(Updated) Dana 20 woes SOLVED?

See last page for (tear down) update....

Started to tackle the d20 removal so that I can replace the high speed gear and bearing/seal and ball detents.
Removed front and rear driveshafts
Removed exhaust
Supported trans and removed cross member
Disconnected speedometer cable
And started on the six bolts around the adaptor to the C4
Just as people have stated...the top two bolts on the drivers side are a B}*%€H!!!
I got the lower one out but even with a stubby I can't get the top one to break loose.
Upon closer inspection I'm not the first to tackle T-case removal.
The tunnel is hacked to hell and a the Previous owner put in a patch panel with 1" long screws and then bent them over to make clearance for the tcase.
This isn't evident from the interior since it has a nice thick insulated vinyl floor put down.
So the dilemma begins....
To remove carpet I have to take seats out.
To take seats out I'd have to remove the Aux tank (I don't want to do this)
The only option I think I have is to cut the vinyl floor to expose the tunnel and cut my own hole into the tunnel.
Removing the existing patch panel will require me to make a huge hole in the vinyl so I think I'm going to have to do a patch on a patch.
This will screw down on top of the vinyl flooring and I'll use either aluminum or stainless to make it presentable and glue insulation on the back side to keep noise and heat out.

Anyone got a better idea?

Have you pulled out the cross member out and dropped the drivetrain down?
That's a must. You might need to pull the fan off or radiator out too, because they get pretty close.

blubuckaroo said:

Have you pulled out the cross member out and dropped the drivetrain down?

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^^This^^

And I have used 18" of extensions to get at that bolt.

x-2 on dropping the trans down and using a extension, the fan gets close and the valve cover on the firer wall. It's a good idea to have extra hands to help and watch as you drop the tranny.

so your gona gut the interior to drop the t-case? Seems a bit excessive to me but I guess that's broncoing for ya. There is no way I even think of pulling that shit. The fact that you had to remove the exhaust already seems like too much work. Swivel sockets, and some extensions hopefully do the trick for ya.

Seats can be removed from the top unless there was some creative bolting put it.

Viperwolf1 said:

Seats can be removed from the top unless there was some creative bolting put it.

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Seems like creative bolting since underside inspection I can see nuts and when I try to loosen them all they do is spin.

I have tried swivel/extension but the linkage (J-shift) is in the way.
I looked at removing the linkage but this too has clearance issues.
I have also tried dropping floor jack so the trans rotates down, watching the valve cover to fire wall.

Like I said, I only have room for a stubby and not enough leverage to break it free.

Reading several other threads, many say that going through the floor is the most convenient option.
I haven't started cutting yet, I hope I don't have too...

the only thing I can add is I am sure you are capable in your abilities and I am sure you will exhaust all option before you have to cut, as all broncos are a little different than others use your best judgment in accessing what needs to be done. I mean what you have to do to yours all seems like a lot of work, and sometimes it is just that way, no getting around it so just make sure to try to do what will leave the less amount of mess in the long run. I hope that makes since and positively adds to the conversation. good luck buddy

Yup, definitely a PITA, especially without a body lift.
I took an old 9/16" wrench and cut it in half so I could get it up in there and then I could just slip a very short length of pipe over the end of the wrench to use as a cheater for a little more leverage.
Good luck.

Update.... It's out and no cutting.... We'll sort of...
Got a box wrench from my brother with very fine gearing to get the bolts loose.
I didn't think I'd get a trans fluid shower but that was the least of my issues.
I couldn't move the t-case back far enough to clear the trans tail shaft because the previous owners patch of the tunnel was so tight around the shifter. So some careful bracing of the t-case and then crawling into the cab to peel back some metal (about 1").. Holding that sucker over my head was no fun but in the end she is out....

So the good news is that I learned some more about this old girl and I've got a good idea of how to support it when it goes back in.
Thanks for the input CB crew!

It's a little more work, but a lot less of a PITA to just pull the transmission and t-case as a single unit. Especially when you try to put the t-case back and torque down those bolts. Just my two cents.

william.jones2 said:

It's a little more work, but a lot less of a PITA to just pull the transmission and t-case as a single unit. Especially when you try to put the t-case back and torque down those bolts. Just my two cents.

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Agreed after doing it several times over the past few years I have found it is easiest to unbolt the driveshafts at the axles, unbolt the bell housing, remove the cross member and drop the whole thing down then start separating it.

Decided to add to my existing thread vs starting a new one...

