Jag IRS Info

fiftyv8 · Jul 14, 2011

Can anybody post a list or charts of Jag IRS width specs as has been done for Ford 9" rear ends.
Maybe even related to model ID's also...

53sled · Jul 14, 2011

http://www.jalopyjournal.com/forum/showthread.php?t=77729

XKE is a more narrow version than the xj style, most parts interchange 70-86

Hnstray · Jul 14, 2011

just yesterday there was a resurrected thread on Jag IFS that had a post threin with dimensions of Jag IFS and IRS. The thread was titled something like "Jag IFS into F100".

Also, if you google Jag suspension info there is a lot of info that will turn up there including dimensions.

Ray

jrblack30 · Jul 14, 2011

Here is one but I dont think it uses any 9" gear

fiftyv8 · Nov 16, 2011

Well here is some info I've gathered from your prompts.
I figure by putting it here it will help other searches later.
Flanges are old big Chevy bolt pattern (5x4-3/4").
The Jag XJ rear width is about 61 1/2".
If XJ jag rear is too wide XKE control arms and axles can be used and are approx 4" narrower per side. (fit perfect under a model A)
A stock XKE is 53 1/2 inches wide.
Model width List:
Mk 1, 11 58-59
F - 1422 - 56.88"
R - 1381 - 55.24"

Mk X 62-67
F - 1498 - 59.92"
R - 1498 - 59.92"

S type 64-68
F - 1428 - 57.12"
R - 1403 - 56.12"

XJ6 69-73
F - 1479 - 59.16"
R - 1506 - 60.24"

E type, E type Series II
F - 1295 - 51.8"
R - 1295 - 51.8"

E type Series III 72-73
F - 1403 - 56.12"
R - 1403 - 56.12"

XJ6 Series II 74-82
F - 1505 - 60.2"
R - 1520 - 60.8" 

Top of rear should be mounted at 6 degrees for control arm mounts to be level.
Rear locating arms to frame should be level with ground at ride height.

ThunderRocket · Nov 14, 2011

good info!

tahn07 · Jul 28, 2012

Is this hub to hub or outside of tire to tire, or track width?

plym49 · Jul 28, 2012

jrblack30 said: ↑

Here is one but I dont think it uses any 9" gear

Click to expand...

Done wrong, just like most of them that you see.

You do not use trailing arms with a Jag rear end if the rear is solidly mounted to the frame. You only use trailing arms if the rear is resiliently mounted to the frame using the stock Jag cage. If you really really think you need trainig arms, then the axis must be far forward and on a line that exactly goes thru the axis of the lower fulcrum bearings.

The reason for this is that the stock Jag parts are crazy strong and have NO interference motion. All of the bearings are roller bearings.

The stock Jag trailing arms were mounted in rubber, like the cage, and provided a rear-steering effect when the car went hard around a corner. Thus, the entire cage was able to move around but the rear suspension was solidly no-interference.

If you introduce interference motion into the equation, like by solidly mounting the rear and adding trailing arms that do not pivot on the axis of the lower fulcrum bearings, you are bending and stressing parts and something is gonna break.

If you are putting a Jag rear into a shoebox or other vehicle where you do not see the rear, you are probably better off using the stock Jag cage around the rear. They are really easy to mount (use the stock Jag mounts - they look like motor mounts - something like 8 bolts total) and also the stock Jag trailing arms (rotate the robber 90 degrees for stiffer rear-steer, leave it stock for normal rear-steer).

LIFESTYLZ · Jul 28, 2012

jrblack30 said: ↑

Here is one but I dont think it uses any 9" gear
Click to expand...

He didn't want anything with 9" gear.

derbydad276 · Jul 29, 2012

the ford IRS adapts pretty easy for for pick ups and might go into cars easy to

http://team321.com/truckirs/truckirs.html

JEM · Jul 30, 2012

plym49 said: ↑

Done wrong, just like most of them that you see.

You do not use trailing arms with a Jag rear end if the rear is solidly mounted to the frame. You only use trailing arms if the rear is resiliently mounted to the frame using the stock Jag cage. If you really really think you need trainig arms, then the axis must be far forward and on a line that exactly goes thru the axis of the lower fulcrum bearings.
Click to expand...

