I'm looking to change my fluid and filter soon and was wondering about the transmission mount. I've heard negative comments on it quite a bit and many people mentioning "it could kill someone".

How is that so? I've never removed it before but the spring isn't that big, whats so hard about jacking it up and removing the nut?

 

All three of my Jags (XJ6, XJR, XJS) have had a variation of the spring-type mounting. Not sure how they could be called dangerous. Aggravating and needlessly complex, perhaps, but that's just Jaguar-ish.

As you say, simply use a jack (or whatever) to support the transmission while the mounting is unbolted and spring tension released.

Heck, even with a conventional rubber-block type mounting you have to lift and support the transmission to remove the mount.

Cheers
DD

 

Doug is spot on.

I have some DIY owners that really should not be allowed near a car.

One simple undid all that stuff, wanted to change the cotton reel mount, and wondered why his hands got crushed. The trans can only fall so far before the engine hits the heater tap, but that mounting frame and all the spacers etc went flying. What was he thinking, NO IDEA.

I reckon a "killer spring" is a tad harsh. More like a "wake up stupid" spring.

I have done dozens, and simply jacking the trans up into the tunnel (it only goes up about 2" max) with that large nut removed, takes a lot of the punch out of that spring. Obviously common sense HAHA, is still needed.

The first time is the scariest, as with most things, but after that it becomes more settled.

 

Well said.

Sometimes I forget that there are some true novices out there.

As DIY cars go the XJS isn't the best car for learning the fundamentals but, in thinking about it, many might be starting their DIY careers with one.

Still, though, seeing anything mounted with a spring should send up a red flag to anyone with a lick of sense. "What was he thinking?" is an apt question!

Cheers
DD

 

Ok now tell me why would one need to drop rear mount to drain fluid?
There is a perfectly doable way take pan bolts and slide pan forward and out. I have done it 2-3 times before, and hopefully will never have to again.
Also, see how one can weld in nice 6mm nut and make a drain plug in TH400 pan.





I can do it for some lunch money, I love to weld

 

when i changed my transmission to a 4speed auto. 700R4, i used the Chevy trans mount also,new it cost $30. also made a simple cross mount from sq.tubing, works great ,been 16yrs, and V12s are so smooth you cant feel any vibs.

have no idea why jag used such an over engineered, complicated trans mount!

 

Found this which may be of interest; everything that you could possibly want to know about the gear box mount and modifying it.
Replacing and Upgrading the Transmission Mount

Found a pile of other XJS tips and tricks too.
http://bernardembden.com/xjs/index.htm

 

mish mish i haven't done the fluid on this car before but from what i recall being under it before, the rear trans mount is over-top the pan....so its got to be removed to remove the pan

 

That's a must read site.

Good thing he keeps it up even though he has sold his XJS.

 

But Mish just said he's done it 2-3 times. So, despite what you recall ...

 

So, do you plan on keeping your method a secret ?

It's been a few years but I recall several of the rear-most bolts being totally obscured by the transmission mount assembly.

Cheers
DD

 

Bernie did some really neat stuff and had great write-ups. Last I heard...a couple years ago... he had fallen ill.

Just a quick head's up, though, for those who miss it: Bernie's car was a pre-HE, 70s vintage model. Some of the work/particulars might not fully apply to the HE-and-later models.


As from trans mountings and dropping the trans pan he apparently didn't know secret trick either !

Here's a quote:

"That's not all, the center "stud" through the spring support is secured at the bottom to a bracket that bolts to an infernally complex apparatus that bolts to the rear of the transmission and shares two bolts with the transmission pan.

This means that removing the transmission pan for routine service also requires removal of the complete transmission mount assembly as well."


Cheers
DD

 

^^thank you.
I didn't wanna bring out the "my service manual says to" because my service manual says a lot of things...

 

Maybe I do have some kind of magic touch (not likely), but these two bolts come out, spacer slide to the side and pan slides out forward and downward. I did do it twice before and never needed to pull transmission mount, until I got rid of the whole transmission, thank god.
See picture of these two overlapping bolts, being pulled, so spacers and pan can come out to the front and down.

 

On my car the bracket those bolts are going through is also fixed to the pan by studs. Additionally, the bracket is bolted to the gearbox casing by horizontal bolts so it cannot be moved even if the two bolts in your photo are undone. Finally as far as the pan fixing is concerned, a double ended stud with a bolt head in the middle, bolts the pan to the gearbox flange one end, and has a stud for the bracket on the other. So even if the bolts shown in your photo are undone, and the tongue shaped bit moved aside, the bracket still has to be removed to get the pan off, to undo the double ended studs. And that means a full dis-assembly of the lot.



I should have changed the double ended bracket-to-pan studs to a single long bolt, so it would have gone: gearbox flange - gasket - pan flange - spacer - bracket - bolt head. Then I could slide the pan forwards by undoing the two pan fixing bolts and catching the spacers, but I did not...

Next time! I did at least put on a pan with a drain plug though, so I can change the fluid easily, but not the filter.

Greg

 

And I removed that dumb bracket 20 years a go on all my V12's, and the pans basically "fall off".

Just put the 2 large extension housing bolts back after the bracket is gone, and find 2 spare pan bolts.

Then added a drain plug, so now they are "back to normal".

 

IMHO, no big deal.

In my entire life I think I've seen only one dirty filter....on a trans that about two miles away from total self destruction. So, transmission filter changes are way down on my list.

Transmission *fluid* changes, however, are high on my list...making a drain plug very useful.

Cheers
DD

 

Thanks, Doug, that is a relief. How frequently do you think the fluid should be changed?

Greg

 

ALL mine are every year ONCE clean looking fluid comes out.

That can take a few drain and refills.

On our "NEW" S Type I am at change #4 in the 6 months were have owned it, and it is starting to look like ATF at the drain point, so a few more, then off with the pan and a new filter and onto the annual schedule that car goes.

The X300 took about 7 drain and refills to get clean looking fluid draining out.

 

Heh heh. I'm not the right person to ask because I'm a bit over-the-top with fluid changes.

The usual recommendation for non-obssesive types is every 30k miles. I used to change mine every 15k miles. However, with the convenience of a drain plug on my XJR, I drain the pan every 10k miles or so and top off with fresh fluid thus (hopefully) keeping the fluid perpetually sweetened, so to speak. Only takes 15 minutes .....seems a shame to NOT do it!


Cheers
DD