99 Dakota, 3.9, 42 RE. Dismantled it to replace the front band, as I was starting to lose 2nd gear. Havent been into one in a little while. having a brain fart.

While inside, I have bought a few A&A and Sonnax parts to throw at it "while I am in there. A&A front servo (4 seal ring, HD) and Sonnax accumulator piston (billet aluminum), 2-3 governor plugs with seal rings for valve body, new 3-4 OD accumulator spring (because I have seen them broke before, and "I'm already inside this thing so why not") and a new Sonnax "big" accumulator spring to go with that new 4 ring accumulator. No shift kit (yet anyways, in the past I have liked the TF-ODjr in the 4 speed autos. but I have never done the shift kit and these other upgrades, all within the same transmission. 1st time buying the Sonnax parts.
Q#1.... The Sonnax "big" accumulator spring is almost 2x the length and similar spring wire gauge as the original. I didn't realize this til it got here. I know this would limit travel of the accumulator. I also see that this same spring is shown for a similar function on 727 904, all of the RH/RE besides a handful of Chevy applications under the same PN. I can find more ink written about the benefits of thiss pring on Chevys than to use it on any Dodge trans.. (probably should not surprise me huh?) yet the same PN fits many trannys of both brands. The original big accumulator spring looks fine. this one does have the small accumulator spring in the "small end" of the accumulator, which I was gonna leave alone. Any advantage or disadvantage to using this heavier accumulator spring as opposed to the original?

as this is only a weak link 3.9, not a V8 in this truck, it's my "eat up the miles" 70 mile a day commuter, have not tried to haul or tow much with this truck, I did pull my popup once (2 states away) with it last year/// while it did the job, it was a bit under powered in doing so, I also have a V8 Dakota that hauls it with less effort....but WAY more miles on that rig than this one so 90% of the time it will just be a back n forth to work beater.... but I bought the upgrades because it is still a "truck", and most importantly I DON'T want to repeat pulling the trans, I hate redo's///// upgrades are hopefully just some "insurance" that I won't have to.... might occasionally pull the popup a couple times a year, or my utility trailer "around town" loaded with an older Cub cadet and a push mower or 2 would be the "worst" of it.

Q#2.... On the seal rings on the input shaft that came in the seal kit that I bought..... I pulled plastic/(nylon?) seal rings off the input shaft, could find no match in the seal kit for them like I usually can... it had the old 904 style metal "hook/loop" seal rings in the kit, only seals included that were "that" diameter... will that be a problem to use those, or should I find some plastic OE-like ones? seal kit app guide did list this kit as being for a 99-04 42RE, which is exactly what this is (though my 99 has a late 98 build date)

BUMP Nobody? I want to wrap this issue up this weekend and drive to work with this truck come Monday

weren't the "plastic" rings teflon ?
and if so, i remember something about not replacing them with standard rings because of "???",
or maybe it was the other way around. i can't remember the reason why.
sorry for the confusion caused.

I take those cast iron seal rings and slide them in to the support with the ends hooked. If they slide in with effort and the hooks are not bottomed out then they are the correct ones to use.
While the image is a front clutch retainer the practice is useful for any hooked seal ring. Notice daylight on each side of the hook - 12 and 6 O’Clock of the hook area.



As for the accumulator spring, you won’t have any issue by using what was in the trans before.

ok.... that new HD spring was only like $5 bux…. so not enough lost to worry about, if I put the original back in.... I thought that accumulator mostly dealt with 2nd gear, which is what I was having problem with, and 110% the only reason I have the trans out, apart in the 1st place. so I wanted to make 110% sure that it won't have that problem again.... the thought was to beef up anything related to the issue.....

so playing "devil's advocate", would anything be hurt or modified to "not work right" if I put the heavier/taller spring in this thing? It does have the small spring in the "deep end" of the accumulator... I remember a 727, one of the 1st that I ever went into, when I was young and stupid, that I put a B&M shift kit into, with a stock converter behind a pooch 318 with 2.76 gears.... that thing could not even chirp the tires (and it was a peg leg rear) but it would chirp the tires and snap my neck at every shift, which I DON'T want, in this case.... it's been a long time, but as I remember that kit had a "towing/heavy duty" or a "street/strip" option within the same package and that was following the "towing/HD" side of the instruction sheet but I don't remember everything from the 80s either....
that's why, IF I decide to use a shift kit, I have taken a liking to the TF-ODjr since I discovered them, have not used any other shift kit, besides those besides that one B&M 30+ years ago.... I quickly grew to dislike that one. so far I have not put any "kit" in this one, though the Sonnax "Sure Cure" kind of catches my interest.

