727 Issues ..

[hpjunke]

ok so after my trans has been rebuilt it acts totally weird now maybe you guys can help me here .. First i have a 3500 stall and before the rebuild it stalled fine now it seems as if its a "stock" feeling converter when it shifts into second gear it drops rpm like it has a regular stall in it before it would slip all day shifting and acting like a 3500 converter . Second is i have a lokar throttle valve set up on it and i wanted to know if anyone has set this up on a 727 not 100% sure if im making the adjustments it needs because 3rd gear takes a little long to shift . Third is the band adjustment on it causing the trans to feel "tight" ? Has anyone done a lokar set up on a 727 if so how did you do it? Any help would be appreciated. :happy3:

 

[moparleo]

OK You say your trans has been rebuilt and feels different. Did you take the car to a trans shop and have them rebuild your trans and install it back into the car or was this a bench build where the trans was taken to be rebuilt without the car? If this was a bench rebuild you now know why it is more costly to have the shop install and adjust your trans. Instead of you having no idea what the problem is and just stabbing in the dark to " fix it " take your car to a reputable transmission shop and have them diagnose your problem. If it doesn't work, you will have someone to blame besides yourself.

 

[hpjunke]

OK You say your trans has been rebuilt and feels different. Did you take the car to a trans shop and have them rebuild your trans and install it back into the car or was this a bench build where the trans was taken to be rebuilt without the car? If this was a bench rebuild you now know why it is more costly to have the shop install and adjust your trans. Instead of you having no idea what the problem is and just stabbing in the dark to " fix it " take your car to a reputable transmission shop and have them diagnose your problem. If it doesn't work, you will have someone to blame besides yourself.

lol im not blaming anyone dude I just needed a little advice some a guy who repairs or has tons on knowledge on 727 transmissions . so before I take it back to this guy I wanted to get some inside on the possible causes of it acting tight since I used my converter before and worked fine when I tore the car apart , I wanted to see if the causes are probably trans related .. I had no choice at the time to take it into someone and have them rebuild it but they couldnt adjust it and drive it around since it was a bench build trans . I built this car in a two car garage from the ground up .. so we are at the point where it runs and drives fine except for this issue .. so yeah I'll take it back to them just dont want them to say it needs this and this and charge charge charge me if I knew what the "likely" causes of my issues are ...

 

[moparleo]

The transmission should still shift properly on a bench build. Usually the only thing that you would have to adjust would be the kickdown linkage. If this is not adjusted properly the trans will not shift properly. A minor adjustment by the trans guy. Do you know if he installed a shift improver kit? Also, did you give your torque convertor to the trans mechanic or just left it at home. And if you did, did you drain the old fluid from the torque convertor? What type of fluid did the technician recommend for the trans and did you buy a name brand fluid? After you put a few miles on it, you could have him recheck the band adjustment depending on the band material he used.

 

[hpjunke]

The transmission should still shift properly on a bench build. Usually the only thing that you would have to adjust would be the kickdown linkage. If this is not adjusted properly the trans will not shift properly. A minor adjustment by the trans guy. Do you know if he installed a shift improver kit? Also, did you give your torque convertor to the trans mechanic or just left it at home. And if you did, did you drain the old fluid from the torque convertor? What type of fluid did the technician recommend for the trans and did you buy a name brand fluid? After you put a few miles on it, you could have him recheck the band adjustment depending on the band material he used.

i gave him my converter .. when he did the build they also installed a shift kit it shifts ok from first second and third just the time is a little off so I have been messing with that adjustment but it acts weird when it's cold .. seems as if it has a clutch feeling when I pull it out of the garage but when it's warm it's totally fine minus the stall not stalling feeling . I don't know what type of fluid I got but I checked it and it's full .. so at this point it has a 1000 miles so I gotta make an appointment to have these guys look at it .

 

[moparleo]

Great. That's is the best thing to do. If he built it on a bench, how did he put the fluid in before you installed it in the car ? The proper trans fluid level in a 727 is 1 pint low. Always check the fluid in neutral, with the parking brake on. The trans front pump only fully circulates the fluid through the valve body in neutral . So the level will not be correct in park. If your trans is lazy when you first start the car but gets better when warm could be a leaking pump seal. Try to put the car in neutral first for a minute and then put it into reverse. The car should start to move immediately with no hesitation.

