To confirm Steve’s point, the centre hole distances on the diff ‘dog bone brackets are only relevant for ID, not fixing. The holes used for mounting are (left to right) 1&3 or 2&4 depending which side the brackets are fitted (they work either side).
If you place a diff unit with brackets attached on the floor, it points up at the front - the input shaft is not horizontal. The crankshaft, gearbox mainshaft, propshaft and diff input are all pretty much aligned at mid-laden, and because the sump is much deeper than the diff it means the engine slopes down at the back and the diff points up, in a straight-ish line.
The shorter the wheelbase the steeper the slope. This alters the relationship between the inner fulcrum axis and the top diff mounting face. So provided the E-type dog bones stay with the E-type cage you can fit any diff and the angle will be right. But if your diff came from an XJ or XJS with brackets attached, you should fit the E-type dog bones before installing it in an E cage and car.
Mike I just went through this…
Your series 2 can swap to a 307 no problem………
If you want to go to 2 88 which I wanted to , it is VERY complicated which DICK can confirm on one of my rebuild posts.
You would need shims, different bolt and a different front diff yoke holder.
The key is find am EARLY series 1 pumpkin from the UK with the 288 or an early carrier that can except the ring gear…ITS A HUGE PROJECT.
My 66 has a 5 speed with a 288 rear 70 is 2,000 rpm its wonderful for open roads…a little short around town but overall great.
My 67 will be 307 with the original 4 speed , better around town plus there is NO 5 SPEED right now out there that wont blow up…….
GTJOEY1314
If you change your series 2 3:54 posi to 3:07 with gears other than OEM Jaguar, you will have to buy the gear set, special input shaft, special bolts, and shim kit also. The shaft, bolts and shims came with my kit.
Personally, I would opt for the 3:07 and let a pro shop set it up. You retain the positive traction and it is the cheapest and best (IMO) way to go.
Even with the 5 speed the 2:88 is a little short around town…
Don’t forget the acceleration loss with a 2.88. I figure about 20% 2.88/3.54. I was lucky enough to get one of Paul’s 5sp years ago and geared 1st gear for acceleration and 5th gear for high speed low rpm. But there is a noticeable loss of acceleration in 5th gear.
The other thing you lose is engine braking. I feel the difference a bit driving fast twisty mountain roads with my 3.07 – I can imagine I would be on the binders quite a bit more with a 2.88.
That’s true, I notice in my XJR with the 2.8 that I have to go down to 2nd on the Randal Handle (lets see how many get that reference) to feel any significant retardation.
Jim Randle - the champion of the J-gate, introduced with the XJ40 in 86 and allowing for a bit more ‘manual’ selection on the 4& 5-speed autos until 2003. J-gate continues in modified form even today…
You’re right, I suppose. Type first, ask questions later, that’s me…
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
35
A coupla decades back, a diff rebuilder told me that the genuine Jaguar gears were of a higher quality than the generic Dana 44 gears and would run quieter. Do I believe that? No, I do not. But IIRC the Jaguar crown gear bolts to the carrier with larger bolts than the Dana 44 gears, easily dealt with using spacers, but perhaps an indication they are actually different products.
Never mind, might leave it for a couple of years and repost the question with the proviso that those who know leave it for a while, heck even I might have forgotten by then
The Dana gears use larger bolts, which is why the bolt holes in the ring gear have to be sleeved down for use in a Jag.
As far as quality, you have to be careful you’re not comparing OEM gears to aftermarket gears. People have been selling and using aftermarket “Dana” gears in huge quantities for decades, to the point some people are only familiar with aftermarket gears. So, if they’re comparing the noise level of those to factory Jag gears, I’m not surprised they’d claim the Jag gears were quieter. However, if you compared OEM Dana gears to Jaguar gears, I seriously doubt there would be a noticeable difference in noise.
No aftermarket gears compare to OEM gears in quality, and that situation is only getting worse as the gear suppliers merge, gobble each other up, and move production over-seas. I recently had a 9” Ford diff built, and the guy went through three sets of 3.55 gears, and couldn’t get an acceptable mesh pattern. He asked me if I’d accept 3.70 gears instead, and was then able to get an acceptable pattern…but they still whine under light load.
What you say, for sure. After a lot of thought, I rebuilt mine to 3.07, went back to the original high compression pistons on rebuild and added Burlen’s triple SU’s to get the Power and Torque back. Recently passed it on to the next custodian, and here’s what he said when he got it:
“Hi Dana,
I drove the car today for approx 20 miles.
Let me tell you I believe is the best XKE around the world. Everything functions perfect: The torque, smoothness, power, suspension, brakes steering, the beauty., it is just perfect.”
Mike not all E Types came with a limited slip. My '68 was one without. I gather that after Ser 1 production quit it was hit and miss. If a Power Lock it should have a PL tab bolted to the cover. As to visual differences the picture posted by Dana is a Power Lock. The non PL is quite different. Over many years and many cars I think the 3:31 is the best compromise for revs/acceleration. The engine is indifferent to rpm, and lower ratios do not mean higher gas mileage - spent 25 plus years with a 3:31 and 4 speed, now I’ve got 5 speeds in both my cars so I know. It’s a little quieter in the coupe (no difference in the ots) but that’s the only difference (ok better acceleration in equal gears)
Like Terry, I live in Victoria, close to the mountains. When I first got the car, before restoring it, I found the engine to be too busy with the 3.54 at highway speeds. It ran well, but I was concerned that going to the 3.07 could be a bit much based on the initial acceleration and butt dyno impressions. I did consider a 3.31 as a safe intermediate step, but thought the difference wouldn’t be enough off the 3.54 to make it worthwhile in the annoying busy engine department. Hence, the changes back to the original high compression pistons, 3 x SU’s (versus 2 x Strombergs) and electronic ignition on rebuild to make the best of going to 3.07. After rebuild, which may be a bit unfair, the changes to longer overall gearing more than offset the shorter pre-build legs. Anyhow, that was my experience. Here is a short video of the car going up the Malahat shortly after rebuild while we were still sorting the car on it’s longer legs.
Overdrive - not necessarily, some have had a 1 to 1 ratio on fifth designed to use with the higher rear end ratios, but on the current crop of 5 speeds yes. Ratios offered on some of the boxes go from .66 to .8 something.
I’ve always felt that the 1st gear ratio in the stock boxes was too low - should be somewhere between first and second. Using a lower (numerically) diff ratio makes some of that up, so that’s an advantage.
Sometimes 5th is 1:1 or occasionally, as in my 4 speed dog box on the D, 3rd is 1:1 and 4th is overdrive.
1.888, 1.208, 1.00, 0.777
I think the above numbers qualify as a close-ratio cluster, LOL, which one would normally associate with tall gearing, to avoid dropping off the cam. Unfortunately, with 16" wheels and 6.50 bias-ply race tires, first would red line at well over 70 mph. Which is why I’m using a 4.10 Powr-Lok ™ in the diff.
Even at that figure, from memory first gear would still red line around 60 mph. I can see it will be ‘tricky’ in rush hour traffic.
Pete, make sure you get one of those “bear trap” clutches so you get your cardio.
If my math is correct, you can turn your 3.07 into a 3.3 by going to a 205x65 tire from the standard profile. Put the tall tires on for highway, short tires for hooning. Yes ideally you need another set of wheels. But that still leaves you a good $5k left for Labatts Blues over a 5speed strategy. 24.6mph/1000rpm.
