So you broke a nose cone and stripped the holes?

[CruisinGA]

I did, unfortunately. https://forum.ih8mud.com/40-55-series-tech/256940-broken-nose-cone-2.html#post4340162

Faced with this, a wheeling trip this weekend, and not enough time to go through my spare tcase and install the entire thing, I opted to drill out the holes in the old tcase and tap for M10 x 1.5.

There are lots of ways to go about the same thing, helicoils, solid inserts, different threads etc. Helicoil or a solid insert would make more sense if the original bolt size was required, but in this case, sizing up to M10 just requires drilling out the holes on the nose cone. Not worth the hassle/expense of the other options in this case IMO.

Nothing about this is revolutionary, or even particularly creative. So far, it seems that this has worked well for me, so I thought I would post this up so others might not think their case it trash just because of some stripped holes.

I find the stock M8x1.25 bolts pretty trivial to begin with in the soft aluminum of the tcase, and after 35 years only more so. Hopefully this is a little stronger. Certainly with a nose cone saver I would think it would be a significant improvement over stock.

Enough diatribe.
Pic #1
You can see the cracked hole and some of the compromised threads in this pic

 

[CruisinGA]

My M10 tap called for 11/32 drill. I opted for a size smaller, 21/64, since I was drilling by hand and more thread engagement wouldn't hurt in that soft aluminum.

 

[CruisinGA]

Used some grade 8.8 M10x1.5 bolts, split lockwashers, and copper RTV I had lying around to finish it up.

Note Poser's tcase saver on the top of the case. Been doing it's job for 5 years now.

8.8 grade metric is not great. Still, I didn't think it was worth a trip to the store for grade 10.9 when I'm pretty confident the bolts will pull out or the ears of the nose cone will break off before the bolt fails

Loosened up the rear bearing retainer/speedo gear housing before tightening the nose cone. After retightening the rear beaing retainer, checked output shaft bearing preload with the front output disengaged and transfer in neutral, and ended up with a good 10 lbs. (Spec is 10-13 lbs).

All it needs now is one of Georg's nose cone savers!

Note I didn't go to the trouble of cleaning up the entire case. Due to the crack mentioned above, this case does not have a long life ahead of it, and is not worth the trouble of cleaning up.
Hope someone finds this useful information.

 

[amaurer]

You're not worried about what appears to be a monster crack right through one of those holes...?

EDIT: Nevermind, I see you mentioned it.

 

[Cruiserdrew]

Bailey-

I'm looking at your first picture and the crack in the hole extends into the case itself. That whole case could come apart the next time it's used hard. Plus, it's going to leak and cause other problems. Just me, but I think it's time for another case or an Orion. I would not bother to re-install that one.

Still, I like the bigger stud idea-applied to a good case.

 

[CruisinGA]

Yep, know the crack is there. It is not as long as it looks in the picture. Stops in the middle of the wiped off area.

I am going to drill the end of the crack to stop it from creaking and plug the hole with some JB weld.
Just the same this case is not staying in my truck long. Might as well get some use out of it before it gets canned.

Redneck?... I think so. Then again, I am from Georgia.

Look past the crack, and focus on the larger bolt.

I think between some M10 bolts (maybe better, studs?) and some strategic reinforcement, these nose cones could be made to be much stronger. Depending on how long it is before I have the money for a Dana 300 adapter, I may get to experiment with some more of this.

 

[Degnol]

Doesn't Georg or somebody make a steel ring to specifially strengthen that part of the case? Seems like the perfect app for it.

 

[CruisinGA]

Doesn't Georg or somebody make a steel ring to specifially strengthen that part of the case?

Yep - see post #3

I think using a tig welder to add some ribbing to strengthen the stock mounting ears, along with these M10 bolts/studs could make a significant improvement in stock nose cone strength.

 

[Poser]

I think swapping in a Dana 300 would be a significant improvement.

Agree....

 

[CruisinGA]

I thought it was Atlas or nothing?

Hopefully the Dana 300 happens soon enough that I don't have enough time to go crazy with a tig and stock nose cone.

 

[LC_Hamma]

Too bad about the carnage
I made the same mod to mine (10MM) but reinforced the cone w/ a similar saver that Georg sells I fabbed a while back. My bracket wraps around the cone ears & is press fit. I would have used the 4 spd. cone due to more ribbing.
You going to go w/ a Proffitts centered rear for the D300?

 

[CruisinGA]

Saw your brace, Hamma. Slick as usual for your stuff. I just don't have the patience you do.

Haven't seen a Proffitt's centered rear, is it just a centered housing for cruiser third? What brakes/outers/shafts does it run?

I'm thinking cruiser/mini hybrid for rear. Super cheap and would let me get the parking brake off the tcase.

Most my buddies are running $80 14bolts now, but I think that center chuck would be too much plow with my 37's. Plus, already got the cruiser third rebuilt with an ARB.

 

[Poser]

I thought it was Atlas or nothing?