 

[hpjunke]

Leo I put fluid in it when it's warm it stalls when I push down on the gas say in third gear low speed and idle its tight .Before on a slight incline I'd have to give it gas or it would roll back now it will pull you forward . I checked fluid in neutral that's level . and I figured out the shift points via the kick down or throttle valve so the shift times are good , now from a dead stop, the car feels like a stock converter and second then into third but if I raise the rpms in third ,it stalls so I have a feeling it's not the converter. My theory on this is the front band may be to tight not allowing the converter to do its job or a pressure problem meaning the line pressure somewhere is to much or not enough ...

 

[moper]

It's hard not knowing exactly what you're describing. I do transmissions and there's some things that need to be described right to know where to look. The brand and diameter of the "3500 stall" convertor will help too. Some companies make "tight" and "lose" with the same diameters and stall ratings....lol. Also helpful would be the manufacturer of the shift kit, and level of modification.
From what you're describing the kick down is not adjusted properly. If you can't the place that did the transmission should be able to figure it out for you and the more miles you drive in that condition the more damage the transmission will suffer. The "front band" is called the kickdown band and it does not come on in any gear but 2nd. Once "off", it doesn't drag and if it was so tight it dragged - it would shift from first to second properly because that's the only moving part on that upshift. Sounds to me like the kickdown first & the possibility that damage has already occurred to it - or that there's wear on the stator support or forward clutch sealing rings and it's not holding very well. The trans shop should check the pressures now that it's in the car running.

 

[hpjunke]

It's hard not knowing exactly what you're describing. I do transmissions and there's some things that need to be described right to know where to look. The brand and diameter of the "3500 stall" convertor will help too. Some companies make "tight" and "lose" with the same diameters and stall ratings....lol. Also helpful would be the manufacturer of the shift kit, and level of modification.
From what you're describing the kick down is not adjusted properly. If you can't the place that did the transmission should be able to figure it out for you and the more miles you drive in that condition the more damage the transmission will suffer. The "front band" is called the kickdown band and it does not come on in any gear but 2nd. Once "off", it doesn't drag and if it was so tight it dragged - it would shift from first to second properly because that's the only moving part on that upshift. Sounds to me like the kickdown first & the possibility that damage has already occurred to it - or that there's wear on the stator support or forward clutch sealing rings and it's not holding very well. The trans shop should check the pressures now that it's in the car running.

ok the brand is a an older ger 9 1/2 converter mind you i have ran this converter before these guys rebuilt it . It stalled and worked like a converter of this nature should work, its all after i have put all this car back together. I had the same trans shop take a look and a so called expert adjusted the tv cable and what not . it shifts good and on time however it doessnt stall its more like an 1800 ish stock converter . The trans shop says i have to much converter but i disagree i have had several converters in my cars and they worked well like they should .I had an 07 trialblazer ss with a 3200 converter and it worked and stalled like a stall should plus it cut my ets down to about .04 tenths . My car does some weird things when its cold and i start it in park i dosent wanna move unless im on the gas and it sounds like a clutch as im moving it out of the garage until its warmed it doesnt do that anymore . I hate driving the car it just feels like something is holding it back i guess im just used to the "loose" converter feeling i know there is something that is not working right . I also talked to another trans shop and they said it sounds like a pump and your cold start is called a "backflow" problem with it , things this car didnt do before i restored it . He also said if the converter was no good you would know because they hardly go bad , they break instead.
,

 

[moper]

So the convertor worked fine and had 3500 stall before the transmission was rebuilt, but not after? Did you also have the engine rebuilt or was it jsut the engine? What I'm refering to with the pump/stator are the sealing rings that go on the pump and seal to the high gear clutch drum. If the bushings on the pump or drum are worn, or the grooves on the pump or sealing surface on the drum is worn, they don't seal well an dit can give the impression of low pressure. That's why they should really be checking the pressures.

 

[transman]

ok the brand is a an older ger 9 1/2 converter mind you i have ran this converter before these guys rebuilt it . It stalled and worked like a converter of this nature should work, its all after i have put all this car back together. I had the same trans shop take a look and a so called expert adjusted the tv cable and what not . it shifts good and on time however it doessnt stall its more like an 1800 ish stock converter . The trans shop says i have to much converter but i disagree i have had several converters in my cars and they worked well like they should .I had an 07 trialblazer ss with a 3200 converter and it worked and stalled like a stall should plus it cut my ets down to about .04 tenths . My car does some weird things when its cold and i start it in park i dosent wanna move unless im on the gas and it sounds like a clutch as im moving it out of the garage until its warmed it doesnt do that anymore . I hate driving the car it just feels like something is holding it back i guess im just used to the "loose" converter feeling i know there is something that is not working right . I also talked to another trans shop and they said it sounds like a pump and your cold start is called a "backflow" problem with it , things this car didnt do before i restored it . He also said if the converter was no good you would know because they hardly go bad , they break instead.
,

Have I missed something? A "TV CABLE" on a 727? I've had lots of MOPARS and worked in the transmission/converter industry for years and never saw one on a 727.
I wonder how reputable the shop is.

