swap in a 27 spline 8.25 or 8.8?

[obaa-xj]

XJ: '90 2 door, 4.0, AX-15, 231, slip-yoke driveshaft, 32's, Tomken 4" lift with 3" shackles; probably 4" total lift after sagging (5 yrs old). WJ brake master/booster upgrade

My D35 sounds like it is ready to give up the ghost. The thrumming sound it makes under load is getting louder, and it is starting to make a grinding noise while coasting under no load. I'm pretty sure it is the diff, as the lift has been on for 4-5 years with no noise (so I don't think an angle issue), and I replaced the ujoints (the originals seemed fine).

Like everyone else, $$$ is tight right now. Actually, very tight. But I need to fix it before I get stranded, as I need this rig daily for work. My choices seem to be:
1) rebuilt/regear current diff: I'm pretty much ruling this out, as the shop I trust wants $600 for the work, and I don't want to put that into a D35.
2) swap in a 8.25: I could do this swap myself in a weekend, and I have found 8.25s with the right gears locally, but they are all 27 spline
3) swap in a 8.8: I can also find 8.8's with the right gears locally as well. I can get the brakes working. I can't do the welding for the springs/shocks/tubes, and I don't know if driveshaft length will be an issue with the pinion adaptor.
4) swap in a D44: can't find any of these locally, and couldn't afford the gear swap on top of that.

My choices seem limited to the 8.25 or 8.8. Eventually, I'd like to get a LSD or locker. Based on my current (non)braking performance, I'd like to get some rear discs on it as well. My questions are:
1) If I get the 8.25 (easiest/cheapest), are there any lsd/locker options for the 27 spline (I've only seen them for the 29 spline). If I switch to 29 spline axles, can I do it with a locker upgrade, and avoid paying to re-set the gears? I know there will be an added cost to ugrade the brakes, but that can also be done down the line.
2) If I get the 8.8, I'd get the brake upgrade for free. However, I can't do the fab work to get it mounted. The shop I trust is willing to do the fab work for a reasonable price, but they want to install it also (understandable), and will need to have the truck for 2-3 days (I can't afford that). Also, they think the driveshaft might be too long (I have ~1.25" engage of the slip yoke with the current lift), and that the shorter line will cause greater angles, forcing me to go to a SYE/CV shaft. That's too much $$$$.

If the driveshaft length is okay, maybe I can find someone to carefully take measurements and fab up the 8.8. Is that possible, to setup it without having to trial/error testfit it? What are my best options and alternatives?

Thanks!

 

[bails85]

the 8.25 is a very decent axle. most of the people who go 8.8 including my self go for it because of the stock disk brakes. wleding on the new perches isnt hard at all but the driveshaft would be sumthing to consider upgrading. ive never heard of anyone putting in an 8.8 and not adding a sye and a cv shaft. i have a few friends that run 8.25s and never really a problem. its alot cheaper that doing the 8.8 conversion. and the 8.25 is probably a very easy find at the junk yard. but i have heard of a 8.25 disk brake conversion just got to search for it. if it were me id go 8.25. if u had a few more bucks go 8.8. but either one is fine for most off roading

 

[kastein]

How much are you paying for the 8.25? If it is sub $100 I would go for it, toss it in and run it while you prep for an 8.8 or a 29 spline upgrade to the 8.25. You can bolt it in in an afternoon and drive to work the next day. You know it'll fit and work right. You can also sell it after you're done with it, probably for the same amount you paid for it. Bolt-in axles in good shape are pretty fungible

The best way to set the 8.8 up is to get the SYE installed, remove the old axle, put the 8.8 under the jeep with the perches sitting in the right places but not welded in, turn the pinion up or down till it is angled right, tack the perches on, tack the shock mounts on where they need to be, figure out how much to get added or removed from the driveshaft, yank the axle and driveshaft back out, and get everything fully welded all at the same time. It probably is a multi day process unless you find someone in your local area (check the NWC subforum) who has a welder and is willing to help out.

