Five speed gearbox for E-type-- which one?

JIM BAUMANN · Post by **JIM BAUMANN** » Sat May 18, 2013 8:22 pm

Good evening gents! ( and ladies..?). Living with the car ... I am now rather liking the V12 experience ! ( after a few initial doubts s about its low down pulling power ): http://www.etypeuk.com/forum/viewtopic.php?t=3838

However... the relatively high 1:1 rpm at motorway speeds (and above!) ( modern ears like lower rpm at cruising speed... :) seems like I wanted an overdrive or fifth gear.... so who here has experience or thoughts on either of these two set-ups...? I have read good things about both...

e-type fabs: http://www.etypefabs.com/5%20Speed%20Gearbox%20V12.pdf

Derek Watson Jaguar: http://www.derek-watson.co.uk/5speedboxes.php

Interested!

Jim Baumann

Post by **Heuer** » Sat May 18, 2013 9:25 pm

Personally the only 5 speed I would recommend is the Medatronics JT5. They have sold thousands and it is well proven. A better option might be to put a higher diff ratio in.

MarekH · Post by **MarekH** » Sun May 19, 2013 7:54 am

Dear Jim,

This reply slightly widens the terms of reference, but isn't "off-topic".

The Getrag gearbox is the most common 5speed conversion on this side of the pond.

I have fitted a standard Jaguar manual overdrive box box from a late saloon. Whilst my speedometer is not particularly accurate, it looks like I'm running at about 1800rpm on the few times that I have been plodding along on a dual carriageway. This is with 2.88 differential.

Consider the differential as part of the overall gearing because you have ample torque already. You may find that fitting a 2.88 diff is easier and cheaper way to achieve lower rpm when simply eating up the miles is necessary.

There won't be many people who have tried more than one option as the cost of changing your mind is going to cost at least GBP1500, which is roughly what I spent in going from auto to manual.

kind regards
Marek

Post by **1954Etype** » Sun May 19, 2013 8:28 am

I drove a S2 2+2 fitted with a Jaguar box with overdrive. Just fantastic! (and you know it has been tested to destruction and is suitable for the XK engine. I think the total cost was <?1000 as well.

KingRichard · Post by **KingRichard** » Sun May 19, 2013 5:18 pm

Hi,

Thats my way I'm now going after consideration of buying a 5-speed. I now can use my original 4-speed. Having a 2+2 gives the opportunity to add a OD.

Bought a overdrive from eBay complete with mainshaft and adaptorplate. Wil fit it on my gearbox this end of summer.

Costs sofar EUR 600 including new bearing and clutch relining OD.

Richard

vee12eman · Post by **vee12eman** » Sun May 19, 2013 10:18 pm

Hi Jim,

As documented elsewhere, I fitted a Getrag 5-speed, like Marek I was converting from Auto. I managed to find a bell housing which replaced the original - a good job seeing as I did not have one. Most conversions require an adaptor plate, which my conversion does not use. However I did have some minor issues which were overcome by removing the gearbox and making minor modifications to the tube around the input shaft on which the clutch release bearing carrier slides.

Advantages were a rifle shot gear change, if a little stiff - very German in feel and economy of conversion, around 1000 pounds at the time, around 4-5 years ago. This did involve me making my own linkage for the gear lever to bring it out in the right place, the original comes out way back. For the V12, you can use either the long or the short tail shaft Getrag 'box, mine uses the long version not often seen on E-types. I also don't know whether the original tunnel cover works, I converted my Auto cover and the linkage requires quite a bit of space to operate freely.

I considered the 4-speed plus overdrive route, but was warned off by a few who said the overdrive units were not necessarily rated for the torque of the V12, though I have heard of several conversions considered perfectly acceptable by their owners, but if you intend frequently putting all the torque through the rear wheels (whether the overdrive is engaged or not) it may be a consideration.

Regards

JIM BAUMANN · Post by **JIM BAUMANN** » Thu May 30, 2013 8:12 pm

Thank you all for your your views!

