DIY Gear Swap - Step by Step Pic's - Rubicon 4.88

[chevymitchell]

Reviving an old but amazing thread for some question for those more experienced than myself, which is anyone who has done this since regearing will be virgin territory for me.

I've committed to regearing to 4.88s (JLUR auto, 37s), got a killer deal on Dana Spicer gears + master install kits from NR4x4. After reading ChevyMitchell's write up and watching the Dana video on regearing a JL, seems very doable but I have some questions if anyone wants to help out. Sorry if they are silly questions.

1. How important is a pinion seal installer? Dana makes a $300 kit (SPI401) with several sizes of installers, but I've seen other people just carefully tap them in or use something round that is the correct diameter to seat the seal without damaging it.

You can get away with not using a formal seal installation tool. They do make installing super smooth, but it is not needed.

2. Can I use the cheaper of these 2 styles of bearing puller? ChevyMitchell has the more expensive clamshell style (top picture), but if I can get away with the cheaper one (bottom picture) I'll save a few benjamins.

The bearing pullers on the bottom will not work because the smaller carrier bearing sits too close to the carrier itself. You will end up pulling just the cage off and then cutting the rest of the bearing off. The clamshell style will do this, as well, if you do not have it set up right. I ended up cutting bearings off while trying either tool.

If you'd rather just cut the bearings off, you won't need either one of these tools, but that's your call. Cutting the bearings off is super easy, but also nerve racking if it's your first time.

3. How do I know if these race driver kits will have the size I need? (most seem to have the same range of sizes, so I am assuming these kits cover most applications.)

I used a generic kit. It worked well.

4. Any reason this cheap 6-ton HF press wouldn't work...? It's says the capacity is 10.5". It's only $80 from HF and they usually have a 20-25% off coupon. Option two is I use the bottle jack out of my Jeep and weld up a small metal frame to press against, but if I can buy this for $60 and it works well, that's hard to beat.

This should work great. You don't really need a lot of pressure, so any small shop press or desktop press would work. I wouldn't recommend an arbor press, but one big enough might work, as well. I've always used my small shop press.

5. Some people apply a thin layer of RTV silicone to the inside of the pinion seal before tapping it into place, seems like it would add some extra piece of mind. Thoughts or issues with this?

The new pinion seal comes with a layer sealant on it already. You can add more, but it's not necessary at all.

6. Is there any benefit to removing the axles to regear? Seems like extra work, but it it makes the process easier (or getting to tight spaces easier) it might be worth it.

No. Leave them in. Other than the obvious (putting the axle at standing working height), there's no reason to remove the axle.

7. In order to use another set of bearings while setting up the rear end, can I just use the old bearings and sand the inside to make them slip over the shafts, or should I buy an extra set of new bearings so they are identical to the ones I am installing?

This won't be necessary. The shims for the carrier go on the outside of the race and the shims for the pinion are accessible removing the head bearing on these axles. Press on your new bearings and go. If you bought DANA gears and kits, they'll likely come with a Zero Etch and you can use the same shim stack as the original gear set. Mine lined up perfectly with the original stack up.

8. Will a non-digital torque wrench be able to properly measure torque to turn when setting bearing preload? It seems like I could set it to a value and as long as it doesn't click, it'll at least be below that value so i don't over-torque when collapsing the crush sleeve.

Use a beam style torque wrench or a digital. Don't use a spring style torque wrench to set preload. You need one that will provide you with a real-time, live number.

Sorry for the list of questions, trying to plan ahead and have everything ready to rock and roll. Also a special thanks to everyone who has already contributed to this thread, extremely helpful.

No need to be sorry, man. That's what we're all here for... well, most of us, anyway.

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[JLRubiMD]

Man thanks so much for the quick/thorough reply. I watched a video of a guy cutting the old bearing off with some small snips and it seemed easy enough, is there any downside to just cutting them off carefully? I plan to see if anyone would want to buy these 4.10s to keep an extra set around, seems like I can just leave the bearing on the pinion then and possibly carefully remove the bearing from the ring gear assembly (I believe it is pressed on as well?)