OK CB family I'm waving my white flag... I've had my lovely 77 now for 3 years and I knew I was signing for a work in progress but I'm frustrated....
Besides some cosmetic stuff, I thought I had finally gotten the rig to a point where I can drive it, and just do routine maintenance...

So to recap, I had some issues removing my D20 which I finally did. The whole reason I had to pull it was that under acceleration the T-case would occasionally pop into neutral. I researched symptoms and talked to some other owners and narrowed down my issue to a worn out high speed gear (attached to the input shaft of the T-case) and or worn out ball detents. Both were replaced on this adventure.
Now that I've got it all back together, with several other winter projects complete on the rig complete, I took it out for a test drive. Within the first 5 miles going 55 mph I came to a red light. Slowed down and stopped... soon as the light turned green.... Neutral...
As most of you know you can't do any but shut the engine off (to avoid grinding gears) put it in Park, mess with the J-shifter, and start it and go...
I thought, OK maybe it was just a fluke and all of my work wasn't for nothing...

It happened 5 more times before a made it home (10-15 mile round trip).... The symptom has changed though, instead of it popping out during heavy acceleration, it now happens when I back out of the throttle and coast...

I'm racking my brain as to why... and I REALLY don't want to tear it out again...One thing I thought was perhaps the oil I'm using... Again I researched and found that many put diff oil in their T-cases so I put 75-90 Diff oil in mine. I also lubed the ball detents, and all j-shifter linkage with grease to try to make it a little smoother... but I can't see how that would make it come out of 2H into Neutral. One other thing to note is that my first issue of it popping out of 2H you could physically see the shifter pop/move when it went into Neutral.
Now it doesn't move when this happens, you don't even know anything is wrong until you try to give it some throttle...

Long winded story but any input would be appreciated...

There could be a variety of reasons why it's popping. Loose output shaft, wobbly driveshaft, shifter contacting the floor or something else, etc.

77-302 said:

One other thing to note is that my first issue of it popping out of 2H you could physically see the shifter pop/move when it went into Neutral.
Now it doesn't move when this happens, you don't even know anything is wrong until you try to give it some throttle...

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I had a couple comments to make until I reread this post and the part I quoted above. After reading this, my thought is that you are never getting it fully into 2H. I'd suggest rechecking the shifter and mounting points.

Are you still using the stock J-shift shifter?

Viperwolf1 said:

There could be a variety of reasons why it's popping. Loose output shaft, wobbly driveshaft, shifter contacting the floor or something else, etc.

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Viperwolf, totally agree... I'm trying to eliminate causes so I'm up for anything. Just talked to a guy who's done several D20's and the problem is that none of the suggestions he had involved keeping it in the truck. It sounds like its got to come out again which is what I didn't want but I don't see a way around it at this point...

Front driveshaft is brand new, rear is in good shape and no vibrations or shaking prior to the first T-case removal. Shifter contacting floor is a possibility so I'll look.

Couple of other observations or things to note to the CB community. When I had the Tcase out I replaced the mount bushings and even added a snubber (which had never been there before). I replaced all the fasteners to the X-member and T-case mounts....

Lastly, before I pull it out, I'm going to drive it and let it happen again, then safely coast to the side of the road and get under the truck and see if I can figure out what position the shift rails are in. One thing I did notice was that I can now shift past the 2H position. Almost like a 2Lo but I'm not sure since the front hubs were not locked... Not sure if this is adding to the issue or just an unrelated item but I thought I'd share it.

Thanks, Brad

70_Steve said:

Are you still using the stock J-shift shifter?

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Yes stock J-shifter

You said the PO messed with the tunnel that covers the shifter, Its very possible that the shifter is not engaging, when you replace the detent balls, did you replace the springs?

savage said:

You said the PO messed with the tunnel that covers the shifter, Its very possible that the shifter is not engaging, when you replace the detent balls, did you replace the springs?

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Yes both balls and springs... even put some grease in there to make sure they weren't dry the first time they engaged so they didn't gall anything.

william.jones2 said:

It's a little more work, but a lot less of a PITA to just pull the transmission and t-case as a single unit. Especially when you try to put the t-case back and torque down those bolts. Just my two cents.

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Agree 100%, its much easier to pull both at same time. I have some alignment bolts that I cut the heads off of to thread into the tranny, this will make life very simple. I place a wood 2x4 just in front of the t-case to lower and raise and it balances perfect for a floor jack.