Transmission Drain Back Issue and Hardware Tune / Shift Kits

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

This new thread is to continue discussion / learning on the 5-45rfe trans in general and the specific solution to what is apparently a common 'drain back' issue. The new topic is presented to ease other owners finding info on this area, who perhaps may not expect to find that info under my 'Throwing Overboost P0234 code as accelerate through about 60' topic.

Relevant discussion extracted from my other thread:

me: When 'cold' (doesn't really get that cold here... just parked overnight in the garage), there seems to be a delay, or at least a wait for engine speed beyond idle, before the transmission engages leaving Park to Reverse. OK after warm up, even idling for a few minutes. Unlike other automatics I've had, there's no clunk or obvious grab when doing that shift. After searching the forum, I re-checked the fluid level and it's fine. I did have the trans fluid changed (Meineke did their active under-pressure swap out that's supposed to also clean the filters but not apply excess pressure). Trans seems to shift OK otherwise though certainly nothing like the crisp, clean obvious shifts in my post-Banks-upgrade Ford motor home. Should I worry about this?

From papaindigo: Shift issue. Did they use ATF+4, if not that's a problem. If the delay only occurs when parked overnight or elsewhere for like 8+ hrs then you have the classic fluid drain back problem. Try crankup, shift into neutral and hold idle at ca. 1500 rpm for like 10-15 seconds, and then shift into gear and drive. If problem goes away you now positively know what it is. IMHO, personal comment, you couldn't pay me to change fluid that way. I could be wrong but the only way to "clean" a filter is to back flush it and guess where the crud in the filter is going to go. That said if the "try" fixes the problem you need to drop the tranny pan, install new filters, reinstall tranny pan, and refill with ATF+4. If not I'm out of ideas.

(Oh, yes they used ATF+4... though synthetic... after my 1800 mile drive, trans fluid looks great)

Papaindigo: Glad they used ATF+4, just never have been fond of any under pressure tranny fluid flushes that leave the original filters in place; nor for that matter flushes that involve pulling the tranny input line and flushing by filling while fluid runs thru the system and out the input line into a bucket or some such. The latter at least has the merit of filtering what you are flushing and does get rid of all the old fluid. However, leaving the old filters in place is not good idea IMHO especially when IIRC one of those filters has the anti-drain back check valve in the filter body.

me: Confirmed drain-back valve issue. Filter & gasket kit ordered (Wix.... via Amazon).

Did the pan drop and filter changes, everything seated as instructed, but I still have the 'drain back' problem. I used the WIX 58843 kit, so I don't think I got any of those old, bad Chrysler parts. Not planning to go back in anytime soon, but I see a 'VALVE, flow control' (04799681) in the parts fiche (under $8)... from posts I see on other forums, looks like that could be our problem... thoughts/experience?

OK, when I go back in to replace the check valve (not 'if', and probably soon), I'm thinking I'll do the TRANSGO kit too (45RFE-HD2 ?). I found a link for that install, duplicate of that mentioned by Papadingo in an earlier thread, though not really detailed it looks reasonable straight-forward (http://liberty.eurekaboy.com/transgo.htm). Is not doing the resistor change and just letting the TCM 'learn around it' still the way to go?... how long does it take the TCM to do its 'learning'? Any other suggestions or experience out there on the TRANSGO kit, or the check valve (04799681) R&R for that matter?

And still more... just spoke with the Transgo tech folks... seems they feel neither of their kits for the 545RFE trans do too much for the shifts (max 20% shift speed increase) because the computer won't let them go any faster without throwing a code. Both kits do address a poor build quality issue with the accumulator plate (stock is way too thin... can fail and take the trans with it). So now I'm thinking just go with the cheaper SK 45RFE kit. Thoughts / comments ?

Papaindigo: Comments:
1. I have not done the install; SunCoast did it for me.
2. The Eureka Boy post is somewhat old and just deals with installing the valve body parts. I don't recall a LOST post on the full install which includes the pump part(s); if you Google you can find more complete install posts on other forums for the 545RFE tranny. To do the pump stuff requires dropping the tranny.
3. Your best bet on questions about which kit, beyond talking to TransGo might be to talk to Ron Wolverton at SunCoast as they recommend the TransGo kit and routinely install it when they do a torque convertor install
4. There has been a lot of chat over the years about the resistor. Consensus seems to be to omit it from the install as the tranny just learns around it. In fact there is some suggestion the resistor is no longer in the kit.
5. As noted he transgo kit's primary purpose is to beef up some marginal parts in the valve body and to fix the weak portion of the original pump. With respect to the pump the problem is apparently a soft seat. That pump is no longer available, hasn't been for a while, so if a failed pump was "fixed" in the past few years it was probably by installing the newer pump which does not have the "soft seat" problem.

I put up with the tranny drain back problem for about 20k miles by doing the idle in neutral on start up trick with no problem. Beyond that all I can tell you is after SunCoast installed their TC and the transgo kit and serviced the tranny with new filters I no longer have the drain back problem. Exactly what they did that made the problem go away I simply don't know although Ron might have an opinion.

me: Thanks for the reply papaindigo... I'll talk to the Suncoast folks Monday, when they're back in. One question though... on your Suncoast invoice after the trans work, just wondering if there is a parts list, and does that list include the 04799681 , 'valve, flow control' part?

