This month’s STHT contains two pieces of blatantly contradictory advice on jacking the rear of an MX5.
Page 41 says, a couple of paragraphs down the second column, “(you) should avoid jacking the car up by its differential”.
Page 48, step 9, says “The jacking point for the rear of the vehicle is on the cast iron part of the differential casing”.
So - which is correct? I always thought that the diff was OK as a rear jacking point, but now the OC magazine tells us that maybe it isn’t - or maybe it is. Make your minds up, chaps!
Sadly you cannot believe everything you read in STHT, in the recent edition some guy was saying he thought supercharging an MX-5 was a better idea than turbocharging one - total twaddle! lol
The correct jacking points for the rear of the car are either with a trolly jack directly under the steel skid (or the bolt heads of the diff to PPF frame) at the rear of the PPF frame, you can also jack the car by the roadside wheel changing jacking points on either rear sill- seam visible points.
Always ensure the car is on level solid ground and chock the front wheels (in both directions) when jacking both the rear wheels clear of the ground together and always use axle stands for additional support before venturing under the car
Early Eunos Roadsters and Miatas did not have a jacking pad on the diff housing.
So the advice would be…check the year of your car, and what differential housing is actually fitted. And don’t plan servicing operations from reading short articles in magazines, or anonymous forum posts. Whilst STHT has a level of editorial control, there is no such editorial sifting on an internet forum.
AT what are you talking about? The jacking point is not the diff housing itself, rather the bolt heads which protrude through the bottom of the rear of the PPF frame, in the photo you have posted, that would be underneath the the lower protrusion in the bottom right of the photo, just in case you are at all confused.
OK guys you have all succeded in confusing this oldie. I have spent most of my life jacking the rear of a car on the diff casing. Don’t understand what all the alternative locations being offered mean - what is PPF frame Taff.? Why not jack my S2 up on the diff housing to change oils obviously leaving access for the drain plug? Confused of South Norfolk…
Here is a thread from last year which has not been sniped or contradicted since. Hope it explains the PPF frame better, the problem in jacking directly on the diff housing is that the housing is steel at the front and alloy at the rear, you wouldn`t want any of the weight of the car supported on the alloy bit if the jack slipped back from the steel bit. If you jack on the vertical bolt heads sticking down or the steel skid on the bottom of the PPF frame (if the car has one, I have seen cars with and without the skid-block) this is completely avoided
The PPF connects gearbox to the differential carrier.
The Veloce MX5 Enthusiasts Workshop Manual, all editions, described clearly the location of the “jack pad” in differentials of the “finned” type, and how to use a trolley jack with them. Not everyone it seems has this book, though you can find it as an ebook easy enough. As I indicated, refer to that, or the equivalent Haynes manual for best practice (not sure the factory manual specifically indicates methods of lifting the car with a jack; the presumption is that the mechanic has a lift. The factory manual is also widely available on line to download.
Some people take the precaution of using a stout block of wood.
The above copy/paste is not a rear jacking point that I would recommend and I will not be using anytime soon for the reasons mentioned previously make your own mind up as to which is the safer, I already have…
I’m in the market for a trolley jack and interested in clarifying where to jack with one.
Just been out and took a pic of my diff. From what I’d read previously I would have been using a lump of wood under the casing, but if this isn’t the way, is it the bolts to the right, and if so, how do you balance that on the cup on the jack.
Sorry if the questions are basic and sorry for not polishing the diff before posting a photo of it
I prefer to stick it in the best posible place, which is what I’m still not sure about … and yes, digi-cam, garage, knees, flash, laptop, photobucket, forum hey-presto
I prefer putting the cup of the jack under them two bolts & it can’t slip. Anyhow as soon as the car is up i always suport it anyhow which is a good idea .
Just some thoughts on jacking up differentials with fins.
When you jack up under the centre of the diff, the weight of the car is carried by the ally wings at the top down through the ally housing and directly to the jack. From an engineering point of view this is the obvious way to do it.
Jacking under the steel front housing means the weight has to be transfered from the ally housing to the steel housing via its joint and bolts. Not technically a good idea but the joint is no doubt strong enough. Jacking under the power frame bolts is the same but is off centre as well.
Having jacked up the car on the diff I was a little concerned about the large amount of vertical movement of the diff ( ~2") before it lifts the car. I don’t know what sort of mountings are on the top of the wings but I hope they are designed survive being to compressed this amount. The ally diff housing looks strong enough but I did worry about the leverage on the wings, you wouldn’t want those to crack.
If your diff has no fins and no obvious place to jack then maybe the steel bits are the best bet. But for diffs with fins then with all due respect I have to disagree with Taff and Flea.
there is a correct workshop manual written by mazda for a reason , but if others have found alternative methods for safely jacking a car up then thats great! but really , who cares…do what works for you!
Simple - Having not done it before I don’t know what will work best for me, which is why I’ve an interest in the discussion. I agree that at the end of the day its down to the individual to do what they want, but sharing valuable experience to help in the decision making is what I feel the forum is all about.
make your own mind up as to which is the safer, I already have…
and sorry for not polishing the diff before posting a photo of it 
… and yes, digi-cam, garage, knees, flash, laptop, photobucket, forum hey-presto 
Sussed . Just having a bit of fun