You tell me... how bad am I screwed?

[JamesW]

Question: if the preload is bad, what kind of failure time are we talking about... are we talking about failure in 250 miles, 2500 miles, or 25000 miles? Obviously it depends on how bad it is.... my point is that I don't want to be in the middle of death valley in the fall, coming down lippincott pass and have my rear bearings die... so is there some kind of warning that I should be listening for?

Also, if I were to just bolt up the drive shaft and drive it as is... is that really any different knowing that I don't have the proper tools to fix it anyway? Can I just drive it until I hear the warning signs, then drive out to the pick-a-parts place and grab another rear for 100 bucks?

Thanks for any feedback

When it is on the way out a sign of the pinion is noise while driving,that gets louder when you're coasting. My front was doing it,there would be a sound like dragging a shovel along the ground after the fluid warmed up while coasting,and when it was bad it would shake a bit when you're slowing down. I drove mine quite a while like that because I thought the sound was my exhaust heat shield rattling,and with my mud tyres on I couldn't really hear it unless I was driving by a wall with the window down. All I needed to do was torque up the nut again to put preload on the bearings,but I tightened it until the noise went away rather than tightened it to the correct torque,it's doing well now about 1600k later. If you've gotten rid of the play chances are you've gotten rid of the noise too

I like the locking tool,I ended up using my old rear door hinge with 2 bolts stuck through it.

 

[Toasty]

if there's no slop and you can turn the pinion my hand (and torqued to spec) you're likely fine. We drove from Phoenix to Tahoe area, ran the Rubicon, drove to Yosemite, drove to Cartwright Reservior then ran the Dusy Ershim and then drove back to Phoenix on a bad pinion bearing. We were trying to figure out what the noise was the entire time, figured it was because we were overloaded and riding around on the rear bumpstops. It never fully went out, Kevin just figured it out and swapped in a junkyard diff because that was the quick solution. That old diff is still good aside from the bad bearing.

 

[stioc]

Ah, I didn't know Mitsu diffs don't use a crush sleeve.

nckwltn, it looks good to me from over here. Just keep an ear out for any weird noises for the first hundred miles or so.

 

[nckwltn]

if there's no slop and you can turn the pinion my hand (and torqued to spec)

Define "slop". The amount of play in the flange from a rotational aspect feels to be about the same as the other diff I have. Maybe 5 degrees more.


I'm tempted to just throw the drive shaft back on and not measure with a weight hanging off one of the flange bolt holes set at 3 and/or 9 o'clock with the axles pulled.

The thing is, I'm planning on taking the montero on a 2500 mile road trip/camping trip (little to no off road) starting next weekend.... don't want to be broken down in the middle of Utah... perhaps I should bump my AAA to the 200 mile coverage

 

[stioc]

The rotational slop (backlash) looks OK in the video. The slop Andrew is referring to is the in and out or up and down movement of the yoke which would be present if the pinion nut didn't seat everything back properly. Again from the video it all looks fine to me. Not sure if you did but I use a thread locker (or lock washer if available) on the pinion nut to make sure it doesn't back off.

 

[nckwltn]

bolted it all back up and seems to run good... I do get a little whining noise when applying power, but I can't determine if that is something from the engine or the drive train... I'm going to try to pop into overdrive and see if the sound persists when applying power....


As long as I'll have a little warning before catastrophic failure, I can at least try to spy a new rear from a parts yard.

Thanks everyone for the advice and suggestions.