Building a new 8.8 end to end

[twistedneck]

I have a second 8.8 rear end sitting in my garage. This winter I plan on re-building it and swapping it w my stock GT 3.55 setup. (I Destroyed the diff in my first one and to save time Rehagen just swapped out a take off axle assembly so I could get the car running.)

Goal - build a bad azz rear end setup that has the performance of a PWC for less $.

Please point me in the right direction here is what i'm looking at so far. I already had the axle tubes welded to the center section.

1. ARP long wheel studs - tbd on size
2. Replace upper control arm bushing on the axle with a spherical bearing, and I can't find that part anywhere.
3. Eaton Detroit Truetrac diff - I know the lockout is not smooth but I need something for drag racing and road racing - torsen wont work.
4. Ford racing 3.15 gear kit - so cheap why not replace it.
5. Rehagen racing diff cooler kit and a gage
6. Stock Axles OK? still running NA.
7. New bearings - not sure what once to replace.
8. New rear brake rotors - floating ones from Girodisc - got them on the front.


Anything else? paint it black? I'm sure there are some major fundamental errors i'm making!

 

[TMSBOSS]

Breather and or vent system. What are you running now?

Larger rear rotors?

 

[VoodooBoss]

Breather and or vent system. What are you running now?

Larger rear rotors?

Both of these. If you run the larger rear rotors use the stock GT500 brackets and not aftermarket. Frankly I wouldn't spend the money for two piece rotors on the rear. Stick with the one piece and spend the money elsewhere.

 

[ArizonaBOSS]

Surprised by the 3.15 axle choice--why not at 3.31 or 3.55 if you don't want a 3.73? Trap speed?

Stock axles are fine as are Motorcraft bearings at all points.

 

[302 Hi Pro]

I have a second 8.8 rear end sitting in my garage.

1. ARP long wheel studs - tbd on size
2. Replace upper control arm bushing on the axle with a spherical bearing, and I can't find that part anywhere.
3. Eaton Detroit Truetrac diff - I know the lockout is not smooth but I need something for drag racing and road racing - torsen wont work.
4. Ford racing 3.15 gear kit - so cheap why not replace it.
5. Rehagen racing diff cooler kit and a gage
6. Stock Axles OK? still running NA.
7. New bearings - not sure what once to replace.
8. New rear brake rotors - floating ones from Girodisc - got them on the front.

Anything else? paint it black? I'm sure there are some major fundamental errors i'm making!

Here are my thoughts, studs and axles upgrade both use the best axles you can. Diff housing bearing, Steeda makes a good one. The Eaton/Detroit Assy. Indicates some hard launches are expected, hence my axle upgrade comment. Ratio, at 3.15:1, great for speed, not so great for the launch. Consider keeping the 3.55 as its a compromise to improve both duties. Diff cooler and gauge, great idea. New Bearings? Yes, and all of them, Pinion, side carrier and axle bearings and seals. I went with the 13/14 MY GT500 14" (almost), rear rotors, they may increase rotating mass at the end of the axles, but the work great and look great too. Yes, I would clean and paint, or go for the Rusto-Mod look and use a sealer, but I would clean and paint in Ford 60* black.

As far as fundimenndals you are on a good start, just make sure you have a good setup guy with the adjustments.

Dave
302 Hi Pro

 

[twistedneck]

Breather and or vent system. What are you running now?

Larger rear rotors?

I have a bone stock GT rear 3.55 now. I wish I could use the larger rotors but I have to drag race this car also so I need to fit my 15" wheels on the back.

Vent system sounds good, I didn't know you needed one on the rear end.

Both of these. If you run the larger rear rotors use the stock GT500 brackets and not aftermarket. Frankly I wouldn't spend the money for two piece rotors on the rear. Stick with the one piece and spend the money elsewhere.

I like the Girodisc rotors a lot, just the way the look and quality construction and they match my fronts - once I get a couple sets I can just have one refreshed rotor set ready to go, I believe they charge $300 to re-ring them. I know functionally they are not that much better to be floating in the rear.. how does that work anyway with the floating rotors on the solid axle?

