Rear axle choices Ford 9" or 8.8" or other? (2008-2022 bump)

[lookforjoe]

What is it you are going to put together? What is it going in? I can't tell from reading your posts. I have a Ford 9" carrier with a Traction-lok unit in it. Also, the housing that is cut down and the axles that came with the rear axle. It was out of a 1966 T-Bird. I think the ratio is 2.88-3.0. A typical high speed rear axle of the time period. I was about to list it on Facebook and Craigslist.

I should have restated it - I only said it in the first post when I revived this thread. It's for my Volvo pickup truck which is getting the LR4/4l60E drivetrain. Many have said it's not a requirement, I just want to make sure the rear doesn't break if I decide I want to beat on it. This is a street use work truck, I want to be able to tow with it if need be. Not going to drag race or drift the thing, but do want to be able to do burnouts if I feel like it

I was looking for the 8.8 based on ppl's experience & ease of parts access. The parasitic drag of the 9 seems to be an issue - again I want this for street use, not necessary to have quick change gear set / drag / race use

I'll message you on the rear for details

 

[lookforjoe]

A friend just weighed a 8.8 ready to drop into a 240, it came in at 216 pounds with brakes.
The 1031 was 170ish pounds with brakes. I added the "ish" as it was rigged with a chain and that's included in the weight, the 8.8 was with a nylon strap.

There's many flavors of 9in housings, but the lightweight ones are light! You can get them into the 165lb range with brakes if you want to.
With a cast-iron 3rd member you'll probably come in around 195-205 pounds if you use the stock (heavy!) 8.8 rear brakes and a regular 9in housing with 31 spline axles.

As much as I don't like the idea - I'm not sure the weight is a major concern though. I really don't want to spend 2K+ on a 9" rear put together.

 

[lookforjoe]

Yea who knows I rebuilt it and a lot of other 8.8s and they always have a bit of slop compared to a split bolted in axle shaft. I think if it were to break on me I would just go straight to a sheet metal 9 inch or put 1031 tubes on the 8.8 center. Wouldn't surprise me if it's lighter too. Much better to weld to a nice new housing as well.

Fwiw if someone needs a 8.8 I have 3 of them all different flavors

Sent you a PM also.

 

[culberro]

As much as I don't like the idea - I'm not sure the weight is a major concern though. I really don't want to spend 2K+ on a 9" rear put together.

$1200-1400 gets you an all new rear end with whatever gear ratio you want, then add some 8.8 rear disks.

Housings used to be $600 with axles, but now they’re ~$700. You might be able to find a deal out there. Just add a 3rd member, brackets, and brakes.

By all means do the 8.8 f that’s your jam, but 9in is just a smidge more for all new parts that just bolt together.

Speedway Ford 9 Inch Rear End Housing Kit with Axles, 56 Inch

www.speedwaymotors.com

 

[lookforjoe]

$1200-1400 gets you an all new rear end with whatever gear ratio you want, then add some 8.8 rear disks.

Housings used to be $600 with axles, but now they’re ~$700. You might be able to find a deal out there. Just add a 3rd member, brackets, and brakes.

By all means do the 8.8 f that’s your jam, but 9in is just a smidge more for all new parts that just bolt together.

Speedway Ford 9 Inch Rear End Housing Kit with Axles, 56 Inch

www.speedwaymotors.com

Thing is, 56" is too narrow. I'm shooting for 59" or wider - the stock rear on a 700 is around 60" according to Cpt. Bondo's early posts. I've head & seen (YT video) issues with the brake calipers contacting the frame members trying to use a narrow rear on a 700. Maybe it's fine on a 240.

That was the site I was looking at - even the 58" version, with a diff, comes out to over 1800+ then you have to add brakes, and I'd still be looking at a rear that's too narrow to not have potential interference issues.

My thinking is that with the 8.8, it's 59.25" - I can potentially use it as is or add 9" ends & try to get it even closer to 700 stock track width.

 

[culberro]

What’s a 740 track width?

Would a 60” flange to flange width work?

https://www.speedwaymotors.com/Speedway-Ford-9-Inch-Rear-End-Housing-Kit-with-Axles-60-Inch,441149.html

Oddly, just piecing together the 9in kits it’s a bit cheaper, but still money. And adding explorer brakes isn’t exactly cheap when you use all new stuff.

https://www.speedwaymotors.com/Ford-9-Inch-Clutch-Style-Posi-Differential-Third-Members,352886.html?sku=91049345-31-325