 

[dasbulliwagen]

If you want to go with something that needs welded and feel secure enough in your own fab skills to do everything but that, there are guys in most areas that have portable welding setups mounted in the back of a truck that will come right to you, and weld what you need welded for a very reasonable price. I had this done once on a VW of mine where I needed the front trans mount welded in place. Guy was real nice, welds looked great, and I think it cost me $20-$30 bucks. If you can get your new axle ready with perches set where you want, and shock mounts where you want them, and then call the guy, it really wouldnt take long to do the job, and youd be ready to ride, and your truck never leaves the house! Just search the yellow pages, and ask around, see what you can find.

 

[Darky]

Just do the 8.25. It's plenty strong for 32s. I ran one, welded on 30s for a year, and then about another 6 months on 33s. Took it wheeling, had a good time with it. I never worried about it except for the welded spiders, which the weld did break once. The axle was never a problem though.

Doing a 29 spline upgrade would be easy, just shafts and a carrier (full case locker would count as the carrier). There are numerous options for disk brake upgrades: Crown Vic, Liberty, ZJ, and a couple specific kits. You may also try running better pads in the mean time and see if that brings about the improvement you're looking for.

 

[kastein]

You also need the spiders to swap to 29 spline after the fact, and you do have to reset the carrier preload and pinion backlash, but fortunately the 8.25 has side adjusters and the pinion will still be at the right depth so this is really not as difficult as it would be with another axle. You'd have to do all that if you installed a full case locker anyways.

 

[joshdbrooks]

Probably gonna be the least popular reply, but if you've been wheelin on your D35 for 5 years with no issues, i'd slap another D35 in it. I can buy D35's all day from $0-$50. You're only running 32's, and unless your really hammering on it, another D35 will probably last you until you can afford to get what you want (i.e. disc brakes, 8.8/ or 8.25). And it'll bolt in about 20 minutes.

 

[twodoorXJ]

I was in a similar situation as you last year, i had a d35, and wanted to go to 33s and wheel it hard. I weighed the pros and cons of each axle, but i knew i wanted to go to 35s one day and i wanted my rear axle to be ready for it. I say if you dont plan on going above 33s then the 3.25 will be more than good for your needs.

 

[Darky]

Probably gonna be the least popular reply, but if you've been wheelin on your D35 for 5 years with no issues, i'd slap another D35 in it. I can buy D35's all day from $0-$50. You're only running 32's, and unless your really hammering on it, another D35 will probably last you until you can afford to get what you want (i.e. disc brakes, 8.8/ or 8.25). And it'll bolt in about 20 minutes.

Or since it sounds like he can afford to get another axle right now, get the 8.25 instead of spending more time and money on the 35 that will need to go at some point.

 

[90Pioneer]

I have abused the hell out of my 27 spline 8.25 running 33s, LSD, and 4.56 gears. Never had any problems with it.

My dana 30 on the other had has sheered teeth of the ring gear two different times.

 

[joshdbrooks]

Or since it sounds like he can afford to get another axle right now, get the 8.25 instead of spending more time and money on the 35 that will need to go at some point.

"...$$$ is tight right now. Actually, very tight."


I guess it didn't sound, to me, like he could really afford to get the complete upgrade he would prefer. I don't know what it's like in his area, but I can buy D35 on Craigslist for next to nothing.

 

[Rmart30]

if i in your situation and havent broken the 35 yet but could find a 8.25 for $100 or under id go for it but I would not turn down a $50 D35 either to get ya back going.

Around here you can find Dana 35's for $50 and 8.25's for under $100

 

[kastein]

I'd buy the 8.25 and keep it in reserve till the 35 actually shits the bed.

Hell, put it, new ubolts, tools, and brake bleeding materials in the back and swap it out right where it croaks.

 

[Boneless-Jeeper]

Man, if youve got a pull a part in your area go for whichever you choose as each axle is is like 70 bucks with out brakes and prolly like just shy of 110 with brakes .I was recently at the pull-a-part in arlington and there was maybe 2 yeeps with an 8.25 and the lot was littered with posi/disc 8.8's but overall and 8.8 is stronger if you wanna be mean and lock it up itll handle it better but if your gonna lock it with 32's id just go with and 8.25 as it just XXXXin bolts in . and not to thread jack but does anyone know if i can bolt disc brakes onto a drum 8.8 ?

