TF727 inspection and rebuild

Wietse

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He guys,

Today i managed to remove my tranny from my '69 Coronet R/T.
Lucky me i found it is the original transmission with the VIN stamped in the pad.
I will do a full dismantle and check everything and replace what is required.
Some observations i had so far i wanted to share with you guys and see what you think and eventually some recommendations perhaps.
I measured the input shaft axial play and found it to be 0.0750", not sure if that is correct but it seems a lot.
Some metal debris found inside the pan and filter but nothing excessive imo.
I wonder if the filter spacer is stock? Or is this an extension version and my pan is bigger in capacity.
I think i have no stock pan since it has a drain plug so it could be a bigger size capacity?
I already dismantled the valve block and started on the modifications for a TransGo TF-2 kit.
Also not sure about the adjustment screw for the throttle valve is original or not, you can see it partially on the pictures.
I think i can see the same in the TransGo manual but not sure.

Tomorrow i will continue and finalize the valve body modifications, after that i will pull the pump and all other parts.
Will see what is the condition of the bands and clutches, i did not have issues with the transmission but since it is out to change the converter i want to go through it to make sure i do not have to pull it again later on.
Do the bands look stock? I have no idea if someone has gone through it before or maybe nothing has ever been done before.

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66Satellite47

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The filter extension is for the deeper pan like DC sold. The debris looks about normal, maybe a little convertor material. Can't see anything about the bands & clutches until you take it apart. Be careful with the valve body.
 

451Mopar

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The pan and extension are either Mopar performance or from a 518 transmission. Either way it adds capacity.
I think the Manual selector lever and Neutral Safety switch are from a '70 and up transmission. I think the '69 still had the single connection NSS?
Valve body looks mostly unmodified. It may have a shift kit (gold) plate between the body halfs? Not sure of year. If that is a large ball at the bottom of the valve body next to the lower part of pressure regulator valve, that might be an indication of a year change?
Screw for throttle valve is correct (original). Don't remove the throttle valve screw/lock nut. Resetting the distance takes a special tool.

The pump housing is correct, but need to check the stator support, Input shaft, and front drum to see of the drum is the narrow bushing type (Correct for year) or a later wide bushing type drum.

Check the aluminum teeth of the front planet gear for cracking or missing teeth. Should be a 4-pinion planet gear too.

"I measured the input shaft axial play and found it to be 0.0750", not sure if that is correct but it seems a lot."
If that is up/down/sideways, check that the stator support is for the narrow busing drum. The late wide bushing stator support I believe used a larger diameter input shaft? Otherwise the bushing in the support needs replaced. Also, check the input shaft in/out play and look at where the seals are riding inside the front drum. This will let you know if you have to re-set clearances at the pump washer.

I think the front band lever should be a 3.8:1 ratio. The ratios are stamped on the side of the lever.

Front and rear drums should each have 4-clutches.

Don't know about the bands. Not sure when they switched the front from cast to flex type? Just inspect and replace if needed.

When you get to the sprag assembly, take good photos of the rollers and springs. Often on budget rebuilds, the springs won't be re-installed correctly.
 

Lefty71

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I'm pretty sure there were no flex bands in `69 (kickdown band).
 

Wietse

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Thx guys,

The production date in the numbers state June '68, I am not sure the forward band is a flex or solid, from what i understand is that the forward bands tend to wear faster compared to the rear.
It could have been driven without proper throttle pressure in the past and burnt the forward band?
Comparing my pan with some pictures on the web it seems the one i have here is a fair bit deeper indeed.

If that is up/down/sideways, check that the stator support is for the narrow busing drum. The late wide bushing stator support I believe used a larger diameter input shaft? Otherwise the bushing in the support needs replaced. Also, check the input shaft in/out play and look at where the seals are riding inside the front drum. This will let you know if you have to re-set clearances at the pump washer.
I measured the in/out (axial) play which was .0750", up/down/sideways i did not notice any but will double check also.
I have seen there are shim/thrust washer kits available to make any adjustments, guess that will be a requirement including a full seal/gasket kit.
 

dvw

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.076" is with in factory spec (.037-.084). Endplay us nit one of things I would worry about. Some run it even tighter than factory. Never seen it really affect anything if it's close.
Doug
 

66Satellite47

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IIRC the OEM flex bands started '72 or even later. I've used both in high HP with good aftermarket band material. The axial end play at .750 is pretty big. I like them about .040-.050. The selective fit thrust washers on the front pump can correct that.
 

Wietse

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The front is a real flex band, it seems i will not require any new bands or clutch plates.
Some steels have some hot spots but seems nothing damaged or worn excessively.
Pump is a little concern, the outer ring gear is quite low in the pump housing, the housing has some wear on the edge but only on 1 side.
Housing / outer rotor height difference: .0177" (.0015" - .003")
Housing / inner rotor height difference: .0039" (.0015" - .003")
Between rotor teeth: .006" (.005" - .010")
Between outer rotor and housing radial: .004" (.004 - .008")
(note the feeler gauges sizes are mm)
Other things worn are the wear sleeves/bearing rings in the planetary gear housings, gears are all ok with no broken teeth.
Sprag clutch also looks ok, i am not going to open or remove it, axle bearing and bearing sleeve in tail housing also seem fine, just will need a new shaft seal.

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Wietse

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Not really easy maybe to see on this picture, but one side of the lower face has quite some wear/damage, maybe due to cavitation of running on low oil or something. (Left side and upper side, rough surface)

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66Satellite47

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You need to replace all the clutches and steels, as well as the bands. Steels that scored are not to be re-used.
 

Wietse

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You need to replace all the clutches and steels, as well as the bands. Steels that scored are not to be re-used.

