Hi all, Im back again. The Moneyfunnel has been giving me grief ever since getting it out of storage this spring. It hates me for putting it there and is making its feelings known. The "seat of my pants" feeling I get while driving is that I have a miss at 50-60 mph under low load after it is warmed (it seems fine beforehand). Its a feeling that changes to the feeling of the torque converter not locking consistently- as if it was going in and out. I have replaced the ignition parts because I got a light zap off the coil wire and was reading about faulty rotors but got no change. I have no warning lights on the dash and no codes. I plan to clean out the intake and get under the car and check trans connections. I am not really asking a question yet, but rather plan to post my findings as I go through this. More to come.....

 

Jerry,

That 50MPH give or take is the lockup speed for that trans.

Our '40, albeit a 3,6, did that, and no matter how hard the loud pedal was pressed, at 54MPH it went into lockup. Sitting right on 52ish, "in and out", and harsh with it. Fluid drop and refill, same as the X300, fixed 99% of the harshness, and the undecided notion.

The X300 had the cycles at that speed also, and the ZF guy here I spoke to strongly suggested to drop and refill the trans fluid 5 or 6 times, and use Synthetic trans fluid. I did that via the dipstick tube large flare nut, no drain plug on mine, and after 4 of those drop and refills, MUCH smoother, and although the lockup was still at that 50ish mark, SMOOTH, and no more cycling. After 8, I went teh full whack,that trans was so sweet it was scary, no feeling of changes up or down, other than the tacho needle moving.

Same guy explained that lockup is mechanical, and there is no "fix" as such if the fluid thing does nothing.

 

Ok, that's a great start then. I was going to do one change anyway, I guess I'll just plan on multiples. I was also thinking that the lock up was electric and maybe I had the persistent bad ground somewhere......

 

Hi Jerry,

The 4HP24 in your '94 does have the electronically-controlled valve body, unlike the 4HP22 in Grant's 3.6L car, which was hydro-mechanically controlled. But as far as I know, the torque converter in your car has no electronically-hydraulically operated lockup clutch.

I ran Dexron VI in our '93 for awhile because it was claimed to be backward-compatible with vehicles for which Dexron II or III was originally specified, and I thought all was fine. But when I changed to Redline Oil D4 ATF at the recommendation of a fellow Jag-Lovers forum member, I was amazed at the difference. The torque converter felt more locked-up, engine braking while descending hills was far better, and Sport mode felt much more distinct from Normal mode, with the transmission holding lower gears longer while accelerating and cornering.

In the years since, I've done a lot of research, and I think the problem is that Dexron VI has a significantly lower viscosity than Dexron III. Ever-thinner transmission fluids have been the trend as automakers have been forced to comply with ever-stricter CAFE and emissions standards. But your 4HP24 really wants a fluid with the high viscosity of original Dexron III. Otherwise, the torque transfer in the converter suffers.

The three fluids I know of that are suitable for use in the 4HP22/24 and readily available in the U.S. are Redline Oil D4 ATF and Mobil 1 ATF (both synthetic), and Valvoline Dex/Merc (the non-synthetic version in the blue bottle, not the synthetic version in the red bottle, which is too thin).

Over time, the viscosity of transmission oils is reduced, and the various friction modifiers and other additives break down, so it is very possible that draining and filling your fluid at least 3 times will completely or mostly resolve your issue.

I would also highly recommend dropping the pan and replacing the filter. I like to drain and fill twice, then drop the pan and replace the filter, then fill again. This way, only mostly-new fluid passes through the new filter.

Cheers,

Don

 

Thanks. I looked at Nicks thread on taking his valve body out, and am considering doing that too since i'll be in there. This is the car that is cat-like to the extent of being on at least its 4th life, so I dont think I can hurt it much more. I dont remember what I put in it when I got it- there was so much to do to it, but I put the Valvoline blue jug in the 92 and its working fine...(probably about time for that one too...)

