Rebuilt 904, no 3rd gear???

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mopardude318

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My brother and I rebuilt my 904 to go behind a mild 318.

We used a high performance rebuild kit, with red clutches, kolene steels, a HD band strut with a 4.2 lever, red low reverse band, red second gear band, and a rebuilt front pump, with a PTC 3000 stall converter, and a transgo 2 shift kit.

Every other gear works, it shifts from 1st to 2nd, but not into 3rd, reverse also works, and i unhooked the kickdown linkage and test drove to see if it shifts into 3rd. it does not. i did the tests the ATSG manual says to do, all the pressures in the tests are higher across the board, my guess is because of the shift kit, correct? any help would be appreciated on what you guys may think they problem might be?
 
The Trans-go shift kit mentions that if a 3/8" check ball is used in place of a 11/32" ball in one spot in the valve body it'll cause no 3rd gear. Do you think that could be a possibility? Here's a picture of the valve body with a red arrow pointing to the check ball.

If your sure it isn't that the only other thing I can think of at the moment is a stuck 2-3 shift valve in the valve body. Did you disassemble the valve body and clean everything real good and lube the valves with atf when you assembled it?

The pressures will be higher because of the shift kit.
 

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ok i pulled the trans pan and the valve body. i noticed there was a piece of a teflon sealing ring...these teflon rings came from the rebuild kit, and i used those instead of the steel ones that came off the trans originally...

I think from my memory, these seals were from the front pump to front clutch pack in front drum...?? which is odd because reverse worked. also, there is no distinct shifting feel at all from 1st to 2nd when you run it in drive.
 
I had a similar issue when I built mine, no 3rd because it leaked. It's possible that the sealing ring installed on the front pump, the beveled lip got tweaked/installed the lip on top of itself instead of inside, then it broke off... I feel your pain, gonna be going thru mine for the 3rd time soon. Always air check your unit too. PM fishy68 for the air check guide.

Fold like the middle seal in the picture:

Seal_rings_t-400.jpg

Seal_rings_t-400.jpg


Good luck!
 
The reaction shaft sealing rings are what your referring to and if one is cut and not sealing I don't know how it'd have reverse, unless the higher reverse pressure gives it just enough to make the piston engage??? That's a bummer man cause the trans. will have to come out and the front end back apart to replace it. That's why I always pressure test all clutch packs and band servo's before I button it up. As for not feeling the 1-2 shift in drive, it's possible the kickdown linkage just needs adjusted. If it's backed off the pressure is low and will shift softer. You might check that before you yank it back out cause if that doesn't cure it you have something else to look for. If you find nothing wrong you can eliminate the spring on the accumulator and put a blocker rod under it to keep it in place. The accumulator is basically softens the application of the front band (2nd gear band). I generally block anything that will have a 3k or higher stall converter cause the loose converter does some cushioning.

BTW: what were the clutch plate clearances?
 
I had a similar issue when I built mine, no 3rd because it leaked. It's possible that the sealing ring installed on the front pump, the beveled lip got tweaked/installed the lip on top of itself instead of inside, then it broke off... I feel your pain, gonna be going thru mine for the 3rd time soon. Always air check your unit too. PM fishy68 for the air check guide.

Fold like the middle seal in the picture:

Seal_rings_t-400.jpg

Seal_rings_t-400.jpg


Good luck!

yep. i think thats exactly what happened. i pulled the tranny from the car this evening, and i found the problem:

IMG_3316.jpg

i noticed some friction material on the bottom of the pan:

IMG_3312.jpg


rubbed my finger in it

IMG_3315.jpg



the piece im holding was on the bottom of my pan, and when i pulled the front pump there it was:

IMG_3322.jpg


I dont know transmissions a whole lot, my brother knows a good amount BUT he's only built chevy stuff, turbo 350's and 400's, 4l80 and 4l60s, 700r4, 200r4 etc...

this was our first chrysler 904 torqueflite we built together. so my guess is there was no pressure to actuate the forward 3rd gear. this broken seal would cause it to leak internally, correct?

it smoked my red clutches and kolene steels....

you can see the one on the far left is what they should be and the rest are gone, the last 2 are for sure done! aint nothin left.