...and one would note in corroboration of that, when Jag revised the rear suspension and changed the mountings for the XJ40 they got rid of the trailing arms completely. Roll understeer in the later setup is handled in the angles of the lower control arm mounts, not by 'steering' the cage with the trailing arms.

JEM · Aug 1, 2012

derbydad276 said: ↑

the ford IRS adapts pretty easy for for pick ups and might go into cars easy to
Click to expand...

Ford's had a few different IRS designs, the MN12/FN10 Thunderbird/Lincoln Mark VIII you're referring to here, the '03-04 Mustang Cobra, the Lincoln LS, etc.

As for the MN12 setup, it's pretty wide, and quite bulky, and you need to pay attention to what parts you're getting (most V6 'Birds had a 7.5in diff and stinky drum brakes, the Thunderbird SCs had iron 8.8s and discs, the Lincolns had aluminum 8.8s with lousy 3.07 open diffs but had aluminum lower control arms and air bags where the 'Birds had cast-iron lower control arms...) and it's a Ford so almost everything was NLA'ed by Ford at least a decade ago, it always amazes me that you can get parts for 20-year-old BMWs with no trouble but any post-1980 Ford is always a disaster.

Not entirely HAMB-able but if you insist...

'64 Country Sedan frame with modified MN12 Thunderbird SC subframe (the front legs had to be narrowed and lowered to mate up properly to the Galaxie frame, easy once I made the jig to do it, unlike some of the truck conversions I'm retaining the original rubber mounts), Mark VIII aluminum lower control arms, '02 Explorer 8.8 rear cover, fabricated rear diff mount with E39 BMW bushings, everything tacked for trial-fitting...

Subframe is bulky enough that there's bugger-all room for the stock gas tank here, I'm planning to do a fabricated aluminum tank under the driveshaft in front of the subframe similar to the MN12 'Bird and a lot of other late-model products.

The 285/40-18 tires look pretty small once the car's back on its wheels, it's not all that low, 6 3/4in from ground to frame as it's set up here. Note that the IRS is just about exactly 3in wider hub-to-hub than the stock Galaxie axle, necessitating some extra offset in the rear wheels.

mgtstumpy · Jul 30, 2012

An old HAMB thread http://www.jalopyjournal.com/forum/showthread.php?t=381637

LIFESTYLZ · Jul 30, 2012

The Ozzie GM Holdens have a good LSD IRS set up as well.
Cheap enough as well.
Just picked one up for $200

mustangsix · Jul 30, 2012

jrblack30 said: ↑

Here is one but I dont think it uses any 9" gear

Click to expand...

That's not a Jag centersection. Looks like some kind of quickchange.

Ditto on not really needing the trailing arms. They aren't there to locate the control arms like on a Vette. They are there to help stabilize the assembly from rotating.

The cage is only held at four points on some rubber mounts and the top and is very wobbly without the arms. Just rebuilt the IRS on my OT Jag XJS and it only took about 30 minutes to undo everything and drop the entire rear from the car.

jrblack30 · Jul 30, 2012

Guys,

The image I placed up there is an all Aluminum Halibrand Independent Quick Change that I have been working on for a customer.

JEM · Jul 30, 2012

LIFESTYLZ said: ↑

The Ozzie GM Holdens have a good LSD IRS set up as well.
Cheap enough as well.
Just picked one up for $200
Click to expand...

I think I've been to the Holden museum where that pic was taken...

That semi-trailing-arm rear suspension originated in the early '90s Opel Omega/Vauxhall Carlton, Holden borrowed it and beefed it up, later ones got a toe-control link that originated on the Lotus Omega/Carlton. Holden thought highly enough of that setup's durability to use it on 3/4-ton utes, as I recall.

In the US that rear suspension's shown up on the '04-06 GTO and the subsequent and much-missed G8, GM's last attempts at resurrecting the Pontiac brand from the horrible plastic-trash reputation it'd descended into from the '80s forward.

Given what the marketplace thought of the Pontiac name by 2004 GM would have been better off just selling them as Holdens.

davidfe · Jul 30, 2012

JEM,

Love the long roof. Had another make and model for years. Loved
the ride and what I could carry.

