How do I install gears?

I just got a quote of $425 from one shop in bloomingdale to go from 3.27s to 3.55s in a ford 8.8 (I know i should do 4.56s but I cant afford to do both and I need to match my D30). Another shop up the road said it would probably be between $250-$350. This is all if I supply the gears and rebuild kit.

I am figuring If I get a caliper/micromiter, a good straight edge, and a book I can probably figure out how to do it on my own. Even if I bust one set of gears and go through two or three crush sleeves I will not spend $425.

I am open to sugestions or somone that knows what they are doing and lives in northern NJ/hudson valley, NY area, that is up for a project one day.

Why not go 3.73 in the D30?

I've been though a similar ordeal with gears before when I had my Detroit installed, I guy my buddy worked with said he could do it for $200, vs $450 at the local 4wd shop, figured what the hell, why not. Bad idea, after installing them wrong twice, and ruining my gears and front hubs, I had to buy another set of gears and hubs, and have the same local 4wd shop install them, end cost: $1500 vs $725 if I wouls have just took it to the pro's.

I'm not saying not to try it, but make sure you have someone who has experiance with setting up gears with you to slap you up-side the head if your doing it wrong.

because the ford is a 3.27, not a 3.73. dont know how it happened but I got the one that came out of an xlt explorer with all the option but had a 3.27 ratio and an open carrier. I am stuck with it now so I figure it is best to just regear the thing and go. I dont do anything too extreme anyway. RC black obsticles has been my limit with the D35 and 33s, all open. ( I now have a bent tube on the D35 so I am guessing it wont survive another trip to RC.)

This whole jeep has been a project to see what I can do so I am not afraid to give it a shot and see what happens but I just want as much info up front as I can get.

good luck, i guess everyone has got to ruin one axle first before you realize you cant do it yourself without proper knowledge.



i did

That is where the book comes in. I have rebuilt every other aspect of a vehicle including an automatic trans so how difficult can it be?

Ill be honest, the trans took two tries but I was linking a 700 R4 to a np231

Kevinma255 said:

because the ford is a 3.27, not a 3.73. dont know how it happened but I got the one that came out of an xlt explorer with all the option but had a 3.27 ratio and an open carrier. I am stuck with it now so I figure it is best to just regear the thing and go. I dont do anything too extreme anyway. RC black obsticles has been my limit with the D35 and 33s, all open. ( I now have a bent tube on the D35 so I am guessing it wont survive another trip to RC.)

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Ah, my bad I guess I can't read today. I was under the empression the Explorers only came with 3.73 and 4.10 gears, didn't know about the 3.27s.

Kevinma255 said:

This whole jeep has been a project to see what I can do so I am not afraid to give it a shot and see what happens but I just want as much info up front as I can get.

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I'm doing the same with my Jeep right now, To this point, I've done or had help on everything I've don't to my Jeep with the exeption of the gears and Detroit, and a few electronics bugs, including rebuilding my junkyard D44 with all new bearings, but original carrier and gears(for now). My next thing I would like to learn is how to set up gears, help cut labor costs out with the exepion of a case of beer or so.

yeah, I got the code of the door tag and it showed a #41 that should have had 3.73 and of course the junker was in a position that I could not get under it to verify a tag so by the time I got to the tag and saw 3.27/open it was too late. This came from a impound/ junk yard so they had to pull it and I was not there when the did. once it was pulled it was mine so I have to work with what I have.

You will also need a dial indicator with a magnetic base, a press, and bearing pullers to setup your gears. That and alot of patience. Also technicalvideos.com has comprehensive dvds specifically for setting up gears, which helped me alot. Good luck!

thanks, I am good on everything except the dial indicator. thanks for directing me to the videos. that is the kind of info I need. thanks again

Go for it. You ain't gonna learn any younger. Like "downhillracer" said patienceis key. Don't get in a hurry,gather as much info as you can. You'll then have a skill many don't. :thumbup:

http://www.pirate4x4.com/tech/
if you think installing gears is something easy enough to be explained for you in your own thread, think again! you got research to do...

It's honestly not that bad, especially if you've been in some auto trans. I mean there's only 4 bearings in the area you're dealing with, to put it in perspective.

8.8's are very easy. Best bet is to find the aftermarket adjustable carrier bearing shims. The factory ones are thick hardened steel in many different thicknesses. The good aftermarket part is two machined halves that lock together with thin shims in the middle. Not sure where to find them but most Ford install kits have no carrier shims, leaving several trips to the dealer to finish setup.

Put an .031" pinion shim in and you'll be very close, but leave the crush sleeve out and use the old nut until you're happy with the pinion depth. Post pictures up for a critique of the pattern. Never run a pattern unless the backlash is in spec or you're wasting your time.

Backlash moves about 2/3 of the side to side adjustment. Say you had zero backlash and zero preload, where a firm push seats the carrier. Subtracting .010 from the ring gear side and adding it to the other side would net about .006" backlash. Or, if your backlash was a little out of spec and you still had no preload, you could fix it by adding to one side only, bringing in preload while opening or closing the lash. I like about .006" total preload.

JJacobs said:

Best bet is to find the aftermarket adjustable carrier bearing shims.

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These come in the Yukon master rebuild kit. I just finished my second 8.8. One in my full size Bronco and one for my XJ.

As for pinion setup bearings, a drill press, brake cylinder hone, oil and time will produce a pretty good set.
Hint: grind out the center of the bearing surface so you don't have to hone as much.

I had somone sugest just running the 3.27 in back and 3.55 up front. From my knowledge that equals a broken drive shaft or a fried np231. their theory was for off road speeds it would not be enough of a differance to matter.

it is a stupid question but I will ask anyway. running difrent ratios, even that close is not an option, right?

you can run up to about a 2% difference with no hiccups from the driveshafts or t case. running different ratios like that is not only dumb, but pointless. it will matter, even at "offroad" speeds

so if you have 4.11 and 4.10 or 3.54 and 3.55.... stuff like that. but not 2 completely different ratios.

unless you want to run different sized tires

i did it by myself for the first time ever about 5 months ago....i had no problems and i didnt use all the measurers and stuff....the only thing i did do was take the pinion and gears in to have the bearings pressed on....i think the whole job took me about 3 days...but i was dealing with rusted on axles, and other repairs too..its really not hard if you just take your time and DO YOUR RESEARCH...my 4.10s work like a charm too...but i cant stress enough...take your time and do your research, you will be fine and save some cash..