Thinking of rebuilding my rear axle. What to use for parts?

My 07 GT500 has pretty good gear whine and I'm thinking about taking a crack at trying to eliminate it or at least tame it down. My question is what parts (gears, limited slip, bearings) do I install? Car has about 51K miles on it. Previous owner logged about 39K pretty hard miles on the car with many trips to different road courses and the occasional drag strip.

I would be installing new 3.73 gear. Thinking Motive? Gears in the car now are Ford racing 3.73.

Obviously new seals and bearings along with fluid would be a must but should I freshen up the limited slip with new carbon gt500 clutch setup while I'm at it even though it's working fine?

I mainly use the car for fun but it may see the drag strip here or there. Nothing too crazy.

I'd get the axle tubes welded, while it's out.

Ford gears !!

ShelbyGT5HUN said:

I'd get the axle tubes welded, while it's out.

Click to expand...

I'm pretty handy with the mig welder. Is there anything special about it? Thought I read something on it once but maybe that was something else.

1 Alibi 2 said:

Ford gears !!

Click to expand...

Ford over Motive? I've read quite a few people complaining about ford racing 3.73 gears having whine. In our restoration shop Motive is the preferred brand for quiet gears but we don't deal with 8.8 axles often.

If you are diving in, and not trying to "do it on the cheap" I wouldn't re-use anything. I would rebuild the limited slip, replace all the seals. If you are still running stock axles I would upgrade them to Strange or another reputable brand. As was stated earlier welding the axle tubes is a great way to beef up the strength of the rear.

Throw a tru trac in it while you are at it.

HKusp said:

If you are diving in, and not trying to "do it on the cheap" I wouldn't re-use anything. I would rebuild the limited slip, replace all the seals. If you are still running stock axles I would upgrade them to Strange or another reputable brand. As was stated earlier welding the axle tubes is a great way to beef up the strength of the rear.

Click to expand...

Welding the tubes will probably go on the list. I don't want to cheap out but trying to spend smart. I have a few other auto projects that I'm working on also at the moment. What kind of power are the stock axles good for? I mostly use my car on the street but it may see a few track runs just for fun.

Klaus said:

Throw a tru trac in it while you are at it.

Click to expand...

I thought about a tru trac but it would add significantly to the rebuild cost. What is the stock limited slip reliably good for? I generally just use the car for fun on the street but it may see a few trips to the track. I'm at about 700 rwhp now but probably won't increase that much. Bigger numbers sound like a good idea but the car is pretty fun as it sits and I don't want to take drivability out of it.

I'm not qualified to give specifics, but the area must be jigged, pre heated, welded in sections, and slowly returned to ambient temp. This is for a Jeep, but I'm sure it's similar for our cars:

builttodrive said:

Welding the tubes will probably go on the list. I don't want to cheap out but trying to spend smart. I have a few other auto projects that I'm working on also at the moment. What kind of power are the stock axles good for? I mostly use my car on the street but it may see a few track runs just for fun.



I thought about a tru trac but it would add significantly to the rebuild cost. What is the stock limited slip reliably good for? I generally just use the car for fun on the street but it may see a few trips to the track. I'm at about 700 rwhp now but probably won't increase that much. Bigger numbers sound like a good idea but the car is pretty fun as it sits and I don't want to take drivability out of it.

Click to expand...

I believe, but have no confirmation due to having bought my car from a dealership, the guy who had my car before me was running track days. He had a rear end cover that used to have a temp gauge and auxiliary cooler and pump, but the gauge and cooler were removed prior to sale. He was running about 530hp at the wheels and the axle tubes were welded. I have since added enough mods to be north of 650 and the wheels on 93 on a nice safe tune and have the ability to add 2 degrees of timing if I run Octanium which should put me right near 700 at the wheels. I daily drive my car and beat on it pretty good on the street, and have tracked the car. If they ever open the tracks back up, I intend to run the car a bit this season at the drag strip and I hope to go to Cleetus and cars in November. Up until last week I had been running MT ET streets so the car was hooking pretty good in all my "spirited" street driving. The rear is the least of my worries with the Strange street strip axles and welded tubes.

ShelbyGT5HUN said:

I'm not qualified to give specifics, but the area must be jigged, pre heated, welded in sections, and slowly returned to ambient temp. This is for a Jeep, but I'm sure it's similar for our cars:

Click to expand...

Yeah thats what I was thinking I had read about years ago when I was researching it. I hadn't planned on removing the axle completely. I'm curious if it's as big of a concern for my car with the torque arm suspension? When I'm looking at it, it doesn't seem possible for the center section to rotate from the tubes the way the suspension is designed. I'll have to research it more.

builttodrive said:

Yeah thats what I was thinking I had read about years ago when I was researching it. I hadn't planned on removing the axle completely. I'm curious if it's as big of a concern for my car with the torque arm suspension? When I'm looking at it, it doesn't seem possible for the center section to rotate from the tubes the way the suspension is designed. I'll have to research it more.

Click to expand...

lol, oh it’s possible. Mine ate a brand new pair of MT SR R tires. Good times. Weld the tubes.

ouch! you are running a torque arm setup?

builttodrive said:

ouch! you are running a torque arm setup?

Click to expand...

no, the car has stock style rear suspension but every aftermarket component you can buy installed by previous owner. The one weak spot he didn’t address I found out the hard way. For the cost welding the tubes is a must

SSSSSSSSSSSSVT said:

no, the car has stock style rear suspension but every aftermarket component you can buy installed by previous owner. The one weak spot he didn’t address I found out the hard way. For the cost welding the tubes is a must

Click to expand...

I think welding them is a good idea. I just think that the torque arm suspension setup would help prevent the housing from being able to rotate as easy. I'm pretty handy with a mig welder but it sounds like there's a little more to it than just laying a bead. I also hadn't planned on fully removing the axle at this time.

There is also a brace form CHE which claims to prevent bending the tubes, I have no idea if it'll work for you but just another option.

Black Cobra '99 said:

There is also a brace form CHE which claims to prevent bending the tubes, I have no idea if it'll work for you but just another option.

Click to expand...

I checked out the che brace. It's looks like it could help but it fastens in the same location as my Griggs torque arm. I may be able to fabricate something similar and weld it to the torque arm. Then again it may be overkill.

You said you weren't planning on removing the rear end, but you were going to have new gears installed. They are much easier to set up out of the car.

HKusp said:

You said you weren't planning on removing the rear end, but you were going to have new gears installed. They are much easier to set up out of the car.

Click to expand...

Yes I'm having another shop set them up that has a lot more experience with the 8.8 and has a great reputation for setting them up right. It may be easier to set them up with the axle out but I didn't figure for the price he was going to completely remove it. I could be wrong and I'll have to ask.

I would find out. I am not saying they can't be done in the car, but it is easier on a bench. If that is the case, you could weld the tubes while they have it out of the car, or have them do it. Again, it's not the greatest, most critical thing that absolutely needs to be done. But, while you are messing around with it, I would consider it.

HKusp said:

I would find out. I am not saying they can't be done in the car, but it is easier on a bench. If that is the case, you could weld the tubes while they have it out of the car, or have them do it. Again, it's not the greatest, most critical thing that absolutely needs to be done. But, while you are messing around with it, I would consider it.

Click to expand...

I'll do a little more research on it. What I have read so far the torque arm suspension I have on the car greatly reduces the risk of having those kind of issues. The shop that is doing the install didn't have any experience welding the tubes and couldn't offer anything better than laying a bead on it with a mig welder, which I can do but I know there is more to it than that. Looks like a jig is recommended along with a heating process and special wire or welding rod.