Course of action for my transmission

rob40wilson03 · **Joined:** Sun Jul 10, 2011 9:43 pm **Posts:** 51

Hey guys,

I have been experiencing the occasional lack-of-power as soon as I start the engine and put it into gear. Usually when this happens, if I get moving and then stop completely after only driving a very short distance, the engine will stall. I think this is related to the transmission pump, correct? I also have not noticed the tranny shudder, as far as I'm aware.

What do you guys recommend as a good course of action for me? This is my daily driver for work so I need to keep it reliable and would like to put some work into preventative maintenance if that's what's recommended.

Thanks for any advice!

RJM · **Posted:** Wed Mar 21, 2012 11:10 pm

Air in fuel? Fuel filter needs changing?

geordi · **Posted:** Thu Mar 22, 2012 12:06 am

No. Not air in fuel.

This is the Transmission Drainback issue. The solution is that a checkvalve in the transmission is buggy, I managed to solve this on my transmission even after 2 fluid changes didn't fix it (it is inside the spin-on filter, cheap chinese crap) - Just put in a bottle of Lucas Transmission Oil. It looks like red bear snot, and helps keep the fluid viscous enough to remain where it should be while the engine is off.

What makes your engine stall is that the fluid is draining back to the pan from the torque converter. It takes hydraulic pressure to make the clutches move, either to engage or to slip for a gear change. When you swap from reverse to drive, the clutches need to unlock, but if there isn't enough pressure, the transmission will try shifting while still "in gear" and stall out the motor.

It isn't damaging OR anything you need to be concerned with. Your transmission is functioning just fine, this is more an annoyance than anything else. If you want a more permanent fix other than the Lucas fluid, search on "grainger check valve" and you should locate the thread with that fix for this problem.

rob40wilson03 · **Joined:** Sun Jul 10, 2011 9:43 pm **Posts:** 51

Thanks for the reply!

I have a couple of questions:

1- Is there a specific type (viscosity/weight) of the Lucas oil to use?

2- Am I adding the stuff to the transmission fluid that I've already got? or am I replacing it with the Lucas bear snot?

Thanks

geordi · **Posted:** Thu Mar 22, 2012 1:28 pm

Lucas Transmission Fix is a single variety, sold in a cylindrical white bottle with a narrow pointed top. There are two sizes of Lucas bottles, the SMALLER bottle is the transmission stuff, the larger is only for engine oil.

You are not replacing any of the transmission fluid with the Lucas (at least right now) you are just adding this to your current transmission fill. The bottle is small, only about 2/3 of a quart or so, and your transmission case has lots of capacity... A full flush or dry-fill would be like 15 quarts.

If / when you do your next transmission change, you would need to add the Lucas back in again. It would be your decision, but I filled mine with 6 quarts of ATF+4, one bottle of the Lucas, and then topped it off with another 2 quarts of ATF+4 until the thing FINALLY read as full. It takes a LOT of fluid to fill these up.

rob40wilson03 · **Joined:** Sun Jul 10, 2011 9:43 pm **Posts:** 51

Thank you so much!

I'm at 73,000 miles right now. I bought the car at 63,000. I dont know the history of transmission work. Should I change the fluid now?

geordi · **Posted:** Thu Mar 22, 2012 4:58 pm

For anything that you can't truly validate when something was done (or if it was done right)... I would say the cost of the fluid / filter is a small one so you know it HAS been done.

I just bought a large piece of equipment with just over 10k hours on it. I have maintenance markings on some of the parts (filters, etc) that lead me to believe when those parts are due for a change... But that doesn't tell me whether they were running on a 250, 500, 1000 hour cycle... So I'm planning on a full swap-out of the fluids as I can do it, so that I know when it was done.

dirtmover · **Posted:** Thu Mar 22, 2012 5:34 pm

geordi wrote:

The solution is that a checkvalve in the transmission is buggy, I managed to solve this on my transmission even after 2 fluid changes didn't fix it (it is inside the spin-on filter, cheap chinese crap) - Just put in a bottle of Lucas Transmission Oil.

If it's inside the spin on filter will simply replacing the filter not fix it?

msilbernagel · **Posted:** Thu Mar 22, 2012 5:45 pm

Possibly not. There's a post in the CRD Tech section describing the installation of a separate (nice) brass check valve in the return line from the cooler (up front). The poster started to experience trouble after replacing his filter, so perhaps the ones in the filter are cheap, ineffective... or don't stop the flow for every path?

His problems apparently ceased after installing the better quality check valve in the return line.

FYI

dirtmover wrote:

geordi wrote:

The solution is that a checkvalve in the transmission is buggy, I managed to solve this on my transmission even after 2 fluid changes didn't fix it (it is inside the spin-on filter, cheap chinese crap) - Just put in a bottle of Lucas Transmission Oil.

If it's inside the spin on filter will simply replacing the filter not fix it?

geordi · **Posted:** Thu Mar 22, 2012 7:55 pm

Dirtmover - You'd think so, as I did too... But no. The rubber flap that is inside the spin-on filter is (I'm guessing) supposed to close when the engine is off. Instead, it must weaken and not work properly, as mine did not have the problem for a short time after changing the fluid, then it was back again. Once I put the lucas in, the problem has not returned... Until I got the entire transmission replaced in a completely unrelated failure. Now my fluid and filters are all fresh again... Doesn't have Lucas in it... And it did it to me just a couple days ago.

I need to get a bottle of Lucas myself.

dirtmover · **Posted:** Fri Mar 23, 2012 8:17 am

For the record here is a link to the TSB for the filter check valve issue http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=3464&p=31093&hilit=mopar+transmission+filter+failure#p31093

While my current filter doesn't fall under this TSB it pretty much sums up the symptoms I'm experiencing. I have a WIX, made in Taiwan, filter kit on the shelf which I'll install. This will hopefully solve the problem for another few years. I'm about due for a fluid replacement anyway so it's failed at a convenient time.

I'd rather avoid additives and mods if the original design is working properly and lasts between fluid changes.

papaindigo · **Posted:** Sat Mar 24, 2012 3:34 pm

A good filter should solve the problem but may not. The inline check valve will solve the problem although I'm not big on cutting the line. Alternatively get in vehicle, crank up, put vehicle in neutral and run at ca. 1200 rpm for 10-15 seconds, then drive off. In my experience the problem does not "seem" to occur at startup in reverse but it does in forward so if you don't do the above and put it in forward and nothing happens when you press the throttle do the high idle in neutral trick. Either work fine for me.

black dog · **Joined:** Sat Dec 27, 2008 11:31 pm **Posts:** 46

I had the stalling problem, changed fluid with ams oil and mopar filters...25k miles later problem still solved

flman · **Posted:** Mon Mar 26, 2012 6:56 pm

Change the fluid and filters, and be sure to use ATF+4. It may take a couple of months until you get results.

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Course of action for my transmission

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