IMG_3323.jpg


same for the kolene steels, they need to be black like the one on the right, they were all burnt up too. lol

IMG_3324.jpg


this was the 2nd clutch pack

IMG_3325.jpg


i need a new band too:

IMG_3326.jpg



so tomorrow ill go get new parts from the trans shop.
 
The reaction shaft sealing rings are what your referring to and if one is cut and not sealing I don't know how it'd have reverse, unless the higher reverse pressure gives it just enough to make the piston engage??? That's a bummer man cause the trans. will have to come out and the front end back apart to replace it. That's why I always pressure test all clutch packs and band servo's before I button it up. As for not feeling the 1-2 shift in drive, it's possible the kickdown linkage just needs adjusted. If it's backed off the pressure is low and will shift softer. You might check that before you yank it back out cause if that doesn't cure it you have something else to look for. If you find nothing wrong you can eliminate the spring on the accumulator and put a blocker rod under it to keep it in place. The accumulator is basically softens the application of the front band (2nd gear band). I generally block anything that will have a 3k or higher stall converter cause the loose converter does some cushioning.

BTW: what were the clutch plate clearances?

when i did the pressure test on everything, (as in pulling the plugs on the outside of trans and installing a gauge, and running it in gear and such) there was sufficient pressure throughout each test...

so when i pulled the pan, i pressure tested it with the air gun on one of the ports, sure enough the damn thing leaked. this puzzles me because we DID the air pressure test before i installed it and everything was good, no air leaks.

so now that im here and gonna start getting the replacement parts, anything else you suggest I do? should i use the metal sealing rings like the ones i took off originally instead of the teflon ones that come with the rebuild kit? what would the major difference be?

would it be necessary to pull the rest of the trans apart? my brother doesnt think its necessary, and that this was our problem.

do you recommend i should block the accumulator because I have a 3000 stall converter? absolutely necessary? id like a firm shift, chirp into 2nd and 3rd gear is what im after. lol
 
Good to see you found the problem, hey man, kudos for doing it. Don't feel down on yourselves about it, you learn way more from your mistakes than your successes, there's a saying here: Fail better.

It was leaking in the air test because the seal that broke is one side of the seal that sends juice to the 3rd gear packs...

The metal vs teflon is a debate.

Metal seems a little more durable, some say teflon seals better, I'd venture to guess the difference is negligible, especially with your shift kit line pressure boost. Infact your blow up proves the durability point of the steel.

Get new lip and front pump seals, if you can find the meatier/thicker inner piston seal for 3rd gear, grab it, if not just buy an extra filter, you may want to change it a few hundred down the road... #2 sealant the front pump to housing washers so it doesn't leak. Did you move the vent tube? If not might want to do that, these like to spew sometimes, especially when you get on it...

I don't believe you need to dig around behind the rear shaft clip, do the packs, front band, clean the valve body, drain what you can out of the converter, and run it.

If I may: My hard won system for building transmissions is simple and effective: Use the blow up digram, and check it twice. Then leave it for the day then come back and check it again close attention to build quality.

I recommend both of you check it, someone play devils advocate.

Have a blast!
 
when i did the pressure test on everything, (as in pulling the plugs on the outside of trans and installing a gauge, and running it in gear and such) there was sufficient pressure throughout each test...

Sorry I wasn't clear on which pressure tests, I was referring to doing air pressure tests like you mentioned below. It's really odd that it seemed to pass the air test with a cut seal.
so when i pulled the pan, i pressure tested it with the air gun on one of the ports, sure enough the damn thing leaked. this puzzles me because we DID the air pressure test before i installed it and everything was good, no air leaks.

so now that im here and gonna start getting the replacement parts, anything else you suggest I do? should i use the metal sealing rings like the ones i took off originally instead of the teflon ones that come with the rebuild kit? what would the major difference be?

Like Poison Dart said the teflon vs. steel rings is a debate. Some claim they wear less on the drum and that I can see but at the same time I don't remember having to change more than 1 drum due to wear where the rings ride in 30 yrs of doing transmissions. All I have done in the past 30 yrs. until last year got the steel rings. When I installed my 408 I freshened up the trans and gave the teflon rings a try. Had no problems with them but at the same time I can't see anything they did to improve it. Lastly make sure your clutch plate clearance is adequate.

would it be necessary to pull the rest of the trans apart? my brother doesnt think its necessary, and that this was our problem.

