I am going to convert my Shooting Brake into a manual this winter. But I need some help sorting out the info that is out there from the experts. I do not want to buy a kit because I'm not sure extra expense is worth it. I'd also like this thread to serve as a guide for someone in my place in the future.

I am leaning towards a bell housing from:
V12 Jaguar Bell Housing

And using a World Class T5. Why? They are cheap? $700 versus $2500-$3500 for other trans. This isn't gonna be a drag racer or driven that hard so I'm willing to risk some theoretical longevity.

Here are my questions (so far):
1.What are flywheel options? I've seen some that replace the entire flexplate with a new flywheel and then another that looks like some sort of sandwich deal using original flex plate. Aluminum? Steel?
2.Which clutch? Since the tranny, flywheel and engine are all different, how do you choose the right one?
3.Tranny tailshaft yoke (if I'm using the right terms, one that is from the T5 and then have it welded at driveshaft shop?
4.Spoke to an expert who thought that stock 3.35 first gear from a T5 and my soon to be new 3.54 gears would be too steep-any insight?
5.Pilot bushing-what is this exactly and how to source correct one?
6.Does anybody know EXACTLY what T5 (year make and model) lines up the shifter (mostly) correctly?
7.Is the $200 I save buying a already engineered pedal box worth it over modifying my own with a kit?
8. New modified ECU worth it? (Think it'd be nice to have some extra power at same time so mod the ECU for power and fuel cut off adaptation for manual tranny)
9. clutch actuation-the Bell housing I was looking at only uses hydraulic release bearing versus a clutch fork (correct my terms if I'm using them wrong)-any pros or cons to one way or other?

Thanks!

 

Hopefully mike90 will see this, and chime in. He has done extensive research in this area. In fact, if you search for his posts, you will find lots of useful information, and probably answers to some of your questions.

 

I just sold a compete seto up.
early borg Warner bellhousing, adapter plate to t5. High torque starter. Ally flywheel. Concentric slave cylinder. Triple plate clutch.

the t5 borg Warner in the UK is fitted to the Sierra cosworth so they are becoming hard to find. Not sure what American cars they were fitted to.
t56 is much more common in the states I think ?

fidenza do a flywheel and can probably suggest a road clutch. I'm using a mcleod clutch on my v8 conversion.

pilot Bush you can buy the bronze jaguar one I believe that will fit the crankcase. Just have it machined to fit gearbox shaft.

you might have to have the input shaft extended depending on clutch and adapter plate size.

a few of the club racers here use the jaguar getrag gearbox on the back of a v12. I think they just have an adapter from bellhousing to gearbox made.

I pop in and out of here so might be able to help with bits.

 

https://www.jaguarforums.com/forum/xjs-x27-32/convert-v12-manual-transmission-87836/

 

Your gearing (3.34 first and 3.54 diff) will almost be like a low range 4 WD. Next if your not worried about performance I'd stay away from the aluminum flywheel. The hydraulic throw-out bearing (HTOB) mounted on the trans is probably the only way you'll have to go. To big master cyl, hard to push pedal, to small won't engage the clutch. Another thing to consider is a clutch pedal stop, read up on it. The ECU, I had to send mine to AJ6 for reprogramming, mine engine stalled between shifts.
IMO piecing together this type of conversion can be frustrating, that's why I went with a kit. See American Powertrain's video's on HTOB etc.
In your case you have a lot of decisions and homework.

 

Really looking forward to seeing progress on this thread
There appears to be good information about the complete conversion kits available - but I can't find any real information about using the approach you are talking about i.e. t5, generic v12 bell housing, throw out bearing etc
Will be watching with interest as i'm just about to start this process myself

 

Tread carefully in what model of T5 transmission you decide to go with - the 5.3 V12 XJ-S is rated at 300 ft lbs torque & IIRC correctly none of the T5s before 1990 were rated at more than 265 ft lbs. 1990 - 1993 units were rated at just 300 ft lbs & only cobra spec or Z spec T5s were rated at 310 ft lbs & 330 ft lbs respectively.

Rgds.

A.

 

Have stopped in from time to time to see progress on the shooting brake- what a great project!


