Rear end jacking by Differential

[GordonB]

Question on jacking:
Searched all threads on this subject, but did not find any explanation about Rear end jacking by Differential. Why does Ford consider it a No-No to jack up rear by differential? Is this a big deal or is Ford trying to enforce safety concerns on us garage nuts?
I do it on my Lincoln Mark VII all the time when I change the oil because it has 2 drain plugs for oil and I want all of the crud out when I drain it.
I also do it on occasion on my Olds.
On my Vette, I place a 2X8 under the Aluminum crossmember in the rear and jack it up.

Gordon B.:confused:

[RoyLPita]

I work for a Ford service department and I see no problem with jacking up the rear of the MM by the center pumpkin. At times, the technicians have to in order to listen to rear end noise(s). Just be careful with the evap cannister rack that is bolted to the underside of the trunk floor. Go figure on Ford's viewpoint.

Just my .02

[GordonB]

RoyLPita,
Thank you for the insight. That's kinda how I figured it. Didn't realize what was strapped to the underside of the trunk though -- evap cannister rack!!.
Gordon B.:)

[Warpath]

I disagree. The reason you should not jack the car up from the differential is it is possible to distort the pumpkin. It may not destort a lot. But, it may distort enough to leak or change gear lash. It wasn't designed to take that load. I don't see why you really need to. I doesn't seem worth it to me to save myself a few minutes. Jacking up either side only takes a minute or two longer. You can place jack stands on the outside ends of the axle to listen for noises.

[BillyGman]

rear end housing is cast iron, and the axle tubes are steel, I'd have to side w/Warpath on this one. Perhaps it's fine to do that w/some other rear ends. Someone I work with who owns a Falcon that has a 9" Ford rear end in it told me that the Ford 9" rear end housings are steel(I never knew that since I've never really been a Ford guy in the past) and that because of that it's okay to do that w/cars that have the old 9" rears......

[jerrym3]

I always thought that the "do not jack the car up using the rear end housing" was for independent rear axle suspensions like the TBird/Lincoln LS?

I've been jacking up my 64 Galaxy for over 34 years using the rear end, on occasion, without problems. Just lucky?

[BillyGman]

question....I dunno, but I always thought that all rear end housings were cast iron until that guy that I work w/told me that the Ford 9" rear is steel. But I cannot confirm that since I've never worked on, nor owned a car that had a Ford 9". But if that is true, then maybe other Ford rears such as the old Ford 8" also was made of steel, and if so, then I'm sure that your old Galaxie had one of those:confused:

[Warpath]

I doesn't really matter whether it is cast iron or steel. It could be made of a really strong alloy. It is thick enough in sections to do its job. But, those sections may not be thick enough to support about half of the vehicle weight at the bottom. Since I don't know how it was designed and I haven't seen any tests showing that jacking on it is acceptable, I wouldn't try it. If it shows its OK in the manual, then you can jack on it.

[jgc61sr2002]

You should always jack your car a the designated points. Anywhere else could cause damage. Jacking on the rear could distort the cover cause a leak. IMHO.:(

[cyclone03]

I was going to say go ahead and jack by the diff,your not going to hurt it,just make sure you don't bend the cover.

Then I remembered that the axle tubes are pressed into the center section then "plug" welded in place.The pressing is all that keeps them from leaking/sepping.

So I guess if you load,jack,the axle by the center section this could over time cause the alianment of the tubes and center section to become un alianed and leak.

[GordonB]

Thanks guys,
Guess I'll have tp belly under the MM and see what kind of rear it has. My Linc MK VII has a CAST rear end and the main reason to jack it up some is th get all of the old oil out.
With the MM, I plan to do my onw oil just like I do on the rest of my cars, incl. the '00 Vette. I'll use the Rhino ramps tp run the car up on and then jack up the rear to get it level with a slight front slant. If I have to, I will jack from each side in front of the rear wheels and then put jack stands under the frame lift points.
Question: Is it still permissible to place jack stands under the wheel axles in the rear like most of us have done for a Zillion years or is this a No No also??

Gordon B.

[RCSignals]

I think it also has to do with the WATTS linkage set up.

[joflewbyu2]

GordonB, to change the oil - you don't need to raise the car at all. i'm even able to slide my 12 quart oil pan below without raising the MM. i get to the oil filter from top too in order to loosen it then i go below to get off and put on the new filter. i have less than 1,ooo miles to go before my next change - already have the K&N oil filter. just waiting/deciding to get get mobil 1 0w-20 or 5w-30. decisions, decisions ...

[GordonB]

joflewbyu2@aol,
Thank for the info. That is nice to know that you don't need to jack to change oil.
I would like to know about Jackstands under axles towards rear wheels.
Gordon B.:)

[RCSignals]

I'd place the jack stands on the frame

[BillyGman]

that's what I did when I relaced the Ring & Pinion gears. There are arrows(really triangles)on the rocker panels pointing right where you're supposed to let the weight of the car rest on......

[Warpath]

Originally posted by GordonB
joflewbyu2@aol,
Thank for the info. That is nice to know that you don't need to jack to change oil.
I would like to know about Jackstands under axles towards rear wheels.
Gordon B.:)

Same thing goes for the axles. Unless the manual says its OK, you take a risk of doing some damage to the axle by doing so.

[warren]

All Note !

Just thought I would re-visit this thread in view of the fact that many of us
may be installing things in/on our rear ends.

The 2003 Marauder / Owners Guide ---- SAYS

Page 148........Never Use The Rear Differential As A Jacking Point !!!

This means do not lift up by the pumkin.
The techs at the dealer said great damage could result.

Just 2 cents.

WarrenB :)

[martyo]

Resurrected from the great beyond......

[CRUZTAKER]

Yes....but never truley answered!

I read this thread back in the day....it needed CLOSURE.;)

Speaking of closure.....:P

[Krytin]

They advise you not to jack from the center of the rear for safty concerns only. You can't distort the axel tubes, you won't bent or crack the center section. You can very easily drop the car off the jack if you don't know what you're doing! If the front wheels are not chocked correctly, the jack isn't centered/the ground is uneven or the car gets bumped or pushed in some way - there is a good chance it will slip off the jack.
I have been doing this for 30 years now - everything from Pintos & MG's to a fully loaded Mack 10 wheel dump truck. I haven't had ANY rear end damage ever (except once , when one slipped off and bent the rear cover)!