Rear axle seals, gears, axles.

[Cochise]

I had my first HPDE this weekend with the car, it went really well until my 4th heat. I went to check the brakes to see how much pad I had left, and when I check the rear I noticed the inside barrel of the wheel had oil/grease/fluid of some sort. I fear it was a brake leak but after lifting the car and inspecting it appears that it's most likely the axle seals. Not too big of a deal but obviously it ruined my weekend on track. Now on to the questions and there are plenty!

1. Since I'm going to have the seals/bearings replaced, would this be a good time to replace the axles?

2. If its a good idea to replace the axles? is 31-spline necessary, or is 28-spline sufficient? This is a HPDE/Road coarse car and I won't be any crazy launches on drag slicks, hence my question.

3. The car has 3.73 gears, it was like that when I bought it. I'm contemplating going with 3.55's with a Torsen LSD. Any thoughts on this? I was at Barber MSP this weekend and I feel like 3.55's would be better suited for that course and even more suited for courses like NCM and Road Atlanta.

Future plans for the car, in this order are...

1. Full street/track suspension with PH bar from MM.
2. Coyote swap with T56
3. Eventual aero-kit and body work/paint to make it look, well, nicer. Haha!

 

[TMSBOSS]

What year is your car?

 

[Cochise]

What year is your car?

2000 Mustang GT

 

[TMSBOSS]

If you are going to coyote swap, hold on to the gear you have now. See how the 3:37's work with the new power and gear selection, then make that move. I run 3:73's in both my Boss and 350. They fit well with Coyote and Voodoo power.

 

[Cochise]

If you are going to coyote swap, hold on to the gear you have now. See how the 3:37's work with the new power and gear selection, then make that move. I run 3:73's in both my Boss and 350. They fit well with Coyote and Voodoo power.

Thanks a bunch, someone said the same thing on another forum.

 

[PatientZero]

I had my first HPDE this weekend with the car, it went really well until my 4th heat. I went to check the brakes to see how much pad I had left, and when I check the rear I noticed the inside barrel of the wheel had oil/grease/fluid of some sort. I fear it was a brake leak but after lifting the car and inspecting it appears that it's most likely the axle seals. Not too big of a deal but obviously it ruined my weekend on track. Now on to the questions and there are plenty!

1. Since I'm going to have the seals/bearings replaced, would this be a good time to replace the axles?

2. If its a good idea to replace the axles? is 31-spline necessary, or is 28-spline sufficient? This is a HPDE/Road coarse car and I won't be any crazy launches on drag slicks, hence my question.

3. The car has 3.73 gears, it was like that when I bought it. I'm contemplating going with 3.55's with a Torsen LSD. Any thoughts on this? I was at Barber MSP this weekend and I feel like 3.55's would be better suited for that course and even more suited for courses like NCM and Road Atlanta.

Future plans for the car, in this order are...

1. Full street/track suspension with PH bar from MM.
2. Coyote swap with T56
3. Eventual aero-kit and body work/paint to make it look, well, nicer. Haha!

1/2. It's not a bad idea to upgrade to 31 spline if you're planning a Coyote swap but far from a necessity given your intended usage. You do understand that you need to replace the diff also if you change to 31 spine axles correct? Just clarifying, I'm assuming you know this.

3. I'd wait and see how you like the 3.73's. It's going to depend on a lot of things; tire size, transmission gearing, the track, how you drive. It's free to wait and see. It seems like most people with Coyote cars tend to prefer 3.55's but they are also running a taller tire in most cases.

 

[blacksheep-1]

I've run 28 with no issues, but now would be the time to upgrade. You can do the bearing replacement yourself, it's not very difficult. The thing with these diffs is that the rollers in the bearing ride on the axle, so if you place a straight edge on the axle where the bearing rides, you can see any wear.
Also I don't know what " full suspension with PHB," means but if you're using the 4 link, you need to throw away that PHB

 

[johnjamesmiller]

You might consider irs swap. By the time you do axels, gears, torsen, phb, ect you are probably looking at close to the same money but irs will give you a better end result.

