Hi guy if I have a bad lip seal, what more problems will happen?

What’s going on with it is when the car is cold putting it in any gear feels spongy after it warms up. In neutral, Everything seems to work fine. I was told it was a lip seal. I’m not really sure what a lip seal is or what it does.

Just talked with a1. Who did the trans I guess it’s what happens when it’s been sitting too long. The converter drains back. It’s works fine after I drive it every day

When I used steel lip seals my transbrake would sometimes not hold on the starting line. Changing to Teflon seals cured this problem but over time can wear a groove in the aluminum drum. Custom making a steel sleeve pressed onto the aluminum drum cured the problem. Thanks to Pro Trans.

Convertor drainback is one of the FREE FEATURES of the 727 ... You original question says it feels spongy AFTER it warms up ? That didn't make it sound like convertor drainback..

Convertor drainback is one of the FREE FEATURES of the 727 ... You original question says it feels spongy AFTER it warms up ? That didn't make it sound like convertor drainback. Chrysler FINALLY did something to help combat this in the 48RE trans after mid 2003 I believe it was , they added a seat ring to the stator support and more seal surface in the convertor snout for the seal ring to seal against.

Anywho it takes roughly a minute, to a minute and a half, for the entire hyd. system in the trans to charge and the convertor to refill , I assume your trans has the upgrade manual valve , but anyway pop it into neutral after starting and sit for a couple minutes before trying to engage drive.

Actually that added seal isn’t to address drainback - it’s to add to converter capacity in lockup. The only thing Chrysler did to try and address drainback was to add the anti-draindown valve in the cooler line on rear wheel drive vehicles.

Thanks for that clarification , I thought I read in one of the diesel forums it was for drainback. I removed that anti drain valve out of my 2000 because to me it was a flow restriction.

Question unrelated to the op's issue since you know a lot more about these things ... would changing my 47RE front pump to the larger gear/rotor 48RE pump be beneficial? I don't have a 48RE snouted convertor in it so I'll leave that seal ring out.

The only thing Chrysler did to try and address drainback was to add the anti-draindown valve in the cooler line on rear wheel drive vehicles.

And that doesn't fully prevent converter drainback, it's more to prevent the high-mounted cooler in the side tank of crossflow radiators from draining through the converter. This wasn't a problem when the cooler was mounted in the bottom tank of downflow radiators.

You won’t see any benefit going to the 48 pump. Unless you have the 48 cooler lines and hauling a bunch of weight the extra flow won’t help anything.
You can only pump so much fluid to brought the smaller lines.

And if your 47 is behind a gas engine you don’t want to use the diesel pump.

Thanks, that'll save me a couple hundred bucks. But I'll look into the difference in the 48 lines and the factory cooler which I know is on the opposite side of the engine.

The 47 is behind a 24V 5.9 , a 98 , it will be making close to 500 at the rear wheels, I don't tow it a lot it's, mainly my daily driver. The trans right now is in my 2000 lawn ornament that's a rusty 4x4, I've bought a 2wd OD unit out of a gas rig that I'm going to swap the OD guts, extra clutches and such out of the 4x4 OD unit, into the 2wd unit and reseal the trans which has billet shafts and such already to put in my DD and swap the injectors/turbo and chip into it. I thought maybe the extra volume available via the 48 pump would be a positive, I'm going to also put the GPZ clutches in it and have my convertor freshened as the trans was last driven in 2011.

The extra flow isn’t a bad thing, it really comes down to how you plan to use it. We upped the max GVWR on the 48 so to make things live, some things got beefed up.


The other thing that had to be considered was the use of Jake brakes. That added seal helped clutch capacity while in lockup using the Jake.