Thread: FFR 33 Ford Hot Rod

Tweet

Originally Posted by wrp

We test pretty hard to find the weak spots

I'd love to win the coin toss for that job

Come on down, we will take her out and flog her

This week we are getting closer to finishing the body prep. We cut in the engine compartment skirts so we can remove them without having to remove the headlights. We also bobbed the fenders.

IMG_2336.jpgIMG_2337.jpg

Shot of the hood popped.

IMG_2341.jpg

Was it a requirement to run fenders there?

No, I felt investing in a decent paint job mandated running fenders to protect it. I tend to drive a lot

IMG_1564.jpgIMG_1565.jpgIMG_1568.jpg

Lots of guys and gals using 8.8 rear ends for their rides. It is a great rear end, perhaps a little difficult to find truly beefed up versions but I do have an observation having become very intimate with mine. I'd say they are generally rock solid however, most of the time we get them from wrecked cars and we never really know what sorts of force and pressure have been exerted on the axle tubes. I had never heard of a tube twisting though I've heard from some Mustang owners that it is not an unheard of event. When a tube twists, it actually rotates in the differential housing, normally towards the rotation of the tire. Generally it bends the tube and pushes the tire into the body or inner fender well. I've seen a few crashes where it was said the four link failed. After experiencing this firsthand I am of the opinion that it was an axle tube twisting that induced the four link failure. Hold my beer and watch this.



Had this failure occurred on the 2-3 or 3-4 shift in something more powerful than a 290 horsepower Chevy small block there would still be pieces of plastic and my butt all over the road there. The driver side tube twisted and the car executed a hard left. Had I not been in control it would have adorned the concrete wall and everyone would be blaming the four link. The four link I had was not adjustable, we assumed it was true. Some binding occurred but I was not familiar and didn't know what to look for. So after a few hard miles she gave her all. The 8.8 tube is affixed to the differential housing with two substantial spot welds on each side, total four. On my driver side, the spot welds were twisted over and sheared off.

I've heard of that problem with the 8.8's as well. I've seen guys weld the tube to the pumpkin, although I doubt it would help much cause it's welding steel to cast. My bil drove his Dodge bros from Iowa to Cali and when he got back he noticed his rear tires were wearing funny. Turns out his 9 inch had a bent tube also.

OUCH! Guess that is what happens when you've exceeded the design spec.

Originally Posted by 53 Chevy5

although I doubt it would help much cause it's welding steel to cast

Turns out his 9 inch had a bent tube also.

Cast can be welded using the right welding rods and procedure. I tig welded my tubes in with nickle filler rods and preheat. It welded fine with no visible cracking. I've had good luck tig welding cast over the years. Tigging seems to help prevent cracking.

The housing is most likely nodular iron (which is made with scrap steel and iron, cheaper than pure cast iron and stronger), but nothing I've found proves that. I will say that it grinds (sparks) like nodular iron or what we used to call in the machine shop "semi steel".

I've had a 9" with a bent tube also. It caused a bearing and axle failure in less than 10,000 miles. I learned to check every junk yard rearend for straightness after that.

Well the tube was bent so we straightened it with a long rod. Then they re welded the spot welds and ran a bead around the tubes and the housing. it wasn't just a bunch of redencks running a bead. They used a high nickel content filler and did a lot of prep to the housing. Don't presume to know the extent of it but a few are running around fixed and claiming this was the way to go.


IMG_1625.jpg

Originally Posted by 34_40

OUCH! Guess that is what happens when you've exceeded the design spec.

yep, I think the 8.8 was designed for a 4 cylinder Mustang? I am not so sure that is true though. I firmly believe the axle tube had been bent by whatever threw it into the junkyard to begin with. Eventual driving stress brought the failure like in the 9 inch housing mentioned above.

I'd say it is probably designed for 300 HP max. But that would be a guess. I don't believe Ford ever figured on 500 HP being applied to an 8.8, but again, that's an assumption on my part. I've only seen one 9 inch with a bent tube and like you it was a take-out from a wrecking yard and probably damaged on removal or when "they" tossed it aside for storage.

I'd think a full circle weld done properly around the tube to cast housing would just about make the rear end bullet proof. But again, for how much horsepower? I'd still think 500 HP would be the limit. I'm not sure the stock splines can handle much more than that.

I've seen this on several diesel trucks. We weld the tubes to the housing on every truck that will be drag racing, hard street playing, and sled pulling. I plan on having my 8.8 welded when I take it apart later.

Well we did check the straightness of it going back in and I changed the four link from non adjustable to adjustable. Innovative rodding specialist Dan ruth makes an adjust able 4 link for the Factory Five Cars. In addition to the adjustability, the set also allows you to extend the wheelbase about 1 1/2 inches centering the wheels better in the wheel well.

Front passenger view.jpgIMG_1604.jpgIMG_1709.jpg