dana 20 detent spring problem

[shifter]

Just wanted to pass on what I found out while troubleshooting a popping out of gear problem since installing twin sticks on my dana 20. Did a search and was suprised how many had the same problem. Mine was caused by a lack of preload on the detent spring, guess after 30 years they must take a set! I checked both spare t-cases in the barn and all the springs varied in length by more than .100 I just installed the 2 longest springs and added preload spacers until there was a nice positive click when shifting, works great now! Will order new springs but this will get me on the trail this weekend. Hope someone finds this usefull, mine always popped out of gear right at the wrong time!

 

[Daddy4zack]

Thanks for the info. Is this a T or a J shift?

 

[shifter]

This is a J shift, not sure if the T has the same setup.

 

[cmud]

I'm currently in the same boat, I have a J-shift twin sticked. When I'm in 4low the rear keeps popping into neutral. I'm hoping it's the spring. The strange thing is it feel real positive going in and out????

 

[shifter]

Mine would come out of rear low and rear high, usually under light power load. you should be able to feel the detent ball fall into place, before shimming the springs there was nothing holding the shaft from moving. If yours clicks into place and still pops out might be something else wrong, worn out gears maybe? I believe you can buy stronger than original springs if needed. I think it was obriens?

 

[cmud]

That's sort of what I was thinking, we'll see thanks.

 

[Nobody]

When I twin sticked my t-shift, I modified the shift rails for front wheel drive and modified the rear shift rail to make a better pocket for the detent ball.

As you can see, in the picture below, in the REAR low position, there isn't really a pocket, just a gradual slope. I built up a little weld and made a nice pocket with me dremel. Work great, and no problems popping out of gear.

Modified shift rail

Also, have a look at this pic. Note the factory washer/shim with the front axle detent spring.

http://www.tocmp.com/manuals/Bronco/TCase/tcase3.jpg

 

[70_Steve]

Also, have a look at this pic. Note the factory washer/shim with the front axle detent spring.

Here's a better pic.

 

[70_Steve]

When I twin sticked my t-shift, I modified the shift rails for front wheel drive and modified the rear shift rail to make a better pocket for the detent ball.

Just took another look at your pics. You modified the shift rails so you can have independent front and rear shifting, and left the detent rods in, right? Most people just remove the detent rods. What do you see as the advantage to have your modified shift rails with the detent rods vs simply removing the detent rods?

 

[Nobody]

It just prevents shifting one axle in Low and the other in High.

 

[shifter]

Nice work on your shifter rails nobody! In the modified rail photo is that a washer/spacer between the ball and spring? All the ones in my transfer cases were on top of the spring. But mine are J shift, maybe the T is differant? Thanks, dave.

 

[drscotch]

I just had mine apart, I think the pictures above are for T-shift as stated. My '74 truck manual showed the T-shift diagram despite my truck having a J-shift Dana 20.

My J-shift had only 1 pill, the one that lines up with the springs and balls. I believe the twin-stick mod on a T-shift requires you remove the other pill.

I reinstalled the pill and I am able to find all positions for front/rear Hi/Low independently.

 

[Nobody]

Nice work on your shifter rails nobody! In the modified rail photo is that a washer/spacer between the ball and spring? All the ones in my transfer cases were on top of the spring. But mine are J shift, maybe the T is differant? Thanks, dave.

It's just the picture, there is no washer.

My j-shift case didn't require any mods to shift front and rear independantly. I haven't taken it apart yet, so I'm not sure how it's set up.

edit: the j-shift also allows one axle to be in HI and the other in Low....which could be a bad thing if you aren't careful.

 

[welndmn]

When I twin sticked my t-shift, I modified the shift rails for front wheel drive and modified the rear shift rail to make a better pocket for the detent ball.

As you can see, in the picture below, in the REAR low position, there isn't really a pocket, just a gradual slope. I built up a little weld and made a nice pocket with me dremel. Work great, and no problems popping out of gear.

Modified shift rail

Also, have a look at this pic. Note the factory washer/shim with the front axle detent spring.

http://www.tocmp.com/manuals/Bronco/TCase/tcase3.jpg

BTW thanks for the pic, I nabbed it the other day but could not post back on pirates due to server issues