Warning to MII kit owners, Street Scene Mag

I'd love to claim credit for this trick but the fact is, my buddy Jimmy V. whipped up my Mustang II style [only parts left from the mustang is mounting hardware and spindles] front for me building him a hotrod 283 for his [my ex] 35 IHC pickup. He's built many of these and has no complaints.
Just for shits and giggles, here's a photo of the old cornbinder. It had been mine and I had him chop it 4 inches....called me to say it was done but I couldn't have it back because he'd grown attached to it......he still has it.

 

just want to bring this back up, I am fixing a car today, with the exact same problem as the initial post. I will see if I can get some pictures up tonight

 

this looks like the exact same failure. too thin of material, the slots wrap down the inside, and it was not welded to the sides along the slot.

Also a fat man front end, however we noticed the problem when the car was here at the shop, not going down the road.

unfortunately the owner only wants it repaired and reinforced, he will not let me cut the hat off and start over. It is on a rather nice 40, and I will try to shoot some photos of how I fix it.

the shot is looking up through the spring pocket after the front end was pulled apart.

 

Gregg, did it have the narrow T-bolts?

 

for sale complete FATMAN front end stainless uppers and lowers .. NEW .. welded on taken off for safety reasons... complete with spindles larger brake rotors and 5.5-5 on 5 aluminum hubs

 

i know m2 kits are easy to install and work good but this is one reason to stick with gm sub frame,its just alot more fucking work,but everybody gets there balls busted when they say they want to sub frame something

 

How thick is the material? Have you, or the owner, sent this info to Fatman? I would think you'd see a lot of this on cars with the big, wide sticky on big rims tires rather than on traditional 15" wheels with "normal" tires. There's a lot more force available with those big meats.

 

Just another good reason I decided to go with a beam axle on my 46 coupe. Disk brake conversion still sounds like a better front end on a beam than an MII.

 

steve, no this had the stock style bolts with the round head.

the material is about 12 ga., and the front stock is narrow steelies and and 165's or so.

the car has seen slightly above average road miles for a hot rod, but is otherwise an especially well built car.

 

IMHO this subject cannot be brought up often enough. The majority of these aftermarket MII kits have been backyard engineered. Detroit spends 100m to design this stuff and then these guys, who more often than not started out in their backyard, think they can outdesign Detroit, without any real world destructive testing and without the conscience to carry any product liability insurance. Just one successful lawsuit from a victim would put these guys out of business. Listen to ELpolacko - a voice of reason and knowledge in an ocean of stupidity. He understands this subject like no other.

 

here is a shot of the car.

 

This thread is soooooooo good - for a good reason - information & safety.

I'm in the process right now of replacing both front & rear suspensions on my 46 coupe. I looked at ALL the M2 stuff & decided that they didn't fit my large heavy car with small components designed for small cars.... I spent my money on (ALSTON) Chassis Works parts. Money was not very much more but hvy. duty parts & design was well worth it.

I'm still waiting on a few items to arrive from cally......... as they do I will document the construction.

Paco

 

In short terms, the reason for the MII is the fact that they were designed as "unequal A-arms" The geometry between upper control arm and lower control arm made for a better handling and better cornering and better everything, suspension.- thats a period.

 

anybody want to send me they're MII kit, I'll take one.

 

All double wishbone front suspensions are designed with unequal length a-arms...

 

I just looked at the Fatman MII on my sedan.......still looks perfect, 16,000 miles and five years. Must be my red wheels making it last so long.

 

16k in 5 years? Maybe put some miles on it and come back and tell us about it.

 

that is pretty conservative driving. I average 10 to 15K a year on my junk. I just managed over 2k since the first of April on my twin turbo truck and hope to rack up annother grand over this coming weekend. So far I have clocked over 50K in four years without breaking anything. And trust me, this truck isn't a lightweight and I don't baby it, I do radical things like "ride the brakes while driving over rail road tracks" and other destructive behavior.

Gregg, I am actually suprised to hear this had the round head bolts. I wonder what grade material that crossmember was made from. Usually they were using A36 but maybe they were importing thier stuff so god knows what the tensile strength was.

If you need, I will be cutting 10 gauge HS-CR today, I can blow out a pair or reinforcement plates for you guys.

 

thanks steve, I have some plates being made right now, we are going to cut the top out where the notches are and fit a whole new section on both sides.

the thing that amazed me the most was the lack of weld on the underside. if you look at the photo, you can see that all of the damage is in an area where it was only welded on the outside, and ground down. one of the remaining cracks starts right at the weld's edge.