 

[KazarS197]

I had my first HPDE this weekend with the car, it went really well until my 4th heat. I went to check the brakes to see how much pad I had left, and when I check the rear I noticed the inside barrel of the wheel had oil/grease/fluid of some sort. I fear it was a brake leak but after lifting the car and inspecting it appears that it's most likely the axle seals. Not too big of a deal but obviously it ruined my weekend on track. Now on to the questions and there are plenty!

1. Since I'm going to have the seals/bearings replaced, would this be a good time to replace the axles?

2. If its a good idea to replace the axles? is 31-spline necessary, or is 28-spline sufficient? This is a HPDE/Road coarse car and I won't be any crazy launches on drag slicks, hence my question.

3. The car has 3.73 gears, it was like that when I bought it. I'm contemplating going with 3.55's with a Torsen LSD. Any thoughts on this? I was at Barber MSP this weekend and I feel like 3.55's would be better suited for that course and even more suited for courses like NCM and Road Atlanta.

Future plans for the car, in this order are...

1. Full street/track suspension with PH bar from MM.
2. Coyote swap with T56
3. Eventual aero-kit and body work/paint to make it look, well, nicer. Haha!

Welcome to TM0! What side had the oil? I had the same issue during my first HPDE and found out the axle vent was spewing gear oil when it got hot. I think the 2000 axle has the vent in the right side. I'm installing an JLT expansion tank - S197 version. Sorry, I don't know what's available for the SN95. Maybe someone else will chime in.

Don't forget to do a car profile.
Here:

Browse SN95 Mustangs

View Specs, Mod Lists, Photos, and Build Threads for track-prepped SN95 Mustangs on TMO.

trackmustangsonline.com

 

[Cochise]

1/2. It's not a bad idea to upgrade to 31 spline if you're planning a Coyote swap but far from a necessity given your intended usage. You do understand that you need to replace the diff also if you change to 31 spine axles correct? Just clarifying, I'm assuming you know this.

3. I'd wait and see how you like the 3.73's. It's going to depend on a lot of things; tire size, transmission gearing, the track, how you drive. It's free to wait and see. It seems like most people with Coyote cars tend to prefer 3.55's but they are also running a taller tire in most cases.

Thanks for the heads up. Yea, I knew the diff would need to be replaced, but I appreciate you looking out for me. The idea behind it, was since Im having the axles removed due to the bearings, might as well replace them, which if it was deemed necessary I would just have it all done at once with new gears and possible a Torsen LSD since they are in the area already.

I think I'm going to wait as you suggested. Seems there are a lot of other variables that are somewhat unknown right now and I've had people also say the 3.73's are preferred. So I'm going the free route of "wait and see".

I've run 28 with no issues, but now would be the time to upgrade. You can do the bearing replacement yourself, it's not very difficult. The thing with these diffs is that the rollers in the bearing ride on the axle, so if you place a straight edge on the axle where the bearing rides, you can see any wear.
Also I don't know what " full suspension with PHB," means but if you're using the 4 link, you need to throw away that PHB

I could likely do it myself, but I'm gonna have my shop do it. My wife dislikes my car enough already when I track it, let alone live in the garage when I'm working on it.

By "full suspension" I mean a package from MM that is a cross between their "Road and Track" and "Maximum grip box". I've been in contact with them and I'm going to use their tech service to build it so that it suits my needs. I haven't ordered anything yet but the customer service so far is amazing. One guy chatted with me for an hour just giving out free info. I still don't understand all the terms but I'm getting there.

I have read a lot of good things about a PHB set up, I'm still trying to grasp what 4 link means, but I do know from what I've read that "triangulated 4 link" = "bad and binding". Haha.

You might consider irs swap. By the time you do axels, gears, torsen, phb, ect you are probably looking at close to the same money but irs will give you a better end result.

This was actually my initial plan, the problem is that the literature out there is so overwhelming, and there doesn't seem to be any overwhelming cases for one over the other.

Whether it's racers opinions, or scientific explanations, or articles from the likes of grassroots motorsports etc....

Given the split opinions on the matter, and the fact that sn95 Cobra IRS' are getting harder and harder to find at a good price, I'm just gonna stick with what I have.

This car will never be a competition car. I just want to track it when I can and enjoy looking at it when I park at work.