 

[chevymitchell]

Man thanks so much for the quick/thorough reply. I watched a video of a guy cutting the old bearing off with some small snips and it seemed easy enough, is there any downside to just cutting them off carefully? I plan to see if anyone would want to buy these 4.10s to keep an extra set around, seems like I can just leave the bearing on the pinion then and possibly carefully remove the bearing from the ring gear assembly (I believe it is pressed on as well?)

You're very welcome.

You can cut the bearing cage off with snips, but you're still left with the inner race. You will need a die grinder or dremel along with a sharp punch. There are pictures and a short explanation of this in my write-up.

The bearing will stay on the pinion when you hammer it out. The carrier bearings will likely come off in two pieces. It's definitely possible to remove them without damage, but the second the cage gets bent, it's game over. The bearing will never be the same.

All of the bearings are press-to-stop bearings. There's no gap to check. Just press them until you can't press anymore.

 

[2Wheel-Lee]

Question...I have a set of new Dana gears, and the etching on one set is "-05" and the other is "+05". This doesn't seem to fit in with what I know as their common ways of listing this. I'm guessing this is a newer metric designation of -0.05mm and +0.05mm, but I haven't found anything to substantiate this. From the older Dana documentation I have, the designation "M-5" would have been -0.05mm. Does anyone know? Thanks!

 

[chevymitchell]

Question...I have a set of new Dana gears, and the etching on one set is "-05" and the other is "+05". This doesn't seem to fit in with what I know as their common ways of listing this. I'm guessing this is a newer metric designation of -0.05mm and +0.05mm, but I haven't found anything to substantiate this. From the older Dana documentation I have, the designation "M-5" would have been -0.05mm. Does anyone know? Thanks!

DANA, as far I'm aware, has been using the same designation for their gears for a long time. Here's their charts for adjusting etching (Standard and Metric) . SEE BELOW

If you remove a certain etch and are installing a different etch, this chart will help guide you to the correct amount of shim to use. It's not always perfect, but will get you the mathematical equivalent of what the etches say the gears are. This has been spot on except for a couple times.

Metric will have an M+/-, like you mentioned.

Your best bet is to contact DANA directly and verify that these charts are still accurate for the new axles. They haven't developed their new manual yet. Should be coming out really soon, but I'm certain their numbering format wouldn't have changed.

For example: My new gear set came with "0" etch pinions, front and rear. The set coming out of the Jeep were also "0" etch. I used the same shim pack thickness when installing the new 4.88's. Make sure to use new shims and not old ones. Make sure your new shim pack thickness is measured out correctly and you shouldn't have any issues at all.

Standard

Metric

 

[2Wheel-Lee]

Thanks. I was quite familiar with that chart of the old and new. I was thinking my gears might follow a "new-new" nomenclature, but I haven't seen any documentation.

What tech support number do you have? I haven't found one yet.

 

[chevymitchell]

Thanks. I was quite familiar with that chart of the old and new. I was thinking my gears might follow a "new-new" nomenclature, but I haven't seen any documentation.

What tech support number do you have? I haven't found one yet.

 

[2Wheel-Lee]

Thanks! E-mail sent and they responded very quickly! They confirmed that it is metric (0.05 mm)

 

[chevymitchell]

Thanks! E-mail sent and they responded very quickly! They confirmed that it is metric (0.05 mm)

Awesome. Their customer service is normally really good.

 

[2Wheel-Lee]

Just adding more info to the thread. I removed my stock front pinion, and it says 0.62, and Dana tech support again confirmed that it's in mm. So .62 mm off. So much for me getting anything with a 0 etch!

 

[2Wheel-Lee]

Thanks! E-mail sent and they responded very quickly! They confirmed that it is metric (0.05 mm)

So a few follow-up notes. In a later e-mail to Dana, they said that the 05 pinion etch was 0.5 mm not 0.05 mm. I don't know if it was a different person.