Surprised by the 3.15 axle choice--why not at 3.31 or 3.55 if you don't want a 3.73? Trap speed?

Stock axles are fine as are Motorcraft bearings at all points.

Yes, I need to hit about 125mph in 4th at the track.. I use real small 25.5" tall 9" slicks and it works out perfect with the 3.15. Also, with that gear and a normal 26" tire I can do 180mph in a standing mile if all goes well. And, the 3.15 has less torque so it helps coming out of corners. the 3.55 w/ MT82 actually melts first or second and you have to either wait for 3rd or feather the throttle really lightly.

 

[twistedneck]

Here are my thoughts, studs and axles upgrade both use the best axles you can. Diff housing bearing, Steeda makes a good one. The Eaton/Detroit Assy. Indicates some hard launches are expected, hence my axle upgrade comment. Ratio, at 3.15:1, great for speed, not so great for the launch. Consider keeping the 3.55 as its a compromise to improve both duties. Diff cooler and gauge, great idea. New Bearings? Yes, and all of them, Pinion, side carrier and axle bearings and seals. I went with the 13/14 MY GT500 14" (almost), rear rotors, they may increase rotating mass at the end of the axles, but the work great and look great too. Yes, I would clean and paint, or go for the Rusto-Mod look and use a sealer, but I would clean and paint in Ford 60* black.

As far as fundimenndals you are on a good start, just make sure you have a good setup guy with the adjustments.

Dave
302 Hi Pro

Dave, I saw that Steeda has the spherical axle bearing for the older mustangs but did not see the one for the new 3 link suspension in the S197. I use the Steeda poly upper control arm now - would like to stay with them. I also saw maximum motorsports sells the removal tool but its for the older model years.

Can you recommend a good axle assembly? Does anyone use hollow axles now?

 

[VoodooBoss]

I like the Girodisc rotors a lot, just the way the look and quality construction and they match my fronts - once I get a couple sets I can just have one refreshed rotor set ready to go, I believe they charge $300 to re-ring them. I know functionally they are not that much better to be floating in the rear.. how does that work anyway with the floating rotors on the solid axle?

The floating aspect are for expansion and contraction of the rings relative to the hats and won't have any impact elsewhere. I purposely ordered the fixed hardware on my Stoptech two piece rotors to keep the noise to a minimum. I get no noise from mine. Stoptech makes a one piece rear rotor that matches the fronts and I'm using them so I get that aspect with your setup.

For road course work you'll want a vented catch can for the diff.

 

[twistedneck]

The floating aspect are for expansion and contraction of the rings relative to the hats and won't have any impact elsewhere. I purposely ordered the fixed hardware on my Stoptech two piece rotors to keep the noise to a minimum. I get no noise from mine. Stoptech makes a one piece rear rotor that matches the fronts and I'm using them so I get that aspect with your setup.

For road course work you'll want a vented catch can for the diff.

got it and i'm glad you can appreciate little aesthetic stuff that means nothing to pure function guys but it means a lot to me.. does the vented catch can work fine with the cooling pump? you would think with a pump there would be pressure in the system that would spew out the catch can.. or is this like the engine catch can, its only the fumes of the oil you are trying to collect, not the actual working fluid??

 

[VoodooBoss]

got it and i'm glad you can appreciate little aesthetic stuff that means nothing to pure function guys but it means a lot to me.. does the vented catch can work fine with the cooling pump? you would think with a pump there would be pressure in the system that would spew out the catch can.. or is this like the engine catch can, its only the fumes of the oil you are trying to collect, not the actual working fluid??

Not sure about how it works with a diff cooling pump but the two below might.

