Too much AW4 Transmission fluid... bad idea?

OK, so I know that overfilling an engine w/ oil is a bad thing and my 'guess' is that it's bad for an auto tranny as well.... so here's my question.

Last night while cruising down the highway, I noticed that my RPMs jumped up f/ about 2100 to 2600 and then down and then back up again... staying at about 2600 rpms @ 70mph. As I finally pulled off the highway and came to a stop I noticed smoke coming out f/under the XJ .. So I pulled into the nearest convienent store and popped the hood. Then looked under and saw something leaking onto the exhaust down/cross pipe (before the catalytic converter) and so I drove home (about 2 miles) and into the garage. Changed my clothes and came out to see if I could figure out where the fluid was coming from.

I was thinking it could be coming f/my Oil Pressure Sending Unit... as that has popped off the electical connection about 2-4 times in the past month and I've been meaning to replace it... but when I was trying to diagnose the problem and pulled the connector off the OPS there wasn't a significant about of oil dripping or shooting out of that.

So I checked the fluid level in my AW4. Put the XJ in "N" and pulled the emergency brake. The Fluid level was over a Quart Over Full. So I drained about a pint (give or take) of hot fluid out of the tranny. Checked the dipstick and the fluid level is still a bit high so I'm going to just do a transmission fluid change this coming weekend (I just changed the fluid about 4 months back and I'm pretty sure I didn't overfill the tranny at that time so I'm a bit curious/concerned how it got so overfilled).

I couldn't pin-point where the leak was coming from. The 'fluid' that was leaking very very slightly was coming off where the pan and the torque converter area meet. Plus I noticed that the entire passenger lower side of the motor, oil filter and starter are covered in what looks like and oil and water mix. (Mind you I have 218K miles on the XJ and she's not real clean underneath... but has always been real reliable) It was impossible to really see where the leak was coming from so I'm going to have to get some engine cleaner and go to town and try and figure out where this is coming from.

I wanted to know if having too much auto tranny fluid in the AW4 would cause the strange shifting and cause leaks?

Just so you know what I've had to do the past 10K miles to my XJ... New Radiator (3-core CSF), New Power Steering Pump (replace both lines as well), New MORE motor mounts, New Battery, New Alternator, Tune-up w/ new NGK Plugs Cap & Rotor (and while doing this discovered my Distributor needs to be replaced as the rotor shaft has quite a bit of wobble and slop so I'm planning to replace that this weekend also) and I have a new set of Mopar Performance Wires to go in as well.

Any suggestions? Appreciate the help

I wanted to know if having too much auto tranny fluid in the AW4 would cause the strange shifting and cause leaks?(quote)


Yes it can. It sounds like it was leaking from the front input seal.Too much fluid can blow the seals at high speeds. keep your fingers crossed it is ok, or you will be dropping the transmission to change the seals.Drain off some fluid by getting a siphon through the dipstick tube and drain it till it reads, low then let it idle and check for the proper fluid level. Second change that oil pressure switch when that baby goes it will empty your oil in no time. Clean up the engine and tranny with a cool engine at the self clean car washes. Do not directly spray anything elecronic. Good luck.

I once put to much in my 99'. Mr. Daniels threw me off. It was coming out of the vent tube on top of the tranny doing 70ish down towards the ocean.

I figured that overfilling was a BAD idea... thanks for the confirmation of my stupidity...

OK, so I've now been told to check the Tranny fluid w/the Tranny in "P"ark and not "N"eutral. So which is it? Funny thing is that this is only the 2nd vehicle I've owned that was not a 4,5 or 6-speed manual and those are easier (at least they have been for me) the do maintanence on... lol.

Oh... most of my past vehicles have been Mustangs or other various sports cars. Other Auto Tranny vehicle w/a '96 Bronco... miss that bad boy, but don't miss the 9mpg fuel economy that 351W gave me.

Drive at least 15 miles then put it in park and check the level with the engine still running.

Too much and it will bubble out of the stick as you've noticed.

