Yes, I considered the 5/6 speeds. But reading conversion stories on here over last 15 years I interpreted that it can be a real c*nt to tweak and get right. Have you done that conversion?
Plus I have had her laid up for about a year while I was giving her a makeover so not really up for the hassle-i just wish to drive her now.
James, yes I changed my 91 TH400 over to a manual TremecTKO 5sp about 7yrs ago. IMO, from what Iâve read, its not much more labor intense than your other options. The Forums are loaded with info about All 5/6sp, auto 700 and GVâs Trans swaps,ratios, cost, hints, etc.
After your trans is decided you can start thinking about diff ratioâs. Just keep in mind the stock IRS & 10 bolt are not made for âhole shotsâ or âburn outsâ. See ronbros threads for IRS mods.
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Kirby:
Iâm the first to admit that Iâm not familiar with the V12, in any of itâs versions. I did not know that the âface liftâ included an AT with OD. In my view, a huge step forward.
In my case, I âstumbledâ on to the ârightâ version of the LT1 for my car.
Roughly speaking, there are two. The ones with alloy heads and differing cams for the Camaroâs and Corvettes. Lighter cars.
And the iron headed ones, with differing cams for the âbigâ cars. Capriceâs also in cop version, Buick Road Masters, and
Cadillac Fleetwood Broughams. All big and heavy. Especialy (typo) the RM wagon!
In large part, because of the demise of my alloy head on iron block DOHC, I chose the all iron LT1.
It worked out just right. Luck in a large part
Yes, I am well aware that .matching the torque curve to daily driving equals drivability.
My big old Jeep Grand Cherokee is propelled by a âsmallishâ
4.0 OHV 6. Great job in torque match by the Jeep engineers. Reasonably lively, most of the time. Out of breath at about 70!!!
Reminds me of AJ Foyt seeking to get one of his older racers to qualify at Indy. Ordered crew chief to âtwist itâs tailâ. Aka
more gear, more revs. it was working, the speed went up.
But, it blewâŚ
Carl.
700r4 should be easiest to install. the t.v. cable MUST be correct, it is NOT a kickdown cable like the th400. not familiar with the gear venders o.d. but you would obviously be fabricating brackets, drive shaft and floor pan/tunnel. at that point, why not go with a stick. I did the swap, and like everything on my jag, it was double the money and double the time compaired to same work on an '80âs chevy. It is by far the best improvement I have done to the car and well worth the time and money.
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What manual gearbox did you install in yours?
What rear are you running with your TremecTKO 5sp Larry?
I wonât be installing myself, I have access to the tools, and the lift, but I donât want to practice on this with this car.
So what sort of costs were you up against?
I am a very conservative driver. Doing a burn-out was never in my driving etiquette. I suppose I cannot hang with the cool kids.
MY diff ratio is a 3.54. The 5sp is 2.87; 1st, 1.1, 4th and .82, 5th (OD). I believe 60mph is 1,800rpm and 70mph is 2,000rpm in 5th on level straight highway . As stated previously, my goal was to duplicate âthe feelâ of my previously owned GM cars with the close ratio 4sp & 4.11 rear only this time with the OD. I fell I accomplished that âacceleration feelâ.
I did the instillation myself, cost around $6,500 7yrs ago. Everything new, ECU via Bywater, Alum flywheel, Momo stuff, it $$$ all adds up. Getting the instillation done is a conversation in itself regarding cost,( it could drive up the price considerably) finding a qualified XJ_S person, etc.
Can anyone recommend anyone in FL who has experience with and can install one of these 5 speeds?
700r4 should be easiest to install. the t.v. cable MUST be correct, it
is NOT a kickdown cable like the th400.
TH400 doesnât have a kickdown cable, it has a kickdown switch.
not familiar with the gear
venders o.d. but you would obviously be fabricating brackets, drive
shaft and floor pan/tunnel. at that point, why not go with a stick.
Well, thatâs the way I would think as well, but the OP might not want a stick.
â Kirbert
Mine is a 91 conv. red, tan top
I really donât know of anyone, FL or PA that does trans change overs of any kind. I think DrivenMan Co has a list of people or shops but Iâm not familiar. Maybe Paulâs Jaguar in South Florida would know of some place.
I have everything mechanical you need for less than half the 5/6 speed price quoted. All original Jaguar parts.
In 75/76 Jaguar made about 3-400 manual XJS cars for the UK/rest of world (not USA). This is the 4-speed Jag trans from one of those.
I also have the adapter you need to fit a BMW 5-speed Getrag 265 onto a Jag bellhousing. The boxes are dirt cheap from a breaker, so even buying a V12 bell etc still comes out ahead of most options.
I also have a new World Class T5 very cheap (the strong version). Youâd need a T5 version of the V12 bell but again not too dear.
Meanwhile, a question⌠my iron-head LT1 in the 96 Roadmaster Wagon has a 4L60E gearbox. On Jags, the electronic gearboxes are fitted with a Sports/Normal switch to suit different styles. The electronic box in my Buick has no switch, so what do you get for the extra complication? Just smoother changes?
was thinking of the th350. regardless, t.v. cable geometry is critical! do not overlook the importance of having the correct bracket. how much is the bracket? less than buying another tranny!
it raises the shift RPM, and a firmer shift, giving a more spirited performance!
works great in traffic , and pulling out on the interstate merges.
the 700R4 shift cable is not that much of a problem.
when all put together you pull by hand cable full out ,and then let spring it pull back in, set the cable on the Jaguar throttle pedestal about half way.
about mid position, drive the car and then fine adjust it to meet your driving style, by cable housing movement.
full out is to hard/late shift, all in is sloppy / slippery shifts, early.
pic shows GM cable adjuster clip, push in to adjust in or out.
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4L60E great trans and it will fit anyplace a 700 fits, but would need a TCM (transmission control module).
still need an adaptor plate ,Summit/Jegs,etc. would not need the cable thing.
cable is called a TV cable , throttle valve cable.
Pete:
That version of the Lt1 has lottsa torque, down where most used. Just add more throttle and it will be âsportyâ.
But, if you want more, merely put the shifter in "2â. Even âjumpierâ
As if a really big wagon is expected to do so!!!
Carl
The Proboscis seems a bit incongruous with the âsteam punkâ type of architecture. I think you need to look at it again, something less obtrusive and yet aerodynamic or marine smoothâŚIâm still trying to visualize a different hood treatment. Love the rivets, Best, JW
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I am installing a 700R4 at the end of the month. VERY excited. I have wanted That extra Gear for 15 years.
I put one in a 1972 XJ6. It transformed the car. Even with a 4.09 diff it still revâd lower on the highway.
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