Calling All D20 Experts/Strange Happenings

[69Sport]

Ok guys here is the situation, I had my D20 rebuilt and then I was checking it out on the bench when I got it back. Now I can not get the front rail to lock into 4 high. The rear goes into low and high and the front will go into low but not high. When I try and move the front rail into high it just stops and the shift rail will not ingage the gear into high. I am installing a nv3550 and I did not have the spud shaft at the time and I thought maybe with the bearing and the gear not installed that it was the problem. I recently got the new spud and it is all installed in the D20 and it still does not work. None of the insides have been removed, pills are still intact but I did seperate the rails to install a twin stick. NOW the freaky part, if I loosen the plug that hold the spring and the detent ball in on the front rail about half way out the rail shifts fine. And high and low work. As soon as I tighten the plug it binds up and will not go into high.

I did check to make sure the right spring is in the right side. The front rail gets the washer and the longer spring per the book. What would make the rail bind up and what should I do. It did lock in before the rebuild but with the stock T shift and it was real hard like usal. Thanks 69sport

 

[bronco italiano]

iF i RECALL CORRECTLY THE PRE '74 D-20 NEEDED SOME TYPE OF MOD (POSSIBLY TO THE DETENT BALLS) IN ORDER FOR THE TWIN STICK TO WORK. IT COULD ALSO BE FROM NORMAL WEAR. YOUR REBUILDER SHOULD HAVE INSPECTED EVERYTHING BEFORE BUILDING. GOOD LUCK, BI

 

[trailpsycho]

I had a similar thing happen to mine just this past summer. With the new rebuild and the new detent balls, the front axle shaft was very tight for shifting on the bench...and would not at all once installed. Let me rephrase, it shifted fine going into F4-HI but did not want to shift forward of the neutral position into F4-LO. Keep in mind, I have a J-shift, so I can shift my two rails independantly. We pulled it again and investigated the possiblities and it all came down to the spring tension on the detent balls. If we loosened the tension bolt, it shifted like butter. We tried replacing the springs, but could not find one with the appropriate tension. I ended up finding a brass washer, similar to what you use on brake lines, opened up the center with a grinder and spade just enough to allow it to thread onto the plug-bolt and then tightened it back up. This small spacer removed just enough tension from the spring to allow firm shifts of the front axle into F4-LO (all the way forward). You may find that you need to come to a complete stop and bring it out of neutral back toward F4-HI just a bit to get the detent ball moving and then slide it forward into F4-LO. Good luck. It has been working fine since and has gotten smoother.

 

[sixtysick]

Ok guys here is the situation, I had my D20 rebuilt and then I was checking it out on the bench when I got it back. Now I can not get the front rail to lock into 4 high. The rear goes into low and high and the front will go into low but not high. When I try and move the front rail into high it just stops and the shift rail will not ingage the gear into high. I am installing a nv3550 and I did not have the spud shaft at the time and I thought maybe with the bearing and the gear not installed that it was the problem. I recently got the new spud and it is all installed in the D20 and it still does not work. None of the insides have been removed, pills are still intact but I did seperate the rails to install a twin stick. NOW the freaky part, if I loosen the plug that hold the spring and the detent ball in on the front rail about half way out the rail shifts fine. And high and low work. As soon as I tighten the plug it binds up and will not go into high.

I did check to make sure the right spring is in the right side. The front rail gets the washer and the longer spring per the book. What would make the rail bind up and what should I do. It did lock in before the rebuild but with the stock T shift and it was real hard like usal. Thanks 69sport

Sorry, but I am assuming you have the rear output in high when you try to put the front into high? With the pills still in the case, you will not be able to shift the front into high, without the rear output in high as well.. I think. I removed the pills as well as seperated the shift rails during my rebuild and have had no issues what so ever. Also, have you taken off the bottom cover to see what is actually happening when you try to shift into high? This is a tremendous help when trying to troubleshoot issues.

Regards,
SS

 

[69Sport]

D20

Thanks for the replies, first thing I did take the bottom plate off and had the D20 upside down as I shifted it. There is nothing hitting it just will not go in with that spring and detent ball tighten down. I think it is the tension on the spring that is the problem. I tried the copper washer and it did'nt help. Maybe two will help. I think I will PM g-money and ask him more about the pill removal with the case intact. Question, can you see the shift pills by looking down in the case from the bottom side or are they in the rail housing itself. I have the pics of where they are suppose to be I just have not seen them. Is there any cons to removing the pills besides being able to get one in low and one in high. Thanks 69sport

 

[welndmn]

If you can loosen the plug and then the thing shifts fine, I would bet the rail is twisted, where the detent ball can sit in the pocket.
remove the plug and look down the hole to see how stright it is.

 

[69Sport]

Thanks

Hey Welndmn I thought of that and I will double check, but I put the stock plate back in that connects the two rails and it slid right in. I would think if one of the rails were off the plate would not line up. I will check. 69sport

 

[grs44310]

If it's the older D20 that had a "T shift" then you can't shift the front and rear independantly into high or low, (i.e. the front in high and the rear in low) unless you remove the pills between the two shift rails.

You should be able to move the front into low and the rear into low or the front into high and the rear in high at the same time without removing the pills.

 

[69Sport]

Thanks

Yes it is a T-shift and it will not allow it to shift into to different ranges with the pills installed. 69sport

 

[69Sport]

Ttt

Still need some help any suggestions. 69sport

 

[bronco italiano]

Take it back to the individual that "rebuilt" it because the job is not done. BI

 

[trailpsycho]

Have you considered that the shift rails may have been swapped? I doubt it, b/c you say that it shifts fine with less pressure on the detent ball. Did you try using more than one washer...remember you want one large enough to go over the detent bolt, but small enough to fit inside the cast depression of the case. You can try sourcing another spring.....OH yeah, are you sure that they put the pills into the correct slot in the case? I am not looking at a diagram, but figured it was worth asking. Keep us appraised.

 

[69Sport]

Thanks

Hey guys thanks for sticking with this one and giving more than one suggestion, I checked the rails and they are in the right side. I found a few more copper washers for brake lines and they fit perfect. It took three but they are really thin. I tightened the plug down and it shifts fine. I am going to put a little RVT around the plug just to make sure it does not leak. I just don't understand why the washer are having to be used. If it works and does not leak I am willing to give it a shot. Thanks again 69sport

 

[trailpsycho]

Glad the shim washers worked for you. I think its just the tension on the new springs in the kits...that and the new detent balls...it doesnt take much to put things just so out of tolerance. If you did use brass ones, they will crush and should not allow any leaks...think about their funtion in your brake system and thats under significant pressure. Enjoy your new twin sticks and TC.