Jeff's 727 rebuild thread

-
Well.....I'm gonna pull the valve body and try to figure out what I did wrong. ....!
Not the end of the world I guess.....dang!

To be continued. .....

Jeff
 
Just remembered this is the trans that D55Dave pointed out, during your disassembly, he suspected someone may have previously installed a shift kit. If your kit had you shorten a valve, and someone else had done that same mod before, that valve could likely be allowing incorrect fluid flow now. Same is true for valve body casting mods. These issues would definitely cause the issues that KickDown detailed in his posts. Also, I forgot you are using an aftermarket kickdown cable, not the linkage.
 
Would it damage the transmission driving it like it is?

Could over tightening the valve body to the case cause a valve to stick....someone mentioned that earlier. ..???

Also, forgot somehow to mention it won't downshift when I give it the gas....and I verified that the kickdown lever is all the way back ay full throttle. ....

Jeff
 
Last edited:
Damn.....I can't win....

Went to move it to the center of the garage, started it up, put it in reverse and I hear a "clack"...and now no reverse....????

Still have forward....but no reverse now.

Any ideas?

Jeff
 
MrJLR said:
Damn.....I can't win....

Went to move it to the center of the garage, started it up, put it in reverse and I hear a "clack"...and now no reverse....????

Still have forward....but no reverse now.

Any ideas?

Jeff
Click to expand...
Bummer..
Reverse servo broke or snap ring come out?
When mine broke it smacked the pan and dented it..
 
Don't let it sway you too much. Things happen. Get the pan off and see if any parts are in the pan. With any luck, the rear band strut came out and nothing broke. That can usually be fixed in the car, although it's awkward on your back. A servo problem can also be fixed in the car usually. This was probably not related to the other issue.
 
Jeff if you haven't already disassembled it try something first. Adjust the throttle pressure linkage so it puts more pressure on the throttle linkage at idle. I once had a 727 that had a governor that no matter what I did put out a little pressure in drive which would cause it to start out in second gear when the shifter was in drive like you said yours is doing. Once I adjusted the throttle pressure linkage a little tighter the throttle pressure over rode the governor pressure and it would then start in low gear like it was supposed to in drive.
 
MrJLR said:
I'm about ready to give up...
Click to expand...
Woah Jeff. These things happen. Dont let it get you down. Take a break from the car, have a couple of beers & get back on it with new found energy. Tracy has a valid point with regards to govenor pressure, although unless there is a malfunction in the govenor pressure circuit allowing it to override throttle pressure at standstill, I am doubtful. But yeah give it a try by all means. If all checks out, drop the pan & you should be able to see the reason for the loss of reverse. I noticed in the photo in post #270 that you still have the stock rear servo spring retainer in there. I will toss this in the trash if I install a TF-2 a fit a billet aluminium retainer. I've had a few issues where the stock retainer pops out from under the snap ring which will result in a loss of reverse. I am confident that these issues are only a minor set back & you will be back on the road smiling very soon.
 
Have you disconnected the shifter linkage at the lever on the trans shift shaft and moved the lever through each detent and audibly heard possitive engagement of the ball in the shift pawl detents?
 
Thanks guys.....
I'll say, I'd rather build an engine than a transmission any day after this.....

I have some honey-do's today, but I hope to at least get it back up in the air today and get the pan off....
Then during the work week I'll readjust my attitude and dive back in on the weekend. ....

I'm not a quiter......no matter how much I ***** about it.

And thank you all so very much for helping me with all of this.
If I get that pan off today, I'll let you know what I find. ....

Jeff
 
Ugh.....

image000001-5.jpg


I'm done for the weekend. ....

When I pull the valve body, what am I looking for pertaining to the shifting issue (not starting in first)????

Jeff
 
I did the same this past summer, but i broke the band lug trying to free it. I yanked the trans ordered the parts had it back running within a week.
 
MrJLR said:
Ugh.....

View attachment 1715146217

I'm done for the weekend. ....

When I pull the valve body, what am I looking for pertaining to the shifting issue (not starting in first)????

Jeff
Click to expand...

That is the servo that worried me when we put Jason's together. I should have upgraded it. The "hat" looked iffy at best. Espically with more pressure on it.

Sorry to hear about the problems your having.
 
prorac1 said:
That is the servo that worried me when we put Jason's together. I should have upgraded it. The "hat" looked iffy at best. Espically with more pressure on it.

Sorry to hear about the problems your having.
Click to expand...
Thanks.....I have 4 days to readjust my attitude. ....lol

Jeff
 
I'd take a look at the 1-2 valve to make sure it moves freely and the spring pushes it in all the way.

Don't get too frustrated, I forgot the little thrust washer that goes between the mainshaft and the input shaft (slip city). And then, in a hurry to get the transmission reinstalled I managed to break the pump gear dogs. Darn thing actually made it across town into traffic before it died. Oh, and to make matters worse, that 727 was in a Wagoneer so I had to deal with a transfer case. You'll get there.
 
Last edited:
There ya go Jeff just as I thought. The spring retainer popped out from under the snap ring. I'm sorry I didn't mention it earlier during your build up. Grab a billet aluminium retainer. 30 bucks from A&A. Part # AA296AR
As C 130 Chief says, you need to check the 1-2 shift & 1-2 shift control valve for freedom of movement. You have the 2 most important books regarding the 727. Study the valve body sections & you'll be fine.
 
Thanks guys.....I'll order the part this morning.....
Hoping I can do this without pulling the transmission out of the car.....

I'm resolved that crap like this just happens.....

Onward and upward!

Jeff
 
So clearly that pressed steel servo retainer is an issue.... however many modified transmissions do not have this problem, which makes me wonder what the root cause is.

I can see a few possibilities, as below.

Increased line pressure as part of the shift kit instructions which slams the servo down harder.

A mis adjusted or wired back throttle pressure linkage so that the line pressure is significantly higher than it should be when shifting from N to R.

But what makes the most sense to me is a broken or mis adjusted band (too loose) which allows the piston to travel too far forcing the spring and retainer out.

Just trying to figure this out so that we can all prevent it. Clearly the billet piston and retainer prevents it, but what is the cause?
 
So clearly that pressed steel servo retainer is an issue.... however many modified transmissions do not have this problem, which makes me wonder what the root cause is.

I can see a few possibilities, as below.

Increased line pressure as part of the shift kit instructions which slams the servo down harder.
I considered this too.....???

A mis adjusted or wired back throttle pressure linkage so that the line pressure is significantly higher than it should be when shifting from N to R.
Pretty sure I have that set correctly.....

But what makes the most sense to me is a broken or mis adjusted band (too loose) which allows the piston to travel too far forcing the spring and retainer out.
That is possible - question, How do I adapt my inch/lbs wrench to the square head on the adjuster to achieve the 72 inch/lbs ??? Do they make a special socket?

Just trying to figure this out so that we can all prevent it. Clearly the billet piston and retainer prevents it, but what is the cause?

I agree......I SURE don't want it to happen again!

Jeff
 
By the way guys, is this something I should address on the other servo as well?
(the spring retainer)

Jeff
 
You must log in or register to reply here.
-

Back
Top