Looks really good. Will be interested seeing your experience in how it rides.

David

JEM said: ↑

Ford's had a few different IRS designs, the MN12/FN10 Thunderbird/Lincoln Mark VIII you're referring to here, the '03-04 Mustang Cobra, the Lincoln LS, etc.

As for the MN12 setup, it's pretty wide, and quite bulky, and you need to pay attention to what parts you're getting (most V6 'Birds had a 7.5in diff and stinky drum brakes, the Thunderbird SCs had iron 8.8s and discs, the Lincolns had aluminum 8.8s with lousy 3.07 open diffs but had aluminum lower control arms and air bags where the 'Birds had cast-iron lower control arms...) and it's a Ford so almost everything was NLA'ed by Ford at least a decade ago, it always amazes me that you can get parts for 20-year-old BMWs with no trouble but any post-1980 Ford is always a disaster.

Not entirely HAMB-able but if you insist...

'64 Country Sedan frame with modified MN12 Thunderbird SC subframe (the front legs had to be narrowed and lowered to mate up properly to the Galaxie frame, easy once I made the jig to do it, unlike some of the truck conversions I'm retaining the original rubber mounts), Mark VIII aluminum lower control arms, '02 Explorer 8.8 rear cover, fabricated rear diff mount with E39 BMW bushings, everything tacked for trial-fitting...

Subframe is bulky enough that there's bugger-all room for the stock gas tank here, I'm planning to do a fabricated aluminum tank under the driveshaft in front of the subframe similar to the MN12 'Bird and a lot of other late-model products.

The 285/40-18 tires look pretty small once the car's back on its wheels, it's not all that low, 6 3/4in from ground to frame as it's set up here. Note that the IRS is just about exactly 2in wider hub-to-hub than the stock Galaxie axle, necessitating some extra offset in the rear wheels.
Click to expand...

davidfe · Jul 30, 2012

I have been following the recent thread about the JAG
IRS. Here are a couple of links I have found and am still
reading.

 IRS in a Classic Mustang

 [FONT=&quot]http://home.bresnan.net/~dazed/JaguarIRS1[/FONT]

[FONT=&quot][/FONT]
IRS Forum which covers all makes and models.
[FONT=&quot][/FONT]

[FONT=&quot][/FONT]
[FONT=&quot][FONT=&quot]http://irsforum.boardhost.com/viewtopic.php?id=242[/FONT][/FONT]

[FONT=&quot][FONT=&quot][/FONT][/FONT]
[FONT=&quot][FONT=&quot]Fad in the Making
[/FONT][/FONT]

 [FONT=&quot]http://www.jalopyjournal.com/forum/showthread.php?t=530352[/FONT]

[FONT=&quot]yel with body on4.JPG is the link to the posting of his JAG IRS rear end.

WOW lots to see and learn.

Hope this helps.

David
[/FONT]

ThunderRocket · Jul 31, 2012

Wow, that Mustang/XJ info is priceless!

fiftyv8 · Jul 31, 2012

fiftyv8 said: ↑

Well here is some info I've gathered from your prompts.
I figure by putting it here it will help other searches later.
Flanges are old big Chevy bolt pattern (5x4-3/4").
The Jag XJ rear width is about 61 1/2".
If XJ jag rear is too wide XKE control arms and axles can be used and are approx 4" narrower per side. (fit perfect under a model A)
A stock XKE is 53 1/2 inches wide.
Model width List:
Mk 1, 11 58-59
F - 1422 - 56.88"
R - 1381 - 55.24"

Mk X 62-67
F - 1498 - 59.92"
R - 1498 - 59.92"

S type 64-68
F - 1428 - 57.12"
R - 1403 - 56.12"

XJ6 69-73
F - 1479 - 59.16"
R - 1506 - 60.24"

E type, E type Series II
F - 1295 - 51.8"
R - 1295 - 51.8"

E type Series III 72-73
F - 1403 - 56.12"
R - 1403 - 56.12"

XJ6 Series II 74-82
F - 1505 - 60.2"
R - 1520 - 60.8" 

Top of rear should be mounted at 6 degrees for control arm mounts to be level.
Rear locating arms to frame should be level with ground at ride height.
Click to expand...

