Dana 35 Backlash / Rebuild

[TJRD4]

Currently in the process of restoring my 97 TJ w/ 200K miles, (4L/6 cyl, AX-15, NP231, Dana 30/35) and working on the axles.

The Dana 35 has a build up of metal in the left axle tube and some indications of wear on the spider gears. Before I start taking everything out I figured it would be helpful to measure the backlash and look at the wear pattern. My suspicion is the wear products are from a combination of the left carrier bearing and the spider gear wear (pitting).

The ring gear backlash, measured in 3 spots, is ~.015" which is roughly 2x out of spec (.005-.008"). Been trying to find some marking compound but seems like its best to buy that with the rebuild kit since its hard to find by itself anymore.

If I'm already going to replace the carrier/pinion bearings, crush sleeve and all the effort of setting the preload does it make more sense to regear (3.73) a bit and even add a trac lok to the rear? Currently running 31x10.5xR15s - I plan to keep this size or go slightly smaller (30x9.5s). Im not a huge fan of how wide the 31x10.5s were but will address the rub during the resto if needed. The jeep mainly stays on the pavement or light dirt trails. At 70 mph in 5th gear and 31s the RPM is 1840... and with the 30s, 1901. Both a on the low side. Most of my driving is 55 mph or less with my jeep but still looking to run it correctly.

What are your thoughts? Understand that if I regear the rear Ill have to regear the front...but its at 200k miles. Thanks!

 

[Gilaguy23]

You might also find a seat of axles from a 4 banger, they have 4.10 gears. The Bearing kit I bought for my 99 came with the marker, and all new bearings. Might as well do the axle bgs as well if there is a bunch of metalic crap in the tubes. Why bother with a LSD or posi if your mostly street or light dirt road use?.

 

[macleanflood]

That spec is for new gears. I think you're fine.

Is it making any noise or any indication of trouble?

-Mac

 

[TJRD4]

No noise or any other issues. Do you think I need to regear? Replace the spider gears and carrier/pinion bearings?

 

[macleanflood]

I'll let the folks that have a lot more experience than me chime in.

-Mac

 

[Gilaguy23]

Need, or want to regear?

 

[TJRD4]

I get that it worked fine for a good while with the 3.07... but figured this is the time to regear if already needing to replace carrier bearings.

 

[hear]

I get that it worked fine for a good while with the 3.07... but figured this is the time to regear if already needing to replace carrier bearings.

Maybe, maybe not. Changing the bearings shouldn't require a full setup, so if you're looking to minimize work, just change the carrier bearings and call it a day. Although if the carrier bearings are spent then the pinion bearings may not be far behind. That's also not super hard, but does require some careful attention when setting the preload. There are plenty of discussions about that here.

Max effort would be to change out everything and get you into a better ratio for your engine/trans/tires. So I guess it depends on how happy you are with what you have vs how much effort do you want to put in.