I just began noticing a short, whirring sound I think from the tranmission as the engine moving gradually from low seeds. Seems there is a spin, or whir and then the gear or clutch kicks in. No thunk, jolt or bang. Just a very short whirr like you hear from a small motor such as when the telescoping motor retracts the steering wheel.

Big trouble ahead? Harmless quirk at old age? Something in between? . (Though I assume nothing is harmless on ZFs)

Thoughts, guesses or

 

A couple of things you'll want to start reviewing...first is the valve update kit (this should be done anyways)...Transgo ZF5HP24 Valve Body Pressure Regulator Repair Kit...various providers on the net, especially eBay.

Review this thread (the OP does a very nice job), especially the video and the video maker, he has some very good ones for this trans (describes the issue and causes well)...https://www.jaguarforums.com/forum/x...-p1733-231405/

 

Len, my VDP made a similar sound from the transmission as it shifted from one gear to the next, I always suspected a low transmission fluid even though I took it to 3 different transmission shops, who claimed it was full. I ended up buying and installing the dipstick conversion kit and was able to get almost a full quart of fluid in before it reached the mark on the dipstick. The whirring sound went away. No problems since.

 

Thank you. Turned out that a tube of friction modifier eliminated the whirring sound. Otherwise fluid was fine, no metal filings at the corners. Topped up fluid (Esso), and added friction modifier which I am told is available at Ford dealers. Got mine through an AAmco shop.

Only headache is that even with all that and a new pan, I now have a small gearbox leak which I didnt have before. Been running a couple weeks and leak has not stopped entirely.

 

The O-ring seal on the wiring harness connector is well known to leak. You'll want to check that. The O-ring itself isn't available by itself, you have to buy the whole connector, ...which isn't much on ebay.

 

Thanks, HIghhorse. This look like the culprit?

https://xks.com/i-7146778-jaguar-aut...m20217jag.html

 

Too cool ...you found it by itself.

 

So a few months have gone by and I got the dreaded gearbox fault and a P1722 code. I have no forward gear unless I rev to 1500 RPM and I have only reverse. Seems like class is pressure reg valve and and maybe A drum failure? Will know better this week. I think Ive found the right experienced shop to do the work.

My question is with the housing out of the car, I thought it a good idea to replace a leak in the rear main seal. But didn't I read on this forum that there are coolant tubes or heater hoses in this vicinity that might as well be replaced because of age?

What else is there?

It if its indeed A drum failure and a PRV how much further into the tranny need we go? Would you necessarily replace a valve body? Other parts?

All thoughts welcome.

Thanks

LA

 

If I haven't posted this to you before, check this guy out. He has some in depth videos on both the 722.6 and ZF 5HP.... https://www.youtube.com/c/GaryFerrar...h?query=zf+5hp