Setup Gears at Home

[Dzimm]

I know it can be done, I'm looking to get an idea of how feasible it is for me to do it.

 

I'm very mechanically inclined, I've just never done gears before and would like to try it out but also don't want to break things.  

 

I came across a good deal on a rebuilt posi for my C8.25 but don't have the budget to pay a shop to put it in.  Is it as difficult to do as people make it out to be?  I'm only swapping out the carrier so no actual regear will happen, just checking everything for proper clearance, shimming, ect..

 

For those of you who have done regears ect. Before, what's your thoughts?  

[ghetdjc320]

You will at the minimum need a decent press, dial indicator, in lbs beam style torque wrench, dial indicator (recommend a mechanical one with .001 increments) and usual hand tools. I highly recommend a “clamshell” style carrier/pinion bearing tool. You will also need a gear install kit and gear marking compound. Ultimately, it’s not terribly difficult to do but you need to really understand the process well before starting. Preload, pinion depth and backlash need to be well within spec or you’ll damage your gears in short order. Keep in mind that many shops do not even really know how to setup gears.

[ghetdjc320]

I’ve done gears about 4-5 times so I am by no means an expert though 

[Dzimm]

1 minute ago, ghetdjc320 said:

You will at the minimum need a decent press, dial indicator, in lbs beam style torque wrench, dial indicator (recommend a mechanical one with .001 increments) and usual hand tools. I highly recommend a “clamshell” style carrier/pinion bearing tool. You will also need a gear install kit and gear marking compound. Ultimately, it’s not terribly difficult to do but you need to really understand the process well before starting. Preload, pinion depth and backlash need to be well within spec or you’ll damage your gears in short order. Keep in mind that many shops do not even really know how to setup gears.

Well that makes it easier because the bearings are already installed.  I would need to order the measuring toosl though.  It would literally be bolt in for me aside from setting everything to spec.  Id research the crap out of it before attempting.  

 

In the gears you've setup, have you ever had an issue?  The part I don't understand yet is how you read the marking compound.  I've never come across a good explanation of it.

[DesertRat1991]

 

12 minutes ago, Dzimm said:

Well that makes it easier because the bearings are already installed.  I would need to order the measuring toosl though.  It would literally be bolt in for me aside from setting everything to spec.  Id research the crap out of it before attempting.  

 

In the gears you've setup, have you ever had an issue?  The part I don't understand yet is how you read the marking compound.  I've never come across a good explanation of it.

 

I like this article from P4x4.  The bottom 1/3 of the page goes over reading the contact pattern: 

 

https://www.pirate4x4.com/tech/billavista/Gear_Setup/

 

When I looked into this job, I remember the cost for all the right tools was significant.  Hydraulic press, pinion depth setting tool kit, case spreader, etc...  it was hundreds in new tools that I would rarely use.   Could be worth it if you already have that stuff laying around, or you if intend to do the job frequently.  

[Dzimm]

7 minutes ago, DesertRat1991 said:

 

 

I like this article from P4x4.  The bottom 1/3 of the page goes over reading the contact pattern: 

 

https://www.pirate4x4.com/tech/billavista/Gear_Setup/

 

When I looked into this job, I remember the cost for all the right tools was significant.  Hydraulic press, pinion depth setting tool kit, case spreader, etc...  it was hundreds in new tools that I would rarely use.   Could be worth it if you already have that stuff laying around, or you if intend to do the job frequently.  

Is the case spreader necessary?  I pulled the gears out of a D30 to replace the pinion seal and put it back in without one. 

[DesertRat1991]

3 minutes ago, Dzimm said:

Is the case spreader necessary?  I pulled the gears out of a D30 to replace the pinion seal and put it back in without one. 

 

Depends on the diff.  I was researching the D44 at the time and it was recommended per the Spicer service manual.  

 

I will say that my D30 carrier also came out fairly easy without one.  

