47re shudder in first gear

[Whiskeybar1]

Just purchased a 1998 12 valve with 145k miles, I know that's truckshave trans problems so when it went out it was not a surprise, a friend has a trans shop and has worked on many Ford diesel transmissios, he rebuilt it at no labor charged. But there is a problem that will show up maybe once or twice a month, not Shure it it's trans related or not as it was doing it before the end of rebuild. Truck cranks and idles perfect but when you try to accelerate past Maybe 1200rpm there is a violent shudder type vibration, tuck will cut off , a guick cycle of the ignition will fix it and it will not happen again that ignition cycle, and thoughts.all transducer and governor are new , like I said it was happening before the rebuild so I tend to think it not in the trans,

 

[Whiskeybar1]

Any help on this ?

 

[BillBaker]

"Was doing it before end of the rebuild"... what does this mean? Was torque converter replaced?

 

[Whiskeybar1]

Sorry ,before rebuild ,new tc. New v.b.

 

[BillBaker]

What brand TC and valve body? May not be the transmission...

 

[Whiskeybar1]

Factory replacement style parts , no sure of names, plane on getting a towing vb , but I don't think that's the problem as itwas replaced with the rebuild

 

[BillBaker]

Maybe one of the big brains will see this post and have an idea where to start looking..

 

[Timd32]

2 things that I found useful, the ATSG book and the FSM.

Can your friend check the actual governor pressure?

Compare that actual to what the computer is seeing?

When he did the rebuild did he do any the internals? I see from the chart the low roller clutch is held in first, and the front band is not used, then the low roller clutch not used and front band is for 2nd.

Could the low roller clutch be hanging up, unfortunately that is deep in the trans? Or the front band not adjusted to spec?

You can check the TPS also.

The key cycle to fix is odd, so could be a input to the computer is off a bit, there are just a few things it takes in.

 

[Whiskeybar1]

Thanks , I'll ask him about those things, is there any way the t.c. could be trying to lock up ?

 

[Timd32]

Its usually the oppisite fails to lock. Or folks have a bypass switch and forget to unlock and the TCC will kill the engine.

You can check the trans temp sensor that has some effect on TCC, also the Output Speed sensor, I would think either of those would set codes.

Have you tried manual-1st, then shift to manual-2nd? Any difference from just being in "D"

 

[Whiskeybar1]

Won't go above 12-1500rpm in any gear, it's not setting a check engine light, out put speed sensor sound like a good place to start,

 

[DavidC]

Won't go above 12-1500rpm in any gear, it's not setting a check engine light, out put speed sensor sound like a good place to start,

I believe a good sensor ohm's around 600 across the pins

 

[Whiskeybar1]

I gotta think this is a electronic issue, seams like it only happens when I pull out in heavy traffic,! Go to N ccut truck off, restart back to D and it goes,all while almost getting run into!

 

[Timd32]

There have been a good number of issues with the connector for the truck side of the trans as well.

Found this thread.

https://www.turbodieselregister.com/threads/47re-stuck-in-1st-try-this-first.169794/