Does anyone have either a factory drawing or their own measurements they'd be willing to share?

I'm working up to a 6r80 swap on my xjs and it would be great to get the adapter plate made before I tear the entire car apart!
I'll be posting my cad files when it's done in case anyone wants to follow in my footsteps but for the time being I'm stuck unless I can get this bolt pattern, I even tried reaching out to a couple of the usual parts companies but no luck.

Thanks,
Angel

 

I don’t do it that way. I use a thin ish piece of cardboard and tap out holes for the bolts and alignment pins. One piece for the block and one piece for the bellhousing.
Realize the bolts don’t align anything ( they are too loose in the hole for that). It’s strictly the alignment pins. The V12 after 3/4 of 1977 use the same alignment pins as GM TURBO 400 transmission. Which also is the same as Chevy bellhousings.
So the swap is really simple.
All you need to do is measure how long the pilot shaft is. Then make the plate thick enough to meet that need.

 

IM trying to do as much as possible before disassembling the car since it currently runs and drives.
Ideally I would have everything ready to bolt up to the engine so that I can swap it in a day and then the only downtime would be waiting on a driveshaft.
The tranny side of things is easy enough since I'll have it in front of me and as far as I can figure the flex plate is set up for a standard th400 converter so spacing that should be simple enough..
It seems like a bear to pull the transmission out just to transfer some holes and put it all back together but certainly doable if there's no alternative.

 

I understand that approach. I have everything I need here then pull it apart it takes a morning to make the adaptor. Then put everything together.
The drive shaft. Has to be made after everything is assembled.

 

What year is your engine? There have been 3 V12 bolt patterns, the 5.3 Pre HE with the Borg Warner transmission, 5.3 HE with the Th400 and the 6.0 with the 4L80E.

There are about a dozen bolts, it would be an exercise to get the spacing all exact for each of then and the dowel pins. I have never seen a factory drawing of the pattern, as far as I know, they are all unique to Jaguar. The TH400 case/ bellhousing is a unique Jaguar casting, same for the 4L80e, a GM 4L80 is not interchangable with a Jaguar version, either mechanically or electronically.

To put a cat amongst the pigeons, why not use a ZF 8 speed instead of the 6R80? It's more compact and gives 2 extra speeds. You'll be making an adapter and needing a controller for the other transmission anyway, so you're not doing anything much different. As a bonus, the ZF is actually slightly shorter than the TH400, so no body modification is needed. The ZF was used in BMW, and also Dodge trucks with the 5,7, so it should be reasonably available.

Are you thinking of the 6R80 (ZF/Ford) or the 6L80 (GM)?

 

It's an '86 (HE), a pre-HE actually just popped up on craigslist near me so I might end up going that direction and building an entire drivetrain to swap in together.

According to Mguar above the dowel pins should be the gm standard for the th400, my eyes may be deceiving me but aside from the starter bolts it really looks like the bolt pattern is evenly spaced around a circle centered on the crank which would make it actually pretty dang easy to replicate.

Correct me if I'm wrong but the ZF 8hp has no off-the-shelf standalone controller, whereas the 6r80 has the 'quick 6' from USshift.. as far as 6R80 vs 6L80, the 6R80 has slightly better gear ratios (especially 1st) and is significantly stronger even in stock form. The main reason I'm looking at the 6R80 however is because I know for sure it's been done, there's even a couple shops in the UK that offer to do it for you for a cool 13 grand.. yikes!

 

It does, made by TurboLamik. https://www.domi-works.com/products/...n-control-unit

There is a guy on the XJ list who has put the 8 speed into an XJ6.

 

Try this link https://grabcad.com/library/jaguar-5...-flange-dims-1
author is a Paul Kobres

 

Beautiful! And a .step file to boot I could not have asked for better!
I'll be sure to post an update down the road confirming if this fits and will be sharing any cad work I do, I really think these old engines will come to life with better gear ratios.. hopefully more swap options will save these cars from being small blocked...

 

Looking forward to seeing how this goes. 6 speed auto should be the perfect refresh!

Cheers, Dave