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TF727 inspection and rebuild

Measure the pump rotor clearance on each lobe. The OEM measurement spec is just fine.
It seems the outer rotor sits quite low in the pump housing and has excessive clearance i think. (.0177")
1219095-9013ce6e41bed7129927c49409ed2c92.jpg

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.

The lever is a 3.8 ratio indeed and has a 2 spring servo, i have selected the stronger spring from the TF-2 kit from TransGo.
 
I had checked the pump again, the depth of the bore where the rotor sits is 0.7475 on average. (0.7460 - 0.7490)
The outer rotor height is 0.7455" average, the inner rotor is 0.7465"
The bore has some rough surface but is not "deeper" at that spot, it seems only the outer rotor does not meet the proper clearance.

IMG_1439.jpg


IMG_1438.jpg
 
It does appear in the pics that it has been circulating material and wearing the pump housing.
 
There was a magnet installed in the oil pan, which contained quite some metal dust and some metal particles in the suction screen so it's likely something has been going through the pump.
I measured at the rough area's and also on the good parts, including the inner ring and there is .001" difference at best.
Looking at it all i think this tranny is mainly original inside so i guess it is nothing unusual to see wear on the pump.
I think i will go with a set of new rotors and check clearances are within specs.
 
That pump looks pretty worn at the outside of the rotor cavity. It should be as smooth and flat as the inside surface. The pump is the heart of the transmission. If your steelies and frictions were worn because of poor pressure, this could be your culprit. Low pressure would also affect your shift points. I would suggest trying to find a better pump. Nobody rebuilds a motor and leaves a worn pump on it.
 
I agree with you on that, though i think it is going to be hard to find a new pump.
Looks like A&A is the only one so far that sells a front pump for my year, for some reason CRT does not carry the pump for my year ('69).
I wonder if machining the bottom down with .001 - .002" would be acceptable to smoothen it out?
It is just rough, i did barely measure any difference between the "damaged section and the smooth section.
I should have checked the line and max. throttle pressures before dismantling it to see if that pump was still putting out.
It could be the pressure was not sufficient and allowing the front clutch to slip during a hard launch, causing those hot spots?

On the A&A website it says, complete front pump but it shows the picture of just the cover.
Would this be a complete pump with gears and all?
http://www.aandatrans.com/Products/727-Complete-Front-Pump-Stock-(1967-70)__22763CPS.aspx
 
Machining the housing will complicate your gear rotor clearance issue. The A&A description talks about being machined the outer housing to fit the various convertors, so that sounds like a complete front pump. You still had some sort of odd thrust problem. Too bad you are so far away, I think I still have a few around.
 
Do you have a local transmission rebuild shop? Sometimes they have a supply of good used parts they have scavenged from old transmissions.
 
The A&A description talks about being machined the outer housing to fit the various convertors, so that sounds like a complete front pump. You still had some sort of odd thrust problem. Too bad you are so far away, I think I still have a few around.
I assumed also they talked about a complete unit, $195 is same price as CRT sells them for.
Then also need to pay a core charge likely, which is quite useless to send back as it will be more expensive to return a used core.
Though, if you have a good used one lying around that fits my transmission i am happy to buy it from you.
Saves me import tax (since it is used and not new) and no need to pay a core charge and or return shipping.

Do you have a local transmission rebuild shop? Sometimes they have a supply of good used parts they have scavenged from old transmissions.
I know a place that does engine overhaul/rebuilds that fingers with US muscle, but as far as i know mainly Chevy.
Since Chevy parts are much more cheaper here than Mopar you will mainly find Chevy parts here.
I am holding on to every Mopar part i have, it might be a huge drama in the future to find something.
 
The pump is toast, The steels as well. New frictions are cheap, I'd put them in anyway. The rear band is reusable. The flex bands can break. However I've never seen it. All my race stuff use solid bands.

Call the local trans supply house or go here. https://www.transpartsonline.com/TRANS_PARTS_FILE/tpcat.php?TransPartsOnline=727&TransPartsType=727 $154
I've bought plenty of parts from them for rebuilds.

