Safely shifting a nut on a differential bevel pinion

[dennis52]

On my Kubota B7100 there is a 1 and 1/4" nut sitting on the splined drive shaft in front of the 4WD differential oil seal I want to replace.

The torque setting for the nut is listed at about 85ft/lb.

When I begin to turn the nut with my shifting wrench the force is being transmitted through the diff and outer drive axles to the tyres on the floor. There is the desired resistance on the shaft rotation , but it feels like things might be bending and that I might damage the diff if I continue.

Can I safely transmit this much force through the diff so as to get the nut off the bevel pinion shaft then tightened again.Am I being over cautious ?

At a pinch, to remove the nut , I could put a pipe wrench on the splined shaft and against my floor to stop the shaft rotating. Problem is when I come to put the nut back on I'll need a different technique as I'll have to get the right torque setting and use a torque wrench with a socket that encloses the whole splined shaft .

Anyone removed this nut? The seal looks easy.

 

[greasemonkeyok]

Are you certain it is ft/lbs, and not in/lbs? The only pinion nut that I have changed was on a Ford Bronco II, and the pinion nut torque was measured in in/lbs.

 

[TCJatko]

Crank it off. The 1 1/4 nut and shaft should be robust enough to handle most anything you can throw at it. You might have to use an inpact wrench.

 

[dennis52]

Crank it off. The 1 1/4 nut and shaft should be robust enough to handle most anything you can throw at it. You might have to use an inpact wrench.

Thank you.
I guess I was more concerned about the robustness of the spider gear and bevel ring gear inside the diff to take the force of holding the shaft as I shifted the nut.I haven't worked much on diffs.
Still feel it would be OK ?

 

[dennis52]

Definitely ft/lbs.This nut sits outside the diff housing.

 

[orezok]

Crank it off. The 1 1/4 nut and shaft should be robust enough to handle most anything you can throw at it. You might have to use an inpact wrench.

The inch lb number usually refers to the amount of torque required to rotate the assembly after the crush sleeve is tightened to the ft lb required. It verifies that you have "crushed" the sleeve sufficiently to provide the proper amount of pre load on the pinion bearings.

 

[TCJatko]

I'm no expert, but most ring and pinion assemblies, at least in larger vehicles and tractors, are designed to take a huge amount of stress. If in serious doubt, consult a Kubota mechanic.

 

[dennis52]

I'm no expert, but most ring and pinion assemblies, at least in larger vehicles and tractors, are designed to take a huge amount of stress. If in serious doubt, consult a Kubota mechanic.

Thanks again TC. What you say makes sense. I'll get on with it now

 

[greasemonkeyok]

The inch lb number usually refers to the amount of torque required to rotate the assembly after the crush sleeve is tightened to the ft lb required. It verifies that you have "crushed" the sleeve sufficiently to provide the proper amount of pre load on the pinion bearings.

Correct, I had forgotten that was why I had to buy a torque wrench that measured in low-numbered inch pounds.

That was one of those "you want how much to install a $10 seal? Thanks, I'll just install it myself." Two days later and a new torque wrench, I had the pinion seal installed.

 

[Soundguy]

impact gun takes it off.. easier...

 

[dennis52]

Thanks for the helpful advice.
I shifted it this morning ,not without some trepidation. You turn the socket wrench about 90 degrees and only get driveline flexing,then you finally hit firm resistance and wham the nut gives way all of a sudden.
Quite different than other nuts I have removed.
I am sure somone wiser will explain what was happening.

 

[Soundguy]

probably taking up all the backlash in the driveline before it gets tight.

that's why an impact sometimes makes it easier... for instance. not an easy job to take a crankshaft nut off a crank snout without spinning the engine, if you used a wrench.. ont he other hand.. and impact driver spins it right off...

 

[dennis52]

probably taking up all the backlash in the driveline before it gets tight.

that's why an impact sometimes makes it easier... for instance. not an easy job to take a crankshaft nut off a crank snout without spinning the engine, if you used a wrench.. ont he other hand.. and impact driver spins it right off...

Trying to torque it back up to the specified setting , I just could not get the torque wrench to click, so I tightened it back to align with a paint line I had previously made on the diff case