I thought I’d change my rear end (differential) lube ahead of time, and was surprised to see how used up it looked and smelled. I probably should spring for a Blackstone Lab analysis on it , but am reserving that luxury for the engine oil.

By the way, the lube only had 47,665 miles on it (3 years / one month) . I had changed it a few months after I bought the car in 2018,

The new lube I used today was the same product as the old lube removed; Mobil 1 75w-140.

Even worse looking was the grease that was forced out of the half-shaft U-joints when I pumped in the new grease (Mobil 1 Synthetic grease, NLGI No 2 )

As far as I know, the half-shafts have the only zerk fittings on the X100’s . Can anyone verify that ?

Z

 

@22yrs and 160000kms / 100000mls (i suspect)

 

I have never done mine and think it has never been done. I am actually secretly hoping my diff blows up so that I have a valid excuse to upgrade to an LSD.

 

go for it now. Tomorrow may never come. Besides, a
locked up rear end can cause collateral damage.


Z

 

Having wimped out a couple of times before, last October (83,898 miles), I buckled down and accepted the challange. It is pretty much the owners choice for the plan of attack. I opted to not saw through the boot, ( have the extra plate to go through) and I chose to remove the swaybar and brackets. I fashioned a 1/2" wobble bar cut 3 1/2" long with 2 opposing flats ground to accept an extra long open end wrench. Here are my particular notes that I hope will steer me in the right direction next time: (yours may well vary)

Ramps/jackstands (pull parking brk)
Jack up front end higher than rear
3 ½” L special ½” wobble ext. and 12mm extra long open end wrench
(long screwdriver to lever this ext. into drain plug square socket)
13,15,17mm long impact sockets,air ratchet, 3/8” to ½” adptr to rmv 2 rear diagonal brkt screws, loosen
Other 2 front brkt screws. Move both brkts toward rear tires then rmv rear sway bar.
After drain plug is broken loose spray around plug with brk clnr and wipe clean
Rmv drain plug (also to replace plug) by hand. Bar just rear of diff.must be between thumb and forefinger while manipulating plug with fingertips. Your head will need to be well forward of rear axle.
Suck out about 1 qt26oz with 3/8”OD extension hose. (length of all hoses together is ~25”)(use spring clamp to prevent hose from exiting hole .(also, do not pinch hose with clamp or kink hose)(try to barely touch inside bottom of diff. with end of hose)
Clean suction gun before cln oil fill.(make sure hose is inserted beyond all threads or oil will leak out)
After replacing plug, rmv with 14mm open end wrench and cln breather with brk clnr and air (cln around breather as you did the drain plug)

 

Had mine last year at about 65k miles.

 

Looks like somebody's best kitchen jugs !

 

Looks like something brought by someone who wanted to measure oil accurately who had very limited shopping options.

 

Funny you say that because so do I.

 

Sorry Markel,
I Suspect that most people only add to their diff oil at best.
I was forced to change mine on the last clutch change.
Regards,
Ron