If the inside of the case looks clean I wouldn't worry about pulling the rest apart. I can't imagine you ran it enough to crud it all up. My opinion is you definitely found the problem, or at least one of the problems. The one that I wonder about is why is the front band burned up? That seal had nothing to do with it. Could it be possible you had it adjusted too tight? How many springs did you use in the front band servo?

do you recommend i should block the accumulator because I have a 3000 stall converter? absolutely necessary? id like a firm shift, chirp into 2nd and 3rd gear is what im after. lol

Since traction has a lot to do with hearing a chirp when you shift it's kinda hard to say for sure but like I said I always block it with a loose converter. To get a neck snapping 3rd shift is a lot harder cause for one thing your going a lot faster when you hit 3rd and secondly the 2-3 shift requires perfect timing of the release of the front band and application of the direct clutch. Perfect timing is kinda hard to obtain cause several variables come into play. Unless your car doesn't get great traction and you have a torquey stroker I doubt you'll ever hear a 3rd gear chirp but a nice firm shift shouldn't be a problem. Blocking the accumulator generally only affects the 1-2 shift but I have a theory that it may improve the 2-3 shift a little as well. The reason I think it helps the 2-3 shift also is it lets the front band come off quicker. With a spring in the accumulator and the system pressurized the spring is compressed. When the pressure goes away (i.e. switching to 3rd) that spring will extent prolonging the time the front band is applied a little which can possibly cause 2-3 overlap. Overlap not only wears parts fast but it also robs hp. But there are variables that can blow my theory out of the water such as the application of the front clutch being slow. With that scenario you could have flare up (the opposite of overlap) and that'll soften your 2-3 shift but for the most part overlap is a much more common occurrence than flare up so that's why I block it. I have yet to have someone complain of any trans. I did shifting too firm.
 
.............Blocking the acc does help quicken the 2-3 shift........depending on the shift i use lots of times i take out the acc spring between the acc and vb........then i will install a spring inbetween the case and the acc.....there are more ways to make a tf shift faster/harder w/wo a shift kit.......kim.........
 
Sorry I wasn't clear on which pressure tests, I was referring to doing air pressure tests like you mentioned below. It's really odd that it seemed to pass the air test with a cut seal.
Also what might be a possibility is we tore the seal during installation, and the air pressure test we performed wasn't enough pressure to blow through the seal, but when it came time to run the trans the actual fluid pressure could have been much higher to break the seal completely. But either way, we broke it. lol

Like Poison Dart said the teflon vs. steel rings is a debate. Some claim they wear less on the drum and that I can see but at the same time I don't remember having to change more than 1 drum due to wear where the rings ride in 30 yrs of doing transmissions. All I have done in the past 30 yrs. until last year got the steel rings. When I installed my 408 I freshened up the trans and gave the teflon rings a try. Had no problems with them but at the same time I can't see anything they did to improve it. Lastly make sure your clutch plate clearance is adequate.
I talked to my local trans shop where I got my front pump from. He said I'll be just fine with the steel rings, so that's what I'll use. A few others I've talked to also agree to use the steel rings.

If the inside of the case looks clean I wouldn't worry about pulling the rest apart. I can't imagine you ran it enough to crud it all up. My opinion is you definitely found the problem, or at least one of the problems. The one that I wonder about is why is the front band burned up? That seal had nothing to do with it. Could it be possible you had it adjusted too tight? How many springs did you use in the front band servo?
Well, I ended up pulling the tail shaft just to clean everything. The rear band was just fine, as was everything else. There was friction material everywhere, so I cleaned everything up with kerosine.

