NP208 rebuild

Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
I'm in need of a shop to go through a NP208. I attempted to rebuild it a couple years ago, replacing seals, thrust bearings and shift forks. It is definitely improved but is difficult to get into low range. It's a super simple TC, so I think something is wrong with it still. I can get low range, but it will grind while engaging. It has a home brew (i think) slip time eliminator (the main shaft was drilled and tapped for a yoke).

looking to make it a bit more reliable for the trail. BTW, this is in my 1982 Scrambler with a SBC, and 700R4.

I live near Ogden, so closer is better.

Thank you
 

DAA

Well-Known Member
I'm not too far from Ogden and there's a good shop just down the street, Axis. Have had Eric do a few things for me, always fast, fair price, the one time I had an output seal start leaking again he took it in and re-did it immediately, no wait, no muss, no fuss. He's just real easy to work with, stands behind his work.


- DAA
 

Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
Axis has had the t-case for a month and has not been able to complete the repair. The main shaft was damaged enough where it would continue to spin the planetary while shifting, causing the gears to grind. Eric sourced a new main shaft, but this case is using a hack-and-tap SYE and he (and 2 machine shops) have not been able to drill and tap the new main shaft. Eric is going to try to clean up the original main shaft to see if he can get it to work.

I had hoped to save a few dollars and run this t-case for a while, but it's starting to look like I might need another solution ('89 NP241C is a bolt in, but would need a SYE).

Any ideas from the wise RME folks?
 
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Gravy

Ant Anstead of Dirtbikes
Supporting Member
I mean a Dana 300 bolts to a 700r4 and is passenger drop.

You could technically convert almost any 6 hole round tcase to work with the correct input.

What trans output spline count do you have now. 23? It's not too hard to change it and it opens up some options.
 
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Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
It may be 23 spline. I'll have to see. If I have to sink more $ in it, I'd rather do a 300. Atlas cases are 3-4 months build wait
 

mbryson

.......a few dollars more
Supporting Member
It may be 23 spline. I'll have to see. If I have to sink more $ in it, I'd rather do a 300. Atlas cases are 3-4 months build wait

700r4 is a 27 spline. You’d need a Novak spud shaft/adapter (I don’t think you “need” the adapter but that’s how they sell it) for the D300 or the Advanced Adapters (or ????) 23 spline 700r4 output shaft to run the 300. Personally, I wouldn’t run the 300 unless you already have one.
 

Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
Yes, this is a 4x4 version of the 700r4, so it should be a 27 spline. We'll see how work goes towards repairing the 208. I didn't think drilling/tapping the main shaft would be impossible for a machine shop, but it seems to be.

I do not have a 300. It does seem like an option if I can't get this case repaired.
 

Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
Although if anyone has a 300 for sale locally, I may be in the market pretty soon. I think this is a better option than a NP241C. Long term for this jeep may be another engine swap to a diesel, so the 300 is adaptable.

Also interested in why you wouldn't run it if I didn't have one. The Atlas in my TJ has been flawless, but I don't want to wait the 14+ weeks to get one.
 

mbryson

.......a few dollars more
Supporting Member
Although if anyone has a 300 for sale locally, I may be in the market pretty soon. I think this is a better option than a NP241C. Long term for this jeep may be another engine swap to a diesel, so the 300 is adaptable.

Also interested in why you wouldn't run it if I didn't have one. The Atlas in my TJ has been flawless, but I don't want to wait the 14+ weeks to get one.

D300 are getting hard/expensive to find. I wouldn’t buy another. I’d go back to a 241c pass drop with SYE personally. I’ve not had awesome luck with my D300
 

Gravy

Ant Anstead of Dirtbikes
Supporting Member
241c passenger drop was only available 88.5-91. 88,89 is the only years it's got a mechanical speedo.
Not an easy case to find either. But it is 27spline so.

Why can't they do the hack and tap though?
 

Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
Why can't they do the hack and tap though?

Was told that one of the machine shops "burned up two drill bits." I suspect that Eric and the other machine shop had problems drilling it as well.

The old main shaft was drilled and tapped for 3/8 thread and it doesn't look like there was any drama doing so. It also does not look like the shaft was cut at all to get past the hardened outer layer. I've not attempted to drill one of these, but would have to believe a machine shop would be able to do it
 

Gravy

Ant Anstead of Dirtbikes
Supporting Member
I mean there is a way to do it on the cheap. If you anneal the first little bit of it to remove the hardening it will be easy to drill. But a machine shop should have the ability to do it even hardened.
I have not personally seen one that is through hardened. It generally only hardens an outer portion. I broke a 35 spline axle shaft and took the broken stub and dipped it in ferric chloride and you could see the difference where it was hardened and not.
 

Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
Eric told me that one machine shop told him that they could anneal the shaft, drill, tap it and then re-harden for the lowly sum of $1000...glad he said "no."
 

Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
Got "a" 208 back from Eric on Monday. He put it together with another one he had. Basically the only part from my old t-case was the tail housing and main shaft (drilled and tapped). He cleaned up the damage and used the rest of the parts from the other case.

I got the jeep back together last night and was able to drive it a bit. I am able to shift through all ranges, but it still grinds briefly when engaging 4H or 4L sometimes. Most of the time the shifting is quiet and smooth. I think this should be good to get us through the Rubicon trip and hopefully longer.

I need to get to building engine, trans and gas skids, install a Holley Sniper system and a few other items. I am hopeful we can make it through the trail without any major issues
 

mbryson

.......a few dollars more
Supporting Member
Got "a" 208 back from Eric on Monday. He put it together with another one he had. Basically the only part from my old t-case was the tail housing and main shaft (drilled and tapped). He cleaned up the damage and used the rest of the parts from the other case.

I got the jeep back together last night and was able to drive it a bit. I am able to shift through all ranges, but it still grinds briefly when engaging 4H or 4L sometimes. Most of the time the shifting is quiet and smooth. I think this should be good to get us through the Rubicon trip and hopefully longer.

I need to get to building engine, trans and gas skids, install a Holley Sniper system and a few other items. I am hopeful we can make it through the trail without any major issues

Ran into Eric at the grocery store the other day. Sounds like he’s needing to move to a bigger shop in the near future. Good to see him doing well and taking care of people
 

Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
Got to test the transfer case - it seems to shift and operate like it should. Its nice to be able to move on to other work on the scrambler. Eric had a hard time getting this case together, but didn't give up.
 
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Mouse

Trying to wheel
Supporting Member
Location
West Haven, UT
I'm still not real happy with the 208 - it's difficult to shift, hangs low and I'd really like to move to something more reliable. I intend to stay with the 700r4 and passenger drop front axle. I've looked and can't find the super-rare mechanical speedo-241 t-case. Before I contemplate an Atlas or MMW rockbox ($$$), does anyone have a t-case option for sale to help me out (would like 2.7:1 or deeper gearing)?
 
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