Fresh 727 Street Strip Trans S.B. Wont Drive

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IRISH RT

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Spent the last ten days sorting this new trans out , Basically Broke the Sprag in My last Trans .Got Another Casing rebuilt everything bolt in sprag etc, Clutches plates all new , put manual valve body in etc, had to use my original pump housing as my edge convertor would not fit the other pump that came with the casing, counted splines etc , problem is new trans wont drive fwd when on the ground, but will drive with back wheels off the ground, It wants to go fwd but then as I press the gas pedal lightly to get it to move It whines:mumum::mumum:
 
Bumpola. A couple of ideas.... Number one guess: torque converter/possible front pump,not fully engaged and /or, front pump bushing holding it back. Second,would be shifter adjustment,on the new valve body.
 
Drained all fluid today and strained no metal , used original pump And converterthey worked fine previously , selects gear perfectly , im thing its the reverse manual cheetah valve body seems to be a pressure or line issue the whine seems to be a dry whine like there is no fluid somewhere
 
Sounds exactly like the problem I had after I rebuilt my transmission.

It spun the wheels with them off ground, backed up okay on the ground, then wouldn't drive forward and felt like it was loading up and binding internally, and wouldn't move forward.

When I stripped it apart I found I had mistakenly installed the rear clutch piston backwards.

Just a shot in the dark. There are so many things that it can be causing your problem, but it sounds alot like the issue I had.
 

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scatpackbee said:
Sounds exactly like the problem I had after I rebuilt my transmission.

It spun the wheels with them off ground, backed up okay on the ground, then wouldn't drive forward and felt like it was loading up and binding internally, and wouldn't move forward.

When I stripped it apart I found I had mistakenly installed the rear clutch piston backwards.

Just a shot in the dark. There are so many things that it can be causing your problem, but it sounds alot like the issue I had.
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Thanx , Did you have any noises , whining or screeching on slight acceleration???????
 
I don't remember exactly the sounds it made.

This happened around 12 years ago so I really don't remember.

I do remember that the car would not move forward.

Sorry.
 
Or maybe you broke the two tabs off the front pump gear when you slid the convertor in? I've done it and it's not that hard for this to happen.
 
The pump itself should not have been a problem with the converter fitting. Spline counts on the pumps are all the same on all years. The only differences in pumps is the early pumps used a 1/2" wide stator bushing and newer ones used a 1" wide bushing and the vent is different. You cannot mix early style pumps with late front clutch carriers because of the difference in the bushing and the oil ports aren't the same/won't line up.

What year was the old pump? What year is the new trans? Did you count the splines on the input shaft? Did you change the rear clutch pack that has the input shaft pressed in it?
 
We Had problems with the First Pump As The Edge converter snout was a few thou more over a stock converter, We did all the spline counts 24, no didnt change the rear clutch pack, Not sure of the Years But My trans builder said you could not mix old and late model so he must know Thanx
 
IRISH RT said:
We Had problems with the First Pump As The Edge converter snout was a few thou more over a stock converter, We did all the spline counts 24, no didnt change the rear clutch pack, Not sure of the Years But My trans builder said you could not mix old and late model so he must know Thanx
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Ok. I ran into a issue with that a couple yrs. back with a trans. I rebuilt for a buddy. He had the converter worked over and a new snout put on it and it was too tight. Pumps are all the same as far as the bushing goes. I had him take it back and they cut the converter snout down .0025 and it worked fine then.
 
Yeah the early pumps used a 1/2" wide stator support bushing and different oil supply holes to feed the clutch packs. 71 and later uses a 1" wide bushing (better, more support for the stator) and modified oil ports to feed the clutch packs.