Now about that front band, I also discussed with my local trans shop, he believes it was adjusted too tight, and this would cause it to take off in 2nd gear...-Which it did, -only sometimes.....I noticed sometimes I would have a 1 to 2 shift, and come to a stop and there would be no 2nd gear shift, like I was starting out in 2nd gear. And it did this a few times...But thats weird because I followed the specs in the ATSG service manual...It was something like 72 inch pounds then back it off 2.5 turns...The rear band was backed 4 turns from 72 inch pounds. In the "How to rebuild a 727" rebuild book it states for a trango shift kit with a 4.2 lever, (which I have a 4.2 lever) it needs to be backed off 2.25 turns from 72 inch pounds. The shift kit recommended tighten it snug with a short wrench and back it off 2 turns. The transGo 2 kit instructions werent real specific. What was also stated was, If I had less than a 4.0 lever, back it off 2.5 turns from 72 inch pounds, a 4.2 and 4.25 lever is 2.25 turns from 72 inch pounds and a 5.0 lever is 2 turns backed from 72 in. pounds. it if was unknown then back it off 2.25 turns. So with all these damn variables, what do you recommend, with my 4.2 lever??

Since traction has a lot to do with hearing a chirp when you shift it's kinda hard to say for sure but like I said I always block it with a loose converter. To get a neck snapping 3rd shift is a lot harder cause for one thing your going a lot faster when you hit 3rd and secondly the 2-3 shift requires perfect timing of the release of the front band and application of the direct clutch. Perfect timing is kinda hard to obtain cause several variables come into play. Unless your car doesn't get great traction and you have a torquey stroker I doubt you'll ever hear a 3rd gear chirp but a nice firm shift shouldn't be a problem. Blocking the accumulator generally only affects the 1-2 shift but I have a theory that it may improve the 2-3 shift a little as well. The reason I think it helps the 2-3 shift also is it lets the front band come off quicker. With a spring in the accumulator and the system pressurized the spring is compressed. When the pressure goes away (i.e. switching to 3rd) that spring will extent prolonging the time the front band is applied a little which can possibly cause 2-3 overlap. Overlap not only wears parts fast but it also robs hp. But there are variables that can blow my theory out of the water such as the application of the front clutch being slow. With that scenario you could have flare up (the opposite of overlap) and that'll soften your 2-3 shift but for the most part overlap is a much more common occurrence than flare up so that's why I block it. I have yet to have someone complain of any trans. I did shifting too firm.
I also mentioned this to my trans shop, and he said I shouldn't necessarily block it, but if I prefer to do so, he recommends putting in an even stiffer spring than what it came with. So either I'll have an accumulator with a really stiff spring or completely blocked...What are your thoughts on the stiffer spring idea?

thanks very much for your help this far! Whats a good clutch pack clearance you recommend? I only have 4 clutches in each drum.
 
Seen this scenario before.....

If you really don't want to be doing this again then do it right this time.

1 Strip and clean it again buy a paper and rubber kit their cheap.
2 Replace the filter use a Dacron one. Change to a screen later if you like.
3 (Assuming its not a lockup TC) Flush it out,pour a lil solvent in, put the fwd drum and spin it a few times then dump or better yet suck out the solvent repeat again.
4 Get a can of cooler flush their cheap too... Flush those lines and rad with it !!
5 Air check.... you should hear a solid apply with very slight air leakage. Very hard to judge with little experience so that will be your judgement call.
6 If you use teflon rings, grease them in... They don't air check too well when greased in tho. Personally i prefer the steel rings (User preference).
7 Make sure the pump halves are lined up.. use a large hose clamp with the pump Oring off. Pump will install better in the case when lined properly.. Less possibility of " broken Rings "
8 New fluid..... I know its tempting but DONT reuse the old fluid.

Last of all ..Haste makes waste
And... Why is there never enough time to do it right, BUT ALWAYS enough time to do it again.... Think about it Good luck
 
Seen this scenario before.....

If you really don't want to be doing this again then do it right this time.

1 Strip and clean it again buy a paper and rubber kit their cheap.
2 Replace the filter use a Dacron one. Change to a screen later if you like.
3 (Assuming its not a lockup TC) Flush it out,pour a lil solvent in, put the fwd drum and spin it a few times then dump or better yet suck out the solvent repeat again.
4 Get a can of cooler flush their cheap too... Flush those lines and rad with it !!
5 Air check.... you should hear a solid apply with very slight air leakage. Very hard to judge with little experience so that will be your judgement call.
6 If you use teflon rings, grease them in... They don't air check too well when greased in tho. Personally i prefer the steel rings (User preference).
7 Make sure the pump halves are lined up.. use a large hose clamp with the pump Oring off. Pump will install better in the case when lined properly.. Less possibility of " broken Rings "
8 New fluid..... I know its tempting but DONT reuse the old fluid.

