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Gear Swap on D30, Necessary in D35?

HttpWayne

NAXJA Forum User
Location
Auburndale, FL
I turned my 2WD XJ into 4WD. The axle I got for the front had obviously leaked gear oil in its previous life.
I've been driving it for a while, and now when I slow down (as in let off the gas.. when I brake it only does it for a short period and then stops) at speeds above 30 MPH I can hear coarse vibrations/grinding. The faster I'm going the louder and faster the vibration/grinding as I start to slow down.

I was told I might want to regear. So I've been looking around and learning about how the gears work and what's actually in the diff. My plan is to move up to a 4.11 in the front and rear. I'm going to replace EVERYTHING in the front axle, but the rear should be fine.. shouldn't it. ?? I haven't had the drive shaft connected to the front since I got it. I figured I was going to replace the gears anyways, and when I got the axle I just assumed they were 3.55 since only the towing package would have had the 3.73 since he had the AW4 transmission (his was a '97, mine is a '98 Limited). I didn't want to ruin the gears/T-Case.

So my plan was to buy all new gears for the diff with the case and a master install kit for the front AND the rear; but can I get away with just the front and change only the ring and pinion in the rear? Or am I missing something. I've been looking at the links posted about gears, but 85% of it is just people talking and I'm following links and getting sidetracked because I have ADD. So I'm just going to post this now and wait for a response while I jump back in the rabbit hole that is the 'internet' .

Thank You.

Wayne P.~

(1998 XJ Ltd, 33x12.50, 6.5" RC suspension, 4.6 Stroker, Pending gears and D35 super axles)
 
if your regearing, you want the master install kit. thats, that.

but first, i would try to identify the problem in the front. seems it would be cheaper to just get a new axle than to replace EVERYTHING in the housing. maybe the housing itself is the problem! with 33s and the stroker though, why are you keeping the 35? are you trying to keep your ABS?

if not... ill beat everyone to it and say ditch it. get yourself an 8.25 and gear it. (you may be able to find one already with 4.10s cheaper than regearing! use car-parts.com to look up JYs in your area) also note, if your 30 has 3.55s and your going to 4.10s you will need the proper 3.73 and up carrier.
 
So it might not even be the gears at all? I thought that sound was the gears grinding into each other for sure. So a Ford 8.8 is a direct swap? I got the super 35 because it was easier. This vehicle is my only way to get around, and I can't dismantle it unless someone lets me use their property because I don't live in a house. So I'm not going to return it. Plenty of others on here use the 35 with my size tire, some even larger than mine. I'm sure they're more adventurous than me and they get by.

I forgot to mention I got a lockrite locker for it as well. Probably not the best idea. But I'm not a serious off-roader like some of you. I haven't had this thing running in 4wd since the conversion (or before for that matter) and that was 7 months ago.

Maybe one day in the future when I own my own house, have a second vehicle and a yard I'll start doing my own mods and doing more extensive ones. For now I keep it simple.

I'm not paying a mechanic to pull my axle apart to 'find' out what the problem is, then ordering parts and leaving it there until they arrive, then paying for storage fees and being without transportation for 2 weeks. I had been planning on swapping all this out anyways.

Can you explain to me how it would be the axle though and not anything in diff? I don't get that. I thought everything was transferred FROM the axle to the wheels when accelerating, and FROM the axles to the diff when decel... meaning that if I decel and hear noises that it must be the gears inside the diff. I don't see how it could be the axle since there isn't even any torque being applied to it from the diff in the first place (no driveshaft connected). Therefore... (based off my keen newb logic, aka KNL) as I slow the tires slow, causing the axle to slow, causing the diff gears to slow. That's the end of the line, therefore the gears in the diff absorb the shock. And the sound wasn't there for the first 2 months. Then gradually over time it came to life and has gotten worse. It's pretty much at a stand still now though. If it was the axle wouldn't I heard it regardless of speeing up and slowing down?
 
if your regearing, you want the master install kit. thats, that.

but first, i would try to identify the problem in the front. seems it would be cheaper to just get a new axle than to replace EVERYTHING in the housing. maybe the housing itself is the problem! with 33s and the stroker though, why are you keeping the 35? are you trying to keep your ABS?

if not... ill beat everyone to it and say ditch it. get yourself an 8.25 and gear it. (you may be able to find one already with 4.10s cheaper than regearing! use car-parts.com to look up JYs in your area) also note, if your 30 has 3.55s and your going to 4.10s you will need the proper 3.73 and up carrier.

I am also aware of my carrier situation.
 
I got the super 35 because it was easier.

You seem to be missing the bigger picture. You want to install a super 35 kit, right? That means new carrier (Detroit locker) and new shafts. You will need new bearings too. Period. Your current open carrier in the D35 will NOT accept the 30-spline super 35 shafts. You are going to have to have the gears setup again anyway, so get them done right the first time.