I did also have a read through this insightful thread

http://www.etypeuk.com/forum/viewtopic. ... sc&start=0

since the discussion referred to the WATJAG gearbox was fitted pre-2010...

have since then the speedo drive issues with the WATJAG gearbox been addressed / resolved?

I have a past Achilles tendon failure--never really recovered 100%

so... in principle the lighter clutch action modification advertised for the WATJAG version is attractive - see below:

"
For the V12 version of the T5 gearbox, we use a centre push hydraulic release bearing which makes the big 10.5 inch clutch on these cars considerably lighter. In order to do this we do have to have some machining work done on the bell housing so to fit the conversion we?d require the car for 7-14 days to give time for this to be done.

any thoughts on this-- I am very grateful for the Huge font of knowledge found here!

Ref: the idea of just fitting a taller diff ratio...

will this not simply exacerbate this (perceived) issue...

http://www.etypeuk.com/forum/viewtopic.php?t=3838

and blunt initial low-down getaway performance?

alternatively-- is the gearbox that is supplied by E-type UK
( suggested in the above thread--still available...?

Interested--I amhoping to make this my winter project-- so endeavoring to garner the full gamut of info..

ie... ==> looking before leaping ... (for a change! )

Regards and thanks to all posters!

JIM

JIM BAUMANN · Post by **JIM BAUMANN** » Sun Jul 28, 2013 9:18 pm

Having ummed and ahhd about for a month or so ..

( whilst thoroughly enjoying my E-type driving! )

does the following seem reasonable>

1) install 5 speed box fitted with tall .065 ratio rather than .75

2) Install a shorter ratio diff ( late US ratio--as used to keep up performance low down when the US market engines were being emission restricted ( as I understand was the case?)

aims: to get snappier low down pull/ response with shorter ratios low down
and end up with about the equivalent to the more usual .075 top gear for M-way cruising

I am sure I am not the first person to think of this.... 8)

but would like to hear informed comment

Regards

Jim B

abowie · Post by **abowie** » Mon Jul 29, 2013 4:44 am

Try the box first; the 0.65 ratio will only affect 5th gear. The others will be pretty similar to the 4 speed box you have now.
If you then don't like it you can always change out your diff later.

PeterCrespin · Post by **PeterCrespin** » Tue Jul 30, 2013 1:39 am

JIM BAUMANN wrote:does the following seem reasonable>

1) install 5 speed box fitted with tall .065 ratio rather than .75

2) Install a shorter ratio diff ( late US ratio--as used to keep up performance low down when the US market engines were being emission restricted ( as I understand was the case?)

aims: to get snappier low down pull/ response with shorter ratios low down
and end up with about the equivalent to the more usual .075 top gear for M-way cruising

I am sure I am not the first person to think of this.... 8) but would like to hear informed comment

0.65 is a big drop. It's a pity to lug a V12 that is not the world's torquiest design pro-rata (being an over-square engine). They like to rev. More importantly, do you know 100% for certain what diff ratio your car currently has, to see whether the mooted change is doable?

You could always try a 4.10:1 from a Mk2 or similar, but really a manual V12 E is already easily able to destroy its rear tyres in short order. So apart from more smoke for longer, you might find there isn't that much extra get-up-and-go on offer, without improving traction by bigger tyres/wheels.

JIM BAUMANN · Post by **JIM BAUMANN** » Thu Aug 01, 2013 7:43 am

after a drive with the aid of a GPS (which seems to establish that the speedo is over- reading about 3%) it seems to confirm that the car is fitted with the 3.31:1 diff. My chum did some maths for me. Seems like 2024 revs with 3.54 diff and .64 5th will get us 70 mph. This --coupled with the overall lower set gearing of the 4 lower gears ought to achieve what I am seeking? ie more sparkle lower down and a quieter cruise. The V12 in an E-type should be able to pull 70 happily at 2000-2100 rpm?( XJS HE = 2200 rpm @ 70-- but heavier car....

