Perfect thanks shlodzeegar.

Hey Fmix, my 89' is an auto which had the issue. I was able to successfully pull the pot joints out using the separation tool mentioned previously. Worked like a charm! Good luck!

Will this work for auto Minis also?  I've had a little leak since I got the car and would like to at least fix it once.  Figure I might as well while I'm doing brakes and water pump.

Along with other jobs i have just done this job on a pot joint Mini.
I needed to remove the axles completely as i was doing a disc brake conversion and front end re build. The pot joints on either side would not come through the sub frame holes i did manage to get them both out (with the engine supported but still on its mounts) feeding them inwards as they still had the smaller drum brake cv's on them.
Putting them back in with the larger disc brake cv's installed i was able to do so on the longer side from under the car but the radiator side i had install it with the inner cv separate, if i had removed the radiator side motor mount it would have worked.
Personally i prefer the axles out of the way when installing diff seals especially on the tighter radiator side.

I just did this yesterday (but on a remote trans with pot joint outputs-- so just the output shaft seals not the rod change seal) and I have some edits/addendum.

Indeed you can pop the top ball joint and leave the bottom one in and steering tierod attached and get enough movement from the axle to pup the cv joint off of the stub shaft. However, take note of the brake line and ask yourself if it will put too much tension on it to have it flop out. I did this on a car with discs, so it was simple enough to take a 9/16" socket and remove the 2 caliper bolts and hang the loose caliper by a piece of scrap wire / zip tie to the tierod.

And then once you undo the caliper it is only a matter of popping the bottom joint and the steering rod end joint to get the whole axle out of the way. I had to do this on the radiator side short axle because I wanted more access to get the seal pressed in square... BUT I discovered that the pot joint with the rubber boot still affixed would not pass through the particular subframe on the car I was working on. Not sure if it was because the boot was held on by a zip tie or some other anomaly, but I pulled it out up into the subframe as far as i could and worked at it that way.   The clutch side long axle I only undid the caliper and the top balljoint and i used a long dowel to help me tap the seal where I wanted it to sit with far greater ease than the radiator side (my thumb strength is not what it once was). In hindsight, I'm not so sure I should have tried to remove the whole hub/axle assembly on the radiator side.

As for whether or not to drain the oil...  For just the rod change seal, I stand behind the need to not have to drain the oil. But for the output shaft seals... yea, you need to drain some of the oil out or else it's going to be quite a mess.

Thank you so much for the information. Looking at the parts diagram alone isn't very helpful. I appreciate you taking the time to explain this. As it stands, my Mini is completely empty of oil so no draining required haha.

If it is leaking that much you need to check for any play in the output shafts coming from the differential. 
There is a bronze bushing inside the output covers that wears over time and the seal starts to leak badly.

Nice job on the instructions, Spank.

"try and find it in the toolbox or travel tool box or bucket-o-tools or..."
 ---- ah, so I'm not the only one!

The output shaft seals are same deal with regards to draining oil. Wise to drain, not punishable-by-death if you don't. [edit: Umm, yea, you need to drain some of the oil or else tilt the car on each side while you perform the job one side at a time]

I'm not 100% on if you MUST pop both balljoints on each side or if you can get away with just cranking the steering wheel to one side and popping the top top balljoint only (I would personally try popping just the top balljoint only for starters and if necessary go back and pop the bottom one. You'd be wiser still to get a nice scissor joint-popper like the one from Harbor Freight  https://www.harborfreight.com/3-4-quarter-inch-forged-ball-joint-separator-99849.html

To pop the top joint, get car on jackstands up front, put jack under the balljoint or side you want to pop first, remove wheel, jack up that corner and stuff a piece of wood or similar between the top arm and the rubber rebound buffer (or remove the buffer and put a bigger piece of wood in there-- Haynes says to do this but I usually leave the buffer in as getting out that rusty phillips screw takes entirely too much of my day only to find the rubber rebound buffer should be replaced, but I digress) which just needs to hold the top arm up a little bit so it is easier to bet the popped balljoint pin out of the upper arm.

Don't bother with pickle forks...

You will need to also pop the inner cv joints out from their spring clips on the transmission. This tool makes it relatively easy and less nerve-wracking https://www.minimania.com/part/18G1240/Classic-Austin-Mini-Cooper-Pot-inner-Cv-Joint-Removal-Tool
(I have one I can loan you if you pay for postage both directions and give me a paypal deposit that I will refund when I get it back). But you can use two HUGE, CHEAP screwdrivers or 2 smaller crowbars to use as levers. Mind you, I have a bunch of spare sidecovers and If I totally bugger one up while using 2 screwdrivers, I can swap one out pretty painlessly-- well, there's the pain of admitting that i shoulda use the proper tool but didn't because I was too lazy to go try and find it in the toolbox or travel tool box or bucket-o-tools or...

The idea behind it is you need to use 2 equal thickness levers on opposite sides of one another so that you are trying to force the cv cup out while squared to the shaft that's it is on. if you push on one side or the other too much, it'll just rock and the spring clip is less likely to pop out off the groove it sits in. So two opposing levers applied at nearly the same time in a prying force will usually get it to pop. If it doesn't once you've used a bunch of force, rotate the location of the levers 45 degrees and try again. With screwdrivers you're prying against the edge of the aluminum output shaft cover. This can be risky, but be sensible and sensitive to the restrictions of the strong, but still aluminum and you'll be ok. Or if you use the proper tool (buy or loaner), it pushes against a bolt on the transmission that supposedly is stronger than the outer lip of the aluminum side cover. I argue that the amount of energy used against that bolt while wacking it with a hammer is equal to or greater RELATIVELY and in terms of risk as using 2 screwdrivers against the outer lip of the aluminum side cover. I say try to the 2 screwdriver trick. IF it doesn't work within your level of comfort, then borrow or buy the tool.