Welcome to TM0! What side had the oil? I had the same issue during my first HPDE and found out the axle vent was spewing gear oil when it got hot. I think the 2000 axle has the vent in the right side. I'm installing an JLT expansion tank - S197 version. Sorry, I don't know what's available for the SN95. Maybe someone else will chime in.

Don't forget to do a car profile.
Here:

Browse SN95 Mustangs

View Specs, Mod Lists, Photos, and Build Threads for track-prepped SN95 Mustangs on TMO.

trackmustangsonline.com

Both driver and passenger sides had the oil. I faced timed my dad and my mechanic (both long time Ford mechanics) and that was one of the things they had me check. It is in fact on the right side and it was bone dry. I didn't even have to explain anything to my dad, as soon as I point the camera in that direction he said "axle seals are toast". His confidence was a bit annoying, hahaha!

I'll get that car profile up... Thanks!



Thanks to you all for the input. Greatly appreciated and any additional info is welcomed.

 

[TorqueAholic]

Thanks for the heads up. Yea, I knew the diff would need to be replaced, but I appreciate you looking out for me. The idea behind it, was since Im having the axles removed due to the bearings, might as well replace them, which if it was deemed necessary I would just have it all done at once with new gears and possible a Torsen LSD since they are in the area already.

I think I'm going to wait as you suggested. Seems there are a lot of other variables that are somewhat unknown right now and I've had people also say the 3.73's are preferred. So I'm going the free route of "wait and see".



I could likely do it myself, but I'm gonna have my shop do it. My wife dislikes my car enough already when I track it, let alone live in the garage when I'm working on it.

By "full suspension" I mean a package from MM that is a cross between their "Road and Track" and "Maximum grip box". I've been in contact with them and I'm going to use their tech service to build it so that it suits my needs. I haven't ordered anything yet but the customer service so far is amazing. One guy chatted with me for an hour just giving out free info. I still don't understand all the terms but I'm getting there.

I have read a lot of good things about a PHB set up, I'm still trying to grasp what 4 link means, but I do know from what I've read that "triangulated 4 link" = "bad and binding". Haha.




This was actually my initial plan, the problem is that the literature out there is so overwhelming, and there doesn't seem to be any overwhelming cases for one over the other.

Whether it's racers opinions, or scientific explanations, or articles from the likes of grassroots motorsports etc....

Given the split opinions on the matter, and the fact that sn95 Cobra IRS' are getting harder and harder to find at a good price, I'm just gonna stick with what I have.

This car will never be a competition car. I just want to track it when I can and enjoy looking at it when I park at work.




Both driver and passenger sides had the oil. I faced timed my dad and my mechanic (both long time Ford mechanics) and that was one of the things they had me check. It is in fact on the right side and it was bone dry. I didn't even have to explain anything to my dad, as soon as I point the camera in that direction he said "axle seals are toast". His confidence was a bit annoying, hahaha!

I'll get that car profile up... Thanks!



Thanks to you all for the input. Greatly appreciated and any additional info is welcomed.

It's possible that your seals were just old you should replace the vents filters as well. But as you gain more experience you will eventually boil the diff fluid over and blow the seals again. I installed a Boss 302 finned diff cover and installed the Boss 302 "Turkey Baster" bulb that screws on top of the diff as an expansion tank, problem solved.

The cover also has ports to plumb hoses / a pump and oil cooler if you really wanted to get serious.

The finned Diff Cover helps keep the fluid cool / prevent boiling

https://www.cjponyparts.com/ford-performance-rear-differential-cover-8-8-finned-aluminum-with-cooler-ports-mustang-1986-2014/p/M4033KA/?year=1988&gclid=CjwKCAjw8sCRBhA6EiwA6_IF4VNQ_rJwyBB9DvjF4pvWBozctdJdAw3hNfupqQosK6wz7uJcnjzbVxoCRbgQAvD_BwE

The Turkey baster helps vent the extra pressure / catches the fluid when it does boil .

AR3Z-4A058-B AR3Z4A058B - Genuine Ford Hose Assembly

Ford part # AR3Z-4A058-B AR3Z4A058B at FordPartsGiant.com. Wholesale-priced and fast-delivered Ford parts Hose Assembly.

www.fordpartsgiant.com