Jag Rear End Questions

[Old Rotor Flap]

My latest hot-flash is to buy a Jag rear end, but I don't know what years I should look for, what I should stay away from and anthing I else I should look for.

Gerry and Lee are probably most knowledgable and all comments and advice from all members are welcomed.

 

[Lee_in_KC]

Hey ORF, here is a link to a series of web articles done by guy who put a Jag IRS in his Mustang. It's the most comprehensive review of Jags I have found on-line.

Jag in a Mustang

As far as what year... you want a 1987 or earlier rearend. The design was completely changed in 1988 and does not lend itself well to a hot-rod installation.

One of the things you want to be aware of is the Jag comes in several different widths, depending on which model of Jag it was used in. The E-type is the narrowest, followed by the XJS, and the XJ sedan series had the widest. Also, the E-types have knock-off hubs. My rearend is out of a 1977 XJ-6 and it is 61.5" inches wide. The reason this is important is you are limited to a maximum of 5" of backset on your wheels because of the way the hub carrier hangs down. This may cause your wheels to be further away from your body than you'd like. It is possible to narrow the Jag fairly easily, and how to do that is discussed in detail in the articles I gave the link to above. Also, Ma_n_Pa_T on this forum recently shortened and installed a Jag in his T.

Feel free to ask all the questions you want. If I don't know the answer, Ted or GAB probably do. GAB helped me with mine, and I know he has done numerous other Jag installations. I believe Ted has done a few, as well.

 

[Gerry]

My latest hot-flash is to buy a Jag rear end, but I don't know what years I should look for, what I should stay away from and anthing I else I should look for.

Gerry and Lee are probably most knowledgable and all comments and advice from all members are welcomed.

Where do I start.
I used a 60s S type rear end, probably because they were easy to find and not too expensive, plus they were the narrowest at production. I did NOT want a LSD especially for a T using 3/14 wide front tires and 181/2 rears. You will get enough rear wheel steer with out a LSD so forget this option. In the UK, E type rears are V Expensive because they are E types.( decide if you want splined hubs (Very very sexy... or bolt on's)
Thing to remember is that any Jag IRS is quite easily narrowed if you have a bit of engineering prowess about you so dont be put off by the width. You now have to decide if you want to run with rear control arms or not (I have chosen NOT to). People will tell you that this is not the thing to do but after many years, a bit of physics and some experience you can run without them, which gives a really clean look to the rear end. Its about this time that some will talk about ripping the rear out from the bottom arms where they join the diff, and that can happen if you rely on the standard trunion brackets.easy to get over by making your own diff carrier and securing it at more points than the original which had a reputation for always loosening the trunion bolts with time and miles.

I could go on for hours about this but another time or post would be better.
The thing is that IMO there is nothing, and I mean nothing that betters a Jag IRS or a modified Jag IRS. I have been around Ts for over 40 years and you just have to watch the people at meets when they see a fully chromed one of these burbble down a road. They just sit and watch. The flashing of the UJs and drive shafts motoring around is not only a basic instinct thing, it give life to the back of your T. Look at one of these and then look at a solid axle and tell me which one you would rather follow down the street

Sorry If I seem a bit passionate about Jag rears, but I have never seen anything that can beat them for looks, impact and sheer desirability. I dont care if they are fiddly to set up and take more than the usual time to install and finish... its worth EVERY penny and hour you spend on it.

If you want the BEST get a Jag IRS
Gerry

PS early 70s XJs are a good bet. they are a;ll scrappers now so the IRS should be cheap

 

[GAB]

If you need to change the track width on a Jag, you can get a little creative with how you make the parts.

 

[Old Rotor Flap]

Lee, Gerry and George, thanks gents.

Your responses took me up the learning curve rather quickly and have me spooled-up with enthusiasm.

George, great drawing, thank you.

I looked at Jag rears on eBay and can see where the later models wouldn't work as well and certainly wouldn't have the sex appeal of the early ones.