On the manual conversion, and your questions: having done a TKO 5 speed on my car (albeit from a kit, but...you end up learning where the holes are there, too), and doing a lot of messing around with ratios (both diff and trans), I may be able to offer some bits:


1.What are flywheel options? I've seen some that replace the entire flexplate with a new flywheel and then another that looks like some sort of sandwich deal using original flex plate. Aluminum? Steel?


I used aluminum (Fidanza). Works fine, engine spins up well. Biggest problem is the need to slip the clutch a bit on roll out. Just doesn't have the rotational inertia of the steel wheels, but, it IS lighter.

2.Which clutch? Since the tranny, flywheel and engine are all different, how do you choose the right one?


The clutch that came with my kit was for a V8 Camaro or some such. Basically, I would go for a clutch that a) fits the spline of your T5 input shaft, and b) gives enough holding power for the HP and torque your motor makes. One of the GM V8 clutches make sense because they usually will hold up, are reasonably priced and plentiful to locate. BE SURE YOU BALANCE THE FLYWHEEL and PRESSURE PLATE! Match mark them and have them dynamically balanced.

3.Tranny tailshaft yoke (if I'm using the right terms, one that is from the T5 and then have it welded at driveshaft shop?


Tail yoke is your call; my TKO used the same interface as the autobox, if I recall, and the flange at the other end was circular, to match the input flange of the diff. BE SURE TO GET YOUR DRIVESHAFT BALANCED!

4.Spoke to an expert who thought that stock 3.35 first gear from a T5 and my soon to be new 3.54 gears would be too steep-any insight?


I run a TKO with 3.27 first gear. I had this against the OEM 2.88 diff and felt this combination was way too long-legged. But great on gas when cruising! I acquired a 3.31, and at the last minute, switched to a 3.54 because I found a diff with that ratio with the speedo pickup in it. The 3.31 would have had to be modified to get a speedo pickup (my car is 1990, with speedo pickup off the diff). Now, a 3.27 first against the 3.54 final drive makes first gear something- can rip the cage out easily, and its not a long gear. But, you can idle along in city traffic quite nicely and dispense with a lot of clutch action. Better ratios for the 3.54 are first gears somewhere in the 2.8 to 3.0 range. The close ratio TKO box matches well with the 3.54 for this reason. I myself am now looking hard at a custom T56 box, because that 3.54 *just* gets you into usability with the double overdrive T56 if the gears are well chosen.


Great thing about the T5 is that there is an almost infinite choice for gears, so you should be able to fashion what you like.

5.Pilot bushing-what is this exactly and how to source correct one?


This is typically a sintered bronze sleeve bushing that runs on the tip of the input shaft of the trans, and rides in the pilot hole of the crank. Some kits use a roller bearing affair, and locate that bearing in the torque converter pilot of the crank. Which one you use depends on the length of the input shaft and the bell (e.g., how much depth is left on the input shaft to enter the crank). IMPORTANT: if you use the standard approach (a sintered bearing riding in the inner pilot hole), MEASURE the pilot ID on your crank. Jag used one diameter, pre roughtly 89 and another post 89. I had to have mine turned down at a local shop. There's something like a 0.001 to 0.002 inch interference fit that you are looking for, here. To much, and you will not be able to shift the box. Too little and you have lost bearing support. MEASURE!

6.Does anybody know EXACTLY what T5 (year make and model) lines up the shifter (mostly) correctly?


The GM T5's are often at an angle, and you have to contend with this. Other T5's fit square. Where the shifter comes up is always the great concern. On the TKO, there are like 3 locations where the shifter can be set up. On my car, it is exactly where the OEM Jag designers intended the manual lever to come up, because I have a ski slope for the 6 cylinder manual box cars, and it's dead on, in fitment.

7.Is the $200 I save buying a already engineered pedal box worth it over modifying my own with a kit?


If you like fabbing stuff, have at it. I would probably go for the completed assembly. BE AWARE: if your car has ABS, you will need a different pedal box that is used on a NON-ABS car.

