SatiricalHen

I have a hard time doing speed limits on most highways comfortably. Still feels very underpowered. I guess it also doesn't help that when I'm not driving the jeep it's my motorcycle or my little Jetta.

Basslicks

Yeah, I think that chart is pretty subjective. If you're driving mostly city or a combination, I think you'll see an increase in mileage if you gear up. But if all you're doing is Hwy, the larger gears will result in a higher RPM at highway speeds.

The catch is, if the driving you're doing is on hills, you're motor will be working harder to maintain the speed it's at with a smaller gear.... so there's that to consider as well.

I've DEFINITELY noticed a difference with 33" tires on 3.55 gears. I have to kick it down a gear when I'm going up almost any grade to maintain speed.... unless I'm on the highway.

I was going to regear to 4.10 soon, but I might reconsider doing 4.56 instead.

uptownbill

All very interesting...

I think I'm going to just get the 32s / 4" and see how it goes. It's going to be a DD. I'm not concerned too much about power loss to be honest... It's a big lifted jeep. time to head to the right lane.

there's going to be a lot of stuff going into this rig so may just add gears to the bottom of the list.

From what it sounds like... 4.10s on 32s are going to get some power back but kill gas mileage?

Here's the numbers I crunched based on the formula in the sticky. (3.55 = stock)

32s stock gears: 3.10625
32s 3.73 gears: 3.26375
32s 4.10 gears: 3.58

Basslicks

No. That ratio is almost a perfect match for the mix of fuel ecomony and power IN THEORY. In PRACTICE, you drive a lifted wind catcher.... that's another factor. So, to sum up, that's the best combination of gearing for the tires your looking at to maintain the best MPG possible.

Now, all that being said, what's your reasoning for going with 32's?

Rich164

I bought my son a 99 xj today and the rear springs are flat. Not interested in a lift (put the OME 2.5 from DPG on mine but don't want to spend that much) so I ordered Dorman OEM replacements which should get it higher and back to original height. What do you think I need to do to the front? New coils, add a spacer? Any recommendations on this or shocks are appreciated. Just trying to get it back to a nice stock ride. Thanks!

SatiricalHen

Also depends on where you are, if it's hilly or not, if you have armor or not, if you tow anything at all or not. Regearing and theoretical numbers don't go well together.

EZEARL

Same situation here. I've got a pair of Crown springs I'll be putting on when I get mine back from the shop. I'll wait to see what it looks like before I do anything with the front. If it's not too high in the back I'll run it let it settle in then decide what to do with the front. If needed I'll put these in:



As far as shocks and since mine are good again I'm going to wait. I'll use either one or two sets of these to extend the shocks where needed:


https://www.morris4x4center.com/roug...t-rc-1088.html
https://www.morris4x4center.com/roug...t-rc-1089.html

Rich164

Thanks for the info Earl. Do you expect to need shock extensions if just going back to stock height or are you expecting to be taller than stock until springs settle?

NewKindOfClown

You won't need to modify anything going back to stock height. Stock springs and stock shocks are how they were built. Don't over-think the height difference that has occurred over time

EZEARL

Are these the Dorman's you bought?

If so scroll down and read the comments in that Amazon link I posted especially the first one and you'll see he ended up using stock shocks. So I really shouldn't need extensions but after I've settled the new springs we'll see. What he did is duplicate the "Up Country" suspension option that was offered by Jeep for the XJ's. It provides a 1" lift over stock. In the comments I mentioned some used Dorman springs to obtain that 1" lift.

Forgot to add that I've 3/4" lift shackles on it now.

Austin Guerrero

Hi all. I'm new to this chat thing but I have a question and I hope someone could help give me an answer. I just installed a brand new 3in. rough country lift kit on my 99 xj. All the lift was was new shocks, springs, and leads btw. Anyways I went to finally drive it and it has this horrible vibration and clunking noise and it smooths out a little above 40 but like 30-35 mph is really bad. I've heard a t-case drop can fix it but I noticed the rear axle is like tilted back and not square. Is this the problem? And if so how can I fix it. Any help would be greatly appreciated.

Tbone289

Here's mine on Moog CC782's, 3/4" spacer and Crown HD leafs. I removed the 1/4" stock spring isolator. Front settled to 1.5" over stock, rear 1" over stock. Those Moog variable-rate coils ride really smooth and compliment the stiff Crowns well. The Bilstein 5100's (for 2-3" lift) work great with this combo, but you do need more bumpstop. The up/down travel is equal once the stops are set to protect the shocks.:

EZEARL

THANKS for posting. Looks good. I hope I end up with the back a bit higher than the front for when I use my trailer or haul heavy loads. If it's to high my shackles have a position for 3/4" lower. We'll see in time.

Tbone289

I would think my setup with the addition of your 3/4" shackles would achieve exactly what you're looking for. Without the 3/4" spacer I'm using in the front, the Moog coils with factory isolator and Crown HD leafs both give exactly 1" of lift after settling. I tow with mine, but I use a weight distributing hitch so the rake isn't as important, and I'm not a fan of the raked stance look on an XJ.

With that said, I think you'll be impressed with the load-carrying capacity of the Crown leafs. A couple of hundred pounds of stuff in the hatch doesn't make them squat like the stock leafs do.

Martlor13

I've been pretty happy with the Dorman I'd leaf packs as well so that is another option he can consider. Gave me about 1.5 inches at first but settled to around 1.25 inches or so