When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
If you’re in America and have access to American wrecking yards. Most Chevy transmission can quickly and easily installed. Several will even have the shifter line up where it should be.
The part that makes it easy is the alignment pins on a Chevy transmission and on the Jaguar V12 are in exactly the same place. You will need to fabricate an adapter. But that is an easy Saturday mornings work.
ask if you’d like a step by step guide.
Well the first thing required is figuring out how thick the adapter has to be. There is a Big variety of transmission that can be adapted and rather than make a endless list, I’ll show you how to measure your self. What you need to do is measure from the face of the bell housing to the end of the pilot shaft.
There is a video on U tube called the camp Chaos Chronicles where Robert Knodt shows you exactly how to measure it. He’s very precise. Plus he fabricated his own bell housing rather than use the Chevy
I’m a little different since it’s actually not a hyper critical measurement. You can be as much as an .125 or an 8th of an inch short as long as you aren’t anything too long. Too long and you shove the crank forward damaging the engine. I always use that 1/8 as safety. Shorter is safe, longer is ruin for your engine.
Then you need to measure from the face of the block to the bottom of the pilot shaft hole in your crankshaft.
Take those two measurements and find out how thick the spacer needs to be. This is what you will wind up making. I cut this on my bandsaw but it can be done with a hand saber saw Simply trace the inside of the bell housing and the outside for its shape. I use thin cardboard as a pattern to start with. The two alignment holes are the only one hyper critical. When you are drilling the holes the bolt holes are slightly oversized. But the alignment holes need to be exactly to size and location. I drill slightly under size and then ream to the final size. Continued
The bolts going into the block will be tapered Allen head counter bores. While the bolts coming from the bell housing will be threaded. Locate them using the cardboard template.
This is a mornings work if you’re comfortable fabricating. If not you can get a machinist to do it for you. Just don’t use the word Jaguar. ( Hotrod will save you a lot of money) you likely will need the machinist to drill out the Jaguar pilot bushing to the Chevy size.
I'm looking for creating a conversion that is conveniently accomplished and supply of gearboxes is plentiful, thus making the conversion economical. I intend on producing a limited number of converted XJS models.
If you dont want to buy a kit, all you need is a bell housing. There are a few available.
i used a Quicktime spun steel unit as supplied by AmericanPowertrain(Drivenman).
2 notes with this bellhousing.
the locating dowels are the wrong size. I had to get custom dowels made(the bell was 1 size larger than the block - this was the source of many headaches until i realized it.
slight machine work required to allow starter to be mounted like it is from the factory(bolts through bell into starter).
If i did it again, I think I would try and source a Roadcraft bellhousing from thr UK.
I'm looking for creating a conversion that is conveniently accomplished and supply of gearboxes is plentiful, thus making the conversion economical. I intend on producing a limited number of converted XJS models.
you can use a Chevy transmission with a simple adaptor
it only takes a morning to fabricate one adaptor.
Roadcraft will not sell just the bellhousing. The Simply Performance “kit” is the Roadcraft kit, and they won’t sell you a bellhousing without a transmission either Driven Man will sell you a QuickTime bellhousing, and I thought that was the way to go, but now you say you had trouble. What you do you mean the bell was one size larger than the block?
Dellow in AU never wrote me back. I should call them.
I have a 5speed bellhousing but plan to do several conversions and would like a repeatable recipe!
Roadcraft will not sell just the bellhousing. The Simply Performance “kit” is the Roadcraft kit, and they won’t sell you a bellhousing without a transmission either Driven Man will sell you a QuickTime bellhousing, and I thought that was the way to go, but now you say you had trouble. What you do you mean the bell was one size larger than the block?
Dellow in AU never wrote me back. I should call them.
I have a 5speed bellhousing but plan to do several conversions and would like a repeatable recipe!
the quicktime bellhousing is fine, just took a little work to get it to mount.
The original dowel pins on my 1986 HE are .621” but the Quicktime bellhousing is drilled for .625”
I required .007” offset dowels to get the bellhousing aligned to spec(no big deal).
i bought a set of standard .625” .007 offset dowels and had a machine shop turn down one end to .621
regarding the starter, thr Drivenman design for the starter fasteners is terrible. They use studs and nuts coming in from behind the starter. Much better to use bolts like
the factory did. To do this is fairly easy, just drill out the lower hole to accept the correct sized bolt(i user an allen head bolt. You need to do the same to the top hole but you must clearance the area for a bolt to get in there(much easier to visualize what I am talking about if you had the bell in hand)
both of these modifications are simple for a machine shop.
also, you will need new bolts everywhere as factory fasteners are not compatible with the Quicktime unit.
Is there an actual list of manual trannys that swap in to the v12?
