TF727 inspection and rebuild

[Wietse]

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.

I've got pullers, hydraulic press and an assortment of puller/press bushings in a lot of diameters, for sure i could find something that fit to remove and install the bushings.
I measured the bushing from the front drum and stator surface it runs on and it was .001" or .0015" clearance IIRC.
All bushings look good so if they can be reused, i will.
Is there a tolerance limit you know off? I can add a set and in case i measure one that is beyond i will have to change it.
They have a correct year pump housing, incl. new rotors in the Used Parts section, will see when i get the order in what they have.
But in case of no availability i will contact you if you have something that you are willing to sell.

 

[66Satellite47]

Fortunately most bushings in the 727 don't wear much. The only bushing I have regularly replaced is in the front pump. I use a Babbit bushing there just because it's easier to replace the bushing than a convertor snout.

Edit: Wietse, the first version of my post was confusing your 727 with another thread. But bushings are seldom a problem.

 

[dvw]

There are no bushing specs published. Recently someone posted they had swapped an input shaft bushing and it was to tight. I agree pump bushing and possibly th etail shaft bushing. Make sure to test fit the converter and the driveshaft before assembling the trans.
Doug

 

[Wietse]

Thx for clearing that up gents.
So the pump bushing is the small one in the front where the input shaft runs in, correct? The next bushing would be the bigger one where the front drum runs on on the pump stator.
I’ve seen the babbit version bushing available for the front one so i will get that one.
I think i will get a full bushing kit regardless, i am away from home now for the coming 6 weeks so i can order all the parts and have em ready for when i get back home. I will measure the tail shaft bushing at the time to see how much clearance is there. If it is too much i can replace it.
Test fitting is a good tip indeed, don’t want to find that out once already bolted together.

 

[oldbee]

Exactly , measure twice, think 4times. The thrust bearings are way more important.

 

[Fran Blacker]

Tool if you need to replace tailshaft bushing. not mine.
https://www.ebay.com/itm/254104262633

 

[dvw]

The pump bushing is the one that the converter rides in. A rebuilt pump (which you need) will come with that bushing installed. Unless you find a good used pump. Then get a bushing. Watch the pump bushing on install. It gets staked
Look carefully the bushing has a seam. Keep that away from the staked area. Make sure to deburr the stakes after you make them.
Doug

 

[66Satellite47]

The babbitt bushing is not at all required. I used them because they were readily available and provided a little less wear on the convertor. dvw makes excellent points on the bushing install if you choose to do that. The tailshaft seldom needs replacement. Take a good look at it and see if the yoke feels good in the tailshaft. Again listen to dvw.

 

[Wietse]

Thx for all your input guys, good info!
I contacted a local shop to see if they are able to supply a used or refurbished pump, or even maybe they can machine my original one to specs.
Will wait for their reply, then i can order from the US as required and if needed add a pump housing with rotors.

 

[Wietse]

Just going through some stuff, it seems on the parts list online there is a 2-tab washer in between the rear ring gear and rear drum body, i guess this is for later models, right?
I did not find any washer in between those a shown below.
The steel washer on the picture sits inside the ring gear, behind the planetary gear assembly.

 

[dvw]

What you have is correct. No need to change.
Doug

 

[66Satellite47]

Wietse, you appear to have both front & rear 4 pinion planetary's which use a 4 tab thrust washer. The three pinion use a 3 tab thrust washer. Your existing thrust washers look worn, replace them.

 

[Dave6T4]

Just going through some stuff, it seems on the parts list online there is a 2-tab washer in between the rear ring gear and rear drum body, i guess this is for later models, right?
I did not find any washer in between those a shown below.
The steel washer on the picture sits inside the ring gear, behind the planetary gear assembly.

View attachment 1295895

I always flip that thrust washer over to give a fresh surface. If that washer has a wear pattern on both sides, some one has already had this transmission apart once.

 

[Wietse]

What you have is correct. No need to change.

I just happened to see that additional washer on their parts diagram, but i guessed that what they are showing is a mixed drawing of various years maybe?

Wietse, you appear to have both front & rear 4 pinion planetary's which use a 4 tab thrust washer. The three pinion use a 3 tab thrust washer. Your existing thrust washers look worn, replace them.