The sad thing is with both these and other measurements I've seen posted for Ford 9" rearends, you are never quite sure where the measurements are taken from!!!
Above, I am guessing by saying that they are from outside hub flange to other side.

LIFESTYLZ · Jul 31, 2012

fiftyv8 said: ↑

The sad thing is with both these and other measurements I've seen posted for Ford 9" rearends, you are never quite sure where the measurements are taken from!!!
Above, I am guessing by saying that they are from outside hub flange to other side.
Click to expand...

You would be right.
That is the norm when you see figures like this.

Weasel · Jul 31, 2012

Flange to flange for the Jag rears up to '87. After that they had outboard brakes - whole different animal - pun intended. Jag XJs had original style IRS but with outboard brakes from 1992-1996 I believe....

hudson48 · Jul 31, 2012

The Pontiac GTO and G8's were Holdens exported to the USA.After Pontiac ceased in April 09(I think) Holden here was left with a bunch of them.They were basically HSV's without a couple of bells and whistles but all the underpinnings were Clubsport.They rebadged them here as a HSV GXP.I have one I bought in June 2010.Identical to clubsport,317KW 6.2 litre.

JEM said: ↑

I think I've been to the Holden museum where that pic was taken...

That semi-trailing-arm rear suspension originated in the early '90s Opel Omega/Vauxhall Carlton, Holden borrowed it and beefed it up, later ones got a toe-control link that originated on the Lotus Omega/Carlton. Holden thought highly enough of that setup's durability to use it on 3/4-ton utes, as I recall.

In the US that rear suspension's shown up on the '04-06 GTO and the subsequent and much-missed G8, GM's last attempts at resurrecting the Pontiac brand from the horrible plastic-trash reputation it'd descended into from the '80s forward.

Given what the marketplace thought of the Pontiac name by 2004 GM would have been better off just selling them as Holdens.
Click to expand...

warrjon · Aug 2, 2012

fiftyv8 said: ↑

Can anybody post a list or charts of Jag IRS width specs as has been done for Ford 9" rear ends.
Maybe even related to model ID's also...
Click to expand...

I should have mine back together on the weekend I can measure it if you like. It's a later model XJS with inboard brakes.

plym49 · Aug 6, 2012

warrjon said: ↑

I should have mine back together on the weekend I can measure it if you like. It's a later model XJS with inboard brakes.
Click to expand...

The 'best' Jag rear ends are those from an XJ-S or XJ12, as they are all Power-Lock (aka limited slip). Some XJ6's had limited slip rears, but they are rare as the original purchaser would have had to order it that way. On this side of the pond, not likely to have happened.

JEM · Aug 6, 2012

plym49 said: ↑

The 'best' Jag rear ends are those from an XJ-S or XJ12, as they are all Power-Lock (aka limited slip). Some XJ6's had limited slip rears, but they are rare as the original purchaser would have had to order it that way. On this side of the pond, not likely to have happened.
Click to expand...

The problem with that assessment is that many of the XJSes at least were 2.88 gears, and my understanding (someone please slap me down if I'm wrong...) is that the 2.88 Powr-Lok carrier was unique to that ratio and no other gearsets will fit it.

I've seen reference to a ring-gear spacer that allows use of more useful (e.g. 3.54) gearsets with that diff, but I've never seen one. I suppose if one knew how thick the bugger had to be it'd be about an hour to lay it out in Solidworks and another hour of machine time to cut it...

Here's a question no one's ever answered for me: all the XJ diffs retained the early Dana 44 spline patter for the halfshafts - think it was 13-spline or something like that. Did the XJ40/X308 rearends keep that same shaft, or did they update to the later (28? 30?) Dana 44 spline count?

Mojo · Aug 6, 2012

The jag measurement list was from the mounting surface for the wheels, hub to hub.

I think another good source of IRS is the 5 series BMW. Looks like that Holden rear, but it uses a square tube crossmember that the arms mount to. It has chevy 4 3/4 lug spacing too. I had one laying around, it was heavy and solid, real nice piece.

fiftyv8 · Aug 6, 2012

Mojo said: ↑

The jag measurement list was from the mounting surface for the wheels, hub to hub.