8. New modified ECU worth it? (Think it'd be nice to have some extra power at same time so mod the ECU for power and fuel cut off adaptation for manual tranny)


This is essential. The first time you try to drive your new manual, you will stall at the first stop sign. This is because of the overrun cutoff of fueling in the Jag ECU. Bywater of AJ6 can supply a modified box. I have the TT pipes, and my ECU has the full tarting up treatment that Bywater does. I like it well enough, but it's not going to blow your hair back- you'll feel it never the less. Be sure to get the bored throttles (or get yours bored)- much sharper throttle response with those.

9. clutch actuation-the Bell housing I was looking at only uses hydraulic release bearing versus a clutch fork (correct my terms if I'm using them wrong)-any pros or cons to one way or other?


I have the hydraulic release, and I like it. Big problem I had: the clutch line snakes along the trans tunnel where it is a stainless steel flex line and that is fitted to the custom bent flared steel line at the bell. My car's clutch release plumbing fitment was poor (the flare quality sucked, frankly), and I have a slight clutch leak. And it's....you guessed it, right along the trans tunnel where I CANNOT reach it no matter what I try. I will not be able to address this problem until such time as I pull either that engine or the trans, so that I can get to it. Moral: BE SURE you design your lines and fittings to a) be accessible after the whole kit is installed, and b) is leak free! (I know, for a Jag that might be asking a bit much).


It's not as hard as some make out. I see you are a fair hand at making your own bits, so this should not be too bad. Seriously look over your gearing, though, because that 3.35 first and a 3.54 final will definitely make it feel shorted legged.



-M

 

5) depending on the bellhousing & manual box used, this Bearing may be an option:

B15115DDUC4SA Clutch Pilot Bearing Compatible With GM 12557583 PFI 15x43.32x13mm | eBay

The GM400 or GM4L80E pilot is IIRC correctly 1.703" & this Bearing IIRC has an OD of 1.705" - the interference fit mentioned by MIKE90 of 2 thou - although this Bearing sits in the OUTER recess of the crank & not the INNER recess. It won't be suitable if your input shaft protrudes into the INNER recess of the crank.

Rgds.

A.

 

Biggie:


Good points on that particular bearing approach.


The sintered bronze affair, which uses the inner-most bore in the crank, though, can be done using a standard Jag V12 pilot bearing. The ID of this bearing is set to GM pilot diameter specs (so if you get a Ford box, you need to get that input shaft turned down, or, replace it with a GM-spec input shaft, if you are going to open the box anyway). It is the OD of that bearing that needs the interference fit with respect to the crank bore, and the OD you need will depend on the pilot bore ID of the crank.


But getting that particular type of bearing is not difficult, nor expensive, even if it is an OEM Jag part.


I attach pix of the bronze bearing, and of the roller type you have mentioned. The latter pix are from a fellow Jag enthusiast who got that bearing in their TKO kit. One of the pix shows that roller bearing sitting in the torque converter pilot of the crank on the Jag V12.


The pix of the sintered bronze bearings deserves more explanation: the bearing on the left was supplied with my kit, but the OD was turned down to fit my 1990's smaller pilot bore. The one on the right is another bearing I had picked up to have machined, in case the first one did not work out. Note the slight chamfer on the left bearing: makes it easier to drive that bearing into the pilot hole of the crank. Slather it in lithium grease, and drive it in.

 

Mike90,

Did your kit use a FORD TKO which has the longer input shaft than the GM TKO?

Just wondering if that was the case & that's why you needed to fit the sintered bronze pilot bush in the inner recess. Unless the earlier bell housings were not as deep meaning that the input shaft protruded further out of the bell housing & thus ended up sitting in the inner crank recess as opposed to the outer crank recess.

Any advantage of the needle roller bearing fitted in the "bush/blank" over the pictured bearing?





Rgds.

A.

 

Biggie:


That is a very good question! One of the reasons I have been emphasizing MEASUREMENT of the crank and the box/bell being considered.


Some historical details of my setup: I bought a Keisler kit (one of the original Keisler kits, not the Driven Man setup when they were resellers). This kit was part of a group buy by some listers on Jag-Lovers, not long after Keisler introduced the product. It was for a pre-89 XJS. I bought it from a party that had purchased, but never installed, this kit.


