I have an '02 with 9k on it. I've the transmission worked on 4 times for chronic leaking. Each time something different was done to "correct" the leak. Well, this most recent, fourth, and hopefully final, trip yielded a discovery that the transmission dipstick in my truck was the wrong one!! Now tell me how that happens! According to the notes of the dealer service tech who worked on it, it was overfilled by "approx. 4 quarts" as a result of the improper dipstick, which led it to leak out of the transmission vent on the topside of the transmission.

My concern is that after driving my truck with a 4-quart-overfilled transmission there is some permanent damage to the seals and gaskets (or even other parts). What are the (possible) implications, given that I cannot know for sure how many quarts it was actually overfilled or for how many miles it was driven that way? Also, are there any mitigating steps I should take to minimize (risk of) damage?

thanks for any input.

 

There really shouldn't be any "damage" from the trans being overfilled. It's not good to do, because the fluid contacts the spinning trans internals, and that "foams" the fluid, which puts air in it and that's not good for hydraulic pressure. But I don't think you would have gotten any permanent damage. Maybe Gregg will chime in.

 

That brings up a good question. I have a B&M pan. After about 15 minutes of hot lapping at a parking lot track, the tranny puked up about a quart of fluid--all over the chassis. When I mentioned this before, Spike Engineering posted that deep pans should be drained of extra fluid before racing (hhmmm.. what's the point of the pan, then?).

Is there really some kind of vent on the top of the tranny? Under what conditions will it puke? Why would a deep sump cause it to puke? I mean, all of the extra fluid is below the pickup point anyway--how would the tranny know whether the sump is deep?

TIA

 

Tim, under proper operating conditions, the trans fluid should NEVER boil out the vent. If you are boiling the fluid out of the vent, you've got some problems. I'd install an auxillary trans cooler with the built in fan on there if I were you.

 

Wrong dipstick? I think the dealer is trying to snow you on that, there is only 1 stub tube and it's installed at the transmission plant, the fill tube is not even close to being the same, but I don't think it would go on and if it did, I can't see how it would cause an overfill,
Oh, wait, I see, wrong dipstick not fill tube, dipstick too short, overfill, oh well, I guess that could happen.

But it would be more than 4 quarts, the vent outlet in the tranny is on the pump at the very top of the pump, bleeds into a case galley that comes out the top and has a jiggle cap. Prolly wouldn't do too much damage, if you still have gears it didn't blow the forward clutch seal which is the first thing I would worry about. As for a deep pan causeing it to dump, I don't think that's an issue, the deep pan from Ford (F81Z-7A194-BA) is stock on most models of the 4R100 and we don't do anything different to the ones that get it stock, the only reason they don't all get it is it costs more.

The real problem with overfill is as Sal mentioned, foaming. The fluid should go right up to but not in contact with the rotating parts, any foam will put air bubbles in the fluid as it works through the hydraulic system, and the compression of this air in the wormtrail and clutch circuits would give erratic readings/behavior.

4 times, eh? Well, maybe this time they got it fixed, I hope you get it figured out,

G

 

Mine has puked out fluid to.But only on the forced downshifts.what I feel is causing it is the clutches or ? releasing fluid pressure and overpowering the baffle before the vent.I di it n the 93 too.so what I did was run a vac line to the vent and over the brake booster and problem was solved.I run the same pan that you do Tim and have not had any other problems other than when running.stan

 

It's not easy to do unless you have the tranny out, but you can replace the jiggle cap vent with a right angle vent that you can hook a line up to, run the line high enough and it won't vent enough to overflow. It's a factory part, the Superduties get it in place of the jiggle cap.

G