[ghetdjc320]

49 minutes ago, Dzimm said:

Well that makes it easier because the bearings are already installed.  I would need to order the measuring toosl though.  It would literally be bolt in for me aside from setting everything to spec.  Id research the crap out of it before attempting.  

 

In the gears you've setup, have you ever had an issue?  The part I don't understand yet is how you read the marking compound.  I've never come across a good explanation of it.

 

Your job just got a lot harder if the bearings are already on. For the Dana 30 the shims go inside the bearings which means pulling the bearings frequently or using setup bearings to get your backlash set properly. Never done an 8.25 so you have to check that one. The Dana 35 is relatively easy to set since the shims go outside of the bearings. 

[Dzimm]

4 minutes ago, ghetdjc320 said:

 

Your job just got a lot harder if the bearings are already on. For the Dana 30 the shims go inside the bearings which means pulling the bearings frequently or using setup bearings to get your backlash set properly. Never done an 8.25 so you have to check that one. The Dana 35 is relatively easy to set since the shims go outside of the bearings. 

My Dana 30 had the shims outside the bearings.  Did you mean the 35 has the shims inside?

 

I can't imagine a rebuilder would press bearings on if they need shims on the inside.

[ghetdjc320]

HP Dana 30’s should have the shims inboard of the bearings from factory unless you have an aftermarket carrier that is designed to accommodate them on the outside. Dana 35 is reversed and has the shims outside of the carrier bearings by default. If you have setup bearings than installing the shims invoard of the bearings is actually a much easier install than trying to get shims outboard of the bearings. You can use a case spreader “very carefully” but that will be yet another tool that the OP may not have. 

[derf]

I've done several sets of gears.

 

If the shims are between the bearing and the carrier, having setup bearings makes things easier.  If they're between the race and the differential housing, your job is easier.  I've seen shims both ways and they can vary on the same brand axle from one year period to another.  Whatever you do, you stay with the way the axle is set up right now.

 

A dial indicator to measure backlash is is important:  https://www.amazon.com/gp/product/B00UMD1K2M/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1

 

Having a case spreader makes things easier but isn't vital.  I've done it both ways.  I like having the case spreader.

 

Since you're only doing the carrier, you can skip a couple of the tools.  The pinion needs the inch-pound rotational torque indicator and a very big torque wrench (200 ft-lb or bigger).  But you're not touching the pinion so you don't need that.

 

The bearing retainer caps must go back on exactly how they come off.  Mark them so that you know not only which side is which, but which end is "up".  Always put them back on exactly the same way.  Every time.  No exceptions.

 

Step one is to do an initial pattern before you do anything else.  Use the gear marking compound and run the pinion over it a couple of times.  Take a picture.  That's where you want to get back to.

 

Step two is to remove the carrier and measure the shim packs that come out of the axle.  BE VERY CAREFUL TO NOT MIX UP WHICH SIDE THE SHIMS ARE ON.

 

Step three is to use the shims out of the axle with the new carrier.  DO NOT USE ANY OTHER SHIMS TO START.

 

Step four is to install the carrier, run a pattern, and measure backlash.

 

Step five is to evaluate the pattern.  If it's off, adjust the shims and go back to step four.  If it matches the original pattern, you're done.

 

Step 6 is to finish installation.  If you had to use setup bearings, press on the real bearings.  Reinstall everything and torque to spec.  Hose out the differential with some brake cleaner at least.  Inspect the seals and bearings out at the ends of the axle shaft.  Replace if you think it's warranted.  Button it all up and fill.

 

Drain and check the fluid after about 500 miles.

[derf]

2 minutes ago, ghetdjc320 said:

HP Dana 30’s should have the shims inboard of the bearings from factory unless you have an aftermarket carrier that is designed to accommodate them on the outside. Dana 35 is reversed and has the shims outside of the carrier bearings by default. If you have setup bearings than installing the shims invoard of the bearings is actually a much easier install than trying to get shims outboard of the bearings. You can use a case spreader “very carefully” but that will be yet another tool that the OP may not have. 