At that time, Tremec's TKO was only available in a FORD spec box. I believe Kiesler did some custom machining on the input shaft for the purposes of this Jaguar XJS V12 kit. I say that because I have the original Tremec tag that was on the box, and it is a FORD spec Tremec part number, and the box, while clearly brand new, showed evidence of having been opened and resealed. But the shaft pilot diameter measured 0.590, which is a GM spec (FORD spec is something like 0.668). I do not know where the bell came from; it is an aluminum bell, and does not have a port for a lever-actuated clutch release. It is clearly intended for use with a hydraulic release bearing (which is what I have). I did not measure the bell height, but I did measure the input shaft length to be very roughly 6.75". This is a very approximate measurement.


In any case, this meant that the pilot tip of the input shaft fitted well into the inner bore of the crank, for this configuration.


I don't know of any particular advantages of the roller bearing I showed pictures of. That bearing was shipped with later Keisler kits that were probably based on the GM version of the TKO that Tremec later brought to market. It would have made sense for later kits to use this box, since it would eliminate any custom machining of the input shaft.


The message is, if you are planning to use a transmission pulled from a wrecking yard, just be sure you know what you are buying (e.g., did that T5 come from a Ford or a GM, for example), and make the measurements to know the particulars for fitment and so on.


For what it is worth, I measured the distance from the front face of the TKO to the line of the shifter as approximately 18-1/8", and 19-3/8" to the actual pivot point at the entry to the transmission (e.g., the lever attachment is a dog-leg facing forward). The relevance of these measurements only has meaning if one also knows the bell height, so be forewarned. But the final result was that this placed the shifter right where the factory placed theirs for the 6 cylinder manual cars (with the ZF boxes): I know this to be reasonably factual, because I bought a ski slope for the 6 cylinder manual box model, and the lever in my car is dead center of that hold in the ski slope. The whole deal now looks completely factory.


All those things being said, these kits were offered in the so-called 'wide ratio' and 'close-ratio' setups. Wide being a 3.27 first and close being a 2.87 first. The close ratio box is poorly matched to the 2.88 diff ratio, but OK with the wide ratio (not optimal, but workable). The close ratio box is reasonably well matched to a 3.54 diff ratio. Ideally what you are looking for is a total ratio (first gear ratio X diff ratio) in the mid 10's. Higher than that and you are in stump puller territory; lower than that and the box will be very long legged. I run the wide ratio box with the 0.68 OD 5th against the 3.54 diff, and it still accelerates strongly in 5th (around 2.40 total ratio in 5th). But, my, is it ever short legged. I personally am likely to change that box to a T56 6 speed, with a first gear somewhere in the range of 2.8 to 3, and get custom 5/6 gears to match my tastes. Had been looking more seriously at a Richmond 6, as that could be specd with very tailored ratios (and, that box is almost a drop-in replacement for the TKO), but, that box has all but disappeared. Too bad, too, as that one could be set up to work MUCH better with a 2.88 diff. A T56 against the 2.88 is simply unlivable (unless you only want effectively a 4 speed; the double overdrive reaches to the stratosphere against a 2.88), and there are few alternatives in ratios.


This is the main dilemma with fitting a manual box to the XJS: the best setup is always found with a diff ratio that is NOT the 2.88. The easiest diff ratio to match a box to (gives widest selection of boxes and gearing to consider) is the 3.31. The 3.54 enables close ratio boxes to be considered, and to really be able to take advantage of a box like the double overdrive t56, you should be looking at 3.73 gears or higher, numerically.


Once you decide on the ratios, it's all fitment, and those details can be sorted with enough diligence.

 

If budget allows I would look into the White Lighten shifter from American Power Train. Not saying the stock TKO shifter isn't good. This looks like it takes shifting to a new level.
The only set back is i think the trans has to be on the floor to install the shifter, and I'm not pulling the trans unless needed .

 

Any update to this thread? I have a 5speeds bellhousing, fidanza fw, and late v6 mustang t5 going behind an '85 motor and am figuring all this out at the moment. I am currently having a machine shop turn down the bearing retainer so it fits in the bell's register bore.

Next will be determining what input shaft (possibly GM) to use or length/diameter for machining and the proper pilot bushing. I can document what ends up working for me if there is interest. I'm planning to do the entire conversion with quality parts for under $2000.