That's where this subject stands... we'll see what Papindigo finds on his Suncoast invoice parts list, if there is one, and I'll check with Suncoast, as well as Transgo (they may know about the drain-back issue fix too) on Monday or Tuesday.

papaindigo · **Posted:** Sat Nov 10, 2012 12:38 pm

No my SunCoast invoice does not have that part # which is no surprise and no I cannot tell you if that part has anything to do with the drain back issue, which by the way has been a DCJ issue since the 1st generation minivan in my personal experience.

PS regarding calling SunCoast on Monday just a reminder that's a holiday for some folks.

With respect to the transgo kit the invoice just says 45RFE-JR 45-68 JR shift kit $53.80 if that helps any.

In the somewhat distant past the forum had lots of chat about the drain back issue; see for example viewtopic.php?f=98&t=55110 and there is a TSB on the topic TSB 21-007-06 APR 06. The TSB ties to transmission build date which is somewhat in error. The original problem apparently ties to a batch of bad OEM filters that were installed at the factory BUT some of those filters made it into dealerships and were installed as part of tranny service on later trannys and when DCJ dumped the bad filters some were pulled from the trash are resold on eBay as "good" OEM filters. In most cases a fluid and filter change seems to solve the problem but not always. In addition some have had the problem come back some months/miles after the change even with good filters. Also IIRC one of the filters is push on and if not done right can produce similar issues but don't rely on my memory for that comment.

amslube · **Posted:** Sat Nov 10, 2012 1:53 pm

I had the drainback issue about six months after I did the first transmission fluid/filter change. I read about the internal spin-on filter and the drainback issues associated with the anti-drainback valve. Well two filter changes later, one being with a new Mopar filter didn't change anything so I just lived with it for about a year or so. I finally decided to install the euro torque converter and at the same time replaced the front pump with the newer updated version pump. Luckily, I was able to find a brand new pump on Ebay for about half the cost as one from the dealer. Another note, when I inquired about pricing and availability from my local dealer, these pumps were on backorder. Sort of tells you they are in demand. I did the replacement of the torque converter and pump myself and it is now about a year and a half since the replacement and no drainback issues.

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

Thanks for the added background Papaindigo. I can see how not properly installing the seal and 'spout' of the large pan filter (05013470AC) could possibly creat this or a similar problem. The instructions with the Wix filter kit made it very clear how that needed to be done. The external check valve described in the Lostjeeps thread you referenced looked promising until I saw that JcGilmour did it to his in 2009 and it didn't fix the problem. I'll see what Suncoast and Transgo have to say Monday or Tuesday.

Thanks for your feedback amslube, but I don't plan to pull the tranny for this... just looking for any possible cause I can get to, at a reasonable cost, by pulling the pan. Given what I've seen, I have my doubts about it being only due to the check valve in the spin-on filter. I'm thinking there are several possible causes of essentially the same problem / symptom. My current plan: when I drop my pan again, I'll verify the spin-on check valve is free, and replace the flow control valve (04799681), then see where I am with the issue. Of course, that plan may change once I speak with Transgo and Suncoast... or based on new news received via this forum.

Joe Romas · **Posted:** Mon Nov 12, 2012 6:14 pm

A old member who works(worked) for Chrysler at a transmission facility once said the transmission was basically very good but it suffered from air leaks. One air leak was the front pump and the new pump is a simplified unit with less sealing parts.

Behind a Hemi that is just starting to go at 2000 rpms a little air is no big deal. Here we are with our tractor engines that produce full torque at 1900 rpms so air leaks are a bigger problem for us.
But I've not had air problem, knock on wood, and I have the new style pump that was put in with the Euro TC :JEEPIN:

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

Haven't spoken with Transgo or Suncoast yet, but odd event this morning. A little cold here last night (cold for Tucson... 42 degrees), and the trans worked fine, no drain-back issue symptoms. Has anyone else seen this?

papaindigo · **Posted:** Tue Nov 13, 2012 5:16 am

My experience with the drain back is it would only occur after the vehicle sat for ca 8 hrs+ but it would not always occur after that or longer intervals.

pappyrsg · **Joined:** Mon Oct 01, 2012 7:35 pm **Posts:** 70

I Just spoke with Suncoast... aside from the easy spin-on-filter fix possibility, they feel the drain-back issue cause is in a valve in the pump, which is remedied via the Transgo kit (either one if I reading the kit parts pictures right... I think it's that little cylinder-looking part). Of course, installing that portion of the Transgo kit requires pulling the trans, something I don't really want to do.

I just spoke with Transgo and they confirmed what Suncoast said... that it's possible the spin-on-filter check valve might fix the drain-back issue, but it's a long shot. Transgo also said the only effective difference between their two kits for the 545RFE trans (SK 45RFE and 45RFE-HD2) is the resistor, the parts pics on-line are out of date. They re-stated that installing the resistor would increase the pump pressure, that you shouldn't install it if you have or might install an after-market programmer, and that, despite discussion on this forum, the computer won't 'learn around' the resistor not being installed and get to the same place. I plan to install the SK 45RFE kit because it's cheaper and I'm not installing the resistor anyway; mostly because I don't want to rock the apparently already weak-knee pump's boat with higher pressure. I forgot to ask Transgo their opinion on the flow control valve (4799681) I mentioned earlier in this thread.

Oddly, again, my CRD didn't exhibit the drain-back problem this morning... second day in a row... maybe the Jeep / Chrysler fairy fixed it a couple nights back.

Anyway, I still plan to drop the pan and install the lower part of the Transgo kit and replace that flow control valve (4799681) when my parts arrive in a few days.

Transmission Drain Back Issue and Hardware Tune / Shift Kits

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