I've done a Ford 9" and a Dana 44 Front.... and plan on doing my rover when its ready.

The main thing is the backlash needs to be set within spec and the contact patch needs to look good. So you need a dial indicator on a magnetic base for the backlash and something to check the contact patch. In a machine shop setting we use dykem blue for that sorta thing because its what we have laying around... there are other products that are specifically marketed to check the contact patch on ring gears. Whoever is selling the gears should also have a shim kit so fine adjustments can be made. Depending on you mileage and budget you might also consider changing the bearing and seals.

The front axle is going to require a reverse ring and pinion.

 

 

Good evening. I have a 2004 Discovery 2 with 3.5in lift and 31" tires. also have winch and bumper with full rack etc. The 4.6 motor struggles up hill and in general is bad on gas. I use vehicle for mostly off road but also for overlanding. Was looking at gear changes to heavy duty gearing in axles and eventually air lockers front and rear. But I saw t-box gear that would also work. Or should I do do gearing in both t-box and axles? I want to build a heavy duty drive train that I am haul with and abuse on the trail that will hold up to whatever I would put it to. What are your suggestions for ratios. And gear sets?
Drew

 

That's the main reason that I haven't gone with any taller tire. Even with my 30's, mine is sluggish on hills compared to the stock 29's it came with.

 

GBR was a great resource and wealth of knowledge when I re-geared. You can achieve a heavier duty ratio by going from an 8 pinion gear to 7 for example in matching desired ratio.

I’m not sure how you would benefit from tearing down a stock 3.5 carrier in the d2 just for your gearing; as it’s a known weak point in the drivetrain (especially if your aiming to strengthen it) it’s only a 2 Pin carrier..

I’m using 34” BFG AT’s (which measure smaller) with 35 KM3’s on deck. With 4.43 ratio I believe.. 7t pinions. I think it pairs excellent in low & is extremely throttle responsive for off-road.. but my particular driving style is not laying on skinny pedal. I like to crawl. It also doesn’t bother me any doing 75 on highway @28/2900 (which I put a lot of highway miles on). I’ve come to Like it quite a bit.

I also have no problem with stock axle shafts.. 2k to put all 4 HD (3x torsion strength) in there from GBR is a lot for me when these Rover shafts are doin the job just fine. Plus I could source a spare shaft for 50$ from a dead rover..

 

Figured I’d post back up here since I’ve been re-geared for some time now. Wish I had more first hand experience before doing the swap so hopefully I can help those who were in my position.

Ended up going 4.12’s (ring and pinion) for 33’s. Yes it was absolutely with it. I did the gearing myself along with air lockers. There are absolutely no tradeoffs other than time/cost to install. I was very concerned with going too aggressive with gearing (high rpms on the highway) due to the fact this is a functional adventure truck. Setting up the gears was a serious pain in the behind. For reference I can swap a locker in an afternoon, doing the gearing took me easily 4x that.

Below is my educated opinion if I were to do it again:
3.5- Factory ratio
3.75- Worthless
4.12- good for 31”-33” tires
4.37- good for 33”-35” tires
4.75- 35”+ tires

 

ln your original post...you ask..."any thoughts?"

Nowhere did l read...only those that have done this.

 

Thoughts are good, experience is also good. You’re original comment adds a lot to the thread. Much appreciated.

 

4.12 is what I've always thought would be good for me & my LR setups.