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Unread 09-03-2011, 09:38 PM   #1
DoozerPeej
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D30 gearing?

Okay so I am sure there are a ton of threads but instead of bringing up an old post, I figured I would start a new one so I can have recent build experience and trail experience. I am wanting to build up my Dana 30 HP and I am thinking of gearing while I am at it. My question is, I have 3.07 gearing now but I am wanting to go to 4.88. Am I correct in that I will need to get a new carrier? because the 3.73 and up (numerically) have a different carrier than the ratios below it? Also will a rebuild kit (carrier bearings, pinion bearings, pinion seal) for the 3.07 gears work with a 4.88 gearing? or will I have to get bearings for the new ratio. I am also planning on building a ford 8.8 for the rear. I know they come in 4.10 gears, so if I get one with that gearing I wouldn't have to replace the carrier for the new 4.88 right? any input, advice, pro's and con's would be great. Its 90% a trail rig but nothing crazy hard. I have 33"s and the 4.2 with the ax15/np231 combo.

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Unread 09-03-2011, 10:28 PM   #2
timatoe
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Yes new carrier for 3.73 and up, bearings, seal etc. are the same. The 8.8 doesn't have a carrier break.
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Unread 09-03-2011, 10:46 PM   #3
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If you are going with the 8.8 Ford Explorer axle (with disc brakes I hope) why don't you find a HP Dana 30 out of a Cherokee with a 4 cylinder engine (at your local junkyard) so you won't have to re-gear anything for a while. It will give you 4.10/4.11 gears, and stronger axles and minimal cost.

Just a thought.
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Unread 09-03-2011, 10:56 PM   #4
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HP30... just don't forget the GEARS themselvs are different (reverse rotation) compared to a low pinion. Carriers (and lockers), install kits, seals, etc. all can be used in either low or high pinion. Carrier DOES need to be changed to go 3.73 or higher if original were 3.07. And best suggestion so far is bolt in a 4 cyl HP30 that HAS 4.10 already, and install the 8.8 that you bought WITH 4.10s in it.

I have an uto TJ Sport, 35s and 4.88s. 4.10s will do quite nicely with the 33s and a stick. you don't really need 4.88s, and should consider whether the slight difference is worth the cost of regearing both axles over what you can simply buy them with. Add at least 1000 bucks to regear. Why not save that money, or better yet spend it on lockers or RCV shafts?
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Unread 09-03-2011, 11:04 PM   #5
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Quote:
Originally Posted by DoozerPeej View Post
Okay so I am sure there are a ton of threads but instead of bringing up an old post, I figured I would start a new one so I can have recent build experience and trail experience. I am wanting to build up my Dana 30 HP and I am thinking of gearing while I am at it. My question is, I have 3.07 gearing now but I am wanting to go to 4.88. Am I correct in that I will need to get a new carrier? because the 3.73 and up (numerically) have a different carrier than the ratios below it? Also will a rebuild kit (carrier bearings, pinion bearings, pinion seal) for the 3.07 gears work with a 4.88 gearing? or will I have to get bearings for the new ratio. I am also planning on building a ford 8.8 for the rear. I know they come in 4.10 gears, so if I get one with that gearing I wouldn't have to replace the carrier for the new 4.88 right? any input, advice, pro's and con's would be great. Its 90% a trail rig but nothing crazy hard. I have 33"s and the 4.2 with the ax15/np231 combo.

I got an 8.8 with 4.10 and then found a d30 out of a 95 yj with 4.11's which is a HP and is a direct bolt in. my jeep was 3.55 stock and 4.10 with 33 puts me almost back to stock rpm band. so i think 4.88 is way overkill unless you are going to go with bigger tires in the future. you going from 3.07 to 4.10 with 33's is going to be very noticeable.
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Unread 09-04-2011, 02:31 AM   #6
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Originally Posted by 4x4grey88 View Post
If you are going with the 8.8 Ford Explorer axle (with disc brakes I hope) why don't you find a HP Dana 30 out of a Cherokee with a 4 cylinder engine (at your local junkyard) so you won't have to re-gear anything for a while. It will give you 4.10/4.11 gears, and stronger axles and minimal cost.

Just a thought.
just an opinion here but if you go this route then you will have an entire axle assembly rotting on the side of your house. its awful and if you stick it there "for now" it will be there for years. 4.10:1 with 33s suck. it might be fine for the highway but offroad it will be a pain. i know a lot of guys on here use that combo but i think its mostly out of convenience, like suggested here, then what is really desired. how will the axle shafts be stronger? if you are actually referring to the "larger" ujoints i have always disagreed with this assumption. ive seen way too many of both break to definitively say one will survive better then another. all of the 30 shafts i broke were at the splines and never did wreck a ujoint (smaller ones.)

why do so many people "fear the regear?" its not rocket science and can be done by your average garage tinkerer or easily taken to someone else.
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Unread 09-04-2011, 09:26 AM   #7
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Quote:
Originally Posted by 4x4grey88 View Post
If you are going with the 8.8 Ford Explorer axle (with disc brakes I hope) why don't you find a HP Dana 30 out of a Cherokee with a 4 cylinder engine (at your local junkyard) so you won't have to re-gear anything for a while. It will give you 4.10/4.11 gears, and stronger axles and minimal cost.