The Older Dana 44's had shims between the bearing and the carrier.  I have done 3 of them (2 full size Wagoneer, one XJ) with setup bearings.  Very easy to do that way.

 

I just did gears on an 04 Rubicon (same basic Dana 44 center section) and the shims were between the race and the housing.  The case spreader really helped but I really like them in between the carrier and bearing.  They're a lot easier to manage that way.

[Minuit]

Saving this for when I setup my MJ D44 and soon to be acquired D30

[ghetdjc320]

3 minutes ago, derf said:

The Older Dana 44's had shims between the bearing and the carrier.  I have done 3 of them (2 full size Wagoneer, one XJ) with setup bearings.  Very easy to do that way.

 

I just did gears on an 04 Rubicon (same basic Dana 44 center section) and the shims were between the race and the housing.  The case spreader really helped but I really like them in between the carrier and bearing.  They're a lot easier to manage that way.

The Rubicon 44’s use them outside of the bearings because of the lockers. Otherwise they are the same as all 44’s and are normally inboard of the bearings from the factory. I agree 100% that it’s actually a much easier install when they are inside the bearings. But for setting up new gear that will mean that you will need to use setup bearings or have a true carrier/pinion bearing puller. It is highly unlikely that you will hit the right specs on the forest try.  Then again, sometimes people hit a hole in one lol

[Dzimm]

14 minutes ago, derf said:

I've done several sets of gears.

 

If the shims are between the bearing and the carrier, having setup bearings makes things easier.  If they're between the race and the differential housing, your job is easier.  I've seen shims both ways and they can vary on the same brand axle from one year period to another.  Whatever you do, you stay with the way the axle is set up right now.

 

A dial indicator to measure backlash is is important:  https://www.amazon.com/gp/product/B00UMD1K2M/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&psc=1

 

Having a case spreader makes things easier but isn't vital.  I've done it both ways.  I like having the case spreader.

 

Since you're only doing the carrier, you can skip a couple of the tools.  The pinion needs the inch-pound rotational torque indicator and a very big torque wrench (200 ft-lb or bigger).  But you're not touching the pinion so you don't need that.

 

The bearing retainer caps must go back on exactly how they come off.  Mark them so that you know not only which side is which, but which end is "up".  Always put them back on exactly the same way.  Every time.  No exceptions.

 

Step one is to do an initial pattern before you do anything else.  Use the gear marking compound and run the pinion over it a couple of times.  Take a picture.  That's where you want to get back to.

 

Step two is to remove the carrier and measure the shim packs that come out of the axle.  BE VERY CAREFUL TO NOT MIX UP WHICH SIDE THE SHIMS ARE ON.

 

Step three is to use the shims out of the axle with the new carrier.  DO NOT USE ANY OTHER SHIMS TO START.

 

Step four is to install the carrier, run a pattern, and measure backlash.

 

Step five is to evaluate the pattern.  If it's off, adjust the shims and go back to step four.  If it matches the original pattern, you're done.

 

Step 6 is to finish installation.  If you had to use setup bearings, press on the real bearings.  Reinstall everything and torque to spec.  Hose out the differential with some brake cleaner at least.  Inspect the seals and bearings out at the ends of the axle shaft.  Replace if you think it's warranted.  Button it all up and fill.

 

Drain and check the fluid after about 500 miles.

What are the chances it all goes back in with the new carrier and needs no adjusting? 

 

I was actually thinking I should pull the pinion and replace that seal since it would be completely apart.  Currently it sits entirely stripped with the exception of the carrier and pinion.  All new seals and everything are going in, I remember reading a while back that the C8.25 used a crush washer or something on the pinion making it a PIA to change the seal.  

[ghetdjc320]

1 minute ago, Dzimm said:

What are the chances it all goes back in with the new carrier and needs no adjusting? 

