Jag XJ13

[XJ13]

Crawled out from under my XJ13 long enough to post some stuff about shortening driveshafts, transaxles and XJ13 development etc.

http://tinyurl.com/b8dq3h5

There are two previously unpublished Jaguar memos the historians amongst you may find interesting.

Anyone spot the loose tool tip in the video? No sniggering please(I was too busy pointing the camera to notice)

[V8 FOU]

Truly amazing, as usual.
Yes, noticed the loose tip! I assume you laid the two yokes on a surface plate to get them aligned? How did you avoid them moving during the welding process? Are you going to consider a top link to remove the thrust, I always thought when working on Jags what a poor idea it was to use the driveshaft. Mind you, I suppose I made a few quid replacing u/j's over the years.

I hope you are going to produce a book on this! Would love to see it in the metal some time! Perhaps you should do guided tours...

Regards Paul

[XJ13]

Thanks Paul

I was a bit concerned about the yokes moving out of alignment before/during welding so I used the tool I did to end up with a "gramophone" effect so I could get a semi-permanent press fit into my spacer tube. It also gave me a nice deep "V". There's method in my madness! I didn't weld them myself but used a local chap who normally works on motorbike frames. He preheated each driveshaft in an oven before welding and "root-welded" them - starting with a very thin rod then switching to progressively thicker rods as he worked outwards. I am very happy with the result.

Can you, or someone else knowledgeable answer this for me? I heard it is acceptable for the yoke ends to be at 90 degrees to each other as well as exactly parallel. Do you know if this is the case?

Neville

[WJM]

Had not seen this before, what a project. I've seen the real XJ13 at Goodwood and a couple of replicas on the road but having the correct engine and all that attention to detail puts this one in a different league.

Bill

[V8 FOU]

Neville.
As far as I can remember, you are right about no difference in the yoke position. I guess that the dynamic balance is the same because of the yokes being the same on each half of the joint.
I've seen d/shafts and propshafts in both configurations and work OK.
Just wanted to reitterate about the top link?

[XJ13]

V8 FOU said:

Just wanted to reitterate about the top link?

I want to keep as close to possible to the original setup so I won't be adding an extra top link. If you ever see photos of me picking mud out of my teeth on the infield at MIRA you will know I was wrong to do so

[mph]

XJ13 said:

If you ever see photos of me picking mud out of my teeth on the infield at MIRA you will know I was wrong to do so

Better than teeth out of the mud !

Fantastic Project BTW. Thanks for posting.

[Flatinfourth]

I dont understand the need for a top link. Utterly thousands of Jaguars from the E Type onwards had no top link, the same UJ being used in the big saloons with no problems at all. they have no history at all of stress failures, only failure due to neglect with a grease gun. WE has an XKSS and a D type at Goodwood on a private day a few years ago, and E2A was there too, so i took an opportunity to have a look while the rear wheels ere off, i remember that having a top link if my memory serves me correctly, but E2A was an experiment, part of which was to remove the D Types problem of high unsprung weight with that big live axle. anyone that has taken the time to notice how low the E Type's unsprung weight is with the rear springs disconnected will realise that all that design work, with a lovely alloy upright and no top link is just perfect as it is.

[XJ13]

Flatinfourth said:

I dont understand the need for a top link. Utterly thousands of Jaguars from the E Type onwards had no top link, the same UJ being used in the big saloons with no problems at all.

Peter - the difference is that these driveshafts are attached to a transaxle, not a diff as in other Jaguars. These transaxles weren't designed to take the additional loads.

[Flatinfourth]

XJ13 said:

Flatinfourth said:

I dont understand the need for a top link. Utterly thousands of Jaguars from the E Type onwards had no top link, the same UJ being used in the big saloons with no problems at all.

Peter - the difference is that these driveshafts are attached to a transaxle, not a diff as in other Jaguars. These transaxles weren't designed to take the additional loads.

No I understand completely> The Replica i've done a fair bit on had the transaxle fitted, at some cost, and a top link too, but what did the original have? The reason i stuck my head over the parapet was simply the critiscism of Jaguar's very intelligent choice to oversize the driveshaft and it's joints to enable them to both simplify the construction and lessen the unsprung weight. In your situation originality is everything, so in order to be accurate to the original you have to stay with the drawings. All i would say is from personal experience of how difficult it is to bring an XJ13s engine bay temperature down to a safe level, and it;s cabin temperature down to an extent where the driver is not being burned alive in traffic is quite difficult, as the car is designed for speed. I know how i would build some discreet modifications in to make the whole thing less scary and more fun. Building a replica of an underdeveloped and ill fated prototype is always going to be tricky! Very well done though. When i heard there was another engine around a few years ago i couldn't help wondering!!!! you are a very lucky chap!

[Mark-C]

Excellent - thanks for sharing

[Flying Phil]

Thanks for the update and wealth of background information. I saw a replica XJ13 at the Classic Car Show - which highlighted how much more you are putting into yours!

[XJ13]

I've been up to my wotsits in cutting fluid this week and thought some of you might be interested in seeing how I tackled the problem of not having a bellhousing.

I need a bellhousing!

[V8 FOU]

Gawd, Neville! That is a thing of beauty! I can smell the cutting oil from here!

Re: the top link. I used to do a lot of work on Jags, and the number of U/J's I replaced... used to keep exchange XJ ones in stock. It IS a clever idea, but they do shag out quickly, and the least wear causes all sorts of problems.

Here's a usless fact for you! when I was overhauling the bottom swivel on the rear suspension housings, I used to save a small fortune by using 105E Anglia front outer wheel bearings!