 

[obaa-xj]

Thanks for all the suggestions. I spent the weekend crawling around u-pull-its, but could not find any diffs with the right gears. They were charging $140+ for a bare rear axle. With the cost of a setup, I'm better off buying an axle from a salvage yard with the correct gears already, even though they'll charge more. Are the prices they quote negotiable? If so, how do you bargain with them, as most of staff seem pretty surly....

 

[rweaver138]

They were charging $140+ for a bare rear axle.

:scared:

what a rip

 

[obaa-xj]

It was $145 w/o drums, $164 w/drums. Probably not that bad if I needed a bunch of other small things, as they usually let those with it, but I only need the axle.

An 8.25 should be a direct swap, right? No new brakelines, driveline, ubolts, etc.?

 

[kastein]

Brake lines - do em new no matter what. Cleaner, easier, and safer. EDIT: sorry I misunderstood. Rubber brake line you can keep, it's the same one, the steel brake lines on the axle tubes are axle specific though. Hopefully you'll get them with the axle - in fact I usually take a pair of wire cutters to the rubber hose when I pull an axle.

Driveline - if you have more than 3-4" of lift your old d35 driveline will fit fine, according to some math and general polling we did a while ago.

Ubolts - you will need new ones. Expect to spend about 50 bucks on ones from ruffstuff (you will NEVER break these bolts), 25 for semi sketchy ones from autozone, 40-50 from a local spring rebuilder/truck shop.

I sometimes get axles for 100 still around here, because I buy a bunch of stuff pretty frequently (well, used to) so the counter guys know me by name, but usually I end up paying 130-140 for an axle with everything still on it. That means brakes and half a driveline for a rearend or brakes and steering for a frontend.

What gears do you have? 3.55s are easy to find, 3.73s somewhat less, 4.10s not that hard depending on the locale (difficult-ish around here, easy in the south/southwest), 4.56s are rare as hell. That's all for stock XJ axles, an 8.8 with 4.10s is easy to find, I can usually locate 2-3 out of a dozen or two explorers when I go to the yard.

 

[Darky]

Brake lines - do em new no matter what. Cleaner, easier, and safer. EDIT: sorry I misunderstood. Rubber brake line you can keep, it's the same one, the steel brake lines on the axle tubes are axle specific though. Hopefully you'll get them with the axle - in fact I usually take a pair of wire cutters to the rubber hose when I pull an axle.

Driveline - if you have more than 3-4" of lift your old d35 driveline will fit fine, according to some math and general polling we did a while ago.

Ubolts - you will need new ones. Expect to spend about 50 bucks on ones from ruffstuff (you will NEVER break these bolts), 25 for semi sketchy ones from autozone, 40-50 from a local spring rebuilder/truck shop.

I sometimes get axles for 100 still around here, because I buy a bunch of stuff pretty frequently (well, used to) so the counter guys know me by name, but usually I end up paying 130-140 for an axle with everything still on it. That means brakes and half a driveline for a rearend or brakes and steering for a frontend.

What gears do you have? 3.55s are easy to find, 3.73s somewhat less, 4.10s not that hard depending on the locale (difficult-ish around here, easy in the south/southwest), 4.56s are rare as hell. That's all for stock XJ axles, an 8.8 with 4.10s is easy to find, I can usually locate 2-3 out of a dozen or two explorers when I go to the yard.

I would guess 3.07 gears as he has a stick shift.

Buy front and rear axles out of an auto XJ. Then you get 3.55s which will be nicer for the 32s than your current gearing.

 

[obaa-xj]

I've currently got 4.10s. The front was regeared by the shop I trust (when I could afford it). Absolutely no complaints with it. I swapped the D35 with another D35 w/4.10s; that's the one that is currently going TU....
I could not find a single 4.10 (XJ axle), but there were no 4cyl XJs in the yards.
I think I'm bagging the 8.8, just due to the fab/time expense, and the SYE conversion