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8.8 swap advice

kneutonic

NAXJA Forum User
Location
las vegas
im sure this has been gone over but im a newb so here goes. i just got a 3.73 trac lock 8.8 out of a 96 explorer to replace my weak D35.
1. i know i need the brackets... i was planning on getting the M.O.R.E kit for $200 unless anyone knows a cheaper way to go?
2. should i weld the perches in to set my pinion angle or should i use the 4 degree wedges that i just got for my RE 4.5 superflex lift?
3. do i need a new yoke for the jeep style u joint or should i order my Tom Woods driveshaft for a rear ford style u joint and use the ford yoke?
4. do the rear brakes bolt right up or do i need a prop valve to make it work right?
5. last but not least, should i regear it or is 3.73 acceptable for 32s? (i know i will need to regear my front to match)
any other advice would be greatly appreciated.
 
http://www.jeepsunlimited.com/forums/showthread.php?t=371713

Sorry, I don't have time to go into more detail. This thread is a great source of info regarding the 8.8 swap.

You shouldn't use the shims, match everything up when you prepare to weld.

You will need to swap the flange to match the Jeep driveshaft. Most aftermarket shops sell these. I recommend www.carolinadriveline.com For the DS also.

Do not try to gear to 3.73. Most likely you'll end up gearing both front and rear. You'll need a 3.73 and up carrier to gear the D30. Most D30 carriers are set at 3.55 gears and in order to gear lower you need a 3.73 carrier. 4.10s should work great. If you think you might jump up to a 33-35" tire in the future, do you self a favor and do it once. 4.56 would be good on 32's for a while and can stand up to 35's if you go there.

Most do not need a prop valve. I didn't.
 
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Yeah, That thread helped me out a lot. Keep in mind most of the info is directed towards TJ/YJ swaps, although I'm sure you figured that out already. The P/N were right on when I used it. The only trouble I had was with the E-brake lines. I used the ZJ lines but had to do a little fabing on my own to get them to work. I can't remember what the heck it's called but it has a hook on one end and an eye on the other and they both thread into eachother. I can post pics when you get there. It worked out nice.
 
so you think i should just jump to 4.10s front and rear instead of using the 3.73 thats already in there and just changing the front gear ratio to match it? and while im at it i might as do the e-locker i eventually wanted anyway.
 
1) I would do this, Dan is an awesome guy to work with and his stuff is quality:
http://www.ruffstuffspecialties.com/catalog/simple-spline-p-186.html

2) Weld the perches to set pinion angle, might as well not mess with shims if you can dial it in the right way.

3) I would order the standard 1310 yoke and get the adapter flange. (Spicer #211229x) I got mine for like $20. Its more likely someone will have a spare you can get if it fails on the trail.

4) You do not need a prop valve. It will be just fine without one. You will need to use two passenger side soft lines on the calipers and bend your own brake lines from any local auto parts place to use your existing "T" block from the chassis.

5) I would have pulled a 8.8 with 4.10s and a LS and also pulled a D30 non-vac from a 4 banger XJ with 4.10s and swaped those in. That swap in my rig cost me less then $500 from junkyard to running under my Jeep. But all in all, you shouldnt be too bad with 3.73s and 32s, its just not ideal though.

HTH
 
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so you think i should just jump to 4.10s front and rear instead of using the 3.73 thats already in there and just changing the front gear ratio to match it? and while im at it i might as do the e-locker i eventually wanted anyway.

I would. 3.73 is cheaper but you'll wish you went with the 4.10 later on.
 
1)4) You do not need a prop valve. It will be just fine without one. You will need to use two passenger side soft lines on the calipers and bend your own brake lines from any local auto parts place to use your existing "T" block from the chassis.
HTH

it did come with soft and hard lines already on it, i wonder if the flare nuts will fit in my t block.
 
They should fit no problem. The hard line to soft line flare is the same size as the "T" block.
 
I did this swap and have a few pointers...