Tire Diameter (in) 26.34 26.34 26.34 26.34 26.34 26.34 26.34 26.34 26.34 26.34 26.34
Engine RPM 3,477.00 3,477.00 3,477.00 3,477.00 2,023.79 2,608.00 3,477.00 3,477.00 3,477.00 3,477.00 3,477.00

First 2.93 2.93 2.93 2.93 2.93 2.93 2.93 2.93 2.93 2.93 2.93
Second 1.91 1.91 1.91 1.91 1.91 1.91 1.91 1.91 1.91 1.91 1.91
Third 1.39 1.39 1.39 1.39 1.39 1.39 1.39 1.39 1.39 1.39 1.39
Fourth 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
Fifth 0.75 0.75 0.64 0.64
Final Gear Ratio 3.31 3.31 3.54 3.54 3.54 3.31 3.54 3.54 3.54 4.50 4.90

Tire Circumference (inches) 82.75 82.75 82.75 82.75 82.75 82.75 82.75 82.75 82.75 82.75 82.75

Tire RPM 1st 358.15 358.15 334.88 334.88 194.92 268.64 334.88 334.88 334.88 263.44 241.93
Tire RPM 2nd 551.42 551.42 515.59 515.59 300.10 413.60 515.59 515.59 515.59 405.60 372.49
Tire RPM 3rd 756.27 756.27 707.13 707.13 411.58 567.25 707.13 707.13 707.13 556.28 510.87
Tire RPM 4th 1,050.45 1,050.45 982.20 982.20 571.69 787.92 982.20 982.20 982.20 772.67 709.59
Tire RPM 5th 1,400.60 1,309.60 1,534.69 893.27

MPH First 28.07 28.07 26.24 26.24 15.27 21.05 26.24 26.24 26.24 20.64 18.96
MPH Second 43.21 43.21 40.40 40.40 23.52 32.41 40.40 40.40 40.40 31.78 29.19
MPH Third 59.26 59.26 55.41 55.41 32.25 44.45 55.41 55.41 55.41 43.59 40.03
MPH Fourth 82.32 82.32 76.97 76.97 44.80 61.74 76.97 76.97 76.97 60.55 55.61
MPH Fifth 109.76 102.63 120.26 70.00

Post by **Heuer** » Thu Aug 01, 2013 8:36 am

You can use this calculator from our Knowledge Base to do the calculations: http://wahiduddin.net/calc/calc_speed_rpm.htm

MarekH · Post by **MarekH** » Thu Aug 01, 2013 10:36 am

"The V12 in an E-type should be able to pull 70 happily at 2000-2100 rpm?"

Yes it can - mine does. It has a standard Jag box with a compact type-A overdrive fitted. The differential is 2.88. Before you ask, I don't have all of the ratios to hand, but I'm sure they're either already posted on the net somewhere or Pete will remember for me. In my case, I'm guessing 2000rpm equates to approximately 70mph as I was overtaking lorries but not much other traffic was overtaking me on a mostly empty motorway this last weekend.

kind regards
Marek

JIM BAUMANN · Post by **JIM BAUMANN** » Sat Feb 15, 2014 8:36 pm

Happy New Year all...

Well-- I gon-an-dun it!-- or more accurately-- I had it done... by Derek Watson :@ WATJAG Ltd in Derbyshire. The car now runs a with a shorter diff ratio -coupled to a new five speed gearbox which has a tall .63 fifth hear ratio. It has also had the clutch mechanism modified to reduce the pedal effort required by around 40% ( useful for a chap like me - ex torn achilles tendon in left leg -still an inherent weakness there alas). With the (due to the diff ratio) effectively lower gearing in the 1234 gears the car does now feel more effortless when pulling away with a sharper pick up of speed. Overall the car had a pretty thorough going over, among many improvements and replaced parts being new drive shafts giving a smoother drive take up( my old ones where rather sloppy!! ), new discs at the back- taking care of a small brake tremor that has now gone, new rubber throughout the engines cooling circuit, fresh header tank and many many more bits and bobs. The car is a now a true pleasure to drive- effortless and sharper low down and far more relaxed at Motorway speeds- at 80 mph the engine noise is much reduced - ( Just have to try and cure some of the wind whistles) a bonus being that it seems to have had a very positive effect on economy--the 230 mile drive home to Southampton using around half a tank of fuel... I find myself yearning for every opportunity to drive the car-more so than before--tempered only by the current 'classic -unfriendly ' weather.... I am now a happy chap! :D

Currently just a tiny distracted rather by an additional car I have bought albeit with 10 cylinders less that is in the paintshop right now - Panhard 1960, all 843 cc of it!

