Dana20 TC popped out of 2H

[ymelnic1]

Nope. The yoke is solid and super smooth - no weird noises or grinding when I spin the rear and front drive what’s…

 

[ymelnic1]

Nope. The yoke is solid and super smooth - no weird noises or grinding when I spin the rear and front drive what’s…

 

[mpboxer]

I’ve experienced the same symptoms as you on my 73 (T-shift, C4) and tried all the bandaid fixes. Unfortunately a rebuild solved the issue. You don’t have to drop the tranny to remove the transfer case and adapter.

 

[Rustytruck]

remove the rear drive shaft and check it well especially check the centering ball in the cv joint. while the shaft is out grab the output yolk for the transfer case is wiggly and loose. indicating excess bearing slop. My bronco was loose and wiggly and I had to shim the bearing preload. needed to buy a shim kit and a new lock nut.

 

[ymelnic1]

remove the rear drive shaft and check it well especially check the centering ball in the cv joint. while the shaft is out grab the output yolk for the transfer case is wiggly and loose. indicating excess bearing slop. My bronco was loose and wiggly and I had to shim the bearing preload. needed to buy a shim kit and a new lock nut.

I rebuilt the rear drive shaft just in case, but the yoke is solid and not wabbly. No play either. The metal pieces I found inside still has me scratching my head though. I'm tempted just to fill her up with oil and re-connect the drive shaft to see if this has solved my issue, but the metal pieces clearly means that something got pulverized in there and the TC likely needs to be dropped and rebuilt.

I did get the adjustable detent spring kit from Tom's but I can seem to get a socket around the bolt head on the TC to get enough contact to remove it. Might be another reason to drop and rebuild....

 

[ymelnic1]

Update: I cleaned out the TC of all the small metal pieces and re-filled with new 80W90. Re-attached the re-built rear drive shaft and noticed that the bottom of the tub right above the universal joint/yoke has been rubbed on. I'm thinking that there may have been play in the assembly somehow and it rubbed on the bottom of the tub. I stuck some painter's tape over the spot and took her for a drive. I attempted to re-create the failure and things actually ran fine with no rubbing on the painter's tape. Could this be fixed??

 

[Speedrdr]

Sounds like it’s fixed…until something else happens. It IS a 40+ year old vehicle, after all. Good that you are back up and running smoothly. By the way, did you figure out what the metal shavings were from?

Randy

 

[ymelnic1]

Sounds like it’s fixed…until something else happens. It IS a 40+ year old vehicle, after all. Good that you are back up and running smoothly. By the way, did you figure out what the metal shavings were from?

Randy

Well. It happened again lol. Rather than getting mad, I’m just thankful that it didn’t happen on a busy street. I’m going to drop the TC and get it rebuilt and also do the brakes while I’m at it. I really hoped for a bandaid fix, but it’s definitely something internal.

 

[ymelnic1]

I wanted to update this thread in case it may help someone who is going through this. I ended up ordering a rebuilt TC from Tom’s Off-road (formerly Tom’s Bronco) and the gears no longer pop out. There is another very curios thing that is now happening and I’m starting to think that this may have been the root cause of my issue from the beginning. I started hearing a mechanical gear sound from what I thought was the new rebuilt TC. When I got home I noticed a puddle of dark fluid on the garage floor at my rear wheel. At first I thought it was the brake cylinder leaking, I checked all levels and pressure in the pedal and all seemed ok. I smelled the liquid and it’s definitely gear oil, so it must be the axle seal that is busted. The rear wheel did have a slight wobble from the beginning of me owning the bronco so I’m sure the axle rod (ordered a new one) destroyed the axle seal and caused the leak.

Why are you rambling you may ask? Well the puddle of gear oil on the floor was dark but when I wiped my finger over it, it was a mix of the original gear oil and the 80w oil I had filled after draining the front, rear, and TC oil. The oil that I drained from all three was super old and having never drained the oil while owning the truck for 8 years and seldomly driving it for over an hr at a time but not going at high speeds. I did the best I could to scoop out the sludge from the front and rear pumpkin and the TC inspection port and replacing the gaskets thereafter. Shortly after pumping all new oil into all three is when my TC started popping out of gear on a 45 min drive to my new home.

I’m now thinking that replacing the sludgy gear oil with the new stuff, may have somehow affected the gear alignment/connectivity and started my problems…

Does this make sense? Has anyone had or heard of gear oil causing issues such as these - or am I crazy?

 

[DirtDonk]

Well, while I may never have heard of that happening, it happens all the time with automatic transmissions.
In fact there’s a thread about it here currently. It happens with engines all the time too, when they are high mileage or low oil change and build up sludge.
That sludge works its way through the engine when oil gets changed or any flushing is done.
Good news for an already clean engine, bad news for a dirty one.