I measured the backlash on the rear gears prior to disassembly. They were 0.021" - no kidding. I checked and checked again (some of you may have seen a video I posted on one of the JL facebook groups). JL has only 1,800 miles on it.

I suspect the backlash on my front gears was way off as well. Since pinion depth on the front was similar between old and new, I just assembled it with existing shims, and the backlash was still too much. My mistake was not having carrier shim kits on hand. I wanted to try and stay with OE type ships, but this is where I ran into a problem. The front flange-side shim measured about 2.641 mm, but the smallest shim that Mopar offers is 2.789, so I got that along with a shim of the same difference in measurement for the button side. The 2.789 moved it over too far where the backlash was too tight - pretty much zero. So now I'm waiting for some carrier shims.

Not much is ever said on how to install the carrier shims, so I'm still learning the best way to do that. Now, I'm installing the assembly with the button side shim in place, then using a screwdriver to hold the flange side bearing cup to the side to start that side shim in, then knocking it the rest of the way with a brass hammer and/or brass drift.

Since I'm working on the ground in my driveway, I pulled the front axle assembly out so I could weld on an Artec truss. The rear axle I left in place, but it is a bit tough to work under there with so little space. Not enough for me to sit up, so I'm R&Ring the carrier laying sideways - a bit awkward.

 

[vavaroutsos]

Just adding more info to the thread. I removed my stock front pinion, and it says 0.62, and Dana tech support again confirmed that it's in mm. So .62 mm off. So much for me getting anything with a 0 etch!

How can your gears be so far from a 0 etch? 0.62 mm is over 0.024". What is Zack Heisey talking about in the Dana/Spicer videos when he says the Dana/Spicer gears are cut so well? I have never seen an old/new chart that goes anywhere near this far from a 0 etch.

 

[2Wheel-Lee]

How can your gears be so far from a 0 etch? 0.62 mm is over 0.024". What is Zack Heisey talking about in the Dana/Spicer videos when he says the Dana/Spicer gears are cut so well? I have never seen an old/new chart that goes anywhere near this far from a 0 etch.

That video horribly lacks a lot of detail and needed information. I now believe it's merely a marketing video. Sadly, they use that same video as part of their "training" materials.

 

[vavaroutsos]

That video horribly lacks a lot of detail and needed information. I now believe it's merely a marketing video. Sadly, they use that same video as part of their "training" materials.

I just received a pair of 4.88 Advantek gears. I'll check them tonight and see what the pinions are marked.

Also, the Dana/Spicer spec sheet I have on the rear 44 Advantek calls for 0.003” – 0.006” of backlash. How could yours have had 0.021" from the factory? Did you measure it in more than one place? I wouldn't think it would last very long with that much backlash.

 

[2Wheel-Lee]

I just received a pair of 4.88 Advantek gears. I'll check them tonight and see what the pinions are marked.

Also, the Dana/Spicer spec sheet I have on the rear 44 Advantek calls for 0.003” – 0.006” of backlash. How could yours have had 0.021" from the factory? Did you measure it in more than one place? I wouldn't think it would last very long with that much backlash.

I can't answer how it came with 0.021" backlash...I didn't assemble it! Oh yeah, I checked that in multiple locations, and I reset up a few times, because I decided to get a video of it. For only 1,800 miles, I was kind of surprised how dark the fluid was, and locker sensor nub (don't know what to call it) was caked in gear schmegma (correct spelling? lol ).

I can't say that I heard any noise from the rear, but Jeeps are loud, not to mentioned I'm still getting used to all the Jeep noises. And really, I wasn't tuned into listening for gear noise. Also, the last 500 miles had noisy 37" Trail Grapplers.

Last night, I finally got sets of Yukon and Spicer shims (ordered from multiple places to increase my chances of getting them quickly), and I finished setting up the rear. I was a bit surprised how very little carrier movement impacts backlash a lot - seemed backwards (of course, we're still talking thousandths).

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