Hey everyone, looking for a quick bit of advice. My 1970 XJ6 has a BW Model 12 transmission. It’s had a leak at the pan gasket but otherwise has run great and I’ve had no issues. Car shifts well, and as such several other projects have taken priority. I was just about to drop the pan today with a cold engine to do a drain, replace the gasket, and refill. I plan to do this every few years, with limited mileage in between. Given it’s great working condition, good look of the fluid on checks (and in the drip pan…), I didn’t see any reason to mess with a flush. In the interest of comfort and safety, I planned to just do this cold.
My thought is that any added benefit of warming up the transmission is minimal, given only a 1/3rd of the fluid will be drained anyway. It also becomes far less comfortable to work on with the heat and hot fluid. There’s no drain tap on my model 12. Then I realized, I have no real knowledge or experience to support my opinion. What do you guys do? I’ve seen support for both on limited research, so I thought I’d ask the group. Thanks everyone.
You will likely get more fluid out if it has been sitting for a long time so the fluid will drain into the pan from other areas of the gearbox (torque converter etc.)
Easier on the hands too if the fluid is cold.
I seem to remember using type ‘F’ ATF when I had my 1972 Series I XJ6 in the BW model 12.
@motorcarman, Type F is what I’ve been topping off with and plan to use. PO had a service that added about a quart of Dexron a few years ago, but everything else seems to have been Type F. Looking at all the prior discussions, I think Type F is the way to go with these.
Cold is fine and no reason to mess with a flush.
Leave it to drain for 24 hours and lots more fluid will come out.
Since you will have the pan out, I would recommended you add a drain tap, it will make your life so much easier the next time you will have to do this again…
An more important, change the filter.
There is no interchangeable filter on BW12, just a gauze screen. There is also a little magnet which is always worth detaching and cleaning whilst you’re in there.
Cheers,
Mike. 1973 DDS ( with BW12)
I got nothin to add. I concur with everyone. sound like the gasket may already be loose. the PO on my '85 used glue to seal the gasket & I took a Transmission fluid bath trying to get pan off. It takes for ever to get transmission fluid out of your hair.