TECH...well sorta... JAG IFS into mid fifties F100

My memory is that Holmsey soft mounted his Jag. I soft mounted mine. If the frame rail width is close to the Jag mounting width it is certainly easier to soft mount than welding it in. Welding it in is about the same level of effort as welding in a Volare. I installed mine in my 49 Ford pickup. My frame rails are 32" wide outside edge to outside edge.
Most that weld it in eliminate the forward "arms" on the Jag crossmember. I personally like the added strength that the arms provide.
I am sure that you could plug weld and redrill the Jag hubs. As it is, you can use chevy rims.

EDIT: I just reread your post and reviewed Holmsey's build. He did soft mount. Your frame rails are 34" outside and will require notching your frame as Holmsey did. The F-1 frame rails are pinched it the front from 34" to 32". Starting with the F100 in 53 they are 34" all the way forward. The notch is to allow the rear pivot of the upper A arm to slip by the frame.

You need to visit Holmsey's website below. The first few pages document the Jag installation It is the best!

http://www.uk-hotrods.co.uk/v2/garage_scene/me/page_1.php

 

Thanks for the info and the link, I read through his build today. I was happy to see he later changed the front IFS mounting tabs double-sheer. He initially had them single-sheer and that made me cringe a bit.

I'm definitely going to avoid the Jag rear end, that looked like a huge pain to install. I've got a 1990 Mustang 5.0 5 speed I'm using as a donor so it will likely get the 8.8 from that anyway. Too bad it's IFS isn't useable as that car handles very well.

I'm not worried about which install has the least amount of fabrication, I'm pretty comfortable in doing that part but just wanted to choose the best/affordable front suspension. I can weld and make stuff OK but I'm very cheap, lol. Also once you go Volare it's a nightmare to go back to change to anything later so I have a bit of that fear.

Since I have everything for the Volare swap it will take more research to sway me. I'm going to research and find out what parts are actually getting scarce for them and see if I need any of those parts before I get started.

 

Will an 1987 work? I have an 87 already...

 

The change year is supposed to be 1988 which means that you should be ok. Look at pictures like in Holmseys build link above and compare it to your IFS. I believe that there are significant differences in both the cross member and the "tower" that supports the upper A arm on the later Jags.

 

I used an 87' XJ6 as my donor.

 

Any updates? Are you driving yet? Thinking about this for my 54.. Thanks John

 

Hi All.I,m new here and red all the articles about the Jag ifs and desited to put one in my 54 F100.Thanks for all the info and pictures guys.It,s almost done bud have a problem.It sits VERRY low.I only have 12cm clearence between the bumper and the floor.My ifs came out of a '76 XJ6. Question....could it be that the coilsprings are worn out and if I replace them with XJ12 springs it would make the truck stand higher?Front weels are 15x8 with 235/60 tires. The engine is a ford clever 400 bud donno how mutch it weighs.Anyone who can help me out with this issu please.Thanks in advance.

 

XJ12 springs should be plenty to hold up that Cleveland. But not sure if part of the problem is in the mounting.

 

Thanks for the quick reply plym49.Will try the XJ12 springs first.The ifs is welded in like most of the guys do.Holmsy had the same problem and he used std jag springs.Donno what std meens bud it helped to push his ride up a fare bit.Also cleared the problem of the spring travel.He had only 1inch before it hid the bump stop.
O,bjw my name is Jack.

 

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If memory serves, there are three different Jag springs. The 6 cylinder XJ6 are the lightest, and the XJ12/XJ-S the stiffest -- I don't recall if there was a middle one, and if there was what it was about.

A good check might be to compare the front end height settings from the factory manual. These were from the ground to the inner lower arm fulcrum, and from the ground to the lower ball joint. If the inside measurement is way low compared to the outer, that would indicate weak springs. If the numbers match the book, that would indicate the right springs but the crossmember mounted too 'high' in the frame. If the inner number is high compared to the outer number (after you replace the springs) that might indicate too-strong springs.

Does that make sense?

 

Thanks Plym. That make,s sence alright.I,m almost 90% sure that the springs are to weak,bud will do the measurements tomorrow.

 

Great post, just read it all the way through. One thing, how are you going to weld in between the two fillets ? One plate in the middle would be better and neater.
Keep up the good work. Roger.

 

Good observation. Maybe he could also just move the second fillet from the right down and to the left, so that it fills the gap. First weld the left fillets up. Then slide the fillet in question to the left and down. Then weld it all up. Will be way strong and no need to cut more metal.