 

[hpjunke]

So the convertor worked fine and had 3500 stall before the transmission was rebuilt, but not after? Did you also have the engine rebuilt or was it jsut the engine? What I'm refering to with the pump/stator are the sealing rings that go on the pump and seal to the high gear clutch drum. If the bushings on the pump or drum are worn, or the grooves on the pump or sealing surface on the drum is worn, they don't seal well an dit can give the impression of low pressure. That's why they should really be checking the pressures.

yes it was rebuilt and had the same converter and worked totally fine UNTIL after the transmission was rebuilt . the engine has also been rebuilt cam changed but it calls for 3000-3500 converter 3.91 gear 10:1 compression and 800 Cfm car which my car has the reason why I picked this converter . I doubt they checked pressures I'll have to take it somewhere else I guess.

 

[hpjunke]

Have I missed something? A "TV CABLE" on a 727? I've had lots of MOPARS and worked in the transmission/converter industry for years and never saw one on a 727.
I wonder how reputable the shop is.

it's also called a kicked down cable , yeah it measures throttle pressure to not sure on the proper term but either way it has to be adjusted properly. I'm running a lokar cable to it as well as my throttle cable so that's why I called it that

 

[transman]

Ok, my error.
I agree with Moper. Get the pressures checked. He also makes some good points in #10.

 

[hpjunke]

Ok, my error.
I agree with Moper. Get the pressures checked. He also makes some good points in #10.

what are the symptoms of a trans that's low on pressure ? how does it behave ?

 

[moper]

The whole system is driven off the oil flow. If the sealing rings are leaking then even at idle the line pressure will be low which means there's not much holding the forward clutch for 1st gear and the rpm required to reach an automatic ("D"rive) shift point changes. The kickdown pressure will be lower too. Because everything else is driven by fluid flow low pressures can limit holding capacity of the clutches and/or bands, it messes with shift timing and feel, and in some cases changes the way the convertor reacts. Basically anything that is a symptom of low fluid level is a symptom of low pressures. I've had Turbo Action valve bodies come out of the box with not enough pressure, and seen some builders that built for a certain level of pressure that if it's not reached will not let the trans work properly.

 

[hpjunke]

The whole system is driven off the oil flow. If the sealing rings are leaking then even at idle the line pressure will be low which means there's not much holding the forward clutch for 1st gear and the rpm required to reach an automatic ("D"rive) shift point changes. The kickdown pressure will be lower too. Because everything else is driven by fluid flow low pressures can limit holding capacity of the clutches and/or bands, it messes with shift timing and feel, and in some cases changes the way the convertor reacts. Basically anything that is a symptom of low fluid level is a symptom of low pressures. I've had Turbo Action valve bodies come out of the box with not enough pressure, and seen some builders that built for a certain level of pressure that if it's not reached will not let the trans work properly.

alright I'll have to take it in to someone else I just don't want them to sell me something or do anything it dosent need

 

[moparleo]

A good rule of thumb when purchasing anything from anybody is that if they can't show you the problem or explain the problem so that you fully understand what they mean, just pass until you do understand. Just say no.

 

[hpjunke]

does anyone know what pressures this 727 should be running at ? I have a feeling pressures are low making it run the way it does

 

[transman]

To do the pressure check, you'll need 2 pressure gauges that read from 0 to 100PSI and also a 0-300PSI. I'd also recommend you get a manual on the transmission if you haven't got one. ATRA has a good one and I'm sure there are others.
The transmission should be at operating temperature and the rear wheels must be off the ground.
Connect the 2 100PSI gauges, to pressure take off points at the side of the accumulator and at the front servo release. With the transmission in D at the engine at 1000RPM, line pressure must be 54-60PSI and the front servo release pressure must not be more than 3PSI below the line pressure. That's one of the pressure checks.
There is also a pressure check for lubrication pressure, rear servo pressure (this is where you'll use the 300PSI gauge), and also check the pressure at the governor pressure outlet.
These tidbits come from the factory service manual I've got for a 73 Challenger, and I've just lightly gone over the procedure. You'll need a manual to insure that the job is done properly.