Howdy, I've finally got my FD going after lots of trials and tribulations and now after having my rear diff rebuilt by AAMCO in Wilmington Nc, it is leaking fluid from the Passenger side by the exhaust out of the axle seal. Also, it is running super hot for my likings and was wondering if anyone has had the same problem, and if I am just being a hypochondriac. Thanks in advance, and I apologize if I have used this forum incorrectly.

 

Running hot as in the rear end or the engine?

Also, if you just had the rear end rebuilt and its leaking, i'd be bringing it back pronto

 

The actual rear diff is running abnormally hot. Its super hot to the touch, and since I removed the diff and took it to them and put it back in the car, they probably will blame me for "damaging the seals" or something to save a buck.

 

You could check the fluid level in the diff, if the fluid levels good drain the fluid run it through a screen like cheese clothe see if you catch any metal. If you don't want to take it back to the previous shop I recommend taking it to Rotorsports Racing in Kannopolis,NC Bryan and Scott are really good guys and they do great work

 

its really hard to damage the axle seals while installing, also, the rear end is hot, its either low on fluid due to the leak, or they didn't set some sort of lash right and its making a bearing a bearing run uneven and making it hotter as hell

no matter what, I wouldn't be driving it, and would at LEAST make a phone call before the rear end possibly drops from underneath you

 

I'm definitely going to give them a call as soon as I can tomorrow and see what they'll do. I've done business with Bryan at Rotorsports and he's legit. I would love to give him more of my money, but unfortunately its not worth a 5 hour drive for something I can settle here. Hopefully its nothing major, thanks for the advice. I'll check back in tomorrow and let ya'll know what AAMCO has to say.

 

well, I wrapped my exhaust by the diff and it cooled it down exponentially. I called cusco and they said the royal purple I'm running is a no no and they recommended me a few different brands that are mineral based only...long story short, I couldnt find any of those and ended up buying Cusco's overpriced oil. Better 80 bucks now than 1500 later.

 

Royal purple a nono? Thats a first, but hey

 

With a Clutch type LSD apparently all Synthetics are no no's. Cusco said it would be fine to cruise around on, but not spirited driving because synthetic is too thin.

 

I seem to remember everybody recommending Redline Synthetic in the rear end of the S4 LSDs and they are clutch type rear end, and synthetic isn't a different consistency if you get the same weight, synthetic is just slimier and sticks to metal better