Triumph Stag - ZF gearbox conversion project - Part 1

With all this talk about folks replacing their BW35 gearbox with a ZF gearbox, I thought since I have time and I was able to source a gearbox locally for $100, why not have a go. There are handful of folks who have done this as a DIY project. I really don't think I will get it done in my life time as I have 3 spare BW35 boxes and if my car dies, I'd take a chance and rebuild one of them myself.

[@stevesalvage1089]

Interesting, I've added a j type overdrive to a bw35 , makes for very good cruising. , same as Manuel with overdrive, I believe that the zf top gear increases the the propshaft speed similar to that of an overdrive, keep us updated great project to see alternatives,

[@sujitroy]

Did you have to cut the tunnel to get it to fit? I heard OD Spares in UK has or had a kit which you bolt on between the BW35 and prop shaft.

[@stevesalvage1089]

@@sujitroy no , I only had two fabricate the mount bracket that fits between the. stag manual overdrive bracket and the overdrive bracket fitted to the adapter that goes between the automatic and the overdrive, this is because. The whole unit is longer , the speedo cable same as manual overdrive , also shorter drive shaft buy about four inches easily done if you have welder and grinder see UA-cam films how to do it , if you mount the box all in place jack up box at the rear and you can quite clearly see what small bracket you need to fabricate , it's actually. Straight forward , I used to work for formula Ferguson. Doing body work but you could see the overdrives. Fitted to all sorts of automatics and four wheel drive systems,

[@iankidd6500]

Hi, I am from the UK with a Stag using the BW35 box and want to convert it to the Jag ZF4HP22 box and wondered who/where you purchased that adapter plate from as it’s exactly what I will need, also what ideas did you have to make the speedo work as the ZF does not have the figment for a cable? Many thanks, Ian

[@sujitroy]

Reach out to me at [e-mail] I'll send you what I can. Folks have been nice to send me stuff, but some folks have asked me not to share what they sent me. Regarding the speedo, Caerbont Automotive Instruments Ltd have a digital speedo and a pick up which works with the MK2 Stag.

[@SXBoy-q3c]

Hi , great informative videos , thanks.
If I emailed you would it please be possible for you to send me the info you’ve gathered on the ZF conversation as I want to do it to my Mk1 in the next couple of months . Thanks in advance. K

[@sujitroy]

Details sent.