 

It's been a while since I read through this entire thread, but in case this hasn't been mentioned yet--the factory XJ6 setup included circular nylon shims both on top and under the springs. IIRC, these shims collectively are about 5/16" thick, which translates to about 3/4 - 1" of effective height at the hub. Might want to check this out, it's an easy way to fine tune ride height.

 

Don,t think the nylon shims will work in my case.There,s almost no space for the springs to travel up and down before they hit the bump stop.The guy who I boucht the front end from mensioned that he had some shims for me if I needed them.Will try the XJ12 springs first.The XJ12 engine weight is about 300 pounds more then the XJ6.Think the problem will be solved then.Another issu are the brakes.Do I need an adjusteble proportioning valve for the rear brakes couse I run drums in the back and power brakes on front? ( Jag m/c and booster ).

 

I doubt that the Jag m/c has reservoirs that are properly sized for rear drums. I have never built a brake system without an adjustable proportioning valve, they are pretty cheap and a necessity for dialing in the bias, especially if you have some slightly mis-matched hardware.

Another point about the jag front end. Usually, these are retrofitted into vehicles with lighter front end loads than a stock jag. Most of the pics I have seen of installs ignore suspension geometry, particularly with respect to bumpsteer. As a reference point, I have found that the control arm geometry is very close to stock (I happen to own an XJ6C) if the hub is basically level with the frame mating surface of the rear "V" mount (i.e., the upper surface of the rubber mount). At this ride height you have approx. 3" of hub travel to the full compression bump stop. This is also roughly in the center of travel between full compression (lower control arm bumpstop making contact) and full rest (upper control arm bumpstop making contact). Note that in this position, the lower control arm is NOT parellel to the bottom of the crossmember or ground, but rather points down slightly going from the fulcrum to the lower ball joint. I have never checked this angle, but it is probably about 4 degrees or so. You should have no bumpsteer or bumpstop issues if you spring your front end to be close to this at ride height.

Incidentally, I am currently installing an XJ6 IFS onto a '53 Studebaker truck.

 

Hi Chevsen.Did my calculations on the front end today and the conclusion is that the hub travel to the full compression bump stop is not more then 1 inch.And that the lower control arm is almost level with the bottom of the crosmember.About 2 degrees maybe even less.Bolted some 16 inch weels on and that gave me 3cm more ground clearence.
Deffenetly need XJ12 springs.That would make the right ride hight and spring travel without hidding the bumpstop and I can use my 15inch smooties.

 

The photo that was posted above was before I welded them up. My buddy, who is a real welder unlike me ; ) , was able to weld them out without issue. I have since cut out cover plates for them that will bolt on to clean it all up. I am in the process of moving so no work has been done on the truck for a while. Once I'm up and running again...... I will update the thread with new pics.

 

Use hj hx Holden shocks and you won't have to cut anything out of the inner gaurd they are a lot shorter than the jag units

 

THey may be a bit hard to come by in the USA.

 

Pretty good read! I was wondering if anyone has installed one in a 61-66 f100 and bagged it. I am going to be laying it out and want to do it right the first time. Any help would be greatly appreciated.

 

Here is a link that Matt2491 did on his 64... He didn't bag it, but it is an excellent read. (Great job Matt!)

 

Thanks for the link! It has been bookmarked!

 

Hi Chevsen,Can you tell me where I chould install the adjustable proportioning valve?
Can I put it near the master cillinder ore do you prefere to put it somewhere else?
Thanks.
Are you making some progres on your 53 Studebaker project?

 

Rubber or solid?? I've read all the info I can find on Jag IFS installs, and 1 question remains. Which is better, solid mounts or rubber? Does anyone have experience with both that could give an objective opinion on ride quality, handling, etc? I just purchased a `82 XJ6 ifs from the local you-pull for $147. I've got everything to rubber mount it to the chassis of my `58 F100, but I'm still on the fence....

John

 

From what I've read, it all comes down to ride. The solid mount will make it a harsher ride, the rubber mounts a softer one. When I get around to doing mine, I plan on rubber mounting it.

 

I will be bagging mine so I think alot of the harshness will go away. It seems to me that if it is welded in the frame would be stiffer (added crossmember) which would result in better handling. The bags should help smooth out the bumps. WHat about crossmember thickness. I've read that the crossmember is thin. Has anyone actually seen one tear at the welds??

John

 

There were millions made and I've never seen one fail.

 

The Question was about welding the crossmember to the original frame. I've read that is the reason alot of guys don't weld on the crossmember.

John