I recently had a 47rH rebuilt and upgraded internally.
Alto clutches, bands and intermediate shaft, steel rear sun gear, and TransGo kit....TransGo gives you a wide variation on drilling some of the holes - mild to wild - I only went ~ midway. Nice firm shifting that doesn't snap your neck.

The lock up TC is GREAT !! 1st tank - with a few wide open blasts - and my mileage is over 18.5 - compared to under 15 with the 518 - guess it slipped more than I realized.

Only one minor problem....Maybe someone can help me find an answer...

I have a pot installed in place of the TPS. It still works as before - shifts into OD ~ 42 mph and when decelerating out of OD ~ 45 mph.
The problem is that when I hit the switch to engage the lu while in 2nd the trans shifts into OD almost immediately when the trans shifts to 3rd. I moved the pot adjustment to shift into OD ~ 50 mph and there was no change when I hit lu. The trans does NOT lock in 2nd. It does lock as soon as it goes into 3rd then OD kicks in....
I've checked all the wiring and the connections are clean and there are no shorts between the OD wires and the LU wires.

OH - one more thing - I cannot turn OFF the OD using the OD switch when the lu is engaged. If I turn OFF the lu, the OD switch will work as it's supposed to.

Any ideas ??

 

Most of the guys that put the 47RH in there trucks use a toggle switch for both the lock up and the OD. At least then you would know for sure when it is going in and out of OD. I'm sure JD730 will read and correct me if I'm wrong.

 

Was thinking that would be the solution.
Since the trans shifts into OD anytime the lock up is on I was wondering if there might be some other problem I need to correct first.
Besides - there's 3" of snow in my driveway.....
No way am I crawling under the truck now !

 

My thought is you will have to buy a valve body that has that configuration to be able lock up in the other gear ranges.

 

i have the 47rh and just used the toggle switches for lock up and od, it's nice to be able to pick when you want it locked up to roll some good coal, or beat the ricer pullin up next to you.

 

Are you in 2nd on the gear shifter? Or in D? In D it should lock in 2nd, shift into 3rd locked and OD locked if you let it.

How did you wire it? The center pin should be +12 volts and the front and rear pins are the ones that get grounded. Did you check the wire going into the trans case for shorting between each other? The center pin is common to both solenoids, the resistance for the 2 outer pins should be equal to the resistance of the middle and the rear pin and the middle and the front pin added together. If you can't find anything electrically it is possible there is something hydraulic in the vavle body, like a leak.

Thats normal for a stock valve body, you need to have a specially modified one to for it to downshift out of OD locked.


Dunrite sells a shift kit that will do the same thing. Personally I buy the valve body already setup.

 

JD730 --
Yes I 'm in D..
To check it carefully I started in D from a dead stop ~ 1/4 throttle or less.
When it shifted to 2nd at ~ 15 mph I flipped the LU switch.
Truck continued to accelerate to ~ 30 mph then shifted to 3rd and LU hit immediately then OD followed immediately. Like 3, LU, OD - 3 definite separate actions in that order...
I even tried turning off the OD at stop, then accelerating - same thing --
even to shifting into OD

If I leave the LU off and turn the OD off it shifts 1 - 2 ~ 15mph and 2 - 3 ~ 30mph.. No OD. I can hit the LU switch and when it locks the OD kicks in....

The wiring is :
hot from the original 2 wires to the center, 2nd wire from the original 2 wires to the OD. Drove truck to make sure that worked as it used to....All OK.
Then hooked up a separate wire to the 3rd wire in the trans - has to be the LU - then to a switch, other end of switch to ground. Drove truck and with switch OFF everything worked correctly. With switch on - it goes nuts....

If the snow stops and it warms up to freezing I may get back under the truck and chase wires again to be sure there's no shorts I missed ; but I'm not going out with the snow falling and the temps ~ 29* - 30*...

Thanks for the ideas....


EDIT NOTE :
The really weird thing is this will happen even when the trans temp is COLD....Like right when I start it up, drive 2 blocks to a major street, turn right, hit LU and --- BOOM---straight into OD when the trans hits 3rd....
If I don't hit the LU, the trans will NOT shift into OD for ~ 2 miles, when it warms up some.

 

That sounds about normal. The PCM is supposed to keep from shifting the trans into overdrive when the coolant temp is below some number. 2 miles sounds about right.

 

That's what's driving me nuts - more than I usually am

With the LU switch OFF the trans acts totally normal.

Even the TC is better than the one in my 518 - it appears to have a 1700 stall speed compared to 2100 in the 518 - or should I call the 2100 a slip speed - I don't think I could stall a lawnmower with that convertor.

I've noticed ALL speeds are running slightly lower rpms.

If I can just come up with a reason for the edit thing shifting immediately into OD I'd be happy. I'd like to be able to lock up in 3rd while running 35 - 40 mph, but when I try and the OD kicks in my rpms drop almost to idle...
35 mph should be ~ 1300 rpm in 3rd but then the OD hits and they go down to ~ 800. Unacceptable .....

 

how is your lu wired, I know its wired to ground but, you now have a 3pin connector and the (which ever one is which) One is still computer controlled, and the other one has a wire runnign to a switch then to a ground for lu, Is the lock up ground grounded to the dash or to the battery, I'm wondering if its back feeding through the lock up to the od if its grounded to the dash, Now i just read is it a 5 pin plug or a 3 pin plug?

 

Unless it was changed during the rebuild it was a 3 wire plug when he picked the trans up from me.

 

Still a 3 pin plug...

After the initial install, I only connected the OD and drove the truck for a couple of days to be sure everything was shifting right, adjust the shift speeds, etc.

Then I connected the LU wire at the trans to a switch in the dash then to ground - not negative battery.
That's when all this started.
Too cold and snowy to be crawling around under the truck now. IF - WHEN - it warms up, I'll disconnect the ground at the dash and run it to negative battery. I really don't think that's the problem, but ----???
If that doesn't straighten things out, then I'll cut the wire to the OD and run it to a switch also. That way when I turn off the OD it should be OFF....And turning on the LU shouldn't affect the OD. If it does then I'll know for sure it's in the valvebody itself.

 

What i was\am going to do to my cousins truck for lockup, is to take and run it to a 3way switch on off on and then run it so when its in the one on its controlled by the computer and when its the other its manually on, maybe you could try that with your OD switch then if it fixes then its already wired manually and with the computer controlled so then you are set either way.

 

That's what I was thinking....
Today's forecast :
Cloudy, snow, temps mid - to - low 20's, wind 10 - 15 from NW,
wind chill - 5* - 10*

I am NOT going to worry about it today