XJ12 5 speed conversion advice needed

Hello all,

I have a V12 XJC and want to do a 5 speed manual conversion, the pedal box is already installed.

I have heard that the T5 box is the go as the shifter comes out in the correct position on the ski slope?

Is this correct?

If so what model, year or type of T5 do I need to source here in Australia?

Thanks

I have an XJ6L converted by a previous owner to a manual using a T5.

I am no expert so take all this with a grain of salt. My T5 came out of a mid-1980s Ford Thunderbird 2.3L turbo coupe. There are apparently two classes of T5 - one called WC (World Class) and one not. Something about the WC is deemed better quality.

However, are you sure a T5 is suitable/strong enough for the V12? I’m not saying it isn’t. Just asking. There’s an outfit at TheDrivenMan.com that sell manual conversions and they use a Tremec TKO 500 on their conversion for the XJ12C. Link to TheDriveMan.

There are, of course, a lot of other things need to change in such a conversion. On my car they changed the bellhousing, flywheel, gearbox and prop shaft as well as adding, obviously, a clutch and the pedals (and yes, the shifter did fit through the hole in the tunnel with no modification in my car).

Good luck.

David

I used one from mid-late '80’s mustang in my xjs. here is a link with specs on t5’s http://www.allfordmustangs.com/Detailed/349.shtml

Good Day,
I converted my 72 XJ6 many years ago and used the T5 from a mid 80’s Mustang SVO, originally tried one from a Mustang 5.0 but the gears were not quite right, the SVO worked better with the weight of the sedan. The shifter comes out just aft of where the auto stick came out, which for me was great as you can rest your arm on the console and easily shift thru the gears. I removed the ash trays and installed cup holders forward of the shifter. I fabricated a 3/4" thick adapter plate that I attached to the jag bell housing and installed studs facing aft to attach the T5. I used the 9.5" clutch disc from the Mustang and the pressure plate from a Jag. Also, at first I tried to use the original driveshaft set up with the center carrier bearing, but continually tore up the rubber mounts. I recently pulled that out and installed the straight thru driveshaft from the Mustang and it worked perfect. Awesome conversion and it really wakes the car up, fun to drive!

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What did you use in the end?

Have all the parts for my 5 speed conversion finally, I went with the Getrag option…

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excellent information

Looks very nice! Will you dare to drive the car once you are finished?

Yes of course Harry, through all weathers, just will stay off the snow when they salt the roads…

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Thats good news! Salt is what I avoid as well, but as you would say in German, it is a “Fahrzeug”, not a “Stehzeug” :slight_smile:

Engine and Gearbox is in… prop shaft being shortened, should hear it growling this week…

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Wow! Great job.
Looks great. That’s a huge job.
Looking forward to hearing how it runs.
I’m soon to be doing an XJS V12 with Getrag, so I’m excited to hear about yours.
Rob

I sat in the car last week and went up and down the gearbox (making the suitable noises in my head), not quite Civic Type R but a lot better then expected. Was also surprised with the free space in the foot well, the new pedal box has left ample room for a foot rest…

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Massive update from Tom Lenthall… She starts runs and drives… 75 psi oil pressure !!! So chuffed, the sense of relief that it has all gone together and that my hash up at doing something I’ve never done before is palpable.

Will post a video in due course… cant wait to get her home.

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Can’t wait for the video. Oh, to drive a stick again!!! Dreams. left knee no longer up to it…

Carl

**
At what revs and temp, Mike - 75 psi at hot idle is excessive…:slight_smile:

Frank
xj6 85 Sov Europe (UK/NZ)

I’ll check, it was a comment from the engineer building my car, who is renowned for V12 jags… he seems well happy with it… will report back in due course when I get it

Frank, Sorry my mistake, it was 70 PSI at idle on the capillary gauge, not sure it was hot though… but the guy who pieced her back together, Tom Lenthall said its a good pressure…