When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Looking good so far. The driveline shop will dent and scratch up your paint a bit during their work...but that's ok as the rattle can won't last more than a year if you're using the Jeep as it's designed.
One thing I'd recommend doing before putting the axle under the Jeep is welding the axle tubes to the housing. Google this process for further details. If you don't have a strong enough welder, perhaps the driveline shop will. When you are re-building a bare axle, welding the tubes is an easy insurance measure to keep the engine's torque traveling to the tires vs spinning tubes. With a simple 4.0L and 33's it's just added peace of mind, but it will be nice later on to know the rear axle is done and doesn't need attention; until your leaf springs start wearing out and you notice axle wrap while off-road.
Side note after looking at your progress again...did you tighten the drive shaft bolts to spec? Most DIYers forget that drive shaft bolts that retain U-joints caps typically have a light torque spec of less than 25lb-ft...
Looking good so far. The driveline shop will dent and scratch up your paint a bit during their work...but that's ok as the rattle can won't last more than a year if you're using the Jeep as it's designed.
One thing I'd recommend doing before putting the axle under the Jeep is welding the axle tubes to the housing. Google this process for further details. If you don't have a strong enough welder, perhaps the driveline shop will. When you are re-building a bare axle, welding the tubes is an easy insurance measure to keep the engine's torque traveling to the tires vs spinning tubes. With a simple 4.0L and 33's it's just added peace of mind, but it will be nice later on to know the rear axle is done and doesn't need attention; until your leaf springs start wearing out and you notice axle wrap while off-road.
Side note after looking at your progress again...did you tighten the drive shaft bolts to spec? Most DIYers forget that drive shaft bolts that retain U-joints caps typically have a light torque spec of less than 25lb-ft...
Thanks for the input. I will see if I can get one of my buddies to do some welding for me. I didn't torque the ds to exactly 25 ft-lb but I will verify.
On a side note i had a devine intervention by the jeep gods today. I was going to drop my axle off today to have the 4.10s dropped in after work but over lunch I got a call back from a guy who has a dana 30 lp out of a 2000 TJ with 4.56 gears and a Detroit true track limited slip for $400. This guy is about 3.5 hours away from me but the kicker is he is located next to where I have a big wheeling/camping tripped planed in the Sierras in two weeks. Coincident... I think not. If everything pans out I will be bumping to 4.56 gear instead of 4.10s.
My visson for my jeep was to keep it a comfortable daily driver on 33" tires but if I have 4.56 gears it will make it very tempting to bump up to 35" tires if I can stuff them my jeep. Besides my 33s are starting to look small under my XJ
Thanks for the input. I will see if I can get one of my buddies to do some welding for me. I didn't torque the ds to exactly 25 ft-lb but I will verify.
On a side note i had a devine intervention by the jeep gods today. I was going to drop my axle off today to have the 4.10s dropped in after work but over lunch I got a call back from a guy who has a dana 30 lp out of a 2000 TJ with 4.56 gears and a Detroit true track limited slip for $400. This guy is about 3.5 hours away from me but the kicker is he is located next to where I have a big wheeling/camping tripped planed in the Sierras in two weeks. Coincident... I think not. If everything pans out I will be bumping to 4.56 gear instead of 4.10s.
My visson for my jeep was to keep it a comfortable daily driver on 33" tires but if I have 4.56 gears it will make it very tempting to bump up to 35" tires if I can stuff them my jeep. Besides my 33s are starting to look small under my XJ
I would have ignored the invisible man in the clouds and continued onto the driveline shop with your 4.10's. If anything, take the low pinion axle and part it out to pay for your XJ hp30 re-gearing.
Can the Chrysler 8.25 carrier you bought even support 4.56's? I don't know, that's why I'm asking. What's the carrier break for that?
I would have ignored the invisible man in the clouds and continued onto the driveline shop with your 4.10's. If anything, take the low pinion axle and part it out to pay for your XJ hp30 re-gearing.
Can the Chrysler 8.25 carrier you bought even support 4.56's? I don't know, that's why I'm asking. What's the carrier break for that?
Why do you say that?
I don't believe there is a carrier break on the Chry 8.25, if someone knows please correct me. The more searching I do online the more convinced I am that 4.56 will be a solid alternative to 4.10. I will have plenty of power to run 35" tires in the future. Besides if I can pic up this lp d30 it will be quite a bit cheaper than regearing my hp dana 30, plus it has a dana true track limited slip. I know the hp d30 ring and pinion are stronger than the lp d30 but it's still plenty strong for 33-35" tires and if it's not I am only out a few hundred bucks.
