As subject line says I installed my TA rear girdle and endcap bolts from ARP to try and strenghten the 10 bolt a lil. I found out I need a 1/2" hex to fill it with fluid (sucks, I don't have one). Can I just go somewhere and buy the 1/2" hex alone, or do the larger ones only come in sets? And how much rear diff fluid EXACTLY am I supposed to fill it with cause the instructions it came with don't tell me that. Also, I bought some limited slip posi fluid, I guess I'm supposed to put that in too? You can tell I've never worked on a rear end before

Thanks

 

i cant really answer your questions but be prepared for the cover to leak,,dont worry about it when it does,,you will think u screwed something up but 9/10 of them leak

 

The cover itself should NOT leak. What leaks is the pinion seal at the front of the differential housing.

Try a Snap-on or Craftsman dealer for the 1/2 hex head. You can buy it individually.

Torque the main cap support bolts to 5-ft. lbs. Any more and you risk egg-shelling the bearings under load.

For capacity, you should be able to fit in about 2 quarts of fluid, plus the GM LSA. I'm assuming the limited slip additive that you purchased was GM brand, right? With the new cover, your overall capacity has increased.

 

I've never heard of anybody else with this problem of leaking. I only bought the TA girdle cause I've heard good things about it. I guess it would leak if it wasn't installed correctly, but I'm very sure mine is on there good.

 

no, I bought generic LSA additive and generic gear oil for the rear from autozone. I didn't know GM stuff made that much of a difference. Oh yeah, and while I was messing with the rear I noticed that some of the teeth on the gear that is parallel to the driveshaft are chipped! And I get made fun of by my buddies for treating my car like a baby. That's what I get for not doing hard launches and taking it easy...

 

Dont go any buy a special wrench or anything. Just use a 1/2" drive ratchet with no socket, it fits perfect.

 

Definately use the GM additive! And use regular dino gear oil.. not synthetic! Apply rtv to one side of the gasket and stick it on.. then bolt the cover up and open the plug on the front of the differential (it's up on the passenger side right where the drive shaft enters the pumkin).. leave that open and add oil into the fill plug on the cover. When the oil pours out the other plug then it's filled to capacity. Reinstall both plugs and torque the studs.. I recall my instructions saying 5 - 10 ft lbs but I'm not too sure.. 5 ft lbs doesn't sound like enough but I really could be wrong on this. Anyone else think it's 5 ft lbs max?


Oh, and where did you buy the arp studs (I'm still using the studs that came with the cover).

 

I had trouble filling mine because there wasn't room to tip the bottle. Ending up using a small hose. Is there a better way?

 

brilliant. simply brilliant.

 

thanks, I didn't know there is a plug on the other side. Ok, I will go and buy GM LSA. I guess you get what you pay for.
NO. My ARP studs are for the end caps so they don't walk in the housing. I don't think the regular mounting bolts are from ARP, I think they are TA's bolts. (It all came in the same box for me along with like $1800 worth of other mods at the time). It's 5 ft lbs of torque for the jamb bolts, then you just snug the jamb nuts on there. It specifically says "DO NOT OVERTIGHTEN THE JAMB BOLTS" use only 5 ft lbs with a torquwrench or your own guess-o-meter like I did

 

I used one tube of GM additive and Amsoil synthetic gear oil, and my rear end works great. Locks up solid in straight line acceleration and operates properly around corners.


A lot of people will tell you NOT to use synthetic, and they base that on the fact that Eaton recommends you use dino oil.

What they don't tell you is that the REASON Eaton says that is because synthetic is statistically more likely to cause chatter when going around corners and they wanted to cut down on the number of tech support calls they were getting for that.

If you get them on the phone and press them on the issue, which they don't really like by the way, you will discover that, as I said; the chatter issue is why the tell you to use dino.

Chatter is perfectly normal and is merely the sound of the rear end ratcheting as the outside tire overruns the inside tire. Nothing to worry about.


Having said all that, you wont hurt anything running dino oil and a lot of people do, just to feel safe. I just don't want you to think that you will harm anything using synthetic, because you wont.

 

Exactly.

I did the exact same thing with them when I installed my Eaton, and they eventually said that using non-synthetic was to keep the chatter down.

I run GM LSA and synthetic Mobil 1 75W90.

 

Uh.. isn't the stock posi unit made by AUBURN? Not eaton? Either way I'll still take dino oil.. who wants to listen to the clutches chatter - that's probably not good. Synthetic is too slippery for the clutches.. that's what I've always heard anyway. If synthetic were really better (despite the chattering) I think the manufacturer would mention this and let us make our own decision. Why spend extra $$$ for something that may damage your posi unit??? Just stick with dino oil.

And I never did here where you got the ARP studs? Do the online vendors sell them or could I just pick them up somewhere locally? A part number perhaps.....

 

Here is your part# from thunderracing.com ($24.99)

16-TA-1815 TA Performance Products Main Cap Stud Kit, GM

 

Originally posted by Lost


Uh.. isn't the stock posi unit made by AUBURN? Not eaton?
Doesn't matter.


Either way I'll still take dino oil.. who wants to listen to the clutches chatter
My clutches don't chatter. Probably because I use the GM additive.


- that's probably not good.
It's normal.


Synthetic is too slippery for the clutches...
Synthetic is no more slippery than dino oil. It lubricates better because the molecules are long chain instead of short chain. Since I'm not a chemist, I wont go any further than that.


...that's what I've always heard anyway.
Yes, I'm sure it is, and a big part of why you have heard that is because Eaton tells their customers to use dino oil, because they don't want to deal with all the customer service calls from people who don't know that the chatter they hear around corners is normal.


If synthetic were really better (despite the chattering) I think the manufacturer would mention this and let us make our own decision.
Just because you think it, doesn't mean the manufacturer agrees. These issues are not all that simple, and when you are in business, you often make counter-intuitive decisions because of other considerations. Besides, you DO still have the opportunity to make your own decision.


Why spend extra $$$ for something that may damage your posi unit??? Just stick with dino oil.
because synthetic fluid does NOT damage the posi unit. That's a myth, fed by misinformation and incorrect conclusions.


Look, if it makes you fel better to run dino gear oil, then DO it.
I'm not trying to change your mind.

I'm simply trying to correct a misperception.