What Automatic Gearboxes Will Fit The BX?

[David]

Hi all, as the title states, I’m wondering what automatic gearboxes will actually work in the BX?

In short, I’ve found myself in a position where I might need to put an auto box in my car.

I know they were made with the ZF box, but I was very underwhelmed & disappointed with the last one that I drove, so are there any better options, such as a Xantia box? I found the BX box lacked enough gears & didn’t have a high enough top gear, not to mention how weak they seem!

If nothing else will really work, I’ve previously read that it’s best to find a petrol box & use a diesel torque converter, is this the case? I’ve seen a couple of boxes for sale from a Peugeot 205, so if my understanding is correct, one of these should go straight in?

Just for reference, the engine is the 1.9 diesel.

Thanks in advance!

[xantia_v6]

The Xantia 1.9D used the 4HP14 transmission, the same as the BX, perhaps with different ratios. I am not aware that any other transmission was used with the 1.9D.

[Jaba]

My GTi was an auto originally. Not long after buying it I too decided that an Auto was not for me, only 4 gears, sluggish acceleration, too low geared and MPG affected significantly so I put a manual box in and tweaked the 5 gear ratio to lower revs at cruising speed. So I understand why you weren't impressed with your auto.
I am sure that ratios can be changed in auto boxes, no idea how though so it would be a steep learning curve if you ventured down that path. Its a simple swap from a donor car so you could give it try if needs must.
I am not sure how the auto box would mate to your 4X4 RWD.
I have a C3 Auto nowadays for local use and quite like its EAT6 autobox.

[David]

Thanks for your replies.

So from what you’ve said & what I’ve previously seen, it looks like the ratios themselves are the same in all the ZF boxes, but the final drive cogs are independent, so it’s possible that they’re slightly different sizes to achieve different speeds for different engines. Theoretically, the rear shaft & final drive should be able to be swapped for anything to change the ratios slightly. I still can’t see them being very good though.

The only way I can see of mating one to the transfer box is to get a custom made shaft that will bolt to the final drive of the auto box, then slot into the transfer box. I would need to find a good engineer for that.

If I have to do it, then I’ll probably just drop the auto box in for now & then see if I can get an adaptor shaft made later.

I don’t think I’d get a C3 box working because it’s electronically controlled. I’d need something that’s mechanical. I would prefer something that’s ideally 5 or 6 speed with good ratios, but I don’t think what I’d like even exists.

The whole situation is annoying because I’ve just rebuilt the manual gearbox & the ratios in that are perfect now!

Any more ideas or decent engineer suggestions would still be appreciated!

Thanks in advance.

[RMS_TITANIC]

There is a automatic gearbox for a bx on Ebay right now, if it helps at all