BTW: this is something your transmission guy should have easily caught as it's clearly visible. I'd suggest looking for a different trans. guy
 
dwire67 said:
I found this after I was told you cannot interchange the pumps
This was a good read!
http://www.ihpartsamerica.com/forum...t-407-tf727-variations-parts-differences.html
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That's a good read if your rebuilding a IH version of the torqueflite but there are apparently some year variations with what parts were used in the IH trans. vs. a std. Mopar torqueflite. Either that or he doesn't have some of the years correctly identified. I'm just part way through and have found a few things that he says that applies to IH versions of the torqueflite that I'm sure are not correct for a std. Mopar version. Not knocking the article at all. Just saying don't go by everything he says because apparently IH versions are not the same as Mopar versions.
 
fishy68 said:
That's a good read if your rebuilding a IH version of the torqueflite but there are apparently some year variations with what parts were used in the IH trans. vs. a std. Mopar torqueflite. Either that or he doesn't have some of the years correctly identified. I'm just part way through and have found a few things that he says that applies to IH versions of the torqueflite that I'm sure are not correct for a std. Mopar version. Not knocking the article at all. Just saying don't go by everything he says because apparently IH versions are not the same as Mopar versions.
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An interesting read. All the years selling parts to transmission shops throughout the country, I was always told the transmission was a 727 and the year of it, thats all that was ever needed to supply the correct parts. Never had any one ask specifically for IH parts. As far as the valve body is concerned, changes would be mainly linkage and internal springing/valving.
 
transman said:
An interesting read. All the years selling parts to transmission shops throughout the country, I was always told the transmission was a 727 and the year of it, thats all that was ever needed to supply the correct parts. Never had any one ask specifically for IH parts. As far as the valve body is concerned, changes would be mainly linkage and internal springing/valving.
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One nice thing about 727's is there weren't a lot of versions so it made parts interchange easy. I bet you right on the VB. I caught where he mentioned the IH valve body didn't have part throttle kickdown until 77 or 78. Chrysler had it in 71 if I remember right. Funny they didn't add it on the IH transmissions sooner. Not that part throttle kickdown makes much difference. Just thought it was odd there was so much time before IH used it.
 
The problem with my transmission not moving in drives was I had a 71 to 78 pump in a 66-71 trans- I knew the early ones where different and the later OD units
 
dwire67 said:
The problem with my transmission not moving in drives was I had a 71 to 78 pump in a 66-71 trans- I knew the early ones where different and the later OD units
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Yup, gotta watch what year for some parts, others, been the same since 1962
 
Before the Big Pull I decided to remove Pan , All Nice and Clean Filtered oil a couple of times no metal , Removed Valve body and found a steel rod holding one of the Accumalators open ???????? what is the purpose of that?????? Another Question How do you know when a Manual Valve Body is past it ??????? Thanx
 
IRISH RT said:
Before the Big Pull I decided to remove Pan , All Nice and Clean Filtered oil a couple of times no metal , Removed Valve body and found a steel rod holding one of the Accumalators open ???????? what is the purpose of that?????? Another Question How do you know when a Manual Valve Body is past it ??????? Thanx
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Blocking the accumulator makes the 1-2 shift firmer. I believe all manual valve bodies either come with a blocker rod or have the ports blocked internally. Don't understand your question about the manual valve body being "past it"?????

Before you yank the trans why not do a simple air pressure check to find out what's not working? If their all working it's likely a valve body issue in which case the trans. wouldn't need to be removed. When you inject air to each clutch pack you should hear them engage and see them move a little bit. Injecting air to the band servo's will make them extend and clamp the band down. If by the test you find one of the components not working you'll know exactly what to concentrate on when you pull it apart.

BTW: wear a full face shield and safety glasses when doing the test cause ATF will probably spray back at you when you inject air at each port

Here's a PDF file showing where to inject air (30 psi) to engage all the components
 

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Ive nearly had enough of this saga , Pulled the trans again because of the whine that I thought came fron The Edge Converter, Had the whole Trans pulled down again By another Trans Shop, He Checked everything clutch packs tolerences pump etc All was primo, He said he air tested it But How could he if there was no valve body in it ????, Then he said the fault was in the manual valve body, I had the Valve body stripped and cleaned as thats what I checked for blockage or restriction ,I had it laid out on my Bench in order, But it got mixed up then I threw it in a box and gave it to him , He said he could not put it together as All Manual Valve bodys are different and he wouldnt know how So He said he would put a standard valve body in, But I need to know if anyone has an internal assembly Diagram for the Cheetah 17156 Full manual reverse, Thanx
 
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