Here's the long awaited pictures of my bolt-on torque arm design. It is made out of half inch thick steel bolted to cast web on the side of the 8.8" housing.

The shear area really adds up. Flat plate rests on large portion giving more pressure (stress) capacity as the applied force acts over a large area. This design should prove to be very strong- time will tell.

The completely assembled housing assembly should go in this weekend.

Here's a list of the goodies contained in my 8.8";

New wheel bearings and seals
New carrier bearings and pinion bearings
Freshly rebuilt Ford Motorsports 8.8" posi
New Motive 4.10:1 gears
Solid pinion spacer
ABS compatible (uses stock ABS sensor configuration)
New cast aluminum girle (not shown in these pictures).








Let me know what you think? I'd like to hear some feedback!

Oh, please don't rip me off and steal my design.

(You can't see the bolts, but it is secured very well to the cast web on the 8.8")

Ben Theriot

 

looks cool. but it'll also need a custom driveshaft to mate to the ford yoke. now lets see it in a car. maybe you could bolt the torque arm to the axle to demonstrate how it fits. and, Im not sure if its totally nec., but you could have welded the orig. portions of the axle housings to the pig like you did with your adapter tubing.
another idea if time/money/oportunity allows is maybe a dyno test back to back against a 9" to show any HP loss through the bigger diff.s.

whats the total weight vs a 9" or a 12 bolt?

 

No custom driveshaft is needed. I have the corresonding flange off a mustang drive shaft that presses to the STOCK GM driveshaft with a conversion U-joint. This one's already taken care of... thankfully.

I'm contemplating a back-to-back dyno test VS. the 4.10 geared 7.5" that was previously installed in my car.

Ben Theriot

 

Ben,

Looks good, I know you don't want anyone steeling your ideas but can you answer a few questions?

• How many bolts hold each side of the T/A mount?
• Are they through bolts, going all the way through both peices and the webbing?
• Is there any other way it attaches to the rear other then being sandwiched to the webbing?
• What do you think of the compression of the top and bottom peices in that front corner where there is no webbing?

Maybe you could weld a small peice to that front corner, so it doesn't compress and put stresses on the other bolts.

 

how is the tq arm bolted on and like stated above how many bolts hold it on? and how much will you be asking if this proves to hold up?

 

I don't have the time to explain details on the bolt-on bracket now, but will shortly.

The rearend went in last night. Everything bolted together well. It's a GREAT fit with so many things falling into place. ALL the factory connections were able to be reused. It almost looks factory made it comes together so well. My TA cover is on, and it really stepped it up in the looks department as well. I'll get some pictures of it installed for everyone to see.

Price? Still working on one.

Ben Theriot

 

Your setup really looks good. Are you able to use the original Ford axle tube lengths without modification? And do you know the difference in weight between the Ford and a GM 12 bolt?

 

im guessing no since there is extra tubing welded to the original axle tubes.

 

Are there any plans to sell any of these? I had planned on rebuilding my extra 10 bolt this year with 4.10's, a T2R diff, new bearings, put approx 1* total camber in it, install costs, etc; but if the price difference wouldnt be too bad on getting an 8.8" built with a T2R, I would MUCH rather wait and get one of those instead.

Looks great by the way

 

The Ford axle tubes are cut and the GM tubes are pressed on. This is done by using the coupler seen in the pics. So, yes the Ford axle tubes must be modified; they have to be cut. We thought the weight would be similar to that of the 7.5", but after installation last night/this morning I think the 8.8" is a little heavier. How much? Pobably not much at all; the rear could have felt heavy b/c it was midnight when we were putting it in. As far as comparison to a 12 bolt or 9", I don't know, what do these weigh?

 

How is the bracket bolted on? There are THREE bolts that hold it on. They are all hardened grade eight bolts. Lock washers and red loc-tite ensure they won't be coming loose. Grade 8 bolts have a tensile strength of over 100,000 psi- each.

