Hello Terry,
Hear its a welded First Motion Shaft (poorly done at that) and not think its inferior?
Disregarding my low opinion of the welded shaft the DM supplies, the damaged teeth of the First Motion Gear is also a point of lack of quality work. Perhaps not all are like this, but one going out in an assembly is enough.
The damage to the teeth of the First Motion Shaft shown in my earlier Post, wouldn’t affect the operation and as the teeth are relatively soft, any bur the protruded past the surface of the face of the tooth form would be burnished back in line during operation of the gearbox. But in my opinion, damage like seen on this First Motion Shaft is not acceptable. In our own production of parts, slight scuffing of the surface finish by swarf in hard to Chip Break material, no damage per se, just scuffing, is enough to set affected parts aside.
Coming from an oil patch town I’ve seen some amazing fabrications. I had some rear halfshafts shortened by a local shop for my race car. They were forged. Still don’t know how or even where they did the cuts. Nothing is visible, but I put 375 hp through them for years, and still use them in my stroker car.
Done properly, joining the First Motion Shaft by welding would work, but the weld prep that results in circa 3 - 4mm is a long shot from being done properly; even the finished surface of the shaft shown in my earlier Post is not well done, leaving imperfections that have the potential of rising stress points.
I’ve repaired the broken shaft of an axis Servo Motor of a very large machining centre, where at times, had to deal with the inertia of getting many tons of work-piece, fixture and table moving in Rapid Traverse; but I didn’t rely on what equates to a circa 3mm wall thickness tube doing the work.
I’m gonna try the overdrive conversion, A guy in Ireland sold me the box from an XJ6 and shipped it to UK and I just sent the crate with some other gearboxes and overdrives over here. Ive been reading about it for a couple of years so if i’m not ready now I might never be.
Hello nelly88,
I’m assuming your car is a long wheel base, either S1/S2 2+2, or an S3.
In my opinion, its the best way to go; I’m kind of over extra gears. We had a MK2 in work circa a year ago with a Supra W58 (the W58 being the most desirable model), extractors, a 2.5" exhaust, 2 x 2" SUs, a hot 4.2lt engine, grossly uprate brakes and suspension. The owner was 81 years old and jokes that the guy who did all the mechanical stuff must have though he said he was 18, not 81. Anyway, any time I had to take it out for a test drive, I invariably just went from Third to Top (fifth gear). To me there was just an additional gear to get to the long legged gear.
The Top Cover of the XJ6 gearbox will put the gear lever way too far back for the centre console in your car, unless you have in mind modifying it. The Top Cover from a Jaguar S Type or MK10 has the correct Top Cover, the same as the E Type and will be marginally easier to get, than one from an actual E Type gearbox. Denis Welch Motorsports also makes and offers for sale a bare top cover and complete with selector rods. Although the Gear Lever is set back via the XJ6 Top Cover, the selector rods are all the same as the E Type. Accordingly, if you got a Top Cover from Denis Welch, you would only require the bare unit for a bit less than a third of the price for the complete assembly.
We have fitted Jaguar 4 Speed Gearboxes with Overdrive on a number of S3 OTS cars. I don’t mind carrying out uprating conversions, so long as you can’t see that its been done. It works out well with the S3 OTS, because the right most dashboard rocker switch is vacant and so, we use that to switch the Overdrive.
Thank you Sir, Yes I had him remove the XJ6 cover and keep it, intending to use the top from the existing manual box. Of course the compact overdrive condition is unknown and may need to be overhauled but I hope the swap is effective with the US diff ratio as was to give that extra length in 4th. I imagine coming from an auto swap your comment re the top case is very relevant as they must be hard to get so that is good info as another car we are proposing this on is an auto.
Thanks,
The silver S2 has a standard bore stainless Bell system, which is superb. The car runs 6 injectors on three pairs of 45mm throttle bodies with an Emerald K6 ecu from my mate Phil Dobson. The engine is fresh on new Mahle pistons, a big valve S3 head with injection cams
It runs 180 psi on each cylinder.
The air filter is an ITG sausage. The whole combination has given over 6 years of mechanical perfection, having been round Cadwell, Silverstone, the Nurburgring, Shelsey Walsh and other interesting places.
It has an S2 4 speed synchro on a 2.88 diff.
I cant recommend it enough as a bullet proof setup.
I always have to laugh when the topic of higher final drive ratios come up, and the most common response seems to be that taller gears give you longer legs “at the expense of acceleration”, whereas a 5-speed gives you “the best of both worlds”.
I’d be willing to wager that the average E-type owner never utilizes more than 50-60% of their car’s available acceleration, and VERY few ever utilize more than about 85-90%.
It’s as if people don’t realize that most of us could just push the peddle on the right a little harder with taller gears, and still get “the best of both worlds”.
I live at 1 mile high above sea level, and drove my E-type to over 14,000 feet above sea level: it had a 3.07 in it and the “puny” 3.8 engine. Not once in many, many thousands of miles of driving did I ever feel I needed more “grunt off the line,” nor did I ever feel that it was too long-legged on the highway.
I concur completely. Unless the rest of the car is absolutely perfect and you have thousands of dollars burning a hole in your pocket, I would find other things to spend it on. All other suggestions sound like a direct path to grief and heartache for little to no measurable gain. Just my opinion, of course.
Well I have a very heavy right foot, but then again I have never fealt any need for any change in our 1972 Euro spec V12 OTS.
And in the ex S1 1966 2+2 I was also very happy with the Auto → MOD conversion the PO had started, the 4-speed with the 3.31 final drive gave good acceleration and the overdrive gave relaxed high speed cruising, IIRC 65mph was ca 2.000rpm and 130mph was ca 4.000rpm. For me that was indeed ”the best of both worlds” but the V12 is not too noisy at high revs (5.000-6.000rpm) IMHO. YMMV.
I emailed Realm about their W58 conversion for my S2. There’s a fair bit of cutting required to the tunnel and quite a bit of work underneath too. That’s not an option for me so I’m still looking for a 2.88 diff.
I know there are limited slip diffs from the XJS’s that would fit. Any other models? What about the sedans? I’d prefer to simply swap out the diff rather than send mine out for new gears.
