I see threads on this transmission with Valve Body and other issues. My VDP has 40 k miles and the last owner had the Fluid, Filter change at 37K. Does clean fluid keep the Valve Body from the high pressure issue that causes issues?

 

Maybe, maybe not.
The wrong fluid could cause problems?

I bought a 1998 XK8 with a 'bad gearbox' for cheap.

The seller stated is was rebuilt 20,000 miles earlier and had paperwork to prove it.
I removed the gearbox and partly disassembled it to determine a general cause.
First thing I noticed was RED FLUID.(there is no approved RED FLUID)

I pulled the pan and found metal debris.
The valve body had metal pieces between the passageways.

The gearbox was definitely 'grenaded'!

No proof the wrong fluid caused it but???????????????????

I have spare 5HP24s so I pulled one apart and replaced the forward drum and pressure valve. (transgo)

The forward drum is a known 'weak-link'
The pressure valve bore can wear and the Transgo valve has 'O'rings to help seal if the bore is slightly scored.

It's your call, it's your car.

 

Using the wrong type of oil (e.g., wrong viscosity or the wrong oil for the engine type) can lead to poor lubrication, increased wear on engine parts, overheating, or even catastrophic engine damage. so you have to be aware of what type of oil you are using

 

Replacing the pressure regulator with the upgraded one will let you know you have that done / peace of mind

 

If it were me, I would go with the Transgo valve.... sooner than later.

 

My transmission was changed at 35k with BG Synthetic, it looks like it meets Jaguar and ZF along with many other makes.

 

I'd say your tranny is the 5HP24 (you forgot the 5 - for 5-speed).
Using the correct ATF is paramount.
Check for the right fluid and other info in my old thread:
https://www.jaguarforums.com/forum/x...-flush-265900/

 

Thanks for the feedback. The note from the shop, was they have never seen ATF this clean. 35k miles at the time.

 

Perhaps because the fluid was not doing its job!

 

Simple wear is what causes problems. The valve body itself is aluminum and the pressure regulating valve is a small piston (of some harder material) that moves back and forth between orifices against a spring that applies constant pressure. That piston can move back and forth rapidly quite a lot and it doesn't have a very large piston skirt surface area to stabilize it. There's enough clearance for it to move freely, but that means it also can **** at an angle in the bore and dig into the sides of the aluminum. If the fluid is the wrong viscosity, then that could certainly have an adverse affect. Who knows tho if ZF spec is even ideal. I'm sure its a compromise, needing a little thinner for one part of the transmission and a little thicker for this part. The Transgo solution is a new design piston with seals that rides against an un-worn portion of the quite long bore. The Sonnax solution reams out the bore to a larger diameter before installing a new, larger piston.

It does seem rare for the valve body to wear to the point of failure by 40K miles, but not unheard of. I installed a rebuilt valve body by Sonnax more than a decade ago at around 85K miles (yes, the oem made it that far) because Sonnax seemed to me the superior solution (i.e. reamed out meant essentially now free of defects). But then only got about 40K miles out of that before it failed. I had during the procedure refilled it with fluid that met whatever the Jaguar technical specification number was, but I didn't buy the high priced ZF Lifetime fluid so maybe that had something to do with why it failed again prematurely or maybe Sonnax didn't do such a good job or anything else. Anyway, the next time I rebuilt the whole transmission with a brand new lower valve body, clutches, seals, filter, everything direct from ZF - nothing aftermarket. All seems ok after a few thousand miles, but I'll let y'all know in another decade or so after I've put another 40K on it. I'll be retired then and maybe bored enough to pull the whole unit out and disassemble it just to see before changing the fluid again. Both times before, there was an obvious significant ridge worn into the bore of the aluminum valve body.

I don't know BG synthetic, but if I were you, I'd just drive it, try not to worry, but pay close attention to any weird symptoms. If you ever feel anything like like somebody has tapped your back bumper or notice a delay in engagement, like when shifting from park to reverse, then its likely the pressure valve is getting worn and should be repaired ASAP. Seriously, these cars are not worth much so you don't want to have too much invested unnecessarily. Since the previous owner already spent money at a transmission shop having the fluid changed, let's just assume that the shop probably knew what they were doing and its going to be OK (or as OK as it will ever be). Almost guaranteed that something else expensive and unpredictable is going to break next and so I'd save my money for that or spend it on some other preventative maintenance that you know has not been done yet.

 

Thanks for the reply’s. I will get it out of storage in San Diego in February and drive it to Seattle. I have gone over the service that my friend did before giving it to me.
List of service
Bought new in 2001, Spokane kept in a heated and cooled garage, never driven in snow. Serviced yearly by dealer.
my friend bought it from uncle April 2027, had it service at Mercedes of Spokane oil and tires Continental Eco +25 K miles


9-17-17 Euro Tech Denver Engine Oil, Transmission with BG Syn, Def fluid change, Brake Flush.
9/26 headliner recover
April 18 Jaguar Denver replace Timing Chain kit, air filter water pump Thermostat and Battery and Cetek Battery charger, battery, and wire for charging when parked. 35,922 miles
3/20 Tacoma Jaguar service engine 4 wheel Alignment, replace tires with Michelin Premier A/S, Coolant Flush, Battery replaced by mistake with a Interstate MTPH8. The Tires were replaced because the Continental were out of round.
He shipped jthe car to San Diego 4/20
5/22 39,580 Jaguar San Diego tires were rebalanced after check of wheels and suspension. The tires were road force rebalanced and rotated. Water Pump was replaced.
Car was always stored in a inside Garage.

i bought it for $100 12/18/24 and put in storage. They washed it and put the car cover on it.

Terry wanted the cat to go to me to take care of it. I and retired and have been a car guy my whole life. I have owned a MG TD, TR3, Rover 2000, In collage. I also had a detail shop while in college. I currently have 2013 Jeep Grand Cherokee, 2010 New Beatle, 2015 Winnebago View on the Mercedes Chassis, 2018 Ford Fiesta that is towed by the RV. I am on Forums for RVs and Jeep. I find the information I get to be very useful. You on this Forum are a great use of information,
Thanks in advance.

 

I would say don't overthink it it's low mileage and well maintained just enjoy your car avoid sudden gas pedal kicks drive it smoothly it will last long time

 

Good price! Enjoy the ride. I've got to put my transgo valve in and replace the speed sensor this spring. After that drive til it dies then sell for parts. Too much already fixed to sell.

The sadest thing is I found it appropriate to purchase a platinum aaa membership so I can have it towed anywhere within 200 miles.

Enjoy your ride. With the LA fires used car prices just jumped.