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Discussion Starter #1
About 3-4 months ago I swapped the 47re out of 96 12 valve for a nv4500 (2wd), everything went relatively smoothly and the truck drove great. 4th gear would grind going in unless I shifted nice and slow but other than that I had no complaints. I used a luk clutch with valair hydraulics and a trans out of an 01. About a week ago I was driving home and when I went to shift into 4th the trans seemed like it was stuck in 3rd and I really had to pull to get it out and into 4th (grinded bad going into 4th too). since then I parked the truck and now I can't get it into any gear unless I do so before starting the truck. when I go to put it in any gear; it grinds like I'm not even engaging the clutch at all. Ive looked over the hydraulics and they seem to be fine so I'm not really sure whats going on. Im thinking something clutch related or maybe TOB? I plan on pulling the trans this weekend for new sychros, updated main shaft, and input shaft(slight play when I installed it) but I'm looking for some insight as to what (or where) to look for the problem so any 2 cents is appreciated!
 

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Remove the slave cylinder and use a time style steering wheel puller to push the clutch fork in. If you can shift the transfer you have hydraulic issues , if not you have clutch or trans issues. I have also seen bent shift forks cause problems as well as general wear in the shift top.

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Discussion Starter #3
might give that a shot tomorrow. thanks for the advise. really hoping it's just the hydros took a . gonna be going through the trans regardless though. Gonna be my first time tearing into one of these trannies but doesn't seem to bad from the threads I've read. gonna document as much of it as I can.
 

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".......now I can't get it into any gear unless I do so before starting the truck....."

Classic pilot bearing/bushing failure. As a matter of course you should be replacing it and the release bearing anyway.
 
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I agree with the pilot bearing diagnosis GAmes stated. But as a side note because of the previous grinding issue what oil did you put in it, or was already in it, when you swapped it in? The wrong oil doesn't do well with the carbon fiber lined syncros in these transmissions. Make sure you have the right stuff from Mopar (p/n: 4874459)
 
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Discussion Starter #6
I ran amsoil in it. don't remember that the hell exactly it was but it was whatever i saw was recommended. ill see if I can find one of the bottles tomorrow. the pilot bearing/Throw out bearing were both brand new when I put the clutch in and greased with high temp. As I stated before though the input shaft did have some noticeable play in. Would that cause premature failure in pilot bearing?? it would make sense if thats the case. when I bought the trans it came with the flywheel and the pilot bearing in it was totally f'd. Looked like someone went to pull it and had left a collar behind in the flywheel. Total PITA to get it out.
 

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A little side play in the input shaft is normal but if there is end play that can affect shifting especially in 4th.
I don't know if you have a ceramic clutch disk, but I have seen those wear into the flywheel to where you lose some of your disengagement. Reverse and first become almost impossible to get in gear at a dead stop.


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Discussion Starter #8
pulled the trans today and at first glance the only concerning thing I see is the input shaft having a fair amount of play. wondering if this is my issue. Pilot bearing, hydros, and throw out bearing all look good as long as the synchros.
 

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Discussion Starter #9
running amsoil synthetic manual transmission & transaxle gear lube see 75w-90 API GL-4 btw. Should I be running something else?
 

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pulled the trans today and at first glance the only concerning thing I see is the input shaft having a fair amount of play. wondering if this is my issue. Pilot bearing, hydros, and throw out bearing all look good as long as the synchros.


Again, side play or end play? How much?


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running amsoil synthetic manual transmission & transaxle gear lube see 75w-90 API GL-4 btw. Should I be running something else?


The carbon fiber synchros are pretty particular in the transmissions. Most people are of the opinion that you should run only Castrol Syntorque or the GM equivalent.


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Discussion Starter #12
its side to side and up and down but not in and out. I can move it all the way to the edges of the collar though. as far as the syntorque goes I've done a lot of looking around and it seems like castrol discontinued it as you can't even find it on their website directly let alone anywhere else. I know you can get the gm equivalent at dealerships but from as much looking around as I've done people recommended amsoil or gm mostly.
 

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Most dodge dealers keep the synotorque in stock. Just give them the molar number I posted earlier and they can get it either way. It's expensive but worth the pain of replacing syncros if you use the wrong stuff. I've seen the aftermath of having amsoil in these transmissions for a relatively short amount of time. Not worth the lower cost or availability of other "equivalent" oils
 

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its side to side and up and down but not in and out. I can move it all the way to the edges of the collar though. as far as the syntorque goes I've done a lot of looking around and it seems like castrol discontinued it as you can't even find it on their website directly let alone anywhere else. I know you can get the gm equivalent at dealerships but from as much looking around as I've done people recommended amsoil or gm mostly.


That much side play might have something to do with a bad pilot bearing between the input and the main shaft. Or a broken main shaft. Which would explain the hard shifting. Ask me how I know


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Discussion Starter #15
hoping to get some time this weekend to tear this sucker down and get abetter idea of whats wrong. wiggling the input shaft with the top cover off I can definitely see a lot of movement which has me thinking it's a bearing issue. shopping around it seems like I can get a bearings,synchros,seals rebuild kit for about $160, or I can also get all that plus an updated fully splined mainshaft for $320. Wondering if it's with the extra coin considering I already has an upgraded 5th gear nut
 

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Any "upgraded" nut is a half-azzed fix. A fully splined shaft is a good investment.
 
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