My oil filter never appears very dirty, but i still change it. A new pan gasket and filter only cost like 8 bucks...so why not?

 

pic of my 4speed auto overdrive rear mount and aluminum driveshaft, notice the drain plug , put that in 1988,when i had the trans in a Camaro probably ahead of the curve then.

swapped trans into Jag 1994, if i change fluid it will be awhile, only got 6-7k on it, another garage queen!

also pic of my rear cage stabilizer bars,adjustable Hiem joints put a little preload torque on the whole unit.

ques; how many of manual shift V12s guys have put good tires(that grip) and reved up the engine and dropped the clutch, and the whole rear cage diff and all,just ripped out
and fell on the ground?? i suppose thats an embarassing moment.

 

Same here ... once the filter present at purchase has been personally replaced just to get rid of possible machining debris in the likely event that it is the original filter that left the factory.

 

so I have just spent 3 hours changing the mount, spring and bushes. Had to remove one side of the exhaust to get mount plate out. (1995) The original mount had decomposed and was hitting on the side during turns. Now it is quiet.

One question I have is related to the mount components. The exploded diagram shows the spring, with a rubber mount on each end, and a yellow bushing that mounts on the plate. There is one other part, shown on the diagram, some sort of ring inside the spring. I do not have the diagram to hand at the moment, but was number 11. No evidence of what it was or should be. Any ideas of what should be in the mount, beyond the spring and the bushes?

 

There is supposed to be a "special washer" between the lower space and the stepped spacer on that main pin. basically as you remove the big nut, then spacer, then this "special washer" should fall out.

That "special washer" acts as a friction medium with the Yellow bush, hence slowing the "bouncy" effect of the spring, much like a shock absorber slows a suspension spring.

If you no got that washer, use a "flat section" spring washer, as it is very close to the OD required to friction inside that mount bush.

Most I have seen in all my years have had this "special washer" missing.

 

i.m sometimes dont keep up with general maintinence , my wifes car has 120,000 miles on same fluid, around 85,000 trans started acting wierd, so put in a bottle of slippery -slickum, been perfect for 40,000 more ,still fine!

talked to a guy in transmission shop, he said common for Japanese cars to go 150-200K with no more than some friction reducing additive.

he also said that after 70-80K miles,among the know in trans guys,is do NOT change fluids, if done , shortly after all kinds on trans problems show up.

he also said dont spread that info around,he'd be out of business!

course i know most guys on this site drive there Jags 12-15K per year,everyear!

 

Yeah, true enough. I've had 3 used Hondas where the trans fluid was nearly black and the transmissions worked fine.



That makes it sounds as though it's certain a problem WILL occur.

My experience in quite different. I ran a repair shop where we did about 150-200 transmission flushes a year, many on over 100k cars. Intially the "stirring up a bunch of muck" stories had us pretty nervous but in the course of the years only one ever went south. I reckon that particular trans wasn't long for the world anyhow.

Still, though, to keep everyone protected, the usual recomendation is to NOT change fluids on high mileage transmissions.




Yeah, I've been doing 20k/year over the last 4 years. Only about 7k/year in the 3 years prior to that!

Cheers
DD

 

I'm a big believer in "if it feels good, do it!" so, yeah, if your gonna drop the pan you might as well change the filter....especially since the pan gasket and filter a commonly sold together as a kit.

Knowing that filters almost never clog (or even get very dirty), though, I'm perfectly happy with a drain-n-refill on a regular basis. Super quick and easy. Hardly even get my hands dirty :-)

Cheers
DD

 

Yes, there is a big difference between just pulling the drain plug versus dropping the pan, cleaning the pan, cleaning the magnet, changing the filter, maneuvering pan and gasket back into place without getting it dirty.

 

Of course if people spread the word about changing the transmission fluid on a regular basis, he'd be out of business even faster.

 

Having read through all of these entries over the past 6-10 years, there are several key things I would add about this topic that are NOT clearly mentioned:

1. If you want to change the ATF on any JAG without dropping the pan, you can still extract the old ATF (through the ATF dipstick hole) using a Mityvac or other device, and you will still get 98-99% of the fluid out. This saves a lot of aggravation and time dealing with the transmission reinforcement mount/bracket. Warm up the car first to improve the viscosity of the ATF before extracting. If you must, flush and repeat if you are **** about clean fluid.

2. The "filter" for ATF should more accurately be described as a "sediment pan," because all it does is allow any particulates to settle out in the bottom of the filter if they are too heavy to be carried with the fluid. I would recommend changing the filter at 100K or even 150K miles as a precaution, or if you don't know if it has ever been done. See 3 below.

3. The GM Turbo-Hydramatic 400 tranny employed for the XJS was designed for large vehicles, including many GM truck models. For this reason, the designers shock-mounted the entire assembly on springs and bushings - including the very annoying reinforcing bracket that shares two bolts with the tranny pan. This "Killer" spring mounting does make removal of the pan very time consuming, but it was designed to make sure that the sheer weight and downward force of the spring did not bend or warp the plates holding the spring during bumps and potholes, etc.. The whole structure isolates the noise and vibration of the transmission from the chassis - thus adding to the silky smooth XJS ride and preventing engine vibration from reaching the occupants.