Alty Ian · Post by **Alty Ian** » Sat Feb 22, 2014 2:09 pm

Hi Jim

That sounds great, I assume they replaced the clutch plate, cover and bearing as well. Do you feel that the shorter diff ratio was really needed as it appears to me the difference from standard is very small.

Ian

christopher storey · Post by **christopher storey** » Sat Feb 22, 2014 3:59 pm

Jim - is that a 24CT or a saloon model?I have always been fascinated by the Panhards

JIM BAUMANN · Post by **JIM BAUMANN** » Wed Mar 12, 2014 10:26 pm

Apologies--I had overlooked the answers....

@ Alty Ian

"That sounds great, I assume they replaced the clutch plate, cover and bearing as well. Do you feel that the shorter diff ratio was really needed as it appears to me the difference from standard is very small."

They did indeed and the lighter clutch is a true pleasure to operate, especially with my ex-Achilles leg. The shorter diff - in my view- has assisted greatly in the delivery of the sought after low down urge. In reality 0-60 I think overall has probably remained the same per se... but 0-30 gives a rather more worthwhile shove in the back, and the more urgent and immediate accelerative response makes it --to my perceived feelings--a more satisfying drive overall --but especially in nip-and-tuck 'twixt the traffic lights.

The very tall fifth was merely to compensate for the shorter diff ratio at 80 mph its now reads an indicated 2400 rpm

@ Christopher Storey

"Jim - is that a 24CT or a saloon model?I have always been fascinated by the Panhards"

Despite missing 10 cylinders and 220 bhp ...

my Panhard Pl 17 is a most beguiling car.... despite its seemingly laughable engine 843CC spread over 2 horizontally opposed air-cooled cylinders... with its roller bearing crank and big ends , and a few small tweaks it good for around 55 bhp four gears on the column with 3rd being 1:1 and fourth 0.75 it managed to cruise most of the way (on the level !! ) at 70 mph on the motorway back from Macclesfield to Southampton in 4 hours. Currently having a paint ( and steel ...! ) re-vamp-- she should be ready
to play again in 3 - 4 weeks

but while its in the paintshop I am obliged to spend the recent dry weather enjoying the E .....

Dblebill · Post by **Dblebill** » Sat May 24, 2014 2:19 pm

Hi Jim,

It's been a while since you switched from auto to manual and I thought I'd ask if you're still happy with the change, or if you were to do it all again is there anything different you would do. I have a S3 roadster and recently had a 2.88 diff put in, but still it revs too high (2800 @ 70mph) and it hasn't made much difference to the fuel consumption either so I'm now thinking of switching from auto to a 5 speed. I heard someone bragging that since he put in a 5 speed box and 2.88 diff, he's getting 26mpg, if that's true it's twice what I'm getting :-( Any tips or suggestions you think may be of use is greatly appreciated.

Regards,

Bill

JIM BAUMANN · Post by **JIM BAUMANN** » Sun Jun 15, 2014 7:45 pm

Hi Bill

apologies for missing your query until now ... Actually my car was already a manual-- just the standard 4 speed manual. I wanted more "go" low down and a quieter ,lower reving cruise, ergo the use of a lower diff ratio to get more effortless squirt low down off the lights and compensating for the power diff the higher than normal fifth gear at .63 rather than the more usual .75. I am completely satisfied with the set-uo I now have - it having done everything I wanted.

Hope to help

Jim Baumann :D

Dblebill · Post by **Dblebill** » Wed Jun 18, 2014 4:44 pm

Sorry Jim,

I can't think why, but I presumed your car was a auto to begin with. Happy to read you're completely satisfied.

Regards,

Bill

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Five speed gearbox for E-type-- which one?

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