The bands do not have any signs of excessive wear, all worked fine also before dismantling.
Both drums just show contact wear, especially the rear one looks very good, the front drum you can feel some wear has occurred but that is probably why the band likely was replaced in the past.
The front (flex) band really looks like new so it must have even contact with the drum.
The thing with the clutches is that they both have a thick snap ring (0.1075" on front and 0.0885" on rear), other size mentioned in the manual are all smaller.
The clutch pack clearance between pressure plate and snap ring is also good, 0.10" for the front and 0.031" for the rear which are as per the book.
If they were worn out i would expect the clearance would be on the high side.
The steels only show those black hot spots but is only visual and do not show any other damage/wear/warp other than (to me) normal contact wear.
And the friction discs show a clear cross pattern/grooves.

Not to go against your opinion, but i cannot see the reason why these could not be reused?
I guess there is no min. thickness specified for steels and frictions to double check where they are at?
 

Dave6T4

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I have had a lot of 727's apart, but have never seen that pattern of hot spots on the steelies. For the little cost of new steelies, I would replace them. Take a micrometer and measure the thickness of your clutch discs in 4 or 5 places to see if they are warped. Fronts should be around .086" to . 088" ; rears .060" to . 062" .
For real wide clearances, I have used a spare steely as a shim to get the clearance where I want it with the snap rings I have. In your case, you have a .108" snap ring that leaves you .100" clearance. This means you have . 208" gap from top plate to top of snap ring groove. In this case, I would use an extra steely (.062" ) with a .060" snap ring to give you . 086" clearance.
(.208" -.062" -.060 = .086" )
 

66Satellite47

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The steels are junk. Replace them. I would not trust the clutches either.
 

Wietse

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Fronts should be around .086" to . 088" ; rears .060" to . 062"
That is exactly what i measured just now, there are no real bad spots to be seen on the frictions.
But after a clean up of the steels it shows some hot spots surface is a little rough.
The steels are junk. Replace them. I would not trust the clutches either.
I see your point, the frictions could be bad as well.

So i am going to be looking for:
Bands
Frictions & steels
Bushing/sleeve kit
Thrust washer kit
Gasket kit

And i am guessing a new pump, or rotors only? (Should have checked pressures before dismantling actually)
Looks like CRT does not have the pump for my year for some reason?
They do have a gear set with thick lugs but i am not sure that will rectify the clearance issues on my current pump.

Think i will go with CRT their kits, can order all in 1 go.
Would i use the Stock 727 rebuild kit, or Street or Street HP? 440 has a good cam (238/244 @ .050", 1-7/8" headers, Sniper EFI and a 3k stall converter.
Would it be recommended to replace the tail shaft bearing while i am at it? I has a little wobble but nothing concerning to me for a single row roller bearing.
Valve body modification as per TransGo TF-2 kit has been done.

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Dave6T4

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A&A Transmissions near Indy sells a front clutch package that allows you to put 5 clutch discs in a 4 clutch front drum. They are same thickness as rear clutches. This gives you 25% more torque capacity in high gear. I have used them in all my later rebuilds. That one shot of your front clutch discs looks like they are pretty glazed up and should be replaced. Always replace your torque converter seal and output shaft seal. Replace the fiber input/output shaft thrust washer with a bronze one. I hardly ever had to replace the output shaft bushing in my rebuilds. Just do visual inspection for galling or abnormal wear pattern. They are a brute to change.
I always replace the oil pump bushing and front drum bushing as well. There are 2 versions of this drum bushing. Early trans had a narrow one, while later trans had a wide one. Order one appropriate for your drum.
Judging from your burnt front steelies, you might have a front clutch piston problem. It might be worthwhile to replace the piston lip seals and check return springs. I like to use either 9 or 10 springs, depending on style of piston.
 
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Wietse

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I am guessing my 440 has maximum 500hp.
I am not racing the car, just a streeter so i guess i don't need the additional plate, right?
It would be nice to just replace the clutch package without to much fiddling around with different thickness circlips etc.
Since i am in the Netherlands i do not have the ease of ordering as you guys, so finding out i need more will take more time and costs are high due to shipping and import charges.
I hardly ever had to replace the output shaft bushing in my rebuilds. Just do visual inspection for galling or abnormal wear pattern. They are a brute to change.
I read a lot about this, mine seems ok so i will not change it.
Judging from your burnt front steelies, you might have a front clutch piston problem. It might be worthwhile to replace the piston lip seals and check return springs. I like to use either 9 or 10 springs, depending on style of piston.
I will replace all seals regardless, my front clutch has 10 springs as is standard for the 440HP version i have.
Front drum bushing i am not sure about what size mine has (trans is from June '68), i had seen CRT sells a bushing kit that contains both so i cannot go wrong with that.

Any recommendation on the pump?
I had left the clearances in an earlier post.
 

66Satellite47

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I've used the parts from Cope the last several years. Very happy with his parts. The gasket/seal kits are not quite the same quality as years ago. But the last few I have done for customers have worked fine. No complaints. I've never had to change the output ball bearing and maybe 1 tail shaft bushing in 45 years. I also replace the pump bushing, for a race trans I prefer the babbit. Measure the pump rotor clearance on each lobe. The OEM measurement spec is just fine. You need to make sure the front drum and reaction support are the same, early models used a short reaction support & narrow bushing, '71 & later a longer reaction support and wider bushing. The number of springs in the front drum depends on which ratio band lever you have and which springs are in the front servo. A typical 3.8 lever with the 2 OEM springs in the servo will want 10 or 12 springs in front drum. Again it's all a matter or of the parts combination. I always use the bronze thrust washer between the input & output shafts.
 

66Satellite47

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Wietse, if your trans is a '68-69, you should have the narrow bushing front drum/reaction shaft. New steels and clutches with new lip seals are what you need for that.
 
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