Yes, check the AW4 in "P" and not "N".
You didnt (unless I missed it somewhere) say you identified the fluid as tranny fluid. Probably the first step is to powerwash the bottom and under the hood so you can tell exactly where all the fluid is coming from.

EDIT: overfilling is a bad idea because the fluid will foam up. When it does that, it takes up more room and will expell out the dipstick or around seals.

Thanks for the info..

I could not really determine if the leak was Oil, Tranny Fluid or some other fluid. I guess because there is so much 'crud' on the underside of the tranny and engine/oil pans. I think I have 2 leaks... one Oil and one Tranny Fluid. A good power wash is in my plans now to make sure and get this cleaned up and so I can more easilly identify the leak(s)

I think there is a leak f/the OPS unit (that I'm going to replace along w/my bad Distributor) and then the tranny fluid as well. I'll re-check the fluid in the "P" position and see what it reads and go from there.

I once over-filled my 89 AW4, by about 3/4 quart. At 60 MPH, it was blowing the fluid out of the vent tube, and looked exactly like you described. It was dripping in the same place, down onto the exhaust. Metinks you are looking at tranny fluid....

?Who's Mr Daniels?

Hopefully it's something that simple... so we'll see tonight.

Me'thinks Mr. Daniels has a first name of Jack?

...and friends with Cpt. Morgan??

Did you check the fluid with the engine running and trans at operating temp? Because most automatics will show over-full (when they are at the proper level) with the engine off. I hope when you changed the trans fluid, you didn't add the total transmission capacity becuase theres lots of fluid in the converter.

Well could be when I first did the fluid change I checked the fluid levels when they were not at operating temps and then yesterday when the 'trouble' happened my tranny was very much at operating temps as I had been driving down the turnpike @ 75mph for about 45 minutes. Plus when I pulled the drain plug to drain out a bit of fluid it was HOT even wearing mechanics gloves... :|

I'll check it again tonight when I get home after city driving, stop and go, for about 15-20 minutes. That shoul give me an exact idea of how much fluid I have in the AW4

OH... and yes, Engine Running, Tranny in "N" for my check. I'll check it w/ Engine Running and in "P" tonight and see what I get.

Owners manual says to have it in N for the check, on my 89 atleast. Ditto for a few of the newer Grand caravans I've done (Chrysler tranny thing?)

Doesn't you tranny pan have a drain plug?

Redsnake said:

Well could be when I first did the fluid change I checked the fluid levels when they were not at operating temps and then yesterday when the 'trouble' happened my tranny was very much at operating temps as I had been driving down the turnpike @ 75mph for about 45 minutes. Plus when I pulled the drain plug to drain out a bit of fluid it was HOT even wearing mechanics gloves... :|

I'll check it again tonight when I get home after city driving, stop and go, for about 15-20 minutes. That shoul give me an exact idea of how much fluid I have in the AW4

OH... and yes, Engine Running, Tranny in "N" for my check. I'll check it w/ Engine Running and in "P" tonight and see what I get.

Click to expand...

Ok, just making sure

dizzymac... Yes, my tranny has a drain plug.

I drained it last night and replaced the fluid w/about 3 quarts. I didn't let it completely drain empty (pan) before putting the plug back in. I started her back up and tried to let the tranny oil temps get back to operating temp and checked the dipstick again (in P w/ engine running) and my reading as right at the 'add' line... so I'm going to drive her around a couple day and see what happens and recheck the fluid again and add as necessary. I did NOT want too overfill this go around.

Also changed out the Oil Pressure Sending 'Switch' and the old one I took off was filled w/ oil it appeared. This switch cost me $25 at A-zone so I'm not sure where others were getting those $10 switches as had been mentioned before to me. I do have a guage and not just a light in my '96 for oil pressure.

I got mine for $10 at autozone. It's a gauge sender, for my 89'.

After 15+ minutes of driving park it and don't forget to run it through all the gears before you check it (park, neutral, 3, and 2-1).

Checking the fluid can be tricky, so don't feel too bad. Hopefully you can fix the problem!