Just a thought.
YJ's come with HP30's.
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How about this, if you had the Jeep Spirit, you wouldn't abuse the rest of us trying to enjoy a nice day out wheeling by bringing your brokeass broken down junkyard crap out to play where it can't handle it?
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Unread 09-04-2011, 10:38 AM   #8
timatoe
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Originally Posted by jeepinmichguy_ View Post
YJ's come with HP30's.
Yeh, I was a little confused by that entire post.
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Unread 09-04-2011, 10:42 AM   #9
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Yeh, I was a little confused by that entire post.
Most TJ guys don't know any better.
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Jeepinmichguy is a jerk.
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How about this, if you had the Jeep Spirit, you wouldn't abuse the rest of us trying to enjoy a nice day out wheeling by bringing your brokeass broken down junkyard crap out to play where it can't handle it?
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you all have nice rigs, stop being f****** a**holes.
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Unread 09-04-2011, 10:48 AM   #10
DoozerPeej
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Well I am a mechanic so its only the cost of parts, labor is free. The only reason I was thinking of going to 4.88 is because its the lowest gearing the HP30 can go, and like I said its a trail rig so the speeds on the street don't matter. Do all cherokees with the HP30 and 4 cylinder have 4.11 gearing? I haven't looked into how much a 3.73 carrier costs, but would it be worth the time to save the money and get one a 4.11 carrier from a junkyard?
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Unread 09-04-2011, 11:06 AM   #11
Joe Dillard
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Quote:
Originally Posted by DoozerPeej View Post
Well I am a mechanic so its only the cost of parts, labor is free. The only reason I was thinking of going to 4.88 is because its the lowest gearing the HP30 can go, and like I said its a trail rig so the speeds on the street don't matter. Do all cherokees with the HP30 and 4 cylinder have 4.11 gearing? I haven't looked into how much a 3.73 carrier costs, but would it be worth the time to save the money and get one a 4.11 carrier from a junkyard?
How about we backtrack just slightly?

Are you willing to pull a HPD30 from an XJ, then cut off the passenger side upper control arm mount (the driver side upper control arm mount is cast into the top of the housing, so generally you'd leave it there).

Then remove all the lower control arm mounts.

Remove the coil buckets.

Weld on new shock mounts (the XJ shock mounts are in a bad location to use with a leaf sprung YJ).

Weld on new spring perches and set the pinion angle correctly.

Migrate your YJ steering over to the XJ axle.

Do away with the YJ's stock tracbar and swaybar since the XJ uses a different set-up.

More than likely you can reuse your old spring plates (but weld closed some of the holes for the ubolts & redrill new holes where necessary) but get new ubolts & tall nuts since the XJ housing doesn't have the vacuum disco system if you get the right one. With an XJ housing, not all of your ubolts are the same size as the YJ's.

These are the minumum items you'd need to deal with if you swapped the "correct" non-disco XJ HPD30 housing that already has the gears you want.

If you are not willing to do all of what I mentioned above - then maybe get a YJ HPD30 from a 4cyl 5 speed & it'll have 4.10's from the factory & you won't have to deal with what I listed above.
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Unread 09-04-2011, 11:29 AM   #12
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Quote:
Originally Posted by Joe Dillard View Post
How about we backtrack just slightly?

Are you willing to pull a HPD30 from an XJ, then cut off the passenger side upper control arm mount (the driver side upper control arm mount is cast into the top of the housing, so generally you'd leave it there).

Then remove all the lower control arm mounts.

Remove the coil buckets.

Weld on new shock mounts (the XJ shock mounts are in a bad location to use with a leaf sprung YJ).

Weld on new spring perches and set the pinion angle correctly.

Migrate your YJ steering over to the XJ axle.

Do away with the YJ's stock tracbar and swaybar since the XJ uses a different set-up.

More than likely you can reuse your old spring plates (but weld closed some of the holes for the ubolts & redrill new holes where necessary) but get new ubolts & tall nuts since the XJ housing doesn't have the vacuum disco system if you get the right one. With an XJ housing, not all of your ubolts are the same size as the YJ's.

These are the minumum items you'd need to deal with if you swapped the "correct" non-disco XJ HPD30 housing that already has the gears you want.

If you are not willing to do all of what I mentioned above - then maybe get a YJ HPD30 from a 4cyl 5 speed & it'll have 4.10's from the factory & you won't have to deal with what I listed above.
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Jeepinmichguy is a jerk.
Quote:
Originally Posted by mrblaine View Post
How about this, if you had the Jeep Spirit, you wouldn't abuse the rest of us trying to enjoy a nice day out wheeling by bringing your brokeass broken down junkyard crap out to play where it can't handle it?
Quote:
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you all have nice rigs, stop being f****** a**holes.
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Unread 09-04-2011, 01:40 PM   #13
DoozerPeej
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I was meaning take the carrier out of the housing, I already have tj shafts in so I don't have the disconnect axles. If you read my post I was only talking about taking the carrier out of junkyard XJ
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Unread 09-04-2011, 01:52 PM   #14
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carriers are like $60.00 new. totally not worth pulling from a yard.
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Unread 09-04-2011, 06:41 PM   #15
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not when you can get a yj 4.11 axle that will bolt in directly and have the same thing... run the 8.8 with 4.10's while you gather parts for the 4.88 regear if you feel that you need it..

if you can live with it then your mission is complete without much work at all and you most likely have extra shafts/brake parts/etc left off of the old stock axle.
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