Last of all ..Haste makes waste
And... Why is there never enough time to do it right, BUT ALWAYS enough time to do it again.... Think about it Good luck

I agree buddy thanks for the tips. I have it all apart and I've been cleaning everything with Kerosine. I did not take apart the sun gears and planetary gear set though. I just put that whole thing in a bucket of solvent and swished it around for a while and turned the shaft every which way.

You think I should take apart the front pump? Guess I could...

I will stay with the Dacron filter. And I will flush out the torque converter with kerosine as well.

I have a B&M plate style trans cooler, not in the radiator. I'll attempt to flush it out with the cooler flush. where do you get it? Napa, Orielly? I havent looked yet. And yes I'll use the steel rings.

If I have any more automatic trans issues after this, I have a complete brand new rebuilt 4 speed setup waiting on stand by. :)
 
Also what might be a possibility is we tore the seal during installation, and the air pressure test we performed wasn't enough pressure to blow through the seal, but when it came time to run the trans the actual fluid pressure could have been much higher to break the seal completely. But either way, we broke it. lol

Yeah their pretty fragile. I too like steel rings cause it's extremely rare to have an issue with them.
I talked to my local trans shop where I got my front pump from. He said I'll be just fine with the steel rings, so that's what I'll use. A few others I've talked to also agree to use the steel rings.

Well, I ended up pulling the tail shaft just to clean everything. The rear band was just fine, as was everything else. There was friction material everywhere, so I cleaned everything up with kerosine.

good call. If it was that bad I'd take the planetaries apart and clean them too. Dunking and swishing won't get them completely clean.


Now about that front band, I also discussed with my local trans shop, he believes it was adjusted too tight, and this would cause it to take off in 2nd gear...-Which it did, -only sometimes.....I noticed sometimes I would have a 1 to 2 shift, and come to a stop and there would be no 2nd gear shift, like I was starting out in 2nd gear. And it did this a few times...But thats weird because I followed the specs in the ATSG service manual...It was something like 72 inch pounds then back it off 2.5 turns...The rear band was backed 4 turns from 72 inch pounds. In the "How to rebuild a 727" rebuild book it states for a trango shift kit with a 4.2 lever, (which I have a 4.2 lever) it needs to be backed off 2.25 turns from 72 inch pounds. The shift kit recommended tighten it snug with a short wrench and back it off 2 turns. The transGo 2 kit instructions werent real specific. What was also stated was, If I had less than a 4.0 lever, back it off 2.5 turns from 72 inch pounds, a 4.2 and 4.25 lever is 2.25 turns from 72 inch pounds and a 5.0 lever is 2 turns backed from 72 in. pounds. it if was unknown then back it off 2.25 turns. So with all these damn variables, what do you recommend, with my 4.2 lever??

With the 4.2 lever I back them off 2.25~2.5 turns from 72 inch lbs. and have never had a issue. As for the rear band adjustment, is that a double wrap band? If it is, backed off 4 turns is correct, if it's a single wrap band back it off 2.25 turns. This is assuming your torqueing them to 72 inch lbs. to start. If you don't have a torque wrench you can use the method of tightening each band down snug (until you can't turn the drum by hand) then back it off until you feel the drum spinning freely by hand (no drag at all) then back off another 1/2~3/4 turn and lock it down making sure the adjuster don't turn. I haven't noticed any difference in the 1-2 shift when the band is backed off an extra .25 turn and if anything it'll make for a cleaner 2-3 shift. Same goes for the rear band. As for taking of in 2nd, the band hanging up can cause that but so can the governor if it sticks and since everything was so burned up and it had trash in the case it's quite possible a piece of trash got into the governor not letting it move free. It doesn't take much to cause it to stick. I'd take it apart and make sure there is no burrs or trash that can cause it to hang. Same goes for the valve body. Any trash in it can cause problems so take it apart and clean it. And 68GTS's recommendation of flushing the converter and cooler is good. NAPA has trans. cooler flush.

