bnrhodes3

I was having all sort of issues with my XJ's rear axle (thought it was bearings, then after replacing, it ended up being play in the spider gears which started to chip), so I just ended up getting a new rear axle from a salvage yard for $220. I needed something fairly quick as this is my daily driver.

I already had 31" tires on it, so the speedometer has been off a little bit. But, after installing the new axle (still a dana 35, sadly), I realized the gear ratio is different. It used to be a ratio of 3.55, but now is 3.07 or 3.08. So, with that being said, my speedometer is NOWHERE near close to where it should be.

I had my GPS up to check it while on the highway today - speedometer reading/GPS reading:
35mph/~45mph
40mph/~52mph
50mph/~64mph
55mph/~73mph

There is the option of changing the ring and pinion gears out, but I like the way it is driving now (better acceleration), so I don't want to do that. My other options now are to figure out how to install an electronic sensor and speedometer, or to get a new speedometer gear.

I would like to go for the speedometer gear, but I'm not sure how to calculate the correct gear I would need to get (for the 31s + 3.07 ratio).

Any help would be appreciated!

F1Addict

You need a 27 tooth speedo gear for a 3.07 axle with 31" tires. Just remember, if it's 4X do not engage the front axle until you regear one or the other of your axles.

http://www.jeep4x4center.com/jeep-sp...?utm_source=cj

Fred/N0AZZ

Damn $220 for a D35 and you need to change the gears in it to boot.

Around here the D35's are hard to sell and most go to scrap and if you buy one it's never over $50. The Chry 8.25 29 spline I bought 2 weeks ago for $90 and had a cheap locker in it.

bnrhodes3

Thank you! That is exactly what I was looking for!

Yeah, it pretty much sucks. There isn't a whole lot available when it comes to cheap parts for these in Phoenix - there are so many people with Cherokees, and everything else, that they suck anything up super quickly when it comes up for sale (I have seen gutted D35s on craigslist for $150 though lol - I got the entire thing including break assemblies).

As this is my sole vehicle right now, I couldn't wait to find something better and then do the modifications to make them fit. When I went to the salvage yard, I looked through all of the Cherokees to find a D44 (as a few years came standard with them), but no luck. So, I just got an axle I could quickly drop in in an afternoon.

I'm looking to get a new car shortly, then I will be upgrading all sorts of things. But that was the option for now, so I just have to make it work.

Kingfisher

Seems like your acceleration would be worse if you geared it higher.

bnrhodes3

Well, that's what I thought also. But, I'm not sure what is going on with it, but I can get up to 70mph without much effort now and maintain it at around 1600-1700 RPM. Before, I had to get after it to try get up to highway speed.

xjmarc

You could always swap the spiders in the new one into your old one unless it's a newer version since they came in two different sizes. Are you sure it's 3.07s because that should have hurt your acceleration unless something in your old axle was binding causing you to loose power.

bnrhodes3

That was my first plan, but I just wasn't sure if that was the only thing wrong with the old axle (there were a ton of metal shavings - the oil looked like metallic paint). So I didn't want to chance it. When I got home, I put the numbers from the tak into Dana's website search thing, and it is supposed to be 3.07 according to that.

It is very possible that something in my axle was binding from the get go though. When I first bought the jeep, after I drove for any medium distance, it would start to make grinding noises when I took tight turns (I'm assuming something heated up). At first I thought it was the E-Brake, so I disconnected that and didn't notice it for a while, then it came back.

It was just a minor nuisance for months, then about two weeks ago it went really bad by grinding/crunching like crazy when making turns. Took the axle apart, metallic shavings in the oil, no chips in the gears (some of the edges were rounded), but one of the bearings was toast. Changed both bearings and the oil and it was fine for a day, then it started making a loud humming noise any time over 35mph, and worse crunching/grinding around bends. Took it apart this time and a bunch of the spider gears looked chipped up. On further inspection, it looked like the bolt going through the housing was sheared off, so I'm assuming that is where the problem came from in the first place.

krazynezz

The axle could have been (and even with your previous problems I feel possibly was) regeared so it might be beneficial for you to crack the case open and start counting teeth to be sure.