I think another good source of IRS is the 5 series BMW. Looks like that Holden rear, but it uses a square tube crossmember that the arms mount to. It has chevy 4 3/4 lug spacing too. I had one laying around, it was heavy and solid, real nice piece.
Click to expand...

Post a couple of pic's for us if you get the chance.

JEM · Aug 7, 2012

Mojo said: ↑

I think another good source of IRS is the 5 series BMW. Looks like that Holden rear, but it uses a square tube crossmember that the arms mount to. It has chevy 4 3/4 lug spacing too. I had one laying around, it was heavy and solid, real nice piece.
Click to expand...

What variety of 5-series BMW are you referring to?

E12 ('72-81) '75-81 in the US
E28 ('82-88)
E34 ('89-95)
E39 ('96-03) '97 in the US, there was no '96 5-series here
E60 ('04-10)
etc?

I'm guessing E28 or E34, both of which had the semi-trailing arm configuration you're describing, though different from one another in detail. The E12 also used a semi-trailing arm, but they're getting pretty thin on the ground now. The E39 and later models are quite different, with an all-aluminum 5-link setup on an aluminum subframe. Nice design if you can make it fit.

The BMW bolt pattern is not 5 x 4.75, it's 5 x 120mm, but since 4.75in is 120.65mm it's so close that they're more or less interchangeable (the center bore is different, of course...)

Personally, the '90s Lexus GS and LS rear suspensions look like a great package to adapt to something else, and not too hard to drop out of a car at the junkyard...

Log in or Sign up

Jag IRS Info

fiftyv8
Member

from CO & WA

53sled
Member

from KCMO

Hnstray
ALLIANCE MEMBER

from Quincy, IL

jrblack30
Member

from Pot hole infested Western, New York

fiftyv8
Member

from CO & WA

ThunderRocket
Member

from Propwash! (16Xray) D/FW

Jaguar IFS / IRS swap group

Thunderbird Owner's Group

Upholstery

Vintage Trailers

Tarrant County Social Club

tahn07
Member

from New York

plym49
Member

from Earth

LIFESTYLZ
Member

from Mangakino ........ New Zealand

49-51 Mercs - Everything and Anything

KIWI.HAMB

Hot Rod Moggies

Classic Step Vans

Jaguar IFS / IRS swap group

derbydad276
Member

from canton michigan

JEM
Member

from SF Bay Area, CA

JEM
Member

from SF Bay Area, CA

mgtstumpy
Member

from Brisbane Australia

LIFESTYLZ
Member

from Mangakino ........ New Zealand

49-51 Mercs - Everything and Anything

KIWI.HAMB

Hot Rod Moggies

Classic Step Vans

Jaguar IFS / IRS swap group

mustangsix
Member

from Orlando, FL

jrblack30
Member

from Pot hole infested Western, New York

JEM
Member

from SF Bay Area, CA

davidfe
Member

from Illinois

davidfe
Member

from Illinois

ThunderRocket
Member

from Propwash! (16Xray) D/FW

Jaguar IFS / IRS swap group

Thunderbird Owner's Group

Upholstery

Vintage Trailers

Tarrant County Social Club

fiftyv8
Member

from CO & WA

LIFESTYLZ
Member

from Mangakino ........ New Zealand

49-51 Mercs - Everything and Anything

KIWI.HAMB

Hot Rod Moggies

Classic Step Vans

Jaguar IFS / IRS swap group

Weasel
Member

from At my keyboard

hudson48
Member

from Brisbane Australia

warrjon
Member

from Sydney Australia

plym49
Member

from Earth

JEM
Member

from SF Bay Area, CA

Mojo
Member

from palmdale, ca

fiftyv8
Member

from CO & WA

JEM
Member

from SF Bay Area, CA

Share This Page

Archive

Atomic Industry

Support

Subscribe

Log in or Sign up

Jag IRS Info

fiftyv8 Member from CO & WA

53sled Member from KCMO

Hnstray ALLIANCE MEMBER from Quincy, IL

jrblack30 Member from Pot hole infested Western, New York

fiftyv8 Member from CO & WA

ThunderRocket Member from Propwash! (16Xray) D/FW Jaguar IFS / IRS swap group Thunderbird Owner's Group Upholstery Vintage Trailers Tarrant County Social Club