 

I was actually thinking I should pull the pinion and replace that seal since it would be completely apart.  Currently it sits entirely stripped with the exception of the carrier and pinion.  All new seals and everything are going in, I remember reading a while back that the C8.25 used a crush washer or something on the pinion making it a PIA to change the seal.  

about the same chances as winning the lottery. 

[ghetdjc320]

If the 8.25 uses a crush sleeve design than you will have to set you pinion depth using a new crush sleeve. There is a lot of input on this thread so here is my $.02 and I’m sure the rest will provide valuable input. If you are only doing the carrier than you should only have to deal with backlash and preload. If the carrier already has the shims inside of the bearings than you are going to need several special tools aside from just a dial indicator. You will not hit the right pattern using the shims from another axle. That being said, I’ve seen many poorly installed gear setups where they do just that. As for people seeing different version of where the shims go, factory d30 HP will be inboard of the bearings “if done correctly”. Factory d44 with no locker just open carrier will also be inboard of the bearings “if done correctly”. D35 will be outboard “if done correctly”. I do not know where they should be on a 8.25. You will sometimes see shims places on the inside AND outside of a carrier. In those cases, the outside shims are normally just for preload. I have also seen very loose carriers with almost zero preload that almost fall out of the housing. Aftermarket or non-open carriers will have their own requirements which should be followed. Case spreaders are used on occasion to install preload shims outside the bearings. There should be no need to use one to set only your backlash. You can also permanently damage the case with them if you are not careful. You should keep your dial indicator on the case to know how far you are spreading it. 

[ghetdjc320]

14 minutes ago, ghetdjc320 said:

about the same chances as winning the lottery. 

Also, you don’t need to pull the pinion to replace the seal

[Smokeyyank]

Honestly find someone to do it on the side or to help you out if cost is the deterrent. Gears are one of those things that takes a knowing touch and you run the chances of fn it up and having to replace a lot more. 

[Dzimm]

48 minutes ago, ghetdjc320 said:

Also, you don’t need to pull the pinion to replace the seal

How do you replace the pinion seal without pulling the pinion?  I don't see how that's possible.

[ghetdjc320]

It can be done in your driveway or in the trail. I’ve done it in the driveway before in about 10-15minutes. Remove the driveshaft, remove the yoke nut and yoke. Use a chisel or flat head screw driver and a hammer and knock loose the lip of the seal. Pull it out and replace. You may have a splined rubber washer that will need to be replaced as well. 

 

[ghetdjc320]

38 minutes ago, Smokeyyank said:

Honestly find someone to do it on the side or to help you out if cost is the deterrent. Gears are one of those things that takes a knowing touch and you run the chances of fn it up and having to replace a lot more. 

Agreed. An engine overhaul is easier than gears if it’s your first time (at least it was to me). Once you wrap your head arround everything that is needed though it’s not too bad. Same goes for transmissions. You just have to think in 3D when it comes to gears lol

[Dzimm]

35 minutes ago, ghetdjc320 said:

It can be done in your driveway or in the trail. I’ve done it in the driveway before in about 10-15minutes. Remove the driveshaft, remove the yoke nut and yoke. Use a chisel or flat head screw driver and a hammer and knock loose the lip of the seal. Pull it out and replace. You may have a splined rubber washer that will need to be replaced as well. 

 

Oh yeah I misunderstood what you said.  I thought you meant without removing the yoke.  

[Dzimm]

So the only shims in the C8.25 are between the pinion and pinion bearing.  The carrier has adjusters that require a tool that goes in through the axle tube to adjust the preload.  It looks to be pretty darn simple to do.  Especially since I won't be messing with the pinion aside from the seal.  I suppose though with a new carrier, would you need to reset the pinion depth?

 

I'd be looking at $60 to get a dial indicator and the preload tool.  

[ghetdjc320]

You shouldn’t need to reset pinion depth unless it wasn’t right from the get go. This would be the time to replace the pinion and carrier bearings though but it sounds like that is not a feasible option at this point. That’s neat that it has the adjusters. Similar setup to a ford 9”