4L80E TCC stuck locked
Thread Starter
On The Tree
Joined: Mar 2015
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4L80E TCC stuck locked OK, so I fixed my other issues, it was a firmware issue with the controller. Now shifting properly...
I had a sneaky feeling all along that the TCC LU was stuck engaged - and I now know it is. Shift into D with your foot on the brake and it stalls the engine completely. Shift without applying the brake and it all works fine, as soon as you brake again it tries to stall.
I've checked the wiring to the TCC solenoid, and the resistance of the solenoid and they both check out OK.
Questions is, why?
The transmission is freshly built, by myself, it has the transgo HD2 kit installed per their instructions (with the exception of the pressure relief valve), it also has a new standard pump fitted.
The TCC was rebuilt by a reputable shop in the UK, so I expect that's OK.
Any ideas. Wondering if I got a checkball wrong in the case or VB maybe?
I had a sneaky feeling all along that the TCC LU was stuck engaged - and I now know it is. Shift into D with your foot on the brake and it stalls the engine completely. Shift without applying the brake and it all works fine, as soon as you brake again it tries to stall.
I've checked the wiring to the TCC solenoid, and the resistance of the solenoid and they both check out OK.
Questions is, why?
The transmission is freshly built, by myself, it has the transgo HD2 kit installed per their instructions (with the exception of the pressure relief valve), it also has a new standard pump fitted.
The TCC was rebuilt by a reputable shop in the UK, so I expect that's OK.
Any ideas. Wondering if I got a checkball wrong in the case or VB maybe?
Last edited by gothic_sera; Apr 19, 2016 at 01:11 PM.
Teching In
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http://www.sonnax.com/parts/1989-lub...egulator-valve
You may need to install this pressure regulator valve.
You may need to install this pressure regulator valve.
Thread Starter
On The Tree
Joined: Mar 2015
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Thanks, I've just ordered one from Rock Auto - hopefully it will be here before the weekend - depends on FedEx....
I've read mixed reviews about them - some people say they've fixed the problem, others say not. Hope it does, I really don't want to be pulling the transmission again....
I've read mixed reviews about them - some people say they've fixed the problem, others say not. Hope it does, I really don't want to be pulling the transmission again....
TECH Fanatic
Joined: Jan 2015
Posts: 1,114
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From: Fort Worth, Texas
Doesn't the HD2 kit instruct you too drill a Lube to Line bypass in the Pump Cover? If this step was done correctly.....DO NOT install that Sonnax PR Valve.
Have you installed a Pressure Gauge too verify proper pressure?
Have you installed a Pressure Gauge too verify proper pressure?
Thread Starter
On The Tree
Joined: Mar 2015
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It's listed as optional, and I didn't do it... Typical
I haven't put a gauge on it yet, will do after I've done the Sonnax mod. I can control the pressure from my laptop so should be able to check the PC solenoid is working properly too.
Thread Starter
On The Tree
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It stalls almost instantly.
If you shift into D with the wheels off the ground without your foot on the brake and then accelerate and then jab the brakes it immediately tries to stall the motor. So I'm pretty certain the converter is locked
If you shift into D with the wheels off the ground without your foot on the brake and then accelerate and then jab the brakes it immediately tries to stall the motor. So I'm pretty certain the converter is locked
Last edited by gothic_sera; Apr 21, 2016 at 03:44 PM.
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On The Tree
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Sera
Thread Starter
On The Tree
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The Sonnax valve arrived today and I pulled the pan and fitted it. Also replaced the TCC solenoid and checked the valve was in the right way round and free to move (which it was).
I also replaced both shift solenoids with new Delco ones while the pan was off. Couldn't hurt.
After first firing it up nothing seemed to have changed. However after running for a few minutes and then getting angry and putting it in drive with my foot on the brake and giving it a load of revs it all seems to be working... it now idles in gear quite happily. So that's a result.
I just have problems with my Megashift now - thinking of ditching it an using a TCI EZ-TCU if I can't get it working properly tomorrow. Trouble is I really don't have that sort of money to spend
I also replaced both shift solenoids with new Delco ones while the pan was off. Couldn't hurt.
After first firing it up nothing seemed to have changed. However after running for a few minutes and then getting angry and putting it in drive with my foot on the brake and giving it a load of revs it all seems to be working... it now idles in gear quite happily. So that's a result.
I just have problems with my Megashift now - thinking of ditching it an using a TCI EZ-TCU if I can't get it working properly tomorrow. Trouble is I really don't have that sort of money to spend