yeah those "plastic" rings might have been Teflon, you might be right.... part of the "brain fart" that made me post this thread. I remember that within the old 3 speed trannys I have been into, that I usually seen cast iron with the locking ends. on the 4 speeds I have worked on they all had the angle-cut plastic (nylon, Teflon or what ever material they are) I don't remember any method to the madness regarding which ones were used in a particular transmission.... I will say this though. With 120K, I think this is the 1st time that this transmission has ever been dug into beyond a "pan drop" //of which I have record of that having been done by a shop on behalf of the prior owner, twice. better than most owners, who do nothing with a trans til they are stranded and wont move....


I sourced the new band from the dealer, though it came up "discontinued" when they looked it up, the closest warehouse they deal with still had a couple on the shelf..... what bothers me is that upon pulling the thing apart, I really did not see a problem with the original band, and yes I have seen them burnt up..... so I went farther in trying to fix the issue..... nothing I have seen though, looks "bad" so far. weird. Usually when I pull down a trans I can ID the "smoking gun".... not this one.

Probably would help if you explain “ starting to lose second gear “.

If you put the trans in manual second gear does it pull ok and will the engine slow the truck on decel ?

OK.... I bought the truck last June with 105K on it. Previously belonged to an 82 yo retiree. tons of service records since he had owned, came with in the glove box. truck was put up for sale because PO went into retirement home, family took his keys away. I don't see this truck having been used very hard at all, in the 17 years and 52k miles that he had it. Replaced tires as soon as I got it due to age, not wear-out (2 from 2008, other 2 were from 2011) and ball joints/aligned in 1st week I had it. 10 days later I hit a deer, replaced radiator, added factory style aux trans cooler "in addition to" running ATF thru radiator cooler. Was already noticing 1st symptom, (detailed below) for a couple of days, and absolutely no change, before/after deer strike repairs. until weather turned cold that was, Read on/

Shortly after I got it, I noticed (never seen this before, have owned/driven Mopars (only) all my life)
It starts off in 1st just fine. Hits 2nd just fine.
When it would get to a point of "almost" be ready to hit 3rd, it would "hiccup" (neutral out for a split second?) continue in 2nd for ~100-150 RPM, then hit 3rd, then 4th just like anyone would reasonably expect. Temp, or miles since left, or pulling my popup camper/(or not) etc seemed to have no effect. the couple of times that I pulled the popup, the flare did not worsen during trip.
That seemed to go away about 95% for most of the cold weather months, though I wasn't driving the 99 as much then as I have a 96 4wd Dakota as well, so I was "switching off". pretty much drove the 4wd truck any time there was a "chance" of snow/ice salt.
Over the last week and 1/2 I drove the 99 (which is the truck with the trans issue), it didn't act like it had previously, it started "neutral-flaring" when it would switch from 2nd to 3rd, especially when dead cold. would neutral flare for the 1st time, maybe 2 times thru the gears. Again 1st, 3rd 4th and R worked just fine. The one way I take to work, is largely country back roads, STOP sign ~500' from my driveway, then rt turn. About another 800' a left turn. 3 stop signs in 5 miles, left turn, then 2 stop signs next 4 miles, rt turn, 10 miles another stop sign, rt turn, 7 miles another stop sign, then cruise 65ish the rest of the way, (except that 1st 500' and 800' of course..... ) and usually getting close to that, (60-65) between the rest of the stop signs. The truck would neutral flare once, in that 1st 500 feet (very light on throttle) then once after that 1st left turn "hard", then not again the rest of the way to work. (as truck warmed up) At first, when I went to lunch 4 hours later, it would NOT flare/ but would, (hard again) the 1st 2 times thru the gears on the way home, than not again. Then by the end of the week, it would flare "hard" each time it went from 2nd to 3rd, going to and from lunch (usually went less than a mile round trip for lunch, not enough for temp needle to budge) Might have done this major flare for a week and 1/2 max, and always so far only when engine is STONE COLD. As it warmed up, even slightly, the flare would not happen.
At this point, I parked this truck (about 400-500 miles, max since "hard" flare when truck was cold, started) because I didn't feel like having to call my kid with his trailer to come after me..... stayed driving my 96.... ordered a few parts, and pulled this one. I have NEVER had any version of a Torqueflite flare between gears on me, before this one. Ever. so this is definitely weird. I have seen it on Fords especially Rangers, many times. and any troubleshooting chart I see, none specify 2nd gear issues.. things like "NO DRIVE" or "SLIPS IN ALL FORWARD RANGES" neither of which apply to this vehicle. And I know by deduction that it has to have something to do with the band, either via wear or actuation, (valve body?) and NOT the clutch packs or rear band because the rest of the gears work as they should, don't slip, and that band "only" has to do with 2nd gear while other clutch packs apply and release depending on what range it is in.