 

drdave----Fatmans,Heidts,Tci all have complaints.I have a Chassis Engeineering on my 47,havent driven it yet,but checked before I bought it. Cost is more but I could find no complaints on the bolt on assm. Very reliable company so I wonder if they have same problem.The unit seems to be well built.

 

If the MII aftermarket used the stock style lower arms,
and didn't cheap out on material thicknesses,they would
have a LOT fewer problems.


500 miles cruising around town isn't a real test of durability.

 

I never got a chance to update how I repaired this car, for the most part the pictures tell the story.



















fully tig welded, it was a pain getting to it without taking the front end of the car off, and getting up to the inside was even worse.

 

Looks great man. Much stronger I am sure...

 

Nice work, looks great!

 

I was wondering if Elpolacko or anybody else with some experience in this IFS stuff would care to share a comment regarding the use of Jaguar XJ6 front suspension units in early F100 style pickups. I read an Australian article written in a magazine where the editor had great reservations about this application.

In Australia these Jaguar units are being use widely it seems and I was wondering if they could start expecting a spait of failures over there as so many of them start recording alot more highway miles.

Even a comment in general regarding these front ends and there suitability to be employed in hot rodding.

 

I'm building a 37 pickup ( based on a shortened 4 or 6 ton frame) for a guy using an XJ series II front end. They are very easy to install and everything is incorporated into the front x-member, including the steering rack. All you need to fab are the upper shock mounts. They are really rugged out of a VERY heavy car with a HEAVY engine sitting over them. I can't imagine what any problems would be. That is apart from the cost of all the rebuild parts if you get a flogged out one. New rotors seem resonable enough but all the rest is relatively spendy. Of course the front ends themselves are dirt cheap.

The rack is power and Flaming River (& presumably Borgeson) have a spline to DD uni to suit.

They are perfect under trucks and I've seem one under a super low 46 sedan but while it worked pretty well it was on the verge of being too wide.

 

I have to bring this up- Seberal folks have pointed out weight as a contributing factor to this particular form of damage- this isn't caused by weight at all- this is shearing force, plain and simple. the weight of the car would be on (primarily) the spring and cup assembley. this damage appears to be caused by the upper a arm forcing itself towards the motor.

this is because the caster angle is loading the bolts into thin, unsupported sheet metal.

I have to say this, becuase It's true. not every car is well suited for a clip. some are much better suited for upgrades to the stock suspension.

But I am not now, nor have I ever been in love with Mustang II. I have seen this exact damage on light cars, heavy cars, stock style spring, coil over, air bag...it doesn't matter. this is simply, in my opinion, a crappy suspension design.

There are other options for independant front suspension without the calamities of MII and it's many attempted dopplegangers.

I have always thought the way MII upper control arms bolt on to these things is "beyond funky"...it just doesn't make alot of sense to have the bolts running vertically instead of horizontally, so the crossbar bears the forces of the front end instead of the hardware.

am I ranting again? Crap. sorry guys.

Steve- I hereby hold You responsible for building a better mousetrap.

 

Not sure I agree with any of that! The Jag XJ's weigh around 3600 lbs vs maybe 3,000 for the '37 pickup (empty), and the later pickups these are being used on ('48 - 52) weigh a minimum of 3200 lbs. Not a big difference overall, and with a flat V8 the bulk of weight is on the front. I've heard rotors here in the states are well over a hundred bucks a pop. Maybe they're cheaper down there?

My other concern is that the roll center of the truck is at least a foot higher than the Jag's, unless you also Z the frame a fair amount. That translates to higher stress on the suspension.

The Jag suspension compared to any of the other popular alternatives (Nova, Volare, even a proper MII aftermarket system) looks flimsy to my eyes, and god only knows why anyone would want to use a suspension that's hard to find parts for ... Just my opinion, but there are people with this setup on the road on 48 and later trucks and NOT satisfied with it, after it was widely hyped on some other boards, mostly because it is a very cheap and simple swap.

 

do the T.C.I. kits have the same issues? im not defecting from factory, but my buddies considering one for his 52 chevy.

 

Yep, cheap and available the two most dangerous reasons to use a component.
I recall the magazine sighted the very low cross section of the jag cross member as being one of its weakest points. Added to it the stress caused by a high roll center and also the long wheel base and chassis twist leverage that can be exerted.
Bracing a long chassis correctly could actually be stressing a jag IFS even more in this case!