Novak Conversions Jeep Wrangler TJ radiator

2006 LJ Rubicon - First Jeep Build - Even An Idiot Can Do It

If it didn't have one, I wouldn't worry about it.

I am now concerned I screwed up the front differential.

The carrier (eaton) is drilled for 3/8" and 1/2" bolts. The gearset i bought from revolution came with 7/16" bolts and is dual drilled for 3/8" and 7/16" bolts.

They obviously dont fit in the holes for 3/8 bolts, so i stuck them in the 1/2" holes. I learned that bolt sleeves existed today...

Do I-

1. Take it all apart, drill the 3/8" carrier bolts out to 7/16" (probably super hard)

2. Take out all the 7/16" bolts and install 3/8" bolts.

3. Install 3/8" bolts on top of the 7/16" bolts

4. Get bolt sleeves

5. Run its with the 7/16" bolts in 1/2" holes as is.

Pretty crushing to figure this out now...
 
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I am now concerned I screwed up the front differential.

The carrier (eaton) is drilled for 3/8" and 1/2" bolts. The gearset i bought from revolution came with 7/16" bolts and is dual drilled for 3/8" and 7/16" bolts.

They obviously dont fit in the holes for 3/8 bolts, so i stuck them in the 1/2" holes. I learned that bolt sleeves existed today...

Do I-

1. Take it all apart, drill the 3/8" carrier bolts out to 7/16" (probably super hard)

2. Take out all the 7/16" bolts and install 3/8" bolts.

3. Install 3/8" bolts on top of the 7/16" bolts

4. Get bolt sleeves

5. Run its with the 7/16" bolts in 1/2" holes as is.

Pretty crushing to figure this out now...

That's an interesting position to be in. The ring gear is centered by the machining of the locker. The bolts hold it in place, but due to the nature of the ring gear wanting to rotate when force is applied, I think you need to change out your ring gear bolts.

I would defer this question to Revolution and see what they say. Report back and let us all know.
 
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Thanks, I sent them an email.

The eaton instructions say:

" Ring gears exist with 3/8”, 7/16”, and 1/2” fasteners. Eaton performance differentials for this application are typically machined with both 7/16” and 1/2” clearance holes. This allows the fitment of the two smaller bolt sizes into the small pattern, and the larger fasteners into the larger hole pattern, thus ensuring sufficient material under the bolt heads to allow proper tensioning of the fastener. A close fit between the bolt and the differential is not required if correct ring gear bolts are used"

This makes me think its probably fine, but the smaller of the holes was definitely not big enough for the 7/16" bolt.
 
Thanks, I sent them an email.

The eaton instructions say:

" Ring gears exist with 3/8”, 7/16”, and 1/2” fasteners. Eaton performance differentials for this application are typically machined with both 7/16” and 1/2” clearance holes. This allows the fitment of the two smaller bolt sizes into the small pattern, and the larger fasteners into the larger hole pattern, thus ensuring sufficient material under the bolt heads to allow proper tensioning of the fastener. A close fit between the bolt and the differential is not required if correct ring gear bolts are used"

This makes me think its probably fine, but the smaller of the holes was definitely not big enough for the 7/16" bolt.

That makes sense. It is the friction between the ring gear and diff when clamped together that keep it from rotating. Not the shear strength of the bolts. Shear strength would only come into play if the bolts weren't tight
 
@Lou

You run an eaton 19977 with tj thick cut gears. What ring gear bolts are you using?

@freedom_in_4low it looks you also run an eaton locker. What size bolts are using, in which holes? Are you using bolt sleeves, or did you drill the carrier?

@gatertamer what size bolts are you using with your eaton, and which holes are the bolts in on the carrier? Did you drill the carrier or use sleeves?

@macleanflood are you running an eaton locker? What bolts are you using in which holes? Did you use sleeves or drill the carrier?

@cpwolf - are you also running an eaton locker? Install yourself? Do you know what bolts you used in which holes?
 
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@Lou

You run an eaton 19977 with tj thick cut gears. What ring gear bolts are you using?

@freedom_in_4low it looks you also run an eaton locker. What size bolts are using, in which holes? Are you using bolt sleeves, or did you drill the carrier?

Don’t remember what size I used, but I made sure they were the same size as the holes in the locker.
 
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That's an interesting position to be in. The ring gear is centered by the machining of the locker. The bolts hold it in place, but due to the nature of the ring gear wanting to rotate when force is applied, I think you need to change out your ring gear bolts.

I would defer this question to Revolution and see what they say. Report back and let us all know.

So, Revolution says -

Lots of shops run it like that (7/16" bolt in 1/2" hole), and never have problems. He said it should be fine, but said personally it would bother him (bothers me too). Also said the TJ doesn't put out enough power to really be an issue here.

So I guess im down to 4 options.

1. Throw in 3/8" bolts and remove the 7/16" bolts that are in with red loctite. Wondering if that will be a pain or they will break.

2. Add 3/8" bolts alongside the 7/16" bolts. (Mega secure!!!!!)

3. Run it as is

4. Throw jeep away.

Should I do a poll?

Not in a big hurry to take the front back apart.

Northridge says I need to drill the carrier which i think id just assume throw the jeep away before drilling 20 holes through the hardened carrier.
 
Pressed the new bearing on the pinion with the original shim. What a difference in pinion size from 4.10s.

20250811_215358.jpg
 
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So I called Eaton. They said I could either:

1. Use shouldered bolts (ARP makes some with a 1/2" shoulder and 7/16" thread)

2. Drill the carrier

3. Run it as is and its probably fine.
 
Pressed carrier bearings on with my childrens size press. Put the pinion in with nothing behind the race. I suppose its probably normal but the setup race i made fits a lot looser in this axle comparedto the front. May consider making a new one.

Weird to see the bearing without the slinger on there.

Going to send it with the bolts as is.

20250812_210245.jpg


20250812_210447.jpg
 
My luck may be at an all time high. Carrier is tight with oem shims. Backlash at 0.009.

If i remember correctly deepening the pinion made the backlash tighter. Apparently out of paint but hoping the pinion is shallow and I can shim it in to tighten the backlash up.

Weirdly enough, the shims were 0.130 on both sides.

20250812_213038.jpg
 
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Novak Conversions Jeep Wrangler TJ radiator