transmission transfer case and shifting problem

[bobbyray27]

Need some help please. Ok, I have a C4 transmission and J type dana 20 transfer case. When I put it in gear nothing happens. The shifter moves and goes into the gear but the Bronco wont move. If I put the transfer case in 4H again noting happens. Put the transfer case into neutral all of a sudden all gears work. Put the transfer case into 4L again all gears work. I will also mention that in two wheel drive while trying to put it back into park it grinds real bad. I know someone is going tell me to make sure that its a J and not a T dana 20 but I'm positive that its a J and thank you ahead of time.

 

[scsm76]

It sounds like it is not fullly engaging in 2H, I would check the transfer case shifter linkage something may be broken or bent.

 

[Viperwolf1]

Sounds like your C4 is working fine and you have trouble getting the transfer case out of neutral and into 2 high. The tranny is working and spinning when you put it into gear and when you go back to the park position it's still spinning because there is no resistance or load to stop it which causes the parking pawl to ratchet until it catches. It would do the same thing if you where driving 20 mph then slammed it into park. This is not good for the tranny. The problem is with your t-case or shifter. I never did like the way my J shifter operated either so I went with a twin stick setup. It was one of the best mods I ever did for my bronco.

 

[bobbyray27]

I watched while shift the transfer case and the forks seem to move correctly. Left fork back 2WD, both forks even 4H, both forks back one spot should be neutral but for some reason it goes into gear, and both forks back two spots 4L.

 

[Viperwolf1]

Right fork forward is 2 high from the driver's seat.

 

[garberz]

Sounds like your C4 is working fine and you have trouble getting the transfer case out of neutral and into 2 high. The tranny is working and spinning when you put it into gear and when you go back to the park position it's still spinning because there is no resistance or load to stop it which causes the parking pawl to ratchet until it catches. It would do the same thing if you where driving 20 mph then slammed it into park. This is not good for the tranny. The problem is with your t-case or shifter. I never did like the way my J shifter operated either so I went with a twin stick setup. It was one of the best mods I ever did for my bronco.

X2, sounds like an excellent time for the twin stick upgrade. The J shift is just old. Once the socket starts to wear, all sorts of problems start to appear. The twin stick upgrade would be just one more problem spot you could cross off the list.

 

[bobbyray27]

I have a new James duff J shifter that been in for some time now maybe a year or so. I don't think its the shifter it's self.

 

[bobbyray27]

Right fork forward and up on the shifter indicator but if your looking at the forks on the transfer case its the opposite left fork back.

 

[Broncobowsher]

That bad grinding noise is the park pawl grinding itself into park.

Here is a tip that your transmission will thank you for. If you get the transfer case in nuetral (transmission in a driving gear but not moving) don't touch any of the shifters. TURN THE ENGINE OFF! This will stop all the spinning parts inside and will prevent un-necessary damage to gears and parking pawls. At this point it will usually be easier to shift between high and low range as there isn't the parasatic rotation coming from the transmission.

 

[Viperwolf1]

My left shift rail (looking from the driver's seat to the rails) controls the front output side of the t-case. Right side is rear. Because of the cantilever of the shifter, the rails are pulled forward when the shifter is pulled backward. Forward on the rail (backward on the shifter) is high range. The opposite is low range.

 

[bobbyray27]

Thanks for the tip. I have been doing that just thought I would mentioning that it grinds thinking it might help solve the problem

 

[Broncobowsher]

Dana 20 shift rail function simplified;
Rail closer to the rear output shaft countrols the rear output shaft
Rail closer to the front output shaft controls the front output shaft
Rail pushed all the way into the case puts that shaft into low range.
Rail pulled all the way out puts that shaft in high range.
Rail in between all the way in and out is in nuetral.

The above works on T-shift D20 and J-shift D20. Same operation on D300 and NP205 as well. Actually just about any gear drive transfer case that has 2 shift rails. Atlas is the same operation, I am sure the Stak is as well.

The trick is the interlocks. Somewhere there are pills (in the D20, not sure about other models) that prohibit shifting the rails into "bad" combonations. Depending on the engineering that originally went into them is what is prohibited and what isn't. Mixing ratios is always bad. The T-shjift will not allow front drive unless the rear is already in that range, thus the rear cannot shift out until the front is shifted first. Doctoring the pills and rails re-engineers the possibilities allowing new combonations of rail positions (front digs are an option)

 

[Viperwolf1]

Exactly! The T-shift pill goes between the rails into grooves cut into the rails. The J-shift doesn't use the pill. The overlapping forks on the rail do the same thing.

 

[bobbyray27]

That is what I was explaining only a different way, your way is much easier to understand. I still don't understand why it won't go it to gear while in 2WD? But will while the transfer case is in 4L and neutral

 

[bobbyray27]

Broncobowsher you sure that it's the rail closest to the rear shaft that controls it because I believe its the shaft farther away from the the rear shaft that controls it. Remember that every thing you do to the shift lever is done opposite on the transfer case due to the pivot point on the shifter. So if I pull the shift lever to the right and push up as if going to 2WD from 4H on a j shifter I'm really moving the left after the pivot to catch only the left rail and moving it back or into the transfer case. Well I guess your right, I not really putting the rear shaft into 2WD what I'm really doing is moving the left rail or font shaft into neutral

 

[Viperwolf1]

No. The rail on the driver's side of the t-case is for the front drive. Broncobowsher's desciption of the rail/gear positions is accurate. With the J-shifter the case operates like this: In neutral both rails are in the middle position of their travel and neither output sliding gear is engaged. When you shift to 4-low, the pin on the end of the shifter pushes both flags on the rails (because they overlap) in order to move both rails to their most inner position. This moves both sliding gears to the rear position inside the case and meshes the straight cut low gears. When you shift from neutral to 4-high the pin pushes both flags forward. This moves the sliding gears forward and engages both high speed gears. Now when you shift from 4-high to 2-high something different happens. Because you push the shifter to the side, then forward, the pin now engages only the front drive rail in order to move it back to the neutral position. The rear drive rail should stay where it was and you should end up in 2-high. This is possible because of the shape of the flags on the rails.

I can see where this can cause confusion if you are just looking at the movement of the rails and don't know what is happening inside the case. I think you're not getting good engagement of the rear drive rail into high range before you shift to the side and up to disengage the front drive.

 

[Broncobowsher]

I still don't understand why it won't go it to gear while in 2WD?

Question for you, did you recently have the transfer case off of the transmission?

If so you probably put the input gear on backwards. When that happens the shift collar doesn't have anything to engage in high range. But low range will work just fine.

 

[bobbyray27]

Broncobowsher, yes I removed the transfer case a while ago to replace all the seals. It worked fine after the reinstall. Now it does not wont to operate right. I also believe I am leaking transmission fluid past the seal and into the transfer case. I guess I'm going to have to remove the inspection plate and take a look at that input gear. How will I know if it is in backwards, and can the input gear be turned around with out removing the transfer case? I will have to remove the transfer case any how to replace the seal between the transmission but would like to find out if input gear is really the problem before removing it.

 

[bobbyray27]

Well I removed the inspection plate. Here is what I saw When shifting the transfer case. 2wd, rear drive shaft slide gear in neutral and front drive shaft slide gear all the way back and engaged with the strait cut low gear. 4H, both slide gears in neutral. Neutral, both slide gears in neutral. 4L, both slide gears back engaged with the strait cut low gear.

 

[Viperwolf1]

Make sure your shifter is not contacting the floor and preventing it from moving back fully.