tahn07 Member from New York

plym49 Member from Earth

LIFESTYLZ Member from Mangakino ........ New Zealand 49-51 Mercs - Everything and Anything KIWI.HAMB Hot Rod Moggies Classic Step Vans Jaguar IFS / IRS swap group

derbydad276 Member from canton michigan

JEM Member from SF Bay Area, CA

JEM Member from SF Bay Area, CA

mgtstumpy Member from Brisbane Australia

LIFESTYLZ Member from Mangakino ........ New Zealand 49-51 Mercs - Everything and Anything KIWI.HAMB Hot Rod Moggies Classic Step Vans Jaguar IFS / IRS swap group

mustangsix Member from Orlando, FL

jrblack30 Member from Pot hole infested Western, New York

JEM Member from SF Bay Area, CA

davidfe Member from Illinois

davidfe Member from Illinois

ThunderRocket Member from Propwash! (16Xray) D/FW Jaguar IFS / IRS swap group Thunderbird Owner's Group Upholstery Vintage Trailers Tarrant County Social Club

fiftyv8 Member from CO & WA

LIFESTYLZ Member from Mangakino ........ New Zealand 49-51 Mercs - Everything and Anything KIWI.HAMB Hot Rod Moggies Classic Step Vans Jaguar IFS / IRS swap group

Weasel Member from At my keyboard

hudson48 Member from Brisbane Australia

warrjon Member from Sydney Australia

plym49 Member from Earth

JEM Member from SF Bay Area, CA

Mojo Member from palmdale, ca

fiftyv8 Member from CO & WA

JEM Member from SF Bay Area, CA

Share This Page

Useful Searches

Archive

Atomic Industry

Support

Subscribe

fiftyv8
Member

from CO & WA

53sled
Member

from KCMO

Hnstray
ALLIANCE MEMBER

from Quincy, IL

jrblack30
Member

from Pot hole infested Western, New York

fiftyv8
Member

from CO & WA

ThunderRocket
Member

from Propwash! (16Xray) D/FW

Jaguar IFS / IRS swap group

Thunderbird Owner's Group

Upholstery

Vintage Trailers

Tarrant County Social Club

tahn07
Member

from New York

plym49
Member

from Earth

LIFESTYLZ
Member

from Mangakino ........ New Zealand

49-51 Mercs - Everything and Anything

KIWI.HAMB

Hot Rod Moggies

Classic Step Vans

Jaguar IFS / IRS swap group

derbydad276
Member

from canton michigan

JEM
Member

from SF Bay Area, CA

JEM
Member

from SF Bay Area, CA

mgtstumpy
Member

from Brisbane Australia

LIFESTYLZ
Member

from Mangakino ........ New Zealand

49-51 Mercs - Everything and Anything

KIWI.HAMB

Hot Rod Moggies

Classic Step Vans

Jaguar IFS / IRS swap group

mustangsix
Member

from Orlando, FL

jrblack30
Member

from Pot hole infested Western, New York

JEM
Member

from SF Bay Area, CA

davidfe
Member

from Illinois

davidfe
Member

from Illinois

ThunderRocket
Member

from Propwash! (16Xray) D/FW

Jaguar IFS / IRS swap group

Thunderbird Owner's Group

Upholstery

Vintage Trailers

Tarrant County Social Club

fiftyv8
Member

from CO & WA

LIFESTYLZ
Member

from Mangakino ........ New Zealand

49-51 Mercs - Everything and Anything

KIWI.HAMB

Hot Rod Moggies

Classic Step Vans

Jaguar IFS / IRS swap group

Weasel
Member

from At my keyboard

hudson48
Member

from Brisbane Australia

warrjon
Member

from Sydney Australia

plym49
Member

from Earth

JEM
Member

from SF Bay Area, CA

Mojo
Member

from palmdale, ca

fiftyv8
Member

from CO & WA

JEM
Member

from SF Bay Area, CA