A-904 TC fill quandry

The condition is perfectly normal and is often called "morning sickness". There is no converter check valve so converter leakdown will occur when the car isn't running.

There are kits made by TransGo and Sonnax that allow the converter to refill in Park but the cheapest fix is to get in the habit of making the initial startup in Neutral instead of Park.

Actually, the layout having no drive from the converter's turbine in park is a good, well thought out engineering idea, so I'll keep it. Now I have to train the wife for a week on how to do that! It took a month to get her to release the parking brake AFTER applying the service brake to prevent parking pawl binding from being "loaded," which I hear is also common on RWD Chryslers and anything else, from my experience. At least they don't wind up popping into reverse, like the pre-1969 Fords did!

Thanks for the reply, John.

Now if I could only figure a good retrofit to knock off that TCC while climbing a grade in direct drive, life would be serendipitous

look out fellas- next DeserTBob will be telling you to teardown the entire top end of the motor, and pull the oil pan and pump, when the problem is a stuck thermostat

snipped-for-privacy@epix.net snipped-for-privacy@epix.net

You don't understand what John's talking about. The change that the TransGo kit makes to the valve body that allows the TC to fill in park has nothing to do with "drive from the turbine." It has to do with whether or not fluid from the pump (which is NOT driven by the turbine) gets dumped straight back to the pan (factory configuration in "park") or gets circulated through the transmission cooling system as it does in neutral. The idea of *not* circulating the fluid when in park is the only stupid thing the factory did with the Torqueflite transmissions. It has no advantage, and several disadvantages (slow or no filling of the TC in park, no heat rejection in park, less lubrication of the disengaged clutch packs in park, etc.).

Hi...

Anyone know if that also applies to my 94 lhs 3.5?

Better to start and idle in neutral than in park?

Thanks, and take care.

Ken

OK, thanks for that. I'll just idle in neutral until it's time to pull the valve body, and then add a kit. I checked this out on TransGo's site, and there was evidently a common shop "cure" of drilling a small hole in the pressure reg. to allow the TC to fill in park (and thus give cooling and lubrication,) but that makes TC drainback a bigger problem, so I'll just use John's neutral cure for now.

I'm pretty sure it does NOT. The 41TE/42LE transmissions are pretty much unrelated to the older ones. Hydraulically, they have a good number of simplifications to the basic system. Some good- like full circulation in "park." Some really BAD, like no variable line pressure regulator- they run full pressure 100% of the time which is one reason they can run so hot and are so hard on fluid. The giveaway is that the instructions tell you to check the fluid in PARK on those, which implies that full circulation occurs in park.

Well said. The open leak at the manual valve in the Park position is a holdover from the old pushbutton shifter days when there was no Park position in the quadrant and the engine had to be started in Neutral. After 40+ years it's hard to figure why Ma Mopar has chosen to ignore this condition when the aftermarket has recognized it for years and done something about it.

Hi Steve...

Thanks, sure appreciate the info...

Take care.

Ken

I was wanting to ask a question about the 42LE, but didn't want to take the thread too far astray - but, thanks to Ken, it's now one step closer to what I wanted to ask (so Ken and I will share the blame for thread drift here): As a DIY'er, I prefer to replace the ATF+4 by disconnecting the cooler return line and letting the tranny pump pump fluid out (while adding makeup fluid at the filler) - the idea being that, assuming enough fluid (12 to 14 qts. with approx. 10 qt. capacity) is pumped out/poured in, essentially all fluid will be replaced, including what would otherwise be trapped in the torque converter. Is fluid in fact actively pumped thru the torque converter with it in park, or am I fooling myself about that? (Also, this would be done following dropping the pan and replacing the filter - just thought I'd save someone the trouble of saying I needed to do that too.)

Someone in the past - possibly you, Steve, has posted that without the wheels turning (i.e., jacking up the front end), old fluid would sit on the TC during the intended fluid exchange.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

Sorta. What you've done is mix new fluid with old, unless you're evacuating a lot of the old fluid first before adding fresh. What I do is get the TC and trans in general warm by power braking it for a little while, shut down, put the funnel in the filler pipe, remove the outlet hose from the cooler and put a hose down into a drain pan, restart in neutral, pump down until the pump just starts sucking air, add two quarts simultaneously, wait for that to pump down, add two more, pump that down, then shut down and drop the pan to change the filter and adjust the bands. (This if that A-904). Due to the new fluid being cooler than the old in the converter, it will natually be slighly more viscous (especially ATF+3) due to its temperature and tend to gravitate to the outside to the TC shell, forcing the warmer, lighter old fluid out through the annular port. Still have to drop the pan for the filter and bands, then blow out the lines and cooler, replace filter and gasket, done.

From what the experts have said in here about no check valve in the TC circuit of a Torqueflite, I would imagine that shooting air back through the cooler line toward the TC might get a little more fluid out of the TC, but not much.

Steve might have his own views on this. One thing I think we'd both agree upon...wouldn't it be NICE to have drain plugs back on TC shells again?? The got rid of them for what...to save a buck a vehicle?

I recognize that - that's why in several past posts on the subject, I have *always* identified it as a *dilution* process, realizing that it will never be 100% new fluid. I figure doing this with 12 to 14 qts. in a 10 qt. system will conservatively result in 95+% changeout of fluid (beats simple pan drop for less than 50% fluid changeout).

Yep - I drop the pan and change the filter first.

That's what I do except I don't do any power braking, and no bands to adjust in the 42LE. And I add fluid before it sucks air. I put qt. increment marks on the translucent waste bucket and add fluid at roughly the same rate is it gets pumped out.

So does that process pump fluid thru the TC or not? Or do the wheels have to be spinning to accomplish that?

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

TC action is independent of output shaft movement, and yes, on that one, according to Steve and others, the TC is getting new fluid while in park. Not so the RWD Torqueflites, which must be in neutral.

IGNORE THIS TROLL named "DeserTBob"- he was a Bell Telephone "phone guy" who got axed, and is currently unemployed. He has ZERO KNOWLEDGE of cars.

To see who you are getting here, check his "myspace" page below

Please forward this complete post, including headers, to:

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Include the words "trollshifting" and "'nymshifting" in your complaint.

I will not respond to this now obviously psychotic troll again, but I do appeal to you do file complaints of newsgroup disruption with Google Groups, his only Usenet access. Google Groups has left "beta" mode and now is taking troll and spam complaints quite seriously. This troll has had no fewer than 20 Google accounts canceled for these activities, seven in the last 72 hours.

Tks.

Banned accounts of net stalker Charlie Nudo:

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Not me... fluid *is* actively pumped through the TC by the pump (not the convertor or turbine) even with the vehicle stopped. If that didn't happen, all the heat generated by the engine churning fluid against the locked turbine at a traffic light would never be carried out of the convertor. Old Mopars (without the kits John mentioned) don't circulate the fluid in Park, but they do in *every* other gear including neutral, regardless of whether the car is moving or not. Newer ones like the

As for your method of changing fluid, I can't remember right now where the fluid gets routed after the convertor. If it goes straight to the cooler (and I'm 80% certain that it does), then you are indeed doing a reasonably good job of blowing the last of the old fluid out as you add new fluid. If it goes back to lubrication, then you're not doing nearly as good a job. I'll see if I can remember to check the manual on fluid flow path. Or more likely John will post from his encyclopedic torqueflite memory before I can check... :-p