Don't forget the 1350CV drive shaft, fabricated rear axle housing and 4.86/ARB/HI9 center section and CTM shafts.

Works for me.

 

[LC_Hamma]

Saw your brace, Hamma. Slick as usual for your stuff. I just don't have the patience you do.

Haven't seen a Proffitt's centered rear, is it just a centered housing for cruiser third? What brakes/outers/shafts does it run?

I'm thinking cruiser/mini hybrid for rear. Super cheap and would let me get the parking brake off the tcase.

Most my buddies are running $80 14bolts now, but I think that center chuck would be too much plow with my 37's. Plus, already got the cruiser third rebuilt with an ARB.

I agree the 14 bolts are ditch diggers for 37's. I have about 10" (tires were flat in the pic) of clearance running 37" SSR's & a shaved & offset 14 bolt Don't know the specs on the Proffitts option, but that mini hybrid sounds like a good way to go. I like 'em hybrids ;p What calipers w/ ebrake you going to run? Don't go w/ the Eldo's & I wouldn't rely on a Line Lock if you were thinkin that route. Also, I have an SM420/ D300 setup. I went w/ the Novak adaptor mainly due to the depth is shorter than AA's, not by much though, just an FYI.

 

[CruisinGA]

Don't forget the 1350CV drive shaft, fabricated rear axle housing and 4.86/ARB/HI9 center section and CTM shafts.
Works for me.

I bet it does.

I agree the 14 bolts are ditch diggers for 37's. I have about 10" (tires were flat in the pic) of clearance running 37" SSR's & a shaved & offset 14 bolt Don't know the specs on the Proffitts option, but that mini hybrid sounds like a good way to go. I like 'em hybrids What calipers w/ ebrake you going to run? Don't go w/ the Eldo's & I wouldn't rely on a Line Lock if you were thinkin that route. Also, I have an SM420/ D300 setup. I went w/ the Novak adaptor mainly due to the depth is shorter than AA's, not by much though, just an FYI.

If I did the cruiser/mini hybrid, I would probably stick with the minitruck drums and stock parking brake. Cheap and works. (see a pattern?) Self adjusting single wheel cylinder drums are still an upgrade for me.

How long is the Novak adapter? How much driveshaft do you think I can expect to lose from my current setup with 3spd case plate adapted to the SM420?

 

[D'Animal]

Is someone going to bring up Studs with Nuts vs Bolts or in this particular case it does not really matter.

 

[Trollhole]

Used some grade 8.8 M10x1.5 bolts, split lockwashers, and copper RTV I had lying around to finish it up.

Note Poser's tcase saver on the top of the case. Been doing it's job for 5 years now.

8.8 grade metric is not great. Still, I didn't think it was worth a trip to the store for grade 10.9 when I'm pretty confident the bolts will pull out or the ears of the nose cone will break off before the bolt fails

Loosened up the rear bearing retainer/speedo gear housing before tightening the nose cone. After retightening the rear beaing retainer, checked output shaft bearing preload with the front output disengaged and transfer in neutral, and ended up with a good 10 lbs. (Spec is 10-13 lbs).

All it needs now is one of Georg's nose cone savers!

Note I didn't go to the trouble of cleaning up the entire case. Due to the crack mentioned above, this case does not have a long life ahead of it, and is not worth the trouble of cleaning up.
Hope someone finds this useful information.

You cheap bastard. You went through all that to fix a t-case with a big crack in it. You have way too much time on your hands.

 

[CruisinGA]

Is someone going to bring up Studs with Nuts vs Bolts or in this particular case it does not really matter.

I mentioned it above. (Does no one read what I write? )

If I had had studs on hand, that's what I would have done.

If I ever build another 3spd tcase I will switch the nose cone and rear bearing retainer to 10mm. I don't think it is worth it for the top cover or PTO cover, unless some holes are already stripped.

I haven't converted to 10mm studs/bolts... mainly out of concern over taking more material off the ears of the nosecone. Probably undo concern but I haven't seen a patern of bolt breakage during nosecone failures... mostly broken ears

I had the same concern.. for a second. Took very little drilling to fit the 10mm bolt.

I agree, I think larger bolts/studs are only half the upgrade equation. Some kind of reinforcement, whether it is a nose cone saver like Georg sells or welded on braces needs to be done as well.



Me, I'm just hoping this thing holds together until I can afford a D300 adapter.

 

[LC_Hamma]

I bet it does.



If I did the cruiser/mini hybrid, I would probably stick with the minitruck drums and stock parking brake. Cheap and works. (see a pattern?) Self adjusting single wheel cylinder drums are still an upgrade for me.

How long is the Novak adapter? How much driveshaft do you think I can expect to lose from my current setup with 3spd case plate adapted to the SM420?

Novak Adaptor is 3 3/8" long. Subtract 3/4" for your SM420 plate adaptor & you have 2 5/8" There is also the Rube SM420/ D300 adaptor. Not sure on price.....

I have some 6 lug spacers for your front axle if you wanna build that mini rear hybrid a bit wider than stock.