I had been of the mind to have my transmission serviced in the next 7.5k to 12.5k miles (55k-60k total).

I've noticed that on a cold start (usually the morning), shifting into reverse entails slight delay up to 1 second with a jerk involved. Forward gears are fine, and gear selection when warmed up is smooth.

Is this normal when the fluid is at ambient temperature and "bottomed out" in the trans?

 

I'd be curious on this, as I have this exact issue myself, and it's almost ALWAYS in the morning (sometimes at night if it is cool and the car has not been driven all day)

 

Have experienced this w/ every X308 I've owned.

 

Same thing happens to my '308.

 

Could this in any way possibly be related to faulty valve body or clutch packs?

Anyone with the 722.6 gearbox ever have this issue?

For me when it's below 40* outside in the morning and I start the car, if I do not let it run for at least 5 minutes and warm up, I have this issue, when it's warmer it's not nearly as bad, not sure if there really is a "delay" per-say but I do get the sharp jerk.

 

This must be the first problem I've read about on the forum my old girl doesn't have!


I feel somewhat left out

 

I can't give the actual answer to the question whether it's a clutch pack or PRV issue, but the best thing to do is either get the upgraded PRV done or get the transmission serviced. We all know of the A drum failure. My wife's 00' XJ8 has only 33K on it. (We bought 2 1/2 years ago with 23K on it.) I drained and filled it twice with the Pentosin within about 1K miles of each other. We just got the 20L from Amazon. We all know that these transmissions are also expensive to repair and can spell doom for many customers cars. Do yourselves and your car a huge favor and get the transmission serviced immediately to prevent the inevitable!

To answer the question about the Mercedes 722 transmission, my 98' XJR when cold will immediately go into reverse or drive quickly and smoothly.

 

The ZF's have that piston problem that causes reverse to drop and it can trash the A drum.
I have heard many excuses/ reasons for the A drum to fail -- the piston sticks and then releases too fast -- it's just too much pressure in the box to begin with. The A drum is not reinforced in the original ZF box as supplied.

 

My car seems to want to make a liar out of me lately. I decided to test if there is actually a delay/jerk by getting my foot off the brake as soon I work the shifter.

Reverse works instantly and doesn't jerk (though one does "feel" the shift). It seems as though the jerk is the car going against the brakes.

My working theory is that this is part of normal operation. I can't detect any other trans issue under any other circumstance (including selecting reverse when the car is at normal operating temp).

On another note, why all this talk of the A drum in prior posts. My understanding is that reverse uses the B drum.

 

Sounds like the fluid level needs to be checked. The level is significantly higher warm than cold.

 

To avoid creating a new thread I'll describe my problem here. X308 XJ Sport 3.2l ZF5HP24 gearbox. I also have a slight delay and a jerk issue when selecting reverse. In addition it also happens when I select drive. All this is mostly on cold engine when the rpms are higher right after starting the engine. The issue is slightly less when engine and gearbox are warmed up after driving for a while. What I also noticed is now and then there is no jerk after selecting a gear but still there is a delay. And the next gear change (drive or reverse) jerk comes back. When driving the gear changes are very smooth and there is absolutely no issues. Only when selecting D or R.

Last weekend I changed the oil and the filter in the gearbox and I also upgraded the HPV to Transgo valve. I was hoping it will solve the issue but unfortunately the problem persists.

Any ideas what could be wrong here? What else can be done to solve the issue?

Cheers

 

Did you set fluid level with correct temperature and after switching between gears, was it correct fluid type?

Symptoms you describe are usually due to transmission loosing pressure somewhere thus erratic behavior
It took me few attempts to get it right, at last i've pulled the whole valve body out, took it apart and replaced every single spring in there and also (just in case) main pressure solenoid, checked if upper block has no cracks (under magnifying glass) it has none, after dropping vb i got access to pressure pipes and found one a bit loose in its port, sealed it with locktite
Out of curiosity i compared old and new spring lengths, some where few mm shorter, one was 5mm longer, so yes, they get tired with the time, longer one could be mistake of someone who was there previously (was it me? )
i couldn't get at oil pump regulator spring without dropping exhaust, so that one was left out, maybe one day i will get there...
Now it is smooth and nice
If you decide go at it yourself i can tell you who sells the springs for the box, otherwise you can just send vb to reputable service and have them work for you

 

Thank you xjack for your reply. I lifted the car so that all wheels were up and it was level with the ground. I used LT71141 ATF. First topped it up on cold until it overflowed. Then started the car, warmed up the gearbox to 40°C and went through all the gears. 5sec for each gear. It was little scary because each gear change from drive to reverse went with quite loud bang. After that I topped up the oil again until it owerflowed. Was checking the temp with Icarsoft OBD reader. I was finished before reaching 50°C. I think I've done everything right but it was first time for me doing this so not really sure.

Car is my daily and is my only car so all the work I do is over the weekends when I'm not in work. Taking the whole valve body out seems like a really serious job and bit scary ;-) I'll have to prepare for that toroughly. I would appreciate if you could suggest any threads or tutorials on this and what parts should I get for the job. I'm located in UK.

 

You did filling right, so issue is not there.
You mentioned installing transgo valve and to do it you had to drop lower portion of vb, whole body is just few more bolts and is more scary than actually hard job
It took me three days at absolute leisure, i guess weekend is all you need to have it completed
Garry Ferraro have YT tutorial on valve body, and you will find few nice threads on rangerover forum that will help you understand what to look for while having everything apart.

 

Thank you. Lots of research for me to do I guess. Could you also share the source to get the springs and bits please? I greatly appreciate your help.

 

Between those two you should be fixed
www.automatic-berger.de www.mdm-parts.com