727 question

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73-340

73-340

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i'm in the process of rebuilding my transmissionand have found out that it is a 79 lockup tranny . i have another 727 that is non lockup. my plan is to swap input shaft and valvebody off the non lockup over to the other, i believe this will work with no problems. the ? i have is , is the front pump off the lockup tranny any different than the non lockup. thanks
 
Not generally but there are some variations in different yrs. so if you have it it's probably best to use all the accompanying parts. Just make sure and check out the clearances in the pump good.
 
i noticed a crack in the tailshaft, so i removed it discovered this, NICE!! i got all the parts to replace, but what a mess. i had this tranny and knew it needed repair. didn't think i would find this. came out of a truck that hauled junk for scrap. good the i'm rebuilding this thing. can only imagine how this happened. just thought i would share these pics with you guys.

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has anyone experienced soft seal ring. they are a little thin and flexable.are these correct or not. do they swell when fluid gets on them? also is there a certian way you remove and install the metal sealing rings that have locking tabs on them?

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I've used the soft rings several times. Can't comment on them swelling when hot but they seem to work fine. I have a set of special outside flat tip snap ring pliers that works good for removing the old rings if you want to same them but generally I don't worry about it and pop them off breaking them and toss them into the scrap pile since I'll be replacing them anyway.
 
fishy68 said:
Not generally but there are some variations in different yrs. so if you have it it's probably best to use all the accompanying parts. Just make sure and check out the clearances in the pump good.
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what clearences are you talking about? or should i say where?

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Tip to tip clearance between rotor tips is one. Should be .005-.010" max. When you lay the outer gear in the pump housing you can check the clearance between the outer diameter of the outer gear to the housing. Should be .004-.008" max. Lastly is the end clearance. That's when you lay the gears in the housing and lay a short straight edge over them down in the groove the reaction shaft sits in and see how much clearance there is. Should be .0015-.003" max. Also make sure the pump body where the gears sit down in and the reaction shaft surface that meets the gears isn't scored.
 
i got the front clutch apart and saw that it had 9 spring in it . i have another front clutch, would i benefit any by adding 6 more springs. the other ? is on my converter snout has slight grooves can it be machined or something?

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What is the ratio of the front band apply lever? It's stamped on the side of it. Probably a 2.9 or 3.8 ratio. If it's either of those 2 put 12 springs in the front clutch. If by chance it's a 4.2 or 5.0 lever put 15 springs in it.

I always replace the converter if there's anything at all questionable with it. If the trans. it came out of was toasted it'll have tons of junk in it anyway so the least it would need is flushed.
 
i got the 5.0 lever. the tranny the converter came out of was in good working order, its a 3500 stall converter. so i dont want to trash it.
 
73-340 said:
i got the 5.0 lever. the tranny the converter came out of was in good working order, its a 3500 stall converter. so i dont want to trash it.
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Ok. Definetly use 15 springs then and don't go crazy drilling out the hole in the spacer plate that's for the 2-3 shift if your using a kit like a Trans-go that has you drill out the spacer plate. Otherwise you may have shift overlap. I can understand not wanting to trash the converter but by the looks of it there may be a sealing problem and/or problem where the bushing isn't tight and lets the converter walk around. If it were me I'd send it back to the mfg. and see if they can replace the snout and flush it. That'd be a lot cheaper than buying a new converter and will ensure you don't put it in and trash your new transmission.

BTW: if you do a torqueflite again don't use the 5.0 lever. It is designed for the wider/stiffer solid front band that a Hemi trans. uses and is a little too stout for the narrower std. band. It works but sometimes you get shift overlap. Generally if you use 15 springs and don't go crazy drilling the transfer plate your ok but even some will overlap when you've done that. I quit using the 5.0 levers because of that. Now I only use a 4.2 lever and the 2-3 shift is always crisp yet smooth. Just my findings.
 
i got the hd kevlar band for my tranny, i got the 5.0 lever for $20 and the 4.2 we're $40, didnt know about the overlap on the 5.0 issue till after i ordered it. the valve body im using has the b&m mods in it, will that make a difference in the overlap issue. the b&m kit has you drill the plate in a few spots , nothing to crazy. on another issue , what is the max clearence between the input shaft and the output shaft. what i've come up with is the thrust bearing and two shims with no movement between the two. that is with no gasket on the front pump housing. i did it that way as to not mess up the gasket every time i pulled it apart. so when i put the gasket on there will a little clearence. will that work ?

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Ok. Hopefully they didn't drill the 2-3 shift passage very big as the Kevlar band has a higher coefficient of grip so with it overlap is more prevalent. Concerning the end play, most 727's are designed to only use only the bronze washer between the input and output shaft. The way you adjust the end play is with the selective thrust washer between the front pump and front clutch housing. There are different thickness of the fiber washers so you have to try them and see what gives you the right clearance. I shoot for .012~.015" total end play. The different thicknesses of the washers give or take a couple thous are .062", .075", .089", and .105".

BTW: make sure you use the .062" thick fiber washer between the front and rear clutch packs. If you need a different thickness selective thrust washer to get the end play in spec let me know as I have a whole box of them.
 
i put a .064 fiber washer between the front and rear clutch packs then .098(the thickest i have) between the pump and front clutch and still have about a 1/6 th of an inch play. can i use two fiber washers together? if not i need a washer about .133 if there is one that size. how i came up with that was putting two together then measuring those two, that gave me just a hair of clearence. thanks
 
Wow that's a ton of clearance. I've never had one that loose. Are all the thrust washers new or in real good shape? Have you double checked to make sure you didnt' miss one? If all is right and it is that loose I don't think I'd stack 2 washers. I haven't looked closely but stacking them may throw off the alignment of the oil ports on the reaction shaft to clutch carriers. I'd just use the thickest one which is .105". The factory spec is actually .035"~.084" so you'd be in factory spec. with the thickest washer. I set them tight cause I don't like the idea of things banging around that much. I've got a whole stack of different ones so I should have an extra .105" in the box if you want it. That'd get you a little tighter. If you want it just pm me with your name and address and I can stick it in an envelope and you should get it in a day since we're so close.
 
the thrushwashers are all new , fiber washers are all new . the only thing i can think of is that this was a lockup tranny and i swappped in the input shaft for a nonlockup one . the the bushing between the input and the output shafts on the lockup shaft had the tree eared bushing with a shim . could the output shaft be a tad shorter?
 
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