Today in the morning when I was backing car out of the garage it took slightly extra time to switch into rear gear and jerked a tiny bit more than usual. But then it went into drive just fine and got me to work (~45 min with some stop&go traffic).

On the way back backing out of parking lot the pause was even longer, and it jerked stronger. But again went into drive and I was on my way. At some point I decided to swing to car wash, but had to turn into side road to turn around. At that time both: switching to rear and to drive had a hesitation with a jerk. And when I needed to accelerate - car jumped out of the gear, jerked back into the gear and displayed "transmission error". Interestingly it did not go into limp mode(no red light/lamp).
I stopped , turned car off, re-started. The message was gone. Put it in drive, it tried... but did not engage right away, after hesitation and when I gave it a little gas it jerked into a gear, message came back but I could drive the car. It felt like clutch needed more rpm for car to get going, but it would speed up to 30-35mph(and probably more).
I drove it to the wash, went through it(automated, but had to turn off the car). Started after, again it engaged into drive with a jerk after some throttle . On the way home it would disengage if I pushed it, but after one of those I was accelerating gently and made it home ok. Again, I had to give it more than usual after stop to get it going(it would accelerate slower).

Now after maybe an hour I started the car and tried... It goes to reverse fine. When I put it in drive - it tries, goes forward few inches but does not engage. I did not give it gas to "jerk-engage" but think it would. I left it for now, wondering what is the diagnosis..

I did install the "transgo kit" , filter, and did transmission flush maybe two years ago. Also had transmission errors going into limp mode which was due to faulty PPS/TPS , so I got throttle body replaced few months ago and forgot about those. At that time I checked all transmission connectors and cleaned earth cable. There are no ATF leaks. Now I got code P1722.

What do you think? A-drum finally failed?

( I was just thinking how I replaced tensioners, installed trans-go kit, put new shocks..... was hoping for another year or two of relatively worry free driving:-) )

 

My question would have been, if you have an ATF leak, but you wrote already: No.
Did you use the correct ATF, when doing the ATF change 2 years ago?
I assume you have the ZF 6hp26 transmission? it wants ZF lifeguard 6 or 2 or 3 others, but not just any multi-vehicle ATF.
Did you do a full flush?
Did you understand the refill procedure? To get to the correct level, you need to fill the ATF (level) while the engine is running, until the ATF comes out by the filler plug. ATF temperature 40°C, and going thru the gears. Else, your ATF level might be low (or even high) and strange things would happen.

Did you recently check your ATF level (with ATF 40°C and engine running)?

 

Yes, I used correct ATF(per specifications) and correct procedure to refill. It was a partial flush(to install kit and filter). I am pretty sure it is 5HP-24 and, after doing that work for two years tranny was running smooth. Car has 130K now.

I will disconnect/connect main plug tomorrow and try one more time. Not sure if this behavior can be consistent with a one solenoid failure or some connection being bad. I had few problems on this car that were solved by unplugging/spraying/plugging back(knock sensor failure in particular, still have a new one sitting in the box).

 

DTC guide for you.

 

Thank you. The more I read about it the more it sounds like "A drum" failure. It looks like best option is not to drive car to avoid pieces of metal braking off and damaging the rest of the transmission.

I also read that few folks replaced drums in their garages and found that to be a "not so impossible" job... I am not there yet...

 

I had the A drum out of my 97 XK8 to inspect it. It's not very difficult if you refer to the various write-ups on this and the X100 forum. Stand the transmission on it's tail in a garbage can.

 

I have about a dozen broken forward ('A') drums if anybody wants one.
The first thing I did with any Jaguar ZF5HP24 car I bought is replace the drum and tighten the oil gallery plug on the back of the engine!!!!!!!!!

 

Thanks for everyone who replied. I had valve body checked and technician agree that it is likely a-drum.

While I am figuring out my options could anyone suggest a shop around Northern NJ that would do the job? ( remove transmission, fix it, put it back). I am waiting to hear from aamco and would like to call few more places for the quote. Also, links to salvage yards where I can get used tranny would be helpful. (I checked places like ebay, google, www.car-part.com).

Thank you!

pm or reply here would do.

 

I would highly recommend you call: Eriksson Industries

They are in CT, but I can honestly cannot think of a better place when it comes to rebuilt transmissions. They might have a recommendation of a place in your area. Hoping they can just sell you a fully rebuilt unit.


Best of luck.

 

I disagree with the A drum. You probably have a rear upper valve body crack. This means the R and D are on at the same time. Applying throttle in R or D will "defeat" the other but this explains your delay.

A cracked A drum gives you alot of complaints in forward driving but ZERO issues in reverse.

A 5HP24 with a cracked A drum will engage reverse IMMEDIATELY and PROPERLY.
A 5HP24 with a cracked upper valve body part will engage reverse with a delay and when going forward from standstill with quite some throttle, it will give you a bump.

I overhauled my wifes 5HP24. Forward drum was not broken so I upgraded the valvebody with a transgo pressure regulator to make sure it will never break. The rear valve body was cracked (explained our reverse) and I replaced it with a new part.

If indeed your upper valve body is cracked, this part needs to be replaced, it can not be salvaged. I recommend you install a transgo shift kit: https://transgo.com/product-details/...ulator-repair/

This kit can be used if the bore of your valve body main pressure regulator is still round and within spec. The valve has a longer sealing part and 2 o-rings to make sure your valve body will not send pressure spikes to your A drum piston. With this piston you prevent your A drum from cracking. This can only be used if your drum has not cracked yet. If it cracked, your main pressure regulator bore will have wear or ovality and you will need a new main valve body peace.

Pictures:

 

Thanks. I did install the kit 2 yrs ago. And few days ago a shop here removed pan and inspected valve body - no cracks. At the moment reverse is working no problem and forward engages sometimes with a jerk sometimes without but into higher gear... 4th I was told, but when I asked "how do you know what gear" the specialist said "I think so, it probably will engage into direct gear". Transmission error is displayed, but throttle is not inhibited, I can go fast.
Whatever it is - it needs to be fixed. I am looking at my options... so far I have only one ~4k estimate ( which is especially tough choice because I saw beautiful ~60k miles XJ8 for sale at ~$10k negotiable :-) )

 

It is strange your 4th gear works fine. The transmission needs the A drum in 4th so when you apply throttle in 4, you should not take off gently at all.

You can do a drum swap where you replace only the drum for the reinforced one and the dreaded needle bearing and o ring.

 

I don't really drive car now, but that was my experience going to the shop that checked valve body and back. I was very gentle on throttle.
As I described in original post - I had gears jumping in and out when problems started, but since that I am very gentle with the car.