I'm not sure what you are talking about here;
Other things worn are the wear sleeves/bearing rings in the planetary gear housings
I personally wouldn't replace any bushings unless they look bad. The only two that ever see any real wear are the pump bushing. That'll be in the new pump. And the tail shaft bushing. If it looks good it's probably fine. I've had a bunch of new ones lately that are to tight. They must be burnished to get the drive shaft to fit. You also need the proper tools to replace the the bushings. Without them you'll have a mess.
Doug
 
Thx dvw,
You would reuse the rear band? I checked out both bands and cannot see a single flaw on either of them.
The grooves in the rear band are still clearly visible and even.
Regarding the front band, since i am not racing and it has been holding up since whenever it was installed i do not really fear to reuse that also. The lining is like new on the front one.
I will get new steels and clutch discs for sure, i will check out the link you send for parts, seems they have some used good pumps available also.
And they ship international also!
 
Thx dvw,
You would reuse the rear band? I checked out both bands and cannot see a single flaw on either of them.
The grooves in the rear band are still clearly visible and even.
Regarding the front band, since i am not racing and it has been holding up since whenever it was installed i do not really fear to reuse that also. The lining is like new on the front one.
I will get new steels and clutch discs for sure, i will check out the link you send for parts, seems they have some used good pumps available also.
And they ship international also!
For street both bands will work. But they have complete kits with the front band, steels, frictions, seals, rings. You should have the narrow bushing drum if it's original. I've used this kit on high performance street cars with good results.
CAL DELUXE KIT 727, TF-8 62-70
Item #AR225A-R


$103.75​

They also carry TF2 shift kits.
Doug
 
For street both bands will work. But they have complete kits with the front band, steels, frictions, seals, rings. You should have the narrow bushing drum if it's original. I've used this kit on high performance street cars with good results.
IIRC the bushing measured something like .685" wide or something? That is the bushing that runs on the inner side of the pump housing, right? Anyway it's a June '68 build tranny so it must be the narrow one.

For the kit you mentioned, the steels are not included, will have to add separate.
Aside from that kit i will also need to order the remaining bushings and shims separate i guess.
 
Thx dvw,
You would reuse the rear band? I checked out both bands and cannot see a single flaw on either of them.
The grooves in the rear band are still clearly visible and even.
Regarding the front band, since i am not racing and it has been holding up since whenever it was installed i do not really fear to reuse that also. The lining is like new on the front one.
I will get new steels and clutch discs for sure, i will check out the link you send for parts, seems they have some used good pumps available also.
And they ship international also!
Go with dvw, you have it apart; change everything you can. You don’t want to pull apart again just because you skimped a little.
 
Yes, i will change out the stuff as needed.
But since i read so many times people say, reuse the original rear band as there will be nothing wrong with it, which mine also seems reusable i wonder why change it then?
The front band seems brand new also, but the kit dvw mentions includes a front band so i will stick a new one in, just need to get the steels, bushings and steel & fiber washers/sleeves as well.
 
If the band looks good, re-use it. Get the new thrst washers. I have re-used bands by just sanding off the glazing on the front band. But those are drag trans that I normally keep an eye on. If yours is questionable replace it. Rear band seldom wears much unless you abuse it by down shifting. That is how I learned to rebuild 727's. I down shifted my '70 Barracuda excessively. You need the clutches, steels and all the washers. Bushings are a one by one deal depending on how they look. But listen to dvw.
 
The rear band usually does not have to be changed, as it mostly is applying on a drum that is not spinning, as opposed to the front band that is grabbing a spinning drum. The front band is working harder and shows more wear.
 
I will get a front band and reuse the rear one.
What do they mean with clad seals?
And are those metal rings that sit on the hubs (to seal off the control ports) included in the kit? (sealing rings?)
What about the sealing rings for the servo's?
I am very unsure of what exactly is contained in the kit, what do i need aside from the kit?
Don't want to miss out parts i need and sit and wait for it to arrive, incl. additional costs.

I believe i will be happy with the kit dvw recommends incl. front band.
I will have to add steels (regulars), thrust washers (fiber and metal), a bushing set (as insurance) and a complete pump from what i know.
I am currently trying to figure out on the search of the individual part numbers to see what is there.
 
I can't see what the kit is that dvw suggested, but he knows his stuff. I've been using parts from Cope the last few years. They have been good. He even sent me a replacement front drum that I wasn't satisfied with. His clutches and steels, bands have been great. Hope you get all the parts you need.
 
Unless you have experience and tools leave the bushings alone. The pump should come with a new bushing. however I don't see a narrow bushing pump listed. If you can't find one contact me.
Doug
 
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