Now the one time that I dropped the shifter into "2" like the next to last day I drove this thing before I pulled it, it held 2nd fine in "low 2" and flared as soon as I put it into "Drive" HARD, before it caught 3rd. I have the clutches and steels out of the "forward" (not by position in trans) and Hi-rev clutch packs, which look new. The waffling is still there, and I can still read the stamped numbers on the original clutch discs.
The 1st steel has SLIGHT (and I do mean "Slight") scoring, closest to the "pressure plate" though there was no clutch disc between these 2 parts as I dismantled them. (which I thought was weird) No discoloration in the steels, I can see marks in that 1st steel and in the pressure plate but can't catch a nail on them. Discs and steels in Hi-Rev in same condition, I did dismantle those clutch packs and replace the piston seals within "because I have them" and "because it is out and apart". I never did put a pressure gauge onto this trans. Probably should have.

I checked fluid a few times in this stretch, always "FULL" and never a tinge of going dark. this truck does not leak a drop of ATF. Ever.

now I don't do trannys for a living, I have seen my share of welded clutch packs, busted Belleville springs, busted 3-4 servo springs, busted snap rings and fried clutches in the OD, bad output shaft bearings and such within Mopar trannys over the years..... I bought my 96 4wd Dakota, with the trans laying in the bed, got it dirt cheap because of the trans, rebuilt it myself 55K ago and I'm still driving this truck extensively, with over 222K on it... I rebuilt the one in my 01 Durango myself as well, it has even more miles than my 96 does, and it carries on just fine. (wife's daily driver) I rebuild my own when needed, don't rebuild them for anybody else any more.
Ive done 3 speed RWD Mopar, GM and Ford trannys, (years ago) but have never been past a "pan drop" on any 4+ speed/OD auto trans that isn't a Mopar. I've done Mopar 413 trannys, and 604s over the years.
I did buy the ATSG book for this particular job, looks mostly like a rehash of the FSM...for the most part. 1st time I have looked at an ATSG manual. mostly bought it out of "curiosity".

You’re problem lies within the seals of the high gear (front clutch drum). Known issue on this vintage trans. Many of the kits have a revised inner lip seal which is longer to prevent this.

The flare on the 2-3 is not a problem with second but with third. You likely will not see a visual issue with the seal.

Two explanations for the problem, some say the seal groove is too deep and with heat aging the seal retracts in to the groove.
The other explanation is the heat aging makes the seal less responsive to pressures - until it gets warm.
The Mopar seal went to Viton, a much more resilient seal. I think in 2001.

Clean the unit up, replace all the seals and you should be good. My 99 did the same thing.

Remember - these parts and seals lived for some time - like yours before acting up. I never had any drums cut to measure the seal groove but once we went to Viton seals on the old drums the problem never reoccurred.

I was just gonna replace the band and servo and button it up, put it back in.... but the other day, I had that all done, had new band in, pump reinstalled, ready to put the valve body back in. Went in to eat some dinner, came out to air test "just to be sure" all was as OK as it could be, before putting the VB back in and while I was in the house, got to thinking how all I had touched to that point, looked fine. there had to be something else. So I took it back apart, and pulled the clutches out of the clutch packs. Still didn't see a problem and "since I had them anyways" I decided to put the new piston seals in.

a couple of admissions here on this particular job; 1) for some reason I had more difficulty than I usually do, getting the "forward clutch" piston back into place, with the new seals. A job I have probably done oh, probably 25-30 times over the years (I did say I don't exactly make a living doing trannys, so that may seem low to some of you guys) I FUBAR'd the inner piston seal (isn't it funny how you "know" exactly the moment that happens?) I admit that I probably got a wee bit "rammy" in this instance.

and 2) I no longer have the access to the fixture that I used to have access to, to compress the spring in the Hi-Rev clutch pack so I can pop that snap ring since my dealer-trans-guy buddy moved an hour away... in tranny rebuilds past, it was an easy trip to his garage with clutch pack in hand, to remedy that. and as he had said "I have one, no sense you (me) buying one... just cmon over and use this one". But he has now moved over an hour away into Indiana, so 2+ hours drive time, for a few minute job....