Yes, both are 4 pinion type, as i've seen i will need 2ea 4-tab and 1ea 3-tab washer for my application.

I always flip that thrust washer over to give a fresh surface. If that washer has a wear pattern on both sides, some one has already had this transmission apart once.

I was thinking about doing that indeed, only 1 side has wear marks.
I am quite sure it has been open before, but i think only to change the front band since it is a flex type. (original is a solid one i believe?)
From what i can guess now, since my front clutch plates and steels are "burned" and i remembered that when i bought the car the throttle linkage was disconnected, that they might have fried it before and continued doing so?

 

[Dave6T4]

I just happened to see that additional washer on their parts diagram, but i guessed that what they are showing is a mixed drawing of various years maybe?

Yes, both are 4 pinion type, as i've seen i will need 2ea 4-tab and 1ea 3-tab washer for my application.

I was thinking about doing that indeed, only 1 side has wear marks.
I am quite sure it has been open before, but i think only to change the front band since it is a flex type. (original is a solid one i believe?)
From what i can guess now, since my front clutch plates and steels are "burned" and i remembered that when i bought the car the throttle linkage was disconnected, that they might have fried it before and continued doing so?

If the kick down linkage was disconnected, that is what killed your transmission. This linkage controls internal fluid pressures. As more throttle is applied, the transmission requires more pressure to accomplish shifts properly. If the linkage is not connected, the transmission " thinks " it is at idle at all times, so shifts are mis-timed with bands and clutches applied with insufficient pressures.

 

[66Satellite47]

I'd bet it has surely been apart. The OEM front band was a solid band. Your flex band is a replacement. If the kickdown linkage was not connected, that may explain the burned steels. If the steels got burned, so did the clutches. Replace all the steels & clutches and the lip seals in the front drum. The kickdown linkage on a standard style valve body controls the pressure that the components see. A manual shift valve body is usually full pressure all the time, doesn't require the kickdown linkage. Yes you need two 4 tab thrust washers and the 3 tab that goes in the shell.

 

[Wietse]

It was one of several things i found after buying the car, the linkage was there but not hooked up.
When i looked into that i found the importance of it and put it back in place, not sure how long it has been like that.
Some work was done before the car was handed over as part of the purchase, incl. some ignition and carb adjustment, they might have forgot to put it back on for all i know.

I did check the functioning of the front clutch package with compressed air, it worked obviously but i had the feeling that there was an air leak on the piston as well. Was hard to clearly hear as the air gun i used also did not seal against the port properly but i am quite sure i could hear air leaking inside the drum as well.
I had not removed the piston yet as i had not finished fabricating a compression tool, but more than likely the seals in there will be in bad shape.
So either the throttle pressure or the leaking front piston seals probably caused the burnt spots. (or both)
It did work well since i owned the car, but i think i got at it at the right time before a failure was going to occur here.

Replace all the steels & clutches and the lip seals in the front drum.

The whole tranny will get a rebuild for sure.

 

[66Satellite47]

Anytime I build a 727 for a customer, I replace the drum/piston lip seals, the servo seal rings, reaction shaft seal rings, thrust washers, new or perfect steels and new clutches, new bands and inspect all the bushings. On my own stuff I may re-use some parts possibly the rear band and/or clutches. If I'm building a new one for myself I judge if a part can be re-used.
Wietse those steels indicate a major problem that probably was not correctly addressed.

 

[Wietse]

I replace the drum/piston lip seals, the servo seal rings, reaction shaft seal rings

All those seal rings for the servo's and shaft come with the repair kits, right?

Wietse those steels indicate a major problem that probably was not correctly addressed.

Indeed, like i said it was probably due to the throttle linkage or the piston seals are fried. (maybe the pump is also aiding this due to lack of pressure)
The 440 in front of it is not a stock one, i never abused it but it is driven hard at times.
We will see when i get to it again how the piston seals will look when they come out.
I am waiting for a shop here in Europe to respond on my email if they have a front pump housing for me, if not i need to include it in the order i will place from US.

 

[oldbee]

“driven hard” means nothing to a torqueflight. It was your linkage! Guarantee.