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My full manual 4l80-e

6.2 turbo

6.2 turbo

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My tranny is working pretty good,but not quite like I want it to. First of all the converter will stall up to 3000 in 3rd or 2nd with lock up turned off. It will stall 2000 rpm,brake torquing. If I lockup the converter the same time as shifting to second ,the converter slips a lot,and line psi drops from 220-120 psi. I did get the converter to slip at 190 psi when lugging in 3rd. Do I need a triple disc converter,and why is the stock stall speed so high ? If I don't shift or lock up the converter under full power,it works fine,and can occasionally chirp second gear. I need a better converter. I might just get the local converter shop to build one,that way I can get them to make adjustments ,If it don't work on the first try.
 
What converter did you put in it? Sounds like you have a 6.0L medium stall one in it now as they stall pretty high, or the 4.3L one stalls REALLY high. The low stall one for a diesel should only stall around 1500-1600 doing a break torque on it, so it sounds like you got the wrong converter in it. Even teh guys with the DURAMAX vans run a standard low stall converter and they don't get really high stall speeds like yours. I would suggest calling PRECISION INDUSTRIES(in Tennessee, NOT the one up north) as they make a great converter for a better price than many of the other big name companies. And they know what a diesel needs as they build ALOT of converters for diesels. My second choice would be to call GOERAND or SUNCOAST. GOERAND makes great converters as well but does mostly DODGE, and SUNCOAST also makes a great converter but you pay a premium for there name. I'm not 100%, but I believe REVMAX also makes a decent converter, and there prices are pretty good as well. And TRANSTAR I believe can get you a RECON converter that will do the job as well. There are options here, but it sounds like something is screwy with your current tran myself. What all is in it? What year? What shift kit?
 
It is an early one 93 I guess. The trans was taken apart and has the HD-2 Transgo kit. I have no idea what converter I'm using, supposedly 6.2 diesel van/bus. We are going to try a stock diesel converter from Landis Converter, similar to Recon.
 
When you did the HD-2 kit, did you also drill the converter passage? I remember Mike L mentioning a passage in the pump that needs to be enlarged in the 4L80E when you do teh shift kit to make the converter lock in better at low RPM's. I'll see if I can find the info later on about it.
 
how does it feel on the street? are the shifts firm or hard during normal acceleration? do you have a pic of how/where you put the shifter and what brand did you go with? do you still need the TCM or can that be eliminated?
 
6.2 turbo said:
No,that's the HD-3.
Click to expand...

The HD-3 kit is the one for full manual operation and uses the vacuum modulator basically making it shift like a turbo 400. The HD-2 shift kit is just the heavy duty model, so what are you using to shift it?
 
I'm pretty sure that we drilled the pump. It shifts off of the internal pressure switches, a Jakes Performance manual harness plugs in the external tranny plug and only have to connect 12 volt key on,and switched ground for lockup. I removed the center console,and mounted a B&M megashifter there. Everything works fine,untill I shift at full power. It seems worse if I floor it, shift into second,and lockup at the same time,and then 3rd. The shifts get very soft. It seems like the converter slips the whole time. Now if I'm cruising part throttle in 2nd,hit lockup,wait a little and full throttle into 3rd,it feels better. I'm not real sure a heavy duty single disc is going to work like I want it to. But if the stall is tighter I will not have to depend on the lockup as much ? The only time shifts feel harsh is when shifting while coasting. I'm open for any ideas on giving the converter clutch more fluid and psi.
 
I see what you did now. You basically wired the internal pressure switch to trigger the solonoids then if I understand you correctly? Then added in a seperate switch for lock-up? How are you controlling line pressure? Is it just max all the time? A single disc converter with a billet cover I would think would more than hold anything a 6.5 could throw at it. I doubt you are going to get DURAMAX torque from the 6.5 even with a high output pump. Torque is the killer here, not HP. I would think a good low stall single disc kevlar clutch with a billet cover would work fine for you. Give PRECISION a call as they will build you a converter that will work and warranty it for 2 years unconditionally.
 
There is an aluminum plug that replaces the epc solinoid. The line pressure never goes past 220 in forward gears. The pump can make a lot more psi,but the volume is not enough to keep it at 220,when shifting,or engaging lockup.
 
Well ,the tranny is out,and a new stock converter sitting here. I have been studying every flow chart I can find,on the tcc apply. What I want to do ,is give the convertor clutch full line pressure. The way I understand it would be to block the orificed regulator apply pressure ,that pushes the tcc regulator towards off. So far 3 tranny builders are disagreeing. They say there is a tcc valve in the pump that controls how hard the tcc applys . Sonnex makes a upgraded tcc regulator valve,and they say use the lighter spring for firmer lockup. This makes me think I'm looking at the right one ? It is dirrectly behind the tcc solinoid. For as much as these tranny are bragged up,I can find no imformation on how to increase lockup psi,except the Sonnex kit. Even the Transogo HD2 kit does nothing for lockup.
 
Did you bore and install the TRANSGO actuator limit valve kit? If not there is a chance you are getting low valve body pressure that is not allowing the valve body to supply enough pressure to fully apply the TCC valve in the pump. Also you might want to make sure that your box is supplying full power to the TCC solonoid since it is a PWM style solonoid.
 
I will double check the limit valve spring ,and make sure it has the one for firmer shifts. I'm getting a new tcc solinoid since I broke the screens on the old one. I'm going to plug one hole in the separater plate. This mod should give the tcc 220 psi ,which is max line pressure. The tranny guys were confused at first ,since mine is the early style. But we are in total agreement now on which valve does what.
 
The valve I am refferring to isn't one covered in the normal shift kit, but is a known weakness in high milage 4L80E's and causes sloppy shifts and lack of lock-up. Did you also replace all of teh sealing rings in this trans when you built it? GM had ALOT of problems with early 4L80E's and the sealing rings in them early on.
http://transgoonline.com/products.p...d=204&countdisplay=4&start=0&addcountview=Yes
 
I know which valve you mean,I didn't pull it out,but my tranny guy probably did. I helped him with most of the build,but he did the valve body when I wasn't there. As far as I know all the valves are still factory. Tonight I plugged a hole in the separator plate,and removed the outer spring from the accumulator valve. I also want to drill the shift holes for firmer shifts,they are still the smallest size. I might just drill them to .086 and go from there.
 
6.2 turbo said:
I know which valve you mean,I didn't pull it out,but my tranny guy probably did. I helped him with most of the build,but he did the valve body when I wasn't there. As far as I know all the valves are still factory. Tonight I plugged a hole in the separator plate,and removed the outer spring from the accumulator valve. I also want to drill the shift holes for firmer shifts,they are still the smallest size. I might just drill them to .086 and go from there.
Click to expand...

I would be hesitatnt to go too big on the seperator plate holes since your running full line pressure all the time. You could cause em to hit hard enough to actually break the pistons I would think.
 
I drilled them to .086 on size up from the softest setting. The clutch pack pistons have been upgraded to one piece steel . I'm mainly worried about snapping the input shaft. Or grenading the 8.5 10 bolt. I also got type F fluid ,to make the converter clutch grab harder .
 
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