so I ran them down to the local Mr Transmission shop (just the clutch packs) for a hand.... 1st time I have ever had to do that...… luckily they had a "remnant box" for each model/family of trans they work on with "extra" seals to replace my wrecked one.... had to leave them there a couple days as they are just closing things down as I pass by on my own way home from work but for the few bux they hit me for, it was worth it.....

back to 1 more thing... so youre saying, to put the original accumulator "big" spring back in there, not the HD Sonnax one that I bought??? what would I notice (if anything) from how it used to be, (or will be with that stock spring back in place vs that heavy one?) On the units I have been in, since that Cordoba's 727 I mentioned from years ago, I typically have not generally modified much of anything when going thru a trans other than the aforementioned TF-OD shift kit I mentioned in a handful of the... this is going to be the 1st time I have ever replaced things like servos or accumulators, with something besides stock.... I have always replaced seal rings, etc and put the original pieces back in-- except that one Cordoba (again..) but these pieces I put in this one, weren't available back then, either....

and thanks for the help....

Generally speaking raising spring rate on an accumulator spring firms the shift for some shifts.
It also builds clutch capacity for the system.

When the spring is energized you have done work, when the spring relaxes when the acc. piston stroke strokes it adds that fluid pressure to the system, depending on valve body and case design.

ok, some info and another Q.....

I bought the Sonnax aluminum accumulator piston for this transmission. I figure billet aluminum with 4 seal rings would be better than 2 seal rings and plastic, as is the OE accumulator piston;
I had been asking about the heavier spring for the "big end" of the accumulator that Sonnax sells, and what it might do to the transmission's characteristics…. and was told "well, it worked fine with the old one" (or something like that) in an earlier response in this thread. so with that, I was OK to put the original back in...…. well due to life, (you know, the mechanics' own vehicle being the last one to get the attention it needs, kind of thing) I finally got back to this today and got the trans back in.....partially because I had to wait til my son could get over here to help me get it up onto the trans jack...… I can't lift what I used to be able to these days. (yes I have my own 2 post lift at home!)

But anyways, on that spring, some things Sonnax doesn't tell you but I figured put pretty quick when I flipped it over to drop the valve body back on.... If you want to run that Sonnax accumulator, you basically have to run that heavier looking "big" spring.... I put the original accumulator spring onto the new accumulator and realized it would be useless with this aftermarket accumulator.... the "butt" of the new one, is taller than the original accumulator... the spring pocket on the aftermarket one is deeper than the spring pocket on the original plastic one. so for the spring to stick out and actually "dampen" anything you have to use their aftermarket spring..... the original spring does not stick out past the height of the aftermarket part... I looked at a lot of ads for their parts and they never mentioned this.....
old spring + new accumulator = butt of accumulator smacking valve body, and spring unable to "dampen" anything.....

Hopefully that might help somebody down the road.....
I basically waited for a 2nd seal kit to come via Ebay because I had had the pump and clutch packs on, and, off and on again, and off again, a few times/ to be safe, I wanted another new pump gasket and square cut pump O-ring. When I went to air test this thing before I put it back into the truck, I found something that I honestly don't ever remember seeing in the past on these trannys….. and it made me back up, and go "W T f????…….. and wanted to verify that all was good, to avoid a redo...… When I had the clutches and pump all installed in the trans the 1st time, and went to air test the front clutch packs, I had air escaping out the hollow input shaft.... in the past I just remember the "thud" of the clutch pack pistons, if all was good, so I pulled it all back apart for another look..... at this time, I set the pump face down on my opened vise, put the clutch packs onto the pump and air tested the stack that way while out of the trans case.... better result though I did have a little air escaping between the 2 pump halves.... I figure because I didn't have the pump torqued down within the case to seal the 2 machined halves of pump, compressed by the pump to case bolts.... but less it seemed, than I had coming out of the center of the input shaft. This other seal kit I got, did come with the Teflon input shaft seal rings like original, vs the cast ones that came with the 1st seal kit, so I changed them again to the OE style seal rings.

It has been a long while since I have been into a trans, and the last few that I have been into, have been the 46 ("518 style") variants...… IDK if this hollow input shaft and air leak I had may be a difference between the A500 (42/44 RE) vs the 518 (46/47 RE) trannys????? I did look on Google and You Tube a couple of different places other than here and could not come up with anything conclusive on the leaky air during testing.... but, figuring that this part of the trans worked fine before, that it would most likely be OK..... still not completely sure on that though..... at this point all I can do is cross my fingers, put it in, and see what it does...… though I cringe because if it isn't OK, then it will be coming back out..... and all that fresh new fluid will be down the drain. Thoughts??????