 

I have procured 6 gallons of the finest vintage blue bottle Dex/Merc. Yesterday I got the trans drained and see the fluid to be discolored. I would have sworn that I did this already but I do not see it in my repair log. I did not refill it because I also have an oil leak at the oil cooler bypass below the oil filter which I am waiting on Orings to repair. I did that job 2 years ago but used o rings from my local hardware store. Apparently they were not up to the task. I also see that my heater valve has developed a leak. Looking at Larrys "leaky old tub" thread I see that I can get that valve locally so I plan to do that today. All in all, about what I expected. The Moneyfunnel is living up to its name again.

 

Hi Jerry,

The O-rings sold in the plumbing sections of local home and hardware stores are usually made of Buna-N (Nitrile) and are rated for water, petroleum oils and fuel and temperatures up to 250°F, so they're usually acceptable for most automotive applications. But I find their quality varies and some just aren't up to the task. O-rings of Viton rubber are rated up to 437°F, but are expensive, sometimes $5.00 or more per O-ring for small-to-medium sizes.

The chart at the link below shows the properties of various materials used to make O-rings:

O-ring Material Quick Reference

Somewhere in the forums I have posted the dimensions of the oil cooler bypass pipes O-rings, but I can't remember where. If you measure your old O-rings (inside diameter and cross-section), you can order quality replacements from a good industrial supplier like McMaster-Carr (mcmaster.com). Jaguar Classic lists the CAC5118 part as NLA.

Cheers,

Don

 

Hey Jerry - You really can get one of those weird OEM heater valves that the only fitted to the 94's? That is amazing luck!

Not the easiest thing to get a wrench on BTW, I couldn't even get a crowfoot on it ....had to make up a tool and even then it was a 1/4 turn, relocate tool, etc etc.

IIRRC My oil bypass rings came from Rockauto or maybe FCPEuro, I remember them being an odd size and not available from local parts suppliers. <edit> Just checked, Amazon have them.

Larry

 

No, not the correct valve, The one you listed as what you used in your adventure- Four Seasons 74858. I picked it up today at my NAPA store. They had it in stock so it must be for Every car... no...truck on the planet these days (and it was only $20). And as the orings, I suspected the issue and ordered them from Moss motors last week. Hopefully I was right. That hot smoky oil smell does Not make me smile.

 

I have a couple of developments as of yesterday.
The proper o-rings on the oil bypass have sealed up that leak but I still have the hot oil smell inside. I removed the intake ducting with the plan of mucking that all out, but found it really pretty clean. What I did find was a MAF sensor with a partly pushed in screen. I am sure I did it myself, probably in jostling parts around to reassemble it last time. I replaced it with a spare from my parts abyss and the car is idling better. I am leaning toward the rear cover plate on the head as the cause of the oil smell now. The only wet area is the right rear lower corner. I tried looking at it with my inspection camera but could not even get That in where I could see. Maybe a winter project.......
Last week as a test and in preparation for the big heater valve replacement, I tightened the hose clamps in that area. As of yesterday the area is dry. I will continue to evaluate, but I suspect that having the replacement in hand is enough to cure the problem.
And the bigger development is that I finally got time to drain the fluid for the 3rd time and drop the transmission pan. I found a clean pan with almost no grit and even the magnets were almost clean. I decided not to remove the valve body. Instead I quickly cleaned the surfaces, changed the screen, and put it back together before it could realize what happened. I filled/ warmed/ topped/ drove/ etc. And find that the feeling of bucking is still present, although the transmission does feel much better overall. While underneath I noticed that the trans mount is quite springy- to where I can jounce the trans with 2 fingers. I suspect that the rest of the problem lies there and after sufficient stepping away time I will have a go at that.

 

And another edition.. It appears that I really DO need to look at the electrical connections for corrosion, weak solders, etc... As I said, the trans has a Much Smoother shift after the fresh fluid, but the initial problem has not resolved. I do not have any dash lights, and last I checked, no codes. I have rough idle (compared to my 92) and the converter indecision problem has not appreciably changed. The rough running gets worse with length of the trip.