From 4 to 5 Speed , but Which one ?

[MarekH]

A 2.88 differential mated to a standard 4speed with overdrive will deliver the cruising rpm you desire. You are however limited on the gearbox front as you will need a 4speed box which has the two threaded bosses on the right hand side of the box for mounting the slave cylinder - standard six speed boxes had the slave mounted on the bellhousing and that arrangement is not suitable for the v12.

You may need to also alter the top cover by cutting and welding the position of the gear lever boss. The xjs/xj12 had the gear lever come out further back but the s-type top was the same as the e-type.

I have posted pictures of this in the old photo albums of the jag-lovers.com website some years ago if you search there.

kind regards
Marek

[chrisfell]

I know of one S3 which has a 2.88 and an OD. Very relaxed cruising on motorways.

[MarekH]

So do I - it's in my garage.
Feel free to pop round for a cup of tea on the way back from Goodwood tomorrow if you are so inclined Chris.
kind regards
Marek

[Barry]

With respect, listen to those of us that have cars fitted with either option....I’m in the 4 speed / 2.88 camp! Brian’s knowledge is indeed encyclopaedic, but I am reliably informed, not necessarily personal experience on V12’s.

[sideways60]

Absolutely Barry , I'm New to the S3 , less than a Month and Less than 50 miles , thats why i ask , its a Bit of a ol banger atm , Following The Advise ive Brought a late XJS 2.88 Axle and the Diff is away being Reconed , ill Start with that First and then come back to the G/box , Im Local to Quaife , i'll ask if they do a 5sp Gear Set that fits inside the standard Box , thx Russ

[Barry]

Quaife will probably point you in the direction of New Forest Classics. I gather the teething problems are sorted, and NFC will sell you one. I still ask why go for 5 gears? However, despite what I or others might say, go for what you want and enjoy!! Whilst on the subject of Quaife. They do another different, 1 rail 5 speed for Eagle whereas the New Forest Classic one is a 2 rail box, and therefore a different design and made to a different brief. The Eagle one is a more traditional design. But you can’t buy one of those unless your car came from them.

[sideways60]

The Whole Motivation was my Shock on How Low the Gearing is on my First Drive , My Standard 65 MOD Stype sits at 2250rpm at 70 all Day Long , I'm doing 50 at those Revs , if i remember rightly the US had a Blanket 55mph Speed Limit at the Time ? , thanks Russ

[sideways60]

Having Been to Quaffe , They Dont do a V12 Gearbox and the 6 cll is Still being Tested , so the Choice for the V12 is
The Non Turbo Supra Box Reconditioned

The Getrac BMW Box Reconditioned

The Standard Jag Box plus Overdrive

The New Tremac ,

Unless anyone else knows of another ? ,

Russ

[jagwit]

I have a 2.88 in my S3 v12 (auto). 3rd on the auto is same ratio as 4th manual.

It is by far the quickest, easiest and cheapest solution for a v12.

I still long for an overdrive of sorts. IF the auto should fail while I still have the means to do something about it, I will try VERY HARD to get a GM 700R4 in there. Sharper 1st and a 0.7 4th, should get me closer to 2000rpm @ 120km/h (75mph).

[Barry]

Hi Russ,
I haven’t spoken to New Forest Classics about how they are getting on with Quaife. I’ll ask.
My opinion is purely personal based on experience, but not shared by all!
I would not recommend the first two. Shift quality being the main problem, and position of the gear lever. The Tremec T5 has been recommended by many on this Forum, but my experience with the Elite version was not good. After two gearboxes in my S1 FHC, both had noisy 5th gears. As you know I have the standard Jag box, which was rebuilt. Lovely gearchange if perhaps longer than the alternative. If this option with a 2.88 diff is not high enough, then an overdrive might be an option if it will fit. One other option, if he will sell you one, is Uryk’s from Evolution E types in the North East. A friend of mine had one fitted to his S1 and loves it. They do need running in for 1000 miles or so. They are also expensive.

As you can see by the many threads on this subject, one man’s meat is another’s poison!

Best
Barry

[sideways60]

Thanks Barry ,
Just as a Heads up ,
Quaiffe are further down the Line in Releasing a 6 Cyl Gearbox , However there Still Testing it , But No Plans for the V12 ,
And Evolution E Type dont do a V12 Option ,
The Overdrive Does Fit with a Little Easing of the Tunnel BUT the Switching in and out is a Bit 60's ,
so Down to the Toyota , BMW and Ford , the first 2 having to rely on the Skill of the Under Pressure Reconditioner
or the Only New Option The Ford ,
My Car's a Bit of an Old Banger so continuing the Muggle transformation { BCC Calipers and Vicarage Rack so far ] doesn't faze me especially Going from Left to RHD its never gonna go to Slytherin .
regs Russ

[Barry]

Thanks Russ. How is the Vicarage rack? I have been thinking of fitting a quicker rack. The CMC one is based on a Ford Focus rack. I just feel the steering needs to be quicker and more positive. Cheers Barry

[sideways60]

Hi Barry , The Vicarage Steering Rack is Night and Day Away from my OEM Rack one , Having Said that my Car Needed every Bush , Mounting , Joint and rubber so I'm Sure that made if Feel Awful Before as well , the New Rack Mountings are well made and Fit and its now feels Tight , Responsive and gives a Nice Feed Back , they Delivered it on Time , no Hesitation in Recommending Them . Russ
Ps The Tremac Box is on Order .

[Barry]

Thanks for that. I’ll chat to Vicarage.
Cheers
Barry

[sideways60]

Collected the Tremac Gearbox from Elite , Had a Quick Tour around the Factory by Mark in a Boiler-suit covered in Grease , Not Some Millenial in a Poncy Suit , He knew Exactly What he was Talking About answered every Question with Ease , Its a Massive Old School Heavy Engineering Firm that Have Huge Plant and Machinery they could Do Anything , the Gearbox is a Small Sideline for Them , I'm Told they are Heading towards 150 Units now , and i Left feeling Confident that it will be a Trouble Free Upgrade , it was a Pleasure to Chat to Him . R