In need of some edjumacation;

2003 D2
33" Tires on 17" Wheels
Planning to upgrade the shafts with the HD Ashcrofts, figured while its open I put lockers in & do the gears.
Couple of questions;
- How much of this can I do myself, should I just take it all to a shop?
- Currently, I believe the best ratio would be 4.12...When these tires have worn out, I will go to 35s. Probably next year...
Do I want a different ratio? Hoping to only do this once
- Ashcroft vs ARB Air lockers?
- Air locker both ends, or do something like an ATB or DTT in one end?
- Diff pegging worth it or necessary..?
- Does the Air system need to be operational before lockers go in, or can I do that later? Will it wreck anything not having it hooked up...I know I wouldn't be able to use em'.

Territory out here gets you into a bit of everything...I like to overland but you will typically experience mudding, rock crawling, snow, water fording on any trail in BC...typically on long uphill climbs getting up mountains.

**Front & Rear bumpers, diff guards, rock sliders, front skid, fuel skid all coming in about a month or 2 and will add more weight...any consideration needed in regards to gear ratio with this on?
RTT would come as well once axles are done.


Thank you for your input in advance!

 

No, you won't mess anything up as long as the air fitting coming out of the diff is plugged off. That said, I personally like Detroit style lockers. No air necessary. No selectability, but less to maintain. They kick in on their own. That said, onboard air has other benefits like airing tires back up when you're back to pavement.

4.12 gears could be the right choice for 35s. That will put you back to *roughly* the same gearing as stock gears/stock tires. If you drive the highway as well, this is probably your best bet. If it's strictly off road I would go lower. 4.56 or 5.13. Not recommended if it sees much street use though.

How mechanically capable are you? Setting up gears can be done at home if you have the tools and the feel for it. Many, myself included, have done it. If you aren't confident with using dial indicators to measure backlash within a few thousanths of an inch and getting all the spinning torque specs correct though, I'd pay someone. You can order third members already set up that you just drop in. Very good option. Generally you'll then send your original third member back as a core.

As far as pulling the axles and the third member out and installing the new ones, I would say most could probably do that if they're familiar with mechanic type work. Again, use your judgement. If you want to see what's involved in pulling the diff, click the link in my signature to go to my write ups. I've got one for replacing a differential.

Diff pegging - I've never done it. Can't guide you on that. I've also never stripped a set of gears.

 

If you don't have a CDL transfer case already swapped into your 03...l'd look for a defender transfer case and then you wouldn't need to add ring/pinion gears to locker upgrade, just lockers. Defenders have a 1.4 gear ratio in transfer, whereas, Dll has 1.2...so..using a 1.4 will put you in the 4.11 range overall.

 

Whowa004 will chime in I’m sure quick -
these questions are discussed in detail many moons. If you don’t have a locking transfer case, that should be factored in.

Suggesting to invest in HD axels, air lockers, armor, gearing & sit tight on air compressor?

I’ve been on a waiting list for Axles 4 months (ordered November)

 

That high range

Low range is the same between the 1.0, 1.2, 1.3, 1.4, and 1.6 boxes.

 

Correct.

But, supposedly, he'll be running 35's someday...so, he would probably prefer the difference in high range...to maintain decent road speed/rpm...especially, since he mentioned overlanding, and "occasionally" experiencing mud, rock crawling, snow...so, it sounds like his primary concerns would be dealing with road speed, head winds and hills. Personally, l like to build a vehicle for the majority, not the occasionally, but that's just me.

But yes, his low range would be a bit tall with larger tires. Granted, had 33's on my 01 for a while and in low range, first gear...it was stump pulling territory, in my opinion...lol. Now, for super serious rock crawling...maybe 4.11's would fit the bill better.

 

do you even have cdl ?

 

I would make the argument that 4.10s (4.11s, 4.12s, 4.1X) gears would also be easier on driveshafts than the lower geared t-case I've time. If he's doing lockers anyway the the ring and pinion still have to be set up, and this also gives him the ability to go to reverse cut gears in the front diff, which of course the factory didn't do to save on production cost.

Complete agreement, however, that CDL would be a very worthwhile upgrade if the OP has not already done so. Every bit as useful as the lockers themselves. I'd be looking for a D1 Tcase and shifter, or a setup out of an '04 D2.

 

Sunday - I gave up on my 1.4 t-case as it was out of too old of a defender and was missing multiple sensor ports or so it would seem at first glance. Probably something I could have worked around but I didn't have enough time when I went to swap it for extra work.

Kind of worst case scenario as the OP probably will have to do more than add a CDL cable and swap a new one in on top of all the other work. If adding lockers front and rear then doing the ring and pinion makes sense and being able to buy them set up and just swap the whole 3rd in/out is very appealing imo. I can't speak to diff pegging, never done it nor blown up a diff. Oh and since this is going to cost a bunch regardless if you do it or pay someone to do it then I would 100% do air lockers. I love the ability to select when each diff is locked and being able to avoid any wheel spin (when compared to a LSD or detroit) to me is a big plus. Also, the idea of a detroit in the rear kind of scares me for winter driving on the roads

Ashcroft for me every time. I will recommend the high output single ARB compressor though to run the lockers as it's also capable of airing up tires as well...I cheaped out and bought the smallest ARB and I regret it every time I go wheeling or adjust my gear and see another compressor stashed in the back just to air up.

 

Here's my truck with GBR 4.43 and TruTracs front and rear on some heavy off camber terrain. I'm on 33s. I use my truck as a daily and driving on the street I don't notice them at all which I enjoy a lot. Also, I do a lot of wheeling at Rausch Creek on some blue trails and the setup hasn't let me down yet.

As far as gearing at first I didn't like it bc around 70 on the highway I was at 3k rpms but with the truck loaded up with weight and in high altitude it helped a ton. I think once I go to 35s it'll be just perfect. ​​​​​