Simply because I think your vision of a comfortable daily driver can be met with 4.10's and 33's just fine. Do you ever encounter an obstacle off-road where 2" of extra tire height would have made the difference? In my experience, usually not. Pick a different line, stack some stones or use the winch. An XJ on 33's is a lethal off-road rig combo.
35's are about the reasonable limit for the XJ hp30, and now you want to pull the whole axle out and swap in a weaker low pinion unit and increase the drive shaft angles? If you're going through all that trouble why keep it a Dana 30 then? There are Dana 44 and Dana 60 kits readily available for bolting into an XJ at that point with more powerful brakes, much stronger housings & axle sets, better steering and link locations/mounts...ect. Compared to pulling an axle out, re-gearing your current hp30 becomes the cheaper and easier option, plus you get to keep the front drive shaft up higher out of harms way vs low pinion (also keeping the u-joints happier and you wont have to worry about your slip yoke on the shaft pulling out as much).
I'm not saying 4.56's are a horrible idea, but I do think swapping in a low pinion axle is. If you're really set on going to 35's later on, buy 4.56's for both of your current axles now and forget about the low pinion front. The detroit tru-track won't help much in the front when you really need it off-road. I've tried the limited slip idea in the front with all sorts of different combos and it's just left me spinning one wheel too many times to watch someone else go down that same path. When you get used to your rear Spartan, put another in the front.
Btw, have you done the math for your proposed gear calculations? With an AX-15 you have:
3.83:1 1st
2.33:1 2nd
1.44:1 3rd
1.00:1 4th
0.79:1 5th
Here's the rundown for your scenarios going 75mph on the highway, assuming you're in 5th gear:
3.07's & 235/75R15 = 2122rpm
3.07's & 33's = 1880rpm
4.10's & 33's = 2511rpm
4.10's & 35's = 2365rpm
4.56's & 33's = 2793rpm
4.56's & 35's = 2631rpm
Do the math for yourself. The equation is ((MPH * trans ratio * axle ratio * 336) / tire height in inches).
To get a feel of what you're considering for 4.10's, get on the highway, go 75mph and right now with your 3.07 gear set and 33's, keep it in 4th gear. You should see about 2380rpm's in 4th gear of 1:1, which will closely mimic what you'd experience if you had 4.10's and 35's. Imagine if you had 33's, you'd have 200 extra rpm so bump the speed up to 80mph, still in 4th gear and you should be going 2512rpm...that's what you'd feel if you had 4.10's and keep your 33's but you'd be in 5th instead of 4th gear.
Just my 0.02
Last edited by Stroked98Xj; 10-04-2014 at 09:41 AM.
Simply because I think your vision of a comfortable daily driver can be met with 4.10's and 33's just fine. Do you ever encounter an obstacle off-road where 2" of extra tire height would have made the difference? In my experience, usually not. Pick a different line, stack some stones or use the winch. An XJ on 33's is a lethal off-road rig combo.
35's are about the reasonable limit for the XJ hp30, and now you want to pull the whole axle out and swap in a weaker low pinion unit and increase the drive shaft angles? If you're going through all that trouble why keep it a Dana 30 then? There are Dana 44 and Dana 60 kits readily available for bolting into an XJ at that point with more powerful brakes, much stronger housings & axle sets, better steering and link locations/mounts...ect. Compared to pulling an axle out, re-gearing your current hp30 becomes the cheaper and easier option, plus you get to keep the front drive shaft up higher out of harms way vs low pinion (also keeping the u-joints happier and you wont have to worry about your slip yoke on the shaft pulling out as much).
I'm not saying 4.56's are a horrible idea, but I do think swapping in a low pinion axle is. If you're really set on going to 35's later on, buy 4.56's for both of your current axles now and forget about the low pinion front. The detroit tru-track won't help much in the front when you really need it off-road. I've tried the limited slip idea in the front with all sorts of different combos and it's just left me spinning one wheel too many times to watch someone else go down that same path. When you get used to your rear Spartan, put another in the front.
Btw, have you done the math for your proposed gear calculations? With an AX-15 you have:
3.83:1 1st
2.33:1 2nd
1.44:1 3rd
1.00:1 4th
0.79:1 5th
Here's the rundown for your scenarios going 75mph on the highway, assuming you're in 5th gear:
3.07's & 235/75R15 = 2122rpm
3.07's & 33's = 1880rpm
4.10's & 33's = 2511rpm
4.10's & 35's = 2365rpm
4.56's & 33's = 2793rpm
4.56's & 35's = 2631rpm
Do the math for yourself. The equation is ((MPH * trans ratio * axle ratio * 336) / tire height in inches).
