Yesterday I replaced the valve with the updated version: 1058 327 030 01, purchased from California Transmission Supply.

Main Pressure Valve 5HP24 - 5HP30

I had planned on changing the fluid and filter, so it only a little over a hour.
Just remove the sensor and all the T27 screws from the forward valve body and wiggle it off the locating pin. Then on the bench take off the end cap and watch the springs go flying. Refer to the article "Transmission Jaguar & BMW Clutch Drum Failure" on Gus's website jagrepair.com for an excellent diagram of the valve body.

It is difficult to replace the end cap without the use of a couple of bar clamps and an extra pair of hands.

I used 7 qts. atf fluid and about 6 oz. came out while the transmission came up to operating temp.

According to the article, this should help prevent pressure spikes that can damage the A drum, but the valve body should be replaced if there are signs of wear. Mine was still in good shape, but I have no way of knowing if it was the original.

 

What was the cost of the new valve? Was there a core charge/did you have to ship back the old one?

Is it working good so far?

I have to do this job sometime this spring. First 60 degree day today in Minneapolis.

B

 

The valve was $23 + shipping. Scroll down to the thread "Change oil in gearbox" and see my response to EZDriver earlier today.