Rebuilt 47RH Dies after 4 miles.

Measured using the bar across the opening of the OD housing, with a dial indicator. I used a flat wrench used for the collet chuck of my mill. I just corrected for it's thickness vs the correct bar (.500 inch) and then used the chart in my ATSG book. Measured clearance turns out to be in the neighborhood of .070" now that I have the spacer in hand.
 
OK, got the trans put together and in the truck. Did some testing up on jack stands tonight.

Accumulator Port in D:
Idle pressure, 80 psi.
WOT: 115

Seems aweful low to me?? But, also, I see everybody says to go drive it on the road. Does adding a load increase your pressure somehow?

I checked the overdrive piston. When the OD switch is off, there is zero PSI, and when flipped, it comes right up to whatever line pressure is.

A couple things...

1st: I'm going to go the the parts store and get a better pressure gauge as I have doubts about my current gauge's accuracy.

2nd: I have to drop the pan because the pan gasket is leaking (took the pan off after torquing it because i forgot the magnet, now it leaks like a SOB) While I'm in there, should I give the pressure screw a few more cranks?
 
yeah crank it up. ive got mine run all the way out and i can only get 150psi at the most. and 140psi cruising down the road in od. Some spring or shim modifications are in order now to get me to my 180-190psi goal
 
Crank it up, you're not close to the pressure of a performance aftermarket tranny till you hit 185 psi. I doubt you'll be able to get it past 165 psi if it's only at 80 psi right now.

Pressure doesn't increase with load, it does increase with RPM so when your putting around town, pressure has the illusion of being related to load but really its the rise in RPM due to the flash stall looseness of the torque converter that makes pressure rise with load.

At highway speed in overdrive, you better have at least 130 psi if you plan to hold 400+ HP for any length of time.
 
Huh, that's what I though. Craig down at Goerend said that on the tester, it did 85 psi Idle and went as high as 145 psi..... But, that probably doesn't account for internal tranny leakage.. I'll max the thing out when I've got the pan down.
 
OK. Dropped the pan and found that the filter was part plugged up. Bunch of metal shavings in the bottom of the pan. I'm thinking it was residual junk from when it burned up last time. Put a new filter in, along with a reusable rubber gasket. Cranked the pressure screw 8 turns from flush. Looks like there's only 1 turn worth of thread left.

Took it on a lively road test. LOL I've got 90 psi at idle, and WOT in OD, I've got 140psi, with lockup, 130psi.

I am in the process right now of shimming my governor springs as the programming in the shift kit and the governor springs are kind of in an impasse.. hehe. Anyhow, I'm impressed. Running down the road today (it was in the 50's) even when I was beating on it and doing some light boosted launches, it didn't get past 140F.

So, looks like things are good so far. Probably after a couple thousand miles, I'll drop the pan and change the filter and fluid one more time....
 
OK, other than a small leak around the dipstick when parked, everything looks good. The tranny runs great, nice and cool (Never exceeded 169, and that was parked. As soon as I start moving the temp drops right down. Rollin down the highway empty, with tranny locked, it runs about 112-120 degrees)

Apparently the JD Hygard loses heat easily, as my cooler is mounted under the cab with a fan, so that natural airflow driving down the road is basically zero. Even with the fan off, the tranny just don't heat up. I was gettin round bales out of the field with the gooseneck, and even with 13 round bales on the trailer driving along in 1st, she just wouldn't get hot.

All around, I don't miss that 5spd. Thanks for all the help guys! I really appreciate it!

I want to give thanks to Stephan and Bill @ DTT for puttin up with me through this, Craig down at Goerend transmission for checkin' out my valvebody for me, and Phil @ DPC for getting my converter cleaned out and redone in a flash for me....
 
Thats down there. i cant keep mine that low with two coolers, 1 in front of the intercooler, and one under the bed above the axle. I run the cheap ATF from walmart, my trans guy told me to not run the case IH hi tran (pretty much the same as john deere)
 
So you have 140psi mainline before lockup and 130psi after lockup? You should see a increase with lockup not a decrease.
 
Hmm. Weird. Maybe leakage in the converter? I know I see an increase when it goes to overdrive (Boost circuit kicks in)..... I'll have to experiment some more.... I've still got my gauge in the truck.
 
LAmiller said:
So you have 140psi mainline before lockup and 130psi after lockup? You should see a increase with lockup not a decrease.
Click to expand...

thats how im seeing it in my transmission also, about 10 psi lower in OD? Always something else wrong.... bleh
 
Hmm. I'm pretty sure it's not the valve body. Craig down at Goerend Transmission didn't say anything was up when they had it on the tester.
 
Ok, here's a thought.. Pressure seems some lower when the truck is warmed up. Not so much when driving normal, but if I throw it in lockup when the trans is warm in 3rd gear, at lower speeds, it'll pull the pressure down to 70-75 psi. :| Also, when decelerating locked, it will drop way down...

Now, as was shown earlier in this picture:
reactionshaftsupport.jpg


There's some wear on the reaction shaft support. Do you think that's causing low pump output? I have new pump gears, and lobe clearance is .004, which is apparently in spec. I'm wondering if the low pump output is to blame.

Also, Craig at Goerend said they disable the boost circuit so that you have full pressure potential all the time. Anybody know how to do this? Seems like a good idea on a modified truck.
 
I believe excessive clearance around the torque convertor hub will show lower pressures in lockup.
 
zstroken said:
I believe excessive clearance around the torque convertor hub will show lower pressures in lockup.
Click to expand...

LAmiller said:
Did u install a new pump bushing?
Click to expand...


I'm pretty sure that the flow of fluid for lock-up is through the inside of the input shaft.

Therefore, if the two small seals on the input shaft are sealing properly, there are no bushings on the pump or converter hub clearances that can affect lock-up line pressure.

9-17012.jpg



However, if the tip of the input shaft is worn, or the mating surface (assume its a bushing but don't know) inside the converter is worn, then I could see pressure loss in lock-up.

I'm talking about this end of the shaft that mates with the torque converter internals:
9-17006.jpg


The external hub on the torque converter does seal low pressure fluid returning from the torque converter.

I do agree that if the pump bushing is worn, it can lower pump efficiency, especially at low rpm, but line pressure drop would be more related to low rpm, not lock-up.

See the copper colored area on the input shaft where the pump stator bushing rides:
Transmission21.jpg



And here is the bushing where the converter hub rides inside the pump stator right at the pump sealing surface.
Transmission16.jpg
 
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Ok. Makes me wonder about the busing in the stator support that the input shaft rides on. The input shaft and torque converter are both brand new (Sonnax Billet input). All new seal rings.

Maybe a new stator support would be wise? take care of the wear pattern and new busing at the same time.
 
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