Dana 20 Shim Question

WSM29 · Aug 19, 2012

Afternoon All-

So I had my Dana 20 rebuilt with all new bearing and seals. I got my NV3550 installed and then added the Dana 20. All was good with the world until I got back from my first test drive. I had a very leaky Dana 20. So instead of taking it back to the shop, I have decided to make this a learning experience and learn how to do a re-seal on it. So I took apart the sections that were leaking and found one of the shims had a crease or bend in it. The fold looks like someone did this for clearance issue or something, but can not find where or why they would need to do this. So my question is, is this normal and if not how do I get a replacement shim. This was the skinniest shim in the group. I also notices that all the other shims had some sort of RTV on them. Do I need to clean the shims up and install them with RTV and how much should I use? Looking for any another advice on how to make this thing go back together correct and for it not to leak! Thanks again!

TAC71 · Aug 19, 2012

That fold propably came from the screwdriver someone used to take the cover off with. Use a small amount of good quailty sealer between every surface, that means both sides of the shims. I also put a small smear on the seals outside surface and on the ends of the cross shaft. After driving in the parts I smear the small amount of excess with my finger. Some of the bolts also need some sealant on the threads to prevent leaks. Some of the bolts are blind and do not need the sealer, I usually just do it to all the bolts. After all that you must pray that the casting isn't flawed with pores that leak.

addicted · Aug 19, 2012

Copper Spray adhesive works best. Spray each shim individually on a piece of clean cardboard and then transfer them carefully to the cover using the bolts to align them. Once they are all transfered to the cover you can spay the back of the last one and then bolt the cover to the case.

bad 68 · Aug 19, 2012

You should check the output shaft for endplay and bearings for preload and not just assume that the correct shims are in place. You will want to do this before using sealer to prevent a mess if you have to dissasemble to change shims.

Nelson · Aug 19, 2012

Loktite 515 on mine to seal the shim pack. It does not add any clearance to the shims and will seal them. As for RTV I have never used it to seal shims as it does add some clearance to the shim pack.
Good Luck

Bronchole · Aug 20, 2012

I wrote a tech artical about sealing the various leak points on the Dana 20: http://classicbroncos.com/forums/showthread.php?t=207537&highlight=bronchole+dana+20+seal

Here is the post I have compiled for this particular area: http://classicbroncos.com/forums/showpost.php?p=2114760&postcount=14

Notice I have already added in the couple ideas that others have thrown out in this thread.

Notice that I don't mention the hardware in that individule post. Hardware is covered in this post: http://classicbroncos.com/forums/showpost.php?p=2114747&postcount=2

I am not sure why this didn't come up on your search for sealing this area. What search terms did you use? I need to add them to the metetags for that thread.

Dan

Rustytruck · Aug 20, 2012

Notice that shim looks like a screwdriver notch. it is probably a reused shim and when someon took the housing apart they used a screwdriver to wedge the 2 pieces apart. the curreled up material should be removed other wise the shim pack will not compress properly. the notch will not hurt its function just get rid of the hump.

WSM29 · Aug 20, 2012

Thanks to all the replys. I did a quick search for just dana 20 reseal and there were a lot of posts, but the first page was more about the rebuilds and just general dana 20 questions. I didnt search for just the tech articals, ( forgot about it ) and I usually like to do a post to see if any new advice or new members were here to aid in the process. Thanks again and that link is exactly what I was looking for. Looks like I need to order the shim kit from wild horses and get her back together!

Bronchole · Aug 20, 2012

I added reseal and re-seal to the tags.

Thanks,

Dan

WSM29 · Aug 24, 2012

So I received all the new seals and shims today. While cleaning everything up, I noticed these spots in the Dana 20. I could not think of any reason they would be there... Could this be the reason why I was leaking so bad? Does this call for some JB Weld or am I SOL and need a new TCase??

addicted · Aug 25, 2012

Naw. I think thats fixable. Little JB and some sanding and you'll be good. Hell you might not even need that. A dab of RTV would most likely take care of it.

Viperwolf1 · Aug 25, 2012

Doesn't look bad.

Buldozer · Aug 25, 2012

No problem with the case, just use your regular gasket sealer and move on!

Dana 20 Shim Question

WSM29

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TAC71

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addicted

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Nelson

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Bronchole

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WSM29

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Bronchole

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WSM29

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Buldozer

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