My 8.8 also came with soft lines and hard lines. I still ended up getting a passenger side soft line and bending/flaring my own hard lines to match my t-block extended steel braided line. Wasn't easy to find places to mount the axle end of the soft lines.

I re-geared during the swap...went 4:56 with Ected limited slip/locker in the rear, and an Eaton e-locker in the front D30. I run 33's and like the resulting ratio.

I also recommend Ruff Stuff...and set the spring perches without any degree shims...take full advantage of the length of the spring plate to limit axle wrap (most shims are smaller than the Ruff Stuff perches..limiting the ability of the perches and spring plates to limit/resist axle wrap).

Good luck with the swap! I'm loving mine!
 
I did this swap and have a few pointers...

My 8.8 also came with soft lines and hard lines. I still ended up getting a passenger side soft line and bending/flaring my own hard lines to match my t-block extended steel braided line. Wasn't easy to find places to mount the axle end of the soft lines.

I re-geared during the swap...went 4:56 with Ected limited slip/locker in the rear, and an Eaton e-locker in the front D30. I run 33's and like the resulting ratio.

I also recommend Ruff Stuff...and set the spring perches without any degree shims...take full advantage of the length of the spring plate to limit axle wrap (most shims are smaller than the Ruff Stuff perches..limiting the ability of the perches and spring plates to limit/resist axle wrap).

Good luck with the swap! I'm loving mine!

thanks for the help, i have decided to set pinion angle with the perches. how do you like the e-locker up front? i have been considering elocker vs the truetrac LSD. so many lockers out there, its street driven so i dont think i want an auto locker due to the price in tires i will burn through.
 
Aussie locker for the front. Cheap, works well, and hardly noticeable when in 2wd.
 
RuffStuff perches kick serious @ss. though, i prefer the JKS shock mounts. set pinion angle when you weld on the perches. its really easy to do with an angle finder available for cheap at harbor freight. while your getting your spring perches from Dan, grab a diff cover too. its serious beef and you wont have to worry about pealing the stock stamped sheet metal cover.

when i went to rear disks i did a ZJ prop valve as well. is super easy and made it easier to change out the brake fluid (black brake fluid is not a good thing).
 
4) You do not need a prop valve. It will be just fine without one. You will need to use two passenger side soft lines on the calipers and bend your own brake lines from any local auto parts place to use your existing "T" block from the chassis

You don't specificly need a proportioning valve, but you won't get the full benifit of having rear disks without one. I went about a month and a half with the stock valve and the brakes were about on par with the factory drums, but once I swapped the guts out of a rear disk Grand Cherokee into my valve body night and day difference. The stock ford line build up does require running a passenger side soft line on both side however to be compatable with the cherokee lines.
 
Meh to each there own, i run 35s and stock prop valve, DD over 1000 miles a month and i have no problems stopping at all...
 
Not that the brakes are bad without the prop valve, just they are a whole lot better with one. Installation is about as simple as it gets. I kinda figure one of those things you swap out when you run across it in the local pull'a'parts, like I did. I'm still waiting to run across a 95' or 96' dual diaphram booster in the JY. I'm running 35's as well and with an auto its nice to have all the braking you can get.
 
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Gear to 4.56 and be done with it since you have to re-gear anyways.

I didn't go with a kit because it costs too much. I used some D44 perches that I found for $20, they fit with a little grinding on the corners. I made my own shock mounts, very easy to do and then spent about $30 on brake hardware ($20 of it on a new soft line) to get it to work. I already had a Dodge Dakota center line so length wasn't an issue.

Like others said, set your pinion angle when you weld the perches on. As for the driveshaft adaptor...you don't need to buy that Spicer part, the drum brake Explorers have a DS adaptor that works with the XJ driveshaft, uses the 1310 u-joint. Just grab that adaptor off a drum brake Explorer. Bolts to the 8.8 and accepts the XJ driveshaft.

Seriously, I spent about $45 on top of the axle to get it under the XJ. Well, not including the gear lube.
 
I used the more kit I chose it becuase of the shock mounts they realy work well. I also welded a small tab on the back side of the perch to mount my soft line.
 
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