Rear Axle Oil Change Questions

[Purdue_Boiler_Viper]

Getting ready to change the lube in my rear axle (GenII). Two questions:
1. Have not crawled under the snake to figure out what wrench is needed to remove the differential fill plug. Any of you gear heads know what I need?
2. The manual calls for a fluid transfer suction pump to remove the old fluid. I have a brake fluid bleeder that I think will work. Any thoughts or recommendations?

Thanks,
Pat

 

[Big Medicine]

regular socket wrench drive will do the trick; no socket required. Your bleeder wil work, but it's touch & go. Look under the illustrated upgrades section for improvements to your rear diff to make the job easier in the future. Search also, you can find an air pump rig that will vaccum it out for you.

 

[Purdue_Boiler_Viper]

Thanks BM. Will do. Saw the upgrades, but it was not clear why one would want to the drilling, tapping, etc. I'm starting to get the picture.

 

[ViperJoe]

Craftsman 3/8" HEX drive

That way you can put it on the end of an extension to get some leverage

 

[Purdue_Boiler_Viper]

Thanks Joe. How did you drain the existing fluid?

 

[RTED]

Most any Murry's or Auto Zone has a suction transfer hand pump for fluids. Less than $10, does a great job of removing and then adding back the new gear lube to the rearend.

 

[ViperJoe]

I drilled and threaded the case and put in a drain plug.
I believe it is listed in the "Illustrated Upgrades" section

 

[Steve-Indy]

Purdue, I change diff fluid regularly on our Vipers...the brake bleeder will work fine here, noting that I always change the fluid after it is warm. After suctioning all of the old fluid out, I put in some diff fluid as a "rinse", then remove it...then start fill process by adding the 4 oz. additive FIRST, then the diff fluid til full.

While the drain taps are handy, I know that many are reluctant to install same.

 

[Jerry Scott[CO]]

I did the write-up several years ago and all of my friends here in Denver have made the change to the drain plug with no regrets. It's now a lot easier to drain all of the fluid. With the pump, you were never sure if you had pulled it all out.
Jerry Scott

 

[AZTVR]

I'm a newbie Viper owner; however, I just changed my diff fluid 4 days ago after researching the excellent archives here.

I used a 3/8" allen wrench to remove/replace the plug, but the socket mounted hex head would have been more convenient, especially if you want to torque it back to the 15 ft-lb spec.

What worked really well for me was a Suction Gun from Autozone ( OEM Industrial # 25706). It has a short plastic tube with an ID of 3/8". I shoved a 3/8" OD tube into that(very tight fit) & shoved the other end into the fill hole as far as it would go, hoping it was getting to the bottom of the case. I then pulled the plunger, filling the hoses. I disconnected the smaller hose from the bigger hose & put it in the drain pan and walked away for an hour. All (or most) of the fluid siphoned out on its own. I didn't think to add a little new stuff and **** that out - sounds like a good idea. I used the suction gun to inject the new fluid. It took about the right amount, so, I felt that my method got most of the old stuff out.

I suggest a 3 foot long tube to put into the diff instead of the 2 foot piece that I used. My plastic tube was just a little short and only came down to 2 inches above the drain pan. That worked fine until I walked away to watch TV while it drained. It moved on its own to the right by about 6 inches. I can attest to the fact that 3 pints of gear oil makes a puddle approx 3 feet in diameter and 1/32" deep. In order to wipe it up, you will need a half roll of Scott paper shop towels and an old bath towel that you found in the street and kept for this kind of occurence.. Also a pint of mineral spirits and 5 scoops of oil dry will get the remainder up.

 

[Purdue_Boiler_Viper]

Thanks to all for the help. Some good suggestions.

After wrestling around my RT muffler delete, I now understand why Jerry put in the drain plug!

Got the suction gun as you suggested, Jim. LMAO at your spill and clean up. If I could remember enough of my fluid mechanics, I might be able to calculate the viscosity of that fluid. Also got the 3/8 hex socket.

Now, just need some warm weather!