To get a feel of what you're considering for 4.10's, get on the highway, go 75mph and right now with your 3.07 gear set and 33's, keep it in 4th gear. You should see about 2380rpm's in 4th gear of 1:1, which will closely mimic what you'd experience if you had 4.10's and 35's. Imagine if you had 33's, you'd have 200 extra rpm so bump the speed up to 80mph, still in 4th gear and you should be going 2512rpm...that's what you'd feel if you had 4.10's and keep your 33's but you'd be in 5th instead of 4th gear.
Just my 0.02
Solid points, I have been contemplating this over the past week. The more I look at gear charts and mess around shifting to 4th and 3rd gear on the interstate the more I am set on 4.56 gears. In the end I would rather run at a little higher rpm and sacrifice some mpg to have a little more power. As a note, when I searched TJ forums for some gearing guidance the majority recommended 4.56 gears for 33 tires with an ax15. In contrast, on xj forums the majority recommended 4.10 gears for 33 tires with the ax15. Same engine, same ax15 gearing and same tire size so I wonder why the difference in opinion?
As far as the lp vs hp dana 30 I agree 100% that my hp would be a better option to build. As a stop gap between building my hp or going with a dana 44 I can pick up the lp 30 with a limited slip and 4.56 gears from a guy in my area for a decent price. I can get my rig on the road with 4.56 gears all around and can defer building up a front axle for a future project. For me that's a win win.
This weekend I picked up a dana 30 LP with 4.56 gears and a Detroit true track limited slit. The axle has about 100k on it and 30k on the gears and Detroit. I was able to pick it up for relatively cheap. The LP ring gear is not as strong as my dana 30 HP but this was a cheap option to get 4.56 gears in the front. I also dropped my chry 8.25 off today to have 4.56 gears installed.
Just a quick note about going to a LP D30 - keep an eye on your driveshaft length. It's possible it may end up a tad short going from a HP to an LP housing. While the HP gearset is technically stronger, I wouldn't be overly concerned about the LP gears. I run a LP D30 in my XJ, with 4.56s and an ARB, with 35s and 36s, and haven't blown up the gears (I've also got a Warn hub kit on it so hopefully the hubs would be the first to go). It's all in how you wheel it.
Also, depending on how tight that TrueTrac is, you may end up wanting to invest in a 2LOW kit. Before I had the LP30, I had a Waggy 44 up front with a full Detroit (long story as to why I swapped back to a 30...). With the Detroit up front I was having to make 2 and 3-point turns on the trails where previously I could make it in one shot, and if the trail was muddy the Jeep would just plow straight ahead regardless of which direction I turned the wheels. After 2 trips of wheeling like that I put in a TeraFlex 2LOW kit so that I could disengage the whole front end when needed (I also decided I'd never run anything again but a selectable locker up front, lol).
Just a quick note about going to a LP D30 - keep an eye on your driveshaft length. It's possible it may end up a tad short going from a HP to an LP housing. While the HP gearset is technically stronger, I wouldn't be overly concerned about the LP gears. I run a LP D30 in my XJ, with 4.56s and an ARB, with 35s and 36s, and haven't blown up the gears (I've also got a Warn hub kit on it so hopefully the hubs would be the first to go). It's all in how you wheel it.
Also, depending on how tight that TrueTrac is, you may end up wanting to invest in a 2LOW kit. Before I had the LP30, I had a Waggy 44 up front with a full Detroit (long story as to why I swapped back to a 30...). With the Detroit up front I was having to make 2 and 3-point turns on the trails where previously I could make it in one shot, and if the trail was muddy the Jeep would just plow straight ahead regardless of which direction I turned the wheels. After 2 trips of wheeling like that I put in a TeraFlex 2LOW kit so that I could disengage the whole front end when needed (I also decided I'd never run anything again but a selectable locker up front, lol).
Great looking build btw, clean and simple.
Thanks for the insight, I was a little unsure if my ds would work. I will probably try dropping in a stock front drive shaft from an auto XJ to get it on the road. My front ds on my manual XJ is about 1.5 inches shorter then the auto front ds.
I have never heard of the 2LOW kit. What is it? What does it do?
Thanks for the insight, I was a little unsure if my ds would work. I will probably try dropping in a stock front drive shaft from an auto XJ to get it on the road. My front ds on my manual XJ is about 1.5 inches shorter then the auto front ds.
I have never heard of the 2LOW kit. What is it? What does it do?
Scratch that, I looked up the 2 LOW kit. Having low rang in 2 wheel drive would be awesome! I just dropped in an sye and wish I would have known about this when I had my t-case apart.
09-28-2014, 12:58 PM