So - what this means to you: 1) The XJS in the 80's uses a TH400 DEEP PAN, so be careful when replacing or ordering a new pan. New ones run $50 to $150 and are widely available because of their ubiquity. 2) Sometimes mechanics or others will over-torque the screws holding the pan to transmission, causing the lip of the pan to warp - and then drip-drip-drip forever on your garage floor. You can change the gasket over and over again, and the pan will still drip if this is the case. Replace the PAN! 3) Do be careful when taking off the bracket, and follow above instructions due to spring loading. Use NEW screws and washers when replacing the pan. Replace with a new filter and gasket when replacing the pan, of course. 4) A new rubber bushing for the transmission spring is a good idea too, and very cheap, and very available.

If you can get to the point where you have a straight pan, clean fluid and a relatively new filter - the TH400 should be very insignificant on the long list of your XJS headaches and heartaches. P.S. Use the best Dextron II or better ATF you can buy. I like Liqui-Moly Top Tech ATF 1100.

JL

 

JL, appreciate the tip on using the MityVac. I was sitting here thinking, are these guys kidding me, there is no drain plug???!!! Now then, how long of a rubber hose do I need to buy on that MityVac?

 

Make a mark on the tube as long as the dipstick plus another 3 inches, then you know the tube is in, then enough more to comfortably attach and operate the mV.
Greg

 

Warlock: To answer your question, Mityvac comes standard with several extraction tubes - so you do not need to buy extras or add anything.

EVEN if you are going to remove the pan later, extracting the ATF first with the Mityvac will save you juggling and a very messy situation if you were trying to remove a pan filled with heavy ATF.

Tips for Mityvac:

1. Always warm-up vehicle before extraction (70 - 80C).

2. The VAC comes with several tubes, including a STEP-DOWN converter for using the 1/4 inch tube attached to the 3/8 inch tube that actually attaches to the vacuum. As you extract thick fluids, they will move from the smaller radius line to the thicker one and fill the empty void. If it sometimes seems that you are sucking molasses through a straw - you are! It is slow going. Extracting 8-9 Quarts of ATF through a 1/4 inch tube may take 15-20 minutes, but it works! Be patient.

Hint: Only pump the Mityvac until it feels that there is no resistance on the pump handle. You have built up enough vacuum at this point. You will have to pump again in a few minutes when the flow slows down.

3. If you can use the thicker tube on your vehicle or application and it has enough length (unlikely), then remove the black step-down converter (rubber thingy) and vacuum away. ALWAYS remove the step down converter when you reverse the pump to get rid of the liquid from the Mityvac - there's no point in pumping the ATF OUT of the mityvac through the smaller tube!!!! But you knew that...

4. DO NOT over play or wiggle the small 1/4 inch extraction tube in and out of the step down converter. If the converter get's loosened and the seal is broken, you will have a loss of vacuum and the VAC will NOT work. You will have to replace the step-down converter if you do that. They sell a tube replacement kit that contains a new converter - so this likely happens all the time.

5. To contradict GREG's measuring point, just use the 1/4 inch tube, and insert that into the transmission dip-stick tube, and push it down until it hits the bottom of the pan, then pull back a fraction of an inch.

6. Then, start pumping the Mity-Vac. Because you are often dealing with 8 or 9 quarts of ATF, you may actually FILL-UP the MityVac and have to reverse (pump out) and start a second Mityvac Load in order to extract everything from the tranny...

HINT: Buy a five gallon plastic gasoline container and using a Sharpie write "Waste Oil Only" on the outside. Now, you can use this container to transport all of your future used oils to the recycling facility in your area without lugging the MityVac along with you. Recyclers will take old ATF, Motor Oil, etc. P.S. Don't ever use that "waste" container for anything other than Waste Oils, particularly gasoline. You will be sorry.

7. Then, when you hear a sucking sound and you see that the flow of liquid in the tube is mixed with air bubbles, pump the vacuum some more and start moving the tube in and out of the hole very slightly, like a mad proctologist. By doing this, you may (will) hit another pocket of fluid or get a closer to the bottom of the pan. You may see even more thick ATF going through the tube. Think of this as using a tiny wet-vac - you might get a little bit more! You will be surprised at how much extra you can get. BUT, resolve that you are never going to get every single drop of ATF using this method - only dropping the pan solves that.

8. Take the used ATF to a waste-oil facility - they will take it just like motor oil. In fact, in most places you can MIX them and they won't care.

Good luck and happy sucking.

 

I use an old dental vacuum pump for this. Perk of my job I guess. It only takes a few minutes. Changing the fluid by vacuuming it out would not disturb the debris.
Im cautious about using the hi power flush on old trannies. I would think that would break debris free causing problems.

 

i don' t think it would break anything free, trannies are generally extremely clean places with little to no debris anyway. They are fairly high pressure because they use the tranny to dump out old fluid and require enough pressure to promptly provide new fluid to prevent damage.

Its a turbo 400, its not exactly a fragile or complicated thing.