As for the front, I agree with what VAhasnoWAVES said. Identify the problem and then fix it. It's far better and cheaper to fix it right the first time than to cut corners and just throw random parts at it. You said the front axle leaks, are you sure there's still gear oil in it? A little investigation goes a long way.
 
No, an 8.8 is not a direct swap, you would have to weld on leaf spring perches and shock mounts. RuffStuff makes a kit.

I would NOT spend money on the D35. You should be able to locate an 8.25 in the lower gearing cheaper than building up that D35.

You say you haven't had the front DS attached--that makes me think you could have axle u-joints or unit bearing issues up front.
 
Swapping the 35 out for an 8.25 will be easier and faster than installing the super 35 kit. An 8.25 is a direct swap. Sure, som epeople run a 35 with no problems, but the likeliood of sudden and spontaneous destruction is too high to risk it, especially if you're spending close to $1000 on it. I bought my rear D44, already built with Detroit, alloys, discs, and raised shock mounts for $1000 off a member on here.
 
You seem to be missing the bigger picture. You want to install a super 35 kit, right? That means new carrier (Detroit locker) and new shafts. You will need new bearings too. Period. Your current open carrier in the D35 will NOT accept the 30-spline super 35 shafts. You are going to have to have the gears setup again anyway, so get them done right the first time.

As for the front, I agree with what VAhasnoWAVES said. Identify the problem and then fix it. It's far better and cheaper to fix it right the first time than to cut corners and just throw random parts at it. You said the front axle leaks, are you sure there's still gear oil in it? A little investigation goes a long way.

When I was swapping out the front axles I had a certified GM mechanic, ASE as well, tell me that I would need to replace the axle seals. I then looked at what he was pointing out on the end of the axle housing/brakes/rim. There was built up gunk on the passenger side covering it that had obviously been leaking for what looked like at least a year. This came of a cherokee that had been in a collision from the side and had been sitting in someone's yard for about a year.
At that point I knew already I was going to regear, but didn't know what regearing entailed, so I shrugged it off.
The S-35 axles I got are direct replacements from Rocky-Road. They fit where my OEM axles fit, so if I break one I can put the stock in. Or vice versa. I did my research on the axle in advance.
 
If you had researched the axle itself, you would've bought an 8.25 and saved some money...;)
 
Seriously man, if the stuff isn't installed yet, pay the return shipping and get a new rear. I know it wasn't the plan but there on people on this forum that know way more about XJ's than a GM/ASE mechanic. The D35 is a well know horrible weak link, it will break in future, especially with a 4.6 Stroker in front of it. If you are trying to build it right the first time and you are asking for advice; take the advice. These people aren't trying to argue with you over optional mods that don't matter, they are trying to sway your opinion and lead you in the right direction. This is the best advice I can give you.
 
Just went and looked at Rocky Road's "Super 35" kit--he is going to have a locker in a D35 with 27 spline axles.

The word is "grenaded". Not a question of "if", but "when".
 
ya... 27 spline isnt a "super" kit. the only shaft worthy of being called "Super" for the 35 is from superior ring and pinion, and its 30 spline. but the term "super 35" is kind of an oxymoron. sounds to me like they just gave the term to a set of fancy aftermarket shafts.


now, to the OP:
im not going to tell you "ditch the turdy!!!!! itll esplode!!!!!" but common knowledge is that yes, they break. its not a matter of if but when as joe said. if your compitent in changing shafts and dont mind bringing spares... by all means do so. but personally i wouldnt trust anything more than a LSD in a 35. a lot of TJ guys run them, it can be done. but the info people are trying to give you is that you could save yourself hassle down the road, and have a bit of piece of mind by swapping to a 29 spline 8.25. its factory bolt in, and as i posted earlier... you may even be able to find one already geared to 4.10. if you have and are wanting to keep ABS, then i understand that. but if you dont, there is no reason not to do the swap. John D's 8.25 has help up to his 5.3L powered XJ on 35s (to my knowledge). and there are many similar stories.

and if you DO keep the 35... might i suggest a LSD in the rear and a selectable locker in the front? you already have the shafts at a stock spline count, they will work fine. and you will need gears reset when istalling the LSD, its a much better option. especially if being powered by a stroker.
 
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4.6L, a lock right, 33's and a D35.:cheers:
 
But.. I still have faith in the D35. It hasn't failed me yet. They ARE still in the box... I'll see if they take returns next week. So what does spline count have to do with strength?
And what carries an 8.25... the Sebring?
 
I have found a Chr. 8.25 in my area via car-parts.com. Does $450 sound reasonable?

Do they come with 4.10 or 4.11? Because it shows that there are two in the same junkyard, one is 4.10 and one is 4.11. Is that just a typo or DO they come in both. ??

And what does "Part Grade 'A' " mean? The 4.11 has A. I've listed their descriptions down below:

1. 1995 Jeep Cherokee, 4.11NL REAR AXLE ASSY. CHRYSLER (60,000 miles) $450
2. 1995 Jeep Cherokee, 4.10NL CHRYSLER TYPE (no miles) $450
 
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