1999 Jag Sov x308 LWB 4.0 Non-supech.
Early AJ27 (uprated A drum and valve body in AJ27?)


The car drives smoothly but when I start her up sometimes, not always, it experiences a delay in changing into R and thuds into it, likewise when I put it into D at times.
Recently the car was stationary for 2-3 minutes and I went to put It into R but it didn't, it just seemed to sit in neutral. Then I placed it into D again itseemed to be in neutral, then in R eventually catches at thumps into R.
It does this sometimes, maybe 20% of time.
No warning lights or anything, havnt checked codes via OBD2 yet


I understand its the valve body in the transmission and worse the A drum which requires a complete rebuild.
I was planning to do an oil and filter change on the transmission.


What are the options to eliminate this thump apart from a complete rebuild?


regards
Peter

 

You may be low on fluid, worth a check.

 

RJ
Im hoping your correct in every way. I was planning to do an oil and filter change anyway.
Would you be good enough to explain the reasoning behind how a low fluid level would produce this characteristic of no "R" or "D" , almost a neutral selector feel to it .. eventually it catches with a small thud. It never does it on acceleration or anything like that, usually on start up and when selecting "R"
I notice, other times when going into "D", maybe 20% of the time only.
Today I stopped the car , still in D stationary for a few minutes, then I selected R and it wasn't there, changed to D, also wasn't there, then R again and eventually it made a thud into it then ok.
Appreciate your advice.
regards
Peter

 

I guess im just trying to make myself feel better and hope it is indeed a low fluid level... its late at night now, when I get time I will check it proper.
Here is something I found on an AUdi forum wrt low fluid levels In transmission.. Sounds like my situation, but only on initial engagement sometimes is it missing and eventually is there a thud.


"My old car had a leaky transmission seal, and this caused the fluid to drain out. The way I noticed, was when I would put the car in D,P, or R, there would be a delay of a few seconds before the gear was actually engaged. Also, as PZ mentioned, there was some slipping taking off from a stop. Overall, all shifting was harsh. "
"You might get harsh initial gear engagement,harsh downshifting and slipping during hard cornering. That's what happened to me when the body shop changed my trans pan and did not filll it properly. "

 

And some more
"
Symptoms of Low Transmission Fluid
Being well-versed with the role of transmission fluid in the vehicle and knowing how low fluid affects the vehicle can help you diagnose the problem at the earliest and work out a solution before the situation gets worse. If you are facing the problem of low transmission fluid in your vehicle ...... you will experience transmission slip between gear shifts every once in a while.
... you will literally feel the rough movements or jerks when shifting gears.
... you will experience a drag when you shift the gear to move forward or in reverse as the vehicle will take some time to adjust and pick up speed.
... you are likely to see transmission temperature rise due to increased friction.
... you may notice that the transmission fails to engage at times."

 

I expect by tomorrow morning you will have numerous responses from members on this side of the world.

 

As stated, probably your cheapest option is to look at a transmission fluid / filter change.

You don't say what mileage you have on your car?

Just did my X358 at 62k miles

 

The wiring harness to the valve body solenoids can have a loose connection. If the fluid level is ok, then clean/check wiring that is accessible without major disassembly.
Getting a rebuilt valve body with NEW solenoids is a worthwhile investment if you have
to tear it down. You tube has a video of a guy overhauling in his living room! $2600 will take care of removal/ overhaul/ install in the US. Not great, but not the end of the world. Be sure to get it done with a least a 12 month warranty.

 

Yes, valve body needs rebuilt with a new Sonnax main pressure regulator valve. What happens is the OEM valve oscillates in the bore and basically wears ridges in the bore that can cause it to take a while to come up to pressure and stick sometimes. The solution is to ream out the bore a hair larger and install a new valve. Sonnax produces the replacement along with the equipment to ream the bore. Removing and reinstalling the valve body is a fairly easy DIY job. I imagine you could find a shop in Australia to rebuild your valve body with the new valve. Here in the states, I ordered one already done from a company in Florida and then shipped them my old valve body for a refund of the core charge. I think it cost around $550 or so - its been a while. Fluids and filter cost another $175 or so. Total cost of DIY repair about $725.

 

My car has 229,000 km on it. Previous owner had a major overhaul on the transmission it seems at 155,000km which came with a 12 month/20,000km warranty on a nice fancy certificate, but im not sure what that service included as it wasn't stated.


Car seems to have most problems with selecting R say 20% of the time. It fails to engage and acts as if its neutral. Selecting D sometimes gives the same result but more so when selecting R. It doesn't give a thud into the gear all the time, sometimes it gradually catches the gear. Reminds me of fluid trying to build pressure up due to fluid being low.. Hopefully any way that's the case.
I wont be driving the car until I change the filter and oil.


My Question today is:


Is the main pressure valve engaged in the valve body when "R" is selected ?
Ron said that problems with "R" is not a reported issue for Main pressure valve/A drum failiures scenario's. So im wondering if this will rule it out.


regards
Peter

 

pdupler
can you give me a link to that company that sold you the remanufactured valvebody?
Whats the cost if I don't exchange my old valve body? Shipping will be a killer.!


I would rather either rebuild my old valve body with a sonnax kit (if needs be)
OR
purchase a remanufactured one rather than have a local clown try and rebuild it. I wouldn't know who to trust locally really.


Depends on he price.
Opinions appreciated.


Peter

 

Here is one rebuild service that has been mentioned on the froum;

AW55-50, O1M, JF506E, 5R55E, 09G Valve Body Replacement

 

thanks Ron
will send them a request.
I think shippings going to be a killer.
Anyone know of valve body rebuilders in Sydney Australia? doubt it but worth a try.
peter

 

Car is still usable, but with tranny issues,....hmmmm....

What would I do? Well,......(and your situation might be very different)......I would buy used tranny from the junkyard. I would put the thing on the bench, get on the web, and LEARN EVERYTHING that's to be known about this unit. Then I would source the parts, and rebuild that thing by myself, taking a week of my time, working 4-5 hours a day. Once I know that all the wear parts are replaced, everything is buttoned down, and sealed, I'd call my mechanic, and tell him to come over, drop the old one, and install the rebuilt one (in my garage with my tools). He would charge me between 500-700 bucks for the labor.

The only reason I would let him do it, is because it's a dirty job, and too much labor for an old guy like me. I would, of course, supervise his work, tourque everything to specs, and double check everything he does (there are not too many people I trust, although he IS very good).

Total cost here in CA,......about 2K. Few months back I found already rebuilt unit (ready to install) for $1500, but I would much rather do the rebuild by myself (for the reason of trust, as mentioned).

Good luck.