Anyway, popping the outer balljoints will give you the room to swing the outer hub out enough to allow you to slide the inner pot joint cv out enough and off the differential stubb axle and out of the seal. Lever out the old seal with pick/screwdriver and press in a new one. Push or bump it in slightly below flush with the sidecover aluminum is preferred. Why there wasn't a lip or metal collar developed to allow you to push the seal up against (like inner bearing hub seal) is beyond me, but it's one of those things where you just try to get it square when you push it and tap it in with your fingers and/or drift. I usually use a rubber mallet and go around and wack it in to the depth the mallet deforms when it hits the aluminum outer face. Access while on the car will determine what method works best for you. (pesky exhaust pipe will be in the way on the one side, too ). [edit-- mallet from under the car not easy. I used a long dowel or a bunch of 3/8" socket extensions to make final tap adjustments]

CV joint pops in and completely home from the outside while you are pushing on the hub after lining up the cv joint on the stub axle. This is where it is handy to have one balljoint in (lower arm / bottom one is good) so that you can use that as a fulcrum to push the whole hub and axle assembly in until you get the cv joint fully home.

Doing each side probably takes as long as it did for me to type that out.

The roll pin has a flat end and a slightly tapered end. Insert the slightly tapered end.

Welcome to what we mini owners call "A Typical Thursday".


You'd be advised to drain the oil before stating this, but truth-be-told I've done it without draining the oil from the sump and there really isn't that much oil loss if the time between removing one seal at a time and replacing it isn't a multi-hour process. [edit-- for rod change seal you don't need to drain the oil. For output shaft seals, you either need to drain the oil significantly or tilt the car on each side at an extreme angle]

Tips/Tricks include putting the transmission in reverse and use an appropriate sized square nosed punch/drift to push out the roll pin coming from bottom right side of car to upper left side of car and on the forward most pin. You'll need the car high enough to swing a hammer on the end of the drift. Super Pro-level tip here: Those Free -with-any-purchase black handled Harbor Freight screwdrivers make great drifts when you cut the end square off of one.

Fish out the old rod change seal with a very small screwdriver and/or a hook pick. If you have an accordian boot on your transmission (looks like this https://www.minimania.com/part/DAM3022/Classic-Austin-Mini-Boot-Rod-Change-Linkage Then you may in fact already have a anti-oil leak kit upgrade https://www.minimania.com/part/MSSK050/Classic-Austin-Mini-Rod-Change-Anti-Oil-Leak-And-Seal-Kit . I'm not sure when the transmissions changed, but the later / newer transmissions won't take the aluminum collar support dealio of that upgrade kit because Leyland/Rover redesigned the tail housing to include more aluminum already as shaft support. Regardless of what transmission you have or whether or not you have an upgrade kit installed, using the boot is a good idea because it keeps dust and debris off of your stubby shaft  and you gon't get grit adhering to it and grinding against and wearing out the rubber seal has it goes in and out while you row through the gears.

So either buy the rod change seal by itself, consider buying the accordian dust shield as well by itself, or just get the upgrade kit and be prepared to use the seal and boot and not use the aluminum collar w/ o-ring because you have the later trans that won't accept it.


Reassembly is not reverse order, necessarily.

Put in your new seal (a deep socket will work great when reinstalling it and will help you get it square. Flush or just below flush with the case is good. If you use the upgrade collar or if you have the later trans, you can actually just push it in all the way but most would tell you to keep it more towards the outter face of teh gearbox-- think of it like the whole debate of brushing your teeth up and down vs side-to-side. split the difference to save the argument.

Getting the original roll pin (perfectly fine to reuse) started can be a challenge. I like to use channel locks to squeeze it in and then line it up. You may find success with keeping it in reverse or taking it out of reverse and putting it in neutral. But when you get the roll pin to the final point of in but not-quite-home on the opposite side of the collar and you can squeeze no more, stick it back in reverse and use the punch/drift and hammer to give it the final tap/taps home so it is even in collar.

Takes much longer to type than it does to do.

Thank you. I've never encountered a vehicle that loses its entire oil supply on A Thursday afternoon. Good to know it's an easy job to fix. 

1) Minis leak oil. Get over it. If having a mini that leaks oil freaks you out, you really would be best to find a different hobby car.

2) Likely all you need is a side cover output seal
https://www.minimania.com/part/ADU5738/Classic-Austin-Mini-Cooper-Differential-Side-Cover-Seal-yoke--Pot-rod-Change

3) while you're doing that one seal, may as well do the other side as well and then also do the rod change shifter seal.
https://www.minimania.com/part/AHU1672/Classic-Austin-Mini-Cooper-Rod-Change-Shift-Seal

Those are the 3 most common spots for leaks from the classic mini rod change transmission. If you've ever replaced them before, it's really pretty damned easy and less than a 1 hour job to do all 3. But if it's your first time, it may take you a couple of weekends depending on your level of skill, fear, and what you have for tools.

Hey all,

I've got an 89' Mini that sprung an oil leak from where the right CV joint meets the transmission. Is anyone familiar with such an issue? Is there a gasket just behind the CV joint or am I looking at something more serious. Thanks!

-Matt