@Black Boss
@steveespo

 

[Black Boss]

I added a catch can at the same time as the cooler and pump, with no issues. I never expected to see any fluid in the catch can -- I expected that the fluid would fill the hose and drain back. That was pretty much the case initially with the vent hose attached to the top of the Diff cover, but then I had to move the vent hose to the axle tube when I installed the Cortex Watts link as the Cortex cover has no vent provision. I'm now getting some fluid in the can. I attribute this to cornering g-forces (the vent is on the LHS which get's most of the pressure on clockwise tracks).

Another note, you'll want to run the pump when filling the Diff fluid to ensure that the cooler and pump are primed,

 

[302 Hi Pro]

Dave, I saw that Steeda has the spherical axle bearing for the older mustangs but did not see the one for the new 3 link suspension in the S197. I use the Steeda poly upper control arm now - would like to stay with them. I also saw maximum motorsports sells the removal tool but its for the older model years.

Can you recommend a good axle assembly? Does anyone use hollow axles now?

Here is the S197 Chassis 3 link upper diff housing bearing:

http://www.steeda.com/steeda-mustang-spherical-bearing-555-4104/

For some reason it was not found using their drop down menus. But it came up on a search. Here is the bearing info: Part Number: 555-4104 in case the link doesn't work. I'll post up the axle selection my friend uses with 0 issues.

Here is the guy, Mark Williams. This is a full service Ford differential shop and has a nice line of Ford diff products from pinion to lug nuts. See here: http://www.markwilliams.com/default.aspx.

However another quality axle name is Strange Engineering: http://www.strangeengineering.net/dragrace/axle-packages-and-components.html this might be more reasonable pricing. But in general good go fast parts are expensive.

Good luck,
Dave
2HP

 

[LikeABauce302]

If it hasn't been mentioned already, it would be a good idea to weld the axle tubes or add some bracing. 8.8 housings will eventually bend and warp.

 

[twistedneck]

If it hasn't been mentioned already, it would be a good idea to weld the axle tubes or add some bracing. 8.8 housings will eventually bend and warp.

Fornthe tubes welded.. But now would be the time to add proper bracing. Is that for the drag launches? Does 302s have? I ask cause its getting one or 5-10 drag passes a year max.

 

[LikeABauce302]

Yes, it mainly stiffens things up for drag racing. Even street driving though can cause the rear end housings to bend a little over time. Going over potholes or train tracks, etc can eventually cause the rear end to warp.

 

[seca954]

Did you jig your rear end before you welded the tubes? If not, be sure it's square before you do anything. As for axels, I upgraded to Moser 31 spline axels. They allowed me to keep the anti lock system. For the record, I bent my stock 31 spline axels with drag radials.

 

[twistedneck]

Did you jig your rear end before you welded the tubes? If not, be sure it's square before you do anything. As for axels, I upgraded to Moser 31 spline axels. They allowed me to keep the anti lock system. For the record, I bent my stock 31 spline axels with drag radials.

I'll be sure to check squarness but that does not sound simple.

The mosers sound like a great idea since I also want full abs.

If my welded setup is straight.. If.. What bracing do u recommend?

My welder has done many racing axle welds and did a crazy preheating job, the weld itsel was a very slow process. I hope it's good. Sure does look strong.

 

[twistedneck]

I've also looked at the Moser 33 spline axles with the ford 9" 'ends'..

if I've got everything apart is that a good idea? I think our factory setup is 31 spline. not sure the benefit of ford 9" ends and if they have the normal bolt pattern.

 

[LikeABauce302]

Ford 9" ends serve as C-clip eliminators. They will retain the axle if it breaks. It's basically a safety measure. NHRA rules require C-clip eliminators at 10.99 or faster.

 

[2013dibgt]

2. Replace upper control arm bushing on the axle with a spherical bearing, and I can't find that part anywhere.

What...no Cortex Torque Arm to go along with the rest of your Cortex goodies ;D

Car hooks up well with it, even on street tires and considering the less agressive gear ratio you mentioned I would imgaine it would hook up even more so. Plus you get the added handlnig benefits it provides given the dual purpose nature of your car. Just a thought.