I also mentioned this to my trans shop, and he said I shouldn't necessarily block it, but if I prefer to do so, he recommends putting in an even stiffer spring than what it came with. So either I'll have an accumulator with a really stiff spring or completely blocked...What are your thoughts on the stiffer spring idea?

thanks very much for your help this far! Whats a good clutch pack clearance you recommend? I only have 4 clutches in each drum.

All I can do is theorize because I haven't tried experimenting with different rate springs, but I'd think that unless it's as stiff as a board it would soften the 1-2 shift even more cause any dampening effect will slow down the application of the front band. Think of the accumulator as a shock absorber. An old worn out shock does very little dampening so it lets you feel every bump, but it reacts quicker. At the same time if you do use a spring a stiffer one would probably make the 2-3 shift cleaner cause it'll let the accumulator bleed off quicker possibly eliminating any 2-3 overlap. Again this is just my thinking as I haven't actually tried different springs so it's possible my theory isn't correct. Maybe one of the other trans. guys has actual experience and can comment on it.

I shoot for .060~.075" clearance for the front clutch pack and .040-.050" for the rear pack. That's measured dry of course.
 
okay. got the new parts from the shop yesterday, cleaned and washed my cases, and took everything apart to clean everything. valve body too. there were no issues with it, my brother built the valve body perfectly. all checkballs, valves and springs were in the correct places. one thing i did find, my front drum was NO GOOD. had some grooves where the rings on the front pump go..which we missed during the first time, and that also possibly could have taken out the front seal. i got a new front drum from my local trans shop. lucky to just have one sittin around.

13D42133-3C99-4C16-999C-22B304AA280F.jpg


5B30FA6E-B644-45E1-87AB-0B36F2B91746.jpg


rebuilt front pump with new seals, and cast iron rings. :)

18345CCD-7ACF-4E1C-8ED0-614C8FF634AA.jpg


installing the internal hard parts, front and rear drums and such.

6B615F51-3CF5-4B7E-8AD7-83E695C48839.jpg


pressure tested with air, everything works as it should

7836BE20-B8CC-4CAE-A164-075CA2077FBB.jpg


all back together minus the valve body

89FE439E-B9D0-4FAA-83EF-5C44DC293EFC.jpg


this little guy is now in a thousand pieces. we'll put it back together tomorrow. :) im glad i took everything apart, a clean fresh start.

IMG_6210.jpg


thanks you guys for the help. will post more soon.

-james
 
Did you install the 3rd gear orifice plug? Take your time adjusting that front band and get the overlap right, that's how I smoked my last rebuild... We need burnout pics!!!
 
Just in case it got missed somehow (maybe it didn't and I just missed it)

We always flushed the valve body while moving the valves back and forth.
It just too easy for one or two to stick in the bore a bit because of a contamination.

Dang 68, ya shoulda just wrote a diag book there.
Nice info, and by the way. I don't know from experience that your accumulator spring theory is correct but I agree that it makes sense.
 
Hey Guys. Thank you all for the help. Yes I am up and running!! My 318 runs GREAT and my "fixed -rebuilt" trans is working nicely now! lol

It shifts very nicely, very firm. Chirps tires in 2nd gear shift. I'm really happy. I got my cheetah scs floor mount shifter installed yesterday and am very happy how that works too. I can smoke the tires at will any time!! lol

-i do have to adjust my lokar kickdown cable a little bit because it does not downshift on it's own when i floor it...

will damage occur to the trans if the kickdown isnt adjusted perfectly?
 
Good deal Mopardude! No it doesn't have to be adjusted perfectly. Any time it's shifting good and firm your ok. When you install a shift kit it raises the pressure and that greatly reduces the possibility of damaging the trans. if not adjusted right. Does your valve body have the part throttle kickdown module (generally all 71 and newer have it)? If not you may have trouble getting it to kickdown on it's own cause the shift kit raises pressures accross the board which seems to reduce kickdown.
 
.............Blocking the acc does help quicken the 2-3 shift........depending on the shift i use lots of times i take out the acc spring between the acc and vb........then i will install a spring inbetween the case and the acc.....there are more ways to make a tf shift faster/harder w/wo a shift kit.......kim.........

Ok Kimmer, explain more? Think I see the point.
 
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