Inspired by George's drawing and photos, I envision making the lower control arms out of streamline 4130 tubing which is currently $43.75 a foot for the .065" wall stuff.

I'll have to do some calc's but if it needs doublers for additional strength, I already have an idea to make'em even sexier.

Oh yeah, I still have to find a rear end and come up with some money.....I'd better throw some stuff on eBay.

 

[Gerry]

Lee, Gerry and George, thanks gents.

Your responses took me up the learning curve rather quickly and have me spooled-up with enthusiasm.

George, great drawing, thank you.

I looked at Jag rears on eBay and can see where the later models wouldn't work as well and certainly wouldn't have the sex appeal of the early ones.

Inspired by George's drawing and photos, I envision making the lower control arms out of streamline 4130 tubing which is currently $43.75 a foot for the .065" wall stuff.

I'll have to do some calc's but if it needs doublers for additional strength, I already have an idea to make'em even sexier.

Oh yeah, I still have to find a rear end and come up with some money.....I'd better throw some stuff on eBay.

The tubular control arms can be a little problematic. I know a couple of people over here that say they twist (in use) quite easily. Perhaps George can shed some light on this as he has made and run them. I have nt any experience of them. Just shortened standard ones.
The ones on the back of my T are internally reinforced under the plates. Also the front and rear of each arm is made from 1/2 round solid bar
Gerry

 

[Old Rotor Flap]

I found one. I hope it is a Jag. I know nothing more about it other than it turns over and cost me $200. I also got big scrape in the paint on the side on my car because I'm dumb.

The calipers don't have what I expected and that is manually actuated parking brake levers. The calipers are Dunlops and heavier than those on a 747.

After five PM Mountain Daylight Time I will have a glass of wine in my hand, so please wait 'til then to tell me I bought something out of a Yugo or Renault.

 

[Hot Rod Todd]

You can keep drinking and enjoy your day.

Thats a pre-87 Jaguar IRS, so you have found and bought the right one.

Many folk have issues with the handbrake, but I understand that you can actually fit a motorcycle type disc brake to the front of the pinion.

That allows you to get rid of the factory setup, which is problematic and pretty ugly.

 

[GAB]

Looks like an E type that has had a wheel flange welded to the splined stub axle. Lots of offset to the wheel from the bearings.

 

[Lee_in_KC]

You got yourself a good start there, ORF. You have the narrowest version of the Jag there, with the shortest half-shafts and lower control arms. I'd like to see a couple of close-up pix of the hub (the part sticking out from the aluminum hub carrier where the wheel studs are). Can you get a close-up from the front and back, and then one from the side showing how the hub is secured to the hub yoke?

I personally happen to like the Jag e-brake set-up. Yes, it's not particularly attractive, but if you mount the calipers to the front of the diff, they don't show. Some folks like having the calipers in the back, but I think it's too busy looking. You can get brackets to clock the calipers just about anywhere you want them.

I have pix of my caliper/e-brake set-up on the 'puter at work. I'll post them tomorrow.

 

[GAB]

ORF,

Before I'd spend that kind of money on streamline tube, you might be interested in doing something like this. It's semi-oval tube.

My buddy and I have done this on several cars and it gives a kind of unique appearance and is relatively simple to do.

The taller one is 4130 and the short one is mild steel. We've done several diameters and wall thicknesses. The little jig to do it is simple but I am somewhat limited on length to about 12".

 

[Ted Brown]

Hey George, looks like that spindle is on upside down??? or??

 

[Gerry]

You can keep drinking and enjoy your day.

Thats a pre-87 Jaguar IRS, so you have found and bought the right one.

Many folk have issues with the handbrake, but I understand that you can actually fit a motorcycle type disc brake to the front of the pinion.

That allows you to get rid of the factory setup, which is problematic and pretty ugly.

