Got a Weird One For You, Could Use Some Help

jcorlew24 · Sep 6, 2012

I just got done rebuilding my twin stick Bronco Dana 20. The ride before I tore it all down it started making a noise, almost like the front driveshaft was rubbing against one of the link bars ( a metal on metal sound). It only made this noise in low, and it didn't matter if it was in 2WL or 4WL. When I would switch to high the sound went away. It also would feel like the buggy would not want to move sometimes when I would stop. Once I would back up and start again it was fine. This was not the entire reason I rebuilt the case. It started popping out a lot because the teeth on some of gears were worn off on the edges.

So when I rebuilt the case I used the Tera Low 3.15 gears. I did not replace all the bearings because they appeared to be in good shape. The Tera Low kit came with new intermediate shaft needle bearings, and I screwed up the needle bearings in the 32 spline output so I replaced those. Everything else stayed.

So this past weekend we rode and everything at first seemed great. The case shifted good and felt tight. At the end of the weekend however, the noise returned and so did the hesitation when starting. So far I have removed the inspection plate all of the gears and fluid look good. I also have pulled the rear output and everything looks good there. I have pulled both driveshafts and the joints feel fine. I left the snap ring off the front output so I could pull it without removing the case. I didn't have the right size socket to remove the yoke, so I will finish getting the front output shaft out tonight. The shaft has 2 bearings on it and then all that is left is the input bearing.

One thing that did seem odd is when I was a pulling the rear driveshaft. I had the rear in the air so I could spin the driveshaft. The rear is a Sterling 10.25 welded with disc brakes. It seemed to not want to turn at first and also felt like it had a lot of play at the yoke. Thought maybe it was still in gear so I checked and tried again. It then spun fine. When spinning the rear wheels the passeneger side caliper seemed like it was hanging a little bit but nothing severe.

The noise to me felt and sound like it was coming from the transfer case and sounded like it was at the front of the buggy. Being that the noise went away in high I was figuring it had to be a transfer case issue.

Anyone got any good ideas on what this could be before I dive in farther?

payne97 · Sep 6, 2012

check the gears n the front

Sawzall · Sep 6, 2012

Is the end play on the transfer case gears within spec when checking them with a dial indicator? There are shims under some of the bearings to set the end play. I had a NV4500 transmission that was making odd noises and that was the problem with it.

pachary · Sep 7, 2012

Embarrassed to say, I have disassembled tranny/tcase before when the prob was in the rear end.

I swear it sounded like the tranny/tcase was where the noises were coming from.....

jcorlew24 · Sep 7, 2012

Got the front output shaft out and everything looks good. Haven't had a chance to pull the rear diff cover yet. Looks like I will be pulling the case for about the millionth damn time.

payne97 · Sep 7, 2012

Dont think it n the case pull the covers

B.DRAKE · Sep 8, 2012

Pull case and throw it in garbage and put good case in it ;D

Last Rebel · Sep 8, 2012

My brother and I just fixed this in his dana 20. We to tore the stupid thing down several times. the jumping out of low range with a twin stick was part of the problem. we installed a 3 to1 gear set. make sure the out put shafts are within spec on the end play and the pre load on the bearings is very important. It takes an inch pound torque wrench with a dial gauge on it to check the rotational load. this is very important. As far as jumping out of gear, we had to make the low range detent notch deeper by about .050 thousands. I ground it out with a dremel tool and used a cut off disc to to do this. I checked my progress by using a dial caliper to the bottom of the of the u shape in the shaft. We put it back together and installed 3 no. 4 machine washers as spacers to tighten the spring pressure on the detent ball and spring. Put in the ball and spring and then the washers, install the retaining bolt. I know it's a pain in the butt we took it apart way to many times, and swore if this didn't fix this last time we were going to blow it into a million small fragments with tnt and throw the remains in the deepest lake we could find. His jeep is using a case from a 76 ford bronco. I went by their directions and specs on the bearing load. the twin stick shift rail was our own doing with a little internet help from a bronco web site. Man I hope this helps you out because I know exactly what you are going thru. By the way this did fix his problem and he's been playing pretty rough with it ever since. Good luck!

Bronco Buster · Sep 9, 2012

I know you checked the bearing but it sounds like a bearing going bad. I had a 74 Bronco that did the same thing and it needed bearings. The bearing felt good but had enough play that the gear would side load it and bind up.

jcorlew24 · Sep 9, 2012

Pulled the rear diff cover and the ring gear definitely has a good amount of slack in it that needs to be adjusted. That still doesn't explain the noise coming from what seems to be the front. It does explain the hard shifting in low range and maybe the hesitation when trying to move forward. I am going to go ahead and put new bearings on the front output while I have it out. The only other bearing that is left is the front input and after reinstalling the rear output everything feels pretty smooth when you spin it in neutral.