Why only three? Trying to preserve as much of the webbing area as possible I chose to not drill large holes or very many of them. My design uses all factory holes that are only slightly enlarged. There happened to be three of these holes. Two 5/16" bolts hold the larger flat section on the web, and a 1/4" bolt holds the smaller angled sections of 1/2" plate on the angled part of the web.

Are you confident 3 bolts are enough? With four years of background in Mechanical Engineering at LSU (applicable courses; Strength of Materials, Statics, Material Science), I believe this fastening system will be satisfactory. The bolts are currently only loaded due to their slight elongation that torquing them down imposed. If the fastening system is to fail, it would require exceeding the ultimate tensile strength of one of the two 5/16" bolts and snapping them. These bolts can only have additional loads if the .5" plate bends under launch. If the plate deflects in the y-direction, this would be the only situation for the bolts having to carrying an increased amount of force. The plate has to lift off the web for this to happen. There are also two much larger 5/8" torque arm bracket bolts that sandwich the plate to the web preventing the plates from lifting off. The plate's not going to deflect/bend- it's a half inch thick. Thinner plate would have even been able to support the loads being it's not cantileverd off the axle tubes, the extra thick plate is just additional insurance.

These three bolts affectively just keep the TA bracket in position and securely anchor it flat to the web.

A larger concern is the integrity of cast nodular steel web. Looks like another rearend will be built for a local guys 700RWHP camaro. If he doesn't break his, I think it means the bracket "works".

You can't see the bolts very well from the pictures. In the first picture you can see the bolts best. (From left to right) The first bolt is just to the left of the right TA bracket verticle pipe, the second bolt is hidden to the right of the right verticle pipe behind that triangular shaped piece of steel. The third (1/4") bolt is visible to the far right.

Ask any more questions you may have.

Ben T.

 

Congrats on the innovative design.

Don't think bolts breaking will be a problem. I think you are right about the web snapping off being a greater possibility.

In the 2nd pic, looks like the passenger side web has some extra material where it meets the casting at the tube seat to add support to the web. Did the drivers side have this extra support material, and did you have to grind it off for the flat plates to bolt on?

Maybe adding a support strut from the top torque arm bolt holes to the bushing eye for support. A turnbuckled rod would allow pretensioning since such a support strut would be tensioned as the axle rotates when the car launches. Pretensioning would minimize the webbing flex.

 

Ben,

It looks good, but looking at this 8.8 from an explorer I only see 2 bolt holes on that side of the webbing, also after looking at this pic

and the pics of yours then I see your .5" plate on top coveres the fill plug so I guess you need to tell anyone who buys this that they need a cover with a fill plug installed. Also did your 8,8 have more webbing on it then this one?

I am looking forward to see how this woks on your buddies 700 RWHP car.

Oh whould you think of just selling the T/A mount to those of us who know how to swap the axle tubes. That way people don't copy the idea and you can still make money off the deal...

I may still be interested in the whole thing though, I just presented the idea above as a possibility.

 

As stated above, the T/A bracket is BOLTED into place, which means that it can be taken off to fill the rear. The bracket comes off very easily in a matter of minutes.

 

I'm the former owner of a 8.8 extreme chassis rear end so i'm familiar with an 8.8 in an fbody. The 8.8 is much much heavier than the 7.5. I never weighted them but i switched them out by myself so i've lifted both of them several times. I also am sure his half inch plate is going to weigh a lot more than Extreme chassis's design. So i wouldn't be surprised if this rear will weigh close to a 12 bolt or 9inch. I ditched my 8.8 when the axle tube began to crack when i never even launched the car with anything more than street tires. I do like his axle tube bushing design its ugly but it'll work. If you can make these you're self then it'll probably be a good cost effective rear end for a street car, but for people that can't do the work and want a cheap rear i still think a home built 9inch would be better. I'm also interested to see how your ABS setup works. The ABS sensor can be a pain, coming from a guy that built his own ABS setup for the 8.8. It could be the pic but your sensor looks like its mounted at an angle, i hope thats not a problem. Do you know how much clearance you have between the sensor and the reluctor ring? Are you using the 7.5 reluctor ring or did Ford make one for an 8.8?