never bee used for just one reason alone in an automatic transmission, FLASH POINT! The high heat range in an automatic can set motor oil on fire!  

loadholt loadholt
New User | Posts: 18 | Joined: 04/06
Posted: 01/23/06
03:58 AM

Naahhhh, won't hurt a thing. Hook 'er up and let 'er dig!
I had an old Nash Rambler station wagon (1968?) with a massive V8 and I ran recycled 30W engine oil .50 cents a quart in the auto tranny for a long time. HA! Ran it from Cocoa Beach to Daytona and back and literally had a ball.
 

loadholt loadholt
New User | Posts: 18 | Joined: 04/06
Posted: 01/23/06
04:03 AM

"really? You could run regular motor oil in the transmission, say, in an emergency situation? I didn't know that."   Can't say todays modern auto trannys would tolerate engine oil very well and Robert said it would catch fire, so I wouldn't do it under any circumstances.  Auto tranny fluid has an entirely different viscosity index, (thickness), than engine oil so no way I'd put engine oil in an auto tranny today.
 

buddymyra buddymyra
New User | Posts: 32 | Joined: 12/05
Posted: 01/23/06
06:06 AM

a200m5

Motor oil flash point is around 400 degrees minimun. I hope your transmission isn't rurring that hot. The bottom line is you haven't hurt it. And by the way like I said, it will operate on motor oil, but it's not recommended.  

a2000m5 a2000m5
New User | Posts: 5 | Joined: 01/06
Posted: 01/23/06
11:34 AM

Thanks for the input. I'll run it until it's time for a new filter/flush.  

Rapid Robert Rapid Robert
Enthusiast | Posts: 328 | Joined: 01/06
Posted: 01/23/06
01:58 PM

   It's real simple, If motor oil is Ok for an automatic trasmissions, then why do we use, and why do they make automatic transmission fluid? Better yet why don't we just use trasmission fluid in the engine instead of oil, since you guys think they are OK subsitutes? Or have you considered why the vehicle maker should just put in motor oil in their automatic trasmissions, since it is cheaper? Gee, I never read on either cans of these lubricanbts that they could be interchanged, even in an emergency!

There is a whole lot of chemistry in both these lubricants because of differences on what they are supposed to lubricate and cool and not to mention other things such as motor oil will "shellac" and clog up all those really small passages in the transmission when you keep taking the temperature to the "flash point" a hundred times a day!

Yes, it will make it work, but not for long!.

 

a2000m5 a2000m5
New User | Posts: 5 | Joined: 01/06
Posted: 01/25/06
09:51 AM

So, Rapid Robert, do you think I should worry about the small amount of oil that got into my transmission? Should I play it safe and have it flushed?  

Rapid Robert Rapid Robert
Enthusiast | Posts: 328 | Joined: 01/06
Posted: 01/25/06
11:54 AM

Not to worry mate, with that little, just run it!  

gearbox gearbox
New User | Posts: 2 | Joined: 01/06
Posted: 01/25/06
07:55 PM

engine oil will not harm a automatic in anyway, many people still add it for additional lube, adding  4 quarts or more of synthetic engine oil like amsoil or mobil 1 is suggested by companys like transgo....(transgo has registered trademark on the term shift kit...not exactly a new kid on the block. I have used it in many applications.  

a2000m5 a2000m5
New User | Posts: 5 | Joined: 01/06
Posted: 01/30/06
08:26 PM

Gearbox,you're saying some good synth oil is good for the AT?

I've been using Amzoil products for 10 years. Everything they make is great IMHO. Not cheap even if you're a dealer but the best there is.

 

lance_edwards93 lance_edwards93
New User | Posts: 1 | Joined: 06/15
Posted: 06/04/15
08:12 PM

Ya, it wasn't my daughter. It was my 28 year old son and I.  We were getting the hot rod fired up for the summer.  I grabbed a jug of motor oil instead of the tranny fluid (it leaks out all the fluid every year and I honestly can't find the leak) he started pouring it in then after about a quart he started yelling.  The blame game didn't go far.  He said "you gave me the motor oil, I said "you didn't notice  it wasn't red?".  Well, we're both experienced gear heads and we both should have known better.  Thank God the car wasn't running yet.  I sent him under the car to drop the pan.  Why didn't they put in a drain plug?  GEEEEEZE!  Darn Chevy's.  Looks like the oil went straight to the pan, 30 wt is heavier than tranny fluid I guess.  Dropped the car back to level without the pan to let it drain overnight and cleaned out the pan.  We'll flush it with a couple quarts of very expensive fluid, fill 'er up and see if it'll still smoke some rubber.  I think it will.  It's an '84 Z28 with a 355 and a B&M street blower; the Turbo Hydromatic 400 has never let me down.  I'll let you guys know on the manana.  

Just Try It1 Just Try It1
Moderator | Posts: 1152 | Joined: 08/14
Posted: 06/05/15
01:00 AM

i can explain why the fluid leaks when you leave it parked for a while..

the torque converter is filled to the top with fluid.. but the opening is half way up..

when you let car sit with the engine turned off the fluid is not really trapped in the converter like it is a 5 gallon jug on a water cooler.. there is a tiny gap beween the input shaft and the stator shaft where the bushings are.. the fluid will dribble thru that tiny gap over the days, weeks or months of sitting without the engine being started where the fluid will be pumped back into the converter...

the fluid fills the transmission case to the top.. it will either come out the vent  which is just below the top of the case level..  it only takes a quart and a half of leak down out of the almost 4 or 5 quarts in the torque converter to fill the case..

it can also leak from the speedometer drive gear.. you may want to replace the speedo gear support.. the thing the speedo cable is screwed to on the transmission tail housing. inside that is a tiny seal.. a wire ring retainer.. and the driven gear.. if the gear is worn.. you will have to match it by teeth and color.


you could also need a transmission tail housing bushing and seal replaced.   under the car.. the rear wheels in the air.. the parking brake released.. so there is no tension on the drive shaft.. grab the yoke.. see if it will wiggle. (O )  ( O) is bad.  it will probably be bad up and down.. but it could be left or right.. the tail shaft bushing kit is available with a new seal.. press the bushing in with the tail housing off the transmission.. make sure the drive shaft yoke will slide freely thru the bushing before you put the seal in.. sometimes the edge of the bushing mushrooms a sharp knife can carve the edge back open.

lastly there are 2 more places for the transmission to leak down at.

the manual lever seal.. that is in the side of the case.. where the shifter is attached.. and the KICK DOWN wire connector plug.. the TH400 uses an electric kickdown.

because you have your TH400 in an 84 Z28.. you have more stuff to do to get the rear tail housing off .. with all that you might even have the truck arm conversion done to it.. Hot Rods To Hell Centerdrive Truckarm Rear

who knows.

the tail housing unbolts fairly easily if you c  

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