thelaststarfighter13

So.......

I have a 96 4.0l sport. I got the 8.25 in the back and it leaks something horrible. I haven't put any oil in it in a while and there is always a quater size spot under it in the morning. I wanna fix this permanent style.

I know the covers notoriously leak