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Why Try?
04-30-2005, 12:10 PM
Well my GF checked on my car for me today (in storage) and said that "there was dark looking oil on the ground uder the big circle"(rear-end). hahahaha. Well so it seems that ill have to get a new gasket for the rear-end (hope thats the reason for the leak). I have never delt with rear-ends before and i just need to know what i need to do to fix this and where i can get the gasket, since im TDY still my best freind that has SN 95 is going to do it for me but i just want to have all the info to give him and where to get the part. thanks

ausie
04-30-2005, 02:01 PM
I hope that it is not related to fatigue or torsional stress. The SLA does take alot of abuse and can get bent or twisted or worse. I sort of question why the factory does not weld the axle tubes in place from the beginning. Even a slight leak may be an indication that something else is a-miss.

Why Try?
04-30-2005, 09:35 PM
I hope that it is not related to fatigue or torsional stress. The SLA does take alot of abuse and can get bent or twisted or worse. I sort of question why the factory does not weld the axle tubes in place from the beginning. Even a slight leak may be an indication that something else is a-miss.
well i hope not as seeing that will put a damper on my supercharger funds!!!!!!:mad:

ausie
05-01-2005, 10:44 AM
A thourough inspection of the housing will prove otherwise, either damage or just a bad seal. Usually when the rear dumps its contents it is related to damage. I have seen many articles on beefing up the rears in the mustang magazines, some as a precursor to adding power to the mill or an afterthought once the differential case becomes cracked. The cost of re-building the rear is not as expensive as a supercharger. However, it would be insurance that when you do get the supercharger or even a turbo, the rear will hold up. It would probably cost lest to buy a complete rear than to build by components individually. Besides that, when you get the complete package, if done right will be true(square to drive shaft) and straight as well as stronger.

A note on SLA's, it is common to see others, (mechanics included) lifting the car with a jack by the bottom of the differential case. I have even done that myself to the my Explorer. It is not a good thing to do since it loads the center of the axle which may cause the axle tubes to bend or the differential to loose its alignment to the drive shaft. SLA is not the correct term to use for a stock rear. Live rear axle (LRA) is the appropriate term even though it means the same thing. Since the axle tubes are a press-fit connection, they are not solid or fixed in place by welds or cast as a complete assembly. There is a huge difference to rears that were build or design for high HP when compared to stock. It is not only the axle spline count, but the overall support of the differential housing, full welds and support bracing to reduce stress and twisting of the components. The stock axle will hold up to most abuse, but over time it will tend to fail as a result of hard launches, rubber burning excitement that we enjoy from our steed.

Why Try?
05-01-2005, 11:05 AM
so what are signs of a rear-end going out, i mean will you "just know" or is it something that could go un-noticed for awhile???

ausie
05-01-2005, 11:21 AM
In most cases it is difficult if the tubes are bent in relation to the differential. Generally a crack on the differential case at the axle tube joint or at the drive shaft input is a sure sign it is history. It may just be a bent differential cover or loose bolt. The accumulated road dirt or oil film should be an indication where the leak is comming from. There are other reasons for a rear seal failure. Perhaps I should have stated them first than going into the failure mode of components. Most if not all differentials have a breather tube to reduce pressure build up when the fluids heat up and expand. If the tube becomes blocked or pinched it is possible that the expansion of the fluid would cause failure of the gasket or seal of the housing. Over time the differential fluid breaks down just like any oil. Also, metal shavings from the gears will also accumulate in the fluid. Most differentials have a strong magnet attached to the cover to collect the shavings, but if they are left to build up it will lead to excessive wear. Also, if you have driven in deep or high water (level up to the axle shaft) it is possible there may be water in the differential which will also lead to gasket failure (my exploder is prone to this). The leak may just be a simple fix of replacing the gasket or seal along with new rear fluids. If everything looks in good shape, more than likely it is just a seal fault. Perhaps just removing the cover, clean the magnet (assuming that there is one), change the fluids and re-seal the diff cover is all that is needed. I did not intend to set off any alarms. :rolleyes:

Why Try?
05-01-2005, 03:39 PM
thanks Ausie, i just ordered a new gasket and fluid so my friend is going to get me car out of storage next month and go ahead and do some maitnece on it for me so hopefully the gasket is all it needs. thanks again for the fast reply's

ausie
05-02-2005, 06:41 AM
I hope it is nothing major in any case. I have had countless friends tell me once you gain more power you better gain a better rear. I have talked to many who drag race, and most of those do not have the factory rear due to failure. Since they were not designed to handle the additional power that some mods will provide. Every now and then you will see articles on rear rebuild in magazines (5.0 or MM&FF). Some articles cover everything including the cost. I am not saying that you have to rebuild yours. It all depends on what you discover when you change your gasket.

ausie
05-08-2005, 12:13 PM
what was the verdict on the rear seal? Hopefully what you found was no big deal.

Why Try?
05-08-2005, 08:29 PM
what was the verdict on the rear seal? Hopefully what you found was no big deal.
still havent touched it yet (deployed) my friend is going to pull it out of storage next moth, ill PM you if i have any problems, thanks AUSIE