Hello, I haven't found a topic like this anywhere. I have a problem with my 1972 XJ12L, after a test drive I think the transmission is locked in 1st gear. The gear lever is in order and transferred to the control box, the oil is fine. The service told me that the problem was in the clutch. Can someone help me, I'm from Croatia, and the service is located in England, no one here repairs that team of gearboxes. I forgot to write that it is a BORG WARNER 12 gearbox.

 

Ivan,
The BW12 is a very tough box. It is unlikely to fail completely. Get under the car and make sure the lever selects every position in the range. Check that the vacuum line is connected properly. Disconnect the electric kickdown switch. If none of this works then you may have to remove the gearbox and open up. I have three of these boxes under my bench, one from a 1972 V12. It is shame you are not closer!

 

Everything you stated is fine. The problem is probably in the planetariums or in one of the clutches, does anyone have an idea how to unlock it? As if the pantry was stuck in 1.

 

Gonna take some study ad than might yet end up with no present fix!

This is a basic BW box and has been around for decades and used by other car makers.

Two or more planetary gear sets and a multi dis clutch. the planetaries are controlled by hydraulic pressure.

So, research as to the power patrh and how the transmission is controlled. Governor, kick down cable vacum, etc.

Idea: learn the function. tehn see what failire matches your issue. No gears other than first!!

Does it reverse? That calls for a combo of planetaies as i recall, sorta.

Carl

 

Failed vacuum modulator, perhaps?

I have limited experience with the Model 12 but on the TH400 transmission the first and foremost indication of a failed modulator is that the transmission won't shift out of first gear

Cheers
DD

 

Hello people, here we disassembled the gearbox, the problem is in the slats and plates, due to overheating they burned out and stuck. Can someone tell me where I could buy it if it was not too expensive and delivered to Croatia? Attached is a photo of the parts I need, if the price is reasonable I would buy the whole repair kit.

 

Hopefully someone closer to Croatia will offer a solution or a parts contact. If not, I am willing to strip one of my Model 12s (I have three under the bench at the moment) and send you the parts. Postage will not be cheap, but the parts will be.

 

Have a look here: SNG Baratts

 

Thank you all for your answers, I ordered a complete set for reparations from Limora.de, a complete set with delivery costs around € 300.