Thats the way to go. I have a parking brake on the input flange of the diff using a cable operated caliper from a gokart. It works just great and tidys up the rear end.
Gerry

 

[GAB]

Ted,

I'm guessing that you are talking about the 3 items on the top of the spindle boss. Are you thinking that that is the thrust bearing?

Those are spacers that they use for tuning aids. They raise and lower the front of the car for changes in track condition and use different amounts from side to side to do some preloading. At least that is the theory of using them. I would seem that they are just another thing to add into an already impossible tune up equation.

If that is not what you are referring to, maybe this pic will clear up the spindle situation.

 

[Gerry]

Looks like an E type that has had a wheel flange welded to the splined stub axle. Lots of offset to the wheel from the bearings.

Does to me as well. You can just make out the hole for the split pin in the hub behind the flange. If so WHAT A WASTE of a splined hub. They are hard to get hold of and V expensive over here. On top of that they look great with the US E Type nut on. It has no 'ears' just a smooth look.
This is a pic of my parking brake. Ignore the yellow lines they were for something else

G

 

[Old Rotor Flap]

Yes Lee, there are flanges welded onto splined hubs and therefore I've foregone additional pix. These must have been done by someone after the rear came out of the original car. I figured they were modified from the original splined hubs since it would be a waste of time and an added expense to build splined hubs only to weld flanges on them. Of course, knowing the splined hubs are more valued, I'll want some.

Now I wonder how true the flanges are and more importantly, what damage has been done to the splined hubs in the process of welding?
I'm just guessing, but the bolt circle looks off-handedly larger than 4.5".

For now, the rear will be parked under a bench or shelf until such time as I can think about a second go at a T or my wife has to have a yard sale.

Since I have lots of stuff, the most expensive of which is my helicopter parts inventory, awhile back she said I should inventory and list the values of all my stuff in case something happened to me. I told her no-way and that to do so, would mean I'd have to hire a food taster...... Should I trust her after almost forty-five years (this coming Saturdady) of marriage?

George, I'm impressed. I like your funny car chassis. I like the oval tubing idea and it would probably be cheaper buying tubes from you as they could be heavier wall than streamling tubing than trying to make them. Although, we do have a large CNC ?? press in the welding shop. Not CNC, but very controlable. I guess programming the "Z" move is not CNC.

George, what program do you have to create those beautiful drawings?............ and thanks for your valued input.

 

[GAB]

Back when I made quite a few Jag mounting kits, I also made some emergency brake setups that were hydraulic. The rotor mounted to the backside of the pinion yoke and the caliper floated on the mounting bracket. There was a bracket that was welded to the third member for the caliper mounting bracket to bolt onto.

The master cylinder and ratcheting handle were made to mount up under the cowl on the left side.

The biggest problem is that everyone wanted to chrome the rotor and they wouldn't hold then.

 

[Ted Brown]

Ted,

I'm guessing that you are talking about the 3 items on the top of the spindle boss. Are you thinking that that is the thrust bearing?

Those are spacers that they use for tuning aids. They raise and lower the front of the car for changes in track condition and use different amounts from side to side to do some preloading. At least that is the theory of using them. I would seem that they are just another thing to add into an already impossible tune up equation.

If that is not what you are referring to, maybe this pic will clear up the spindle situation.

If you mounted the wheels on the spindles as they were, it must have been a funny angle that made the spindle look like it was pointed down, Sorry ilot:

 

[gfigms]

If you need to change the track width on a Jag, you can get a little creative with how you make the parts.

George, did you actually make those shown in the cad drawing?

 

[GAB]

Milt,

No, I haven't actually built the arms in the drawing. Obviously the arms on the purple car were built. I did build one of the hub carriers shown in the drawing just for the heck of it. I had an extra bearing housing and a lower shaft tube, so I made the rectangular tube section and welded it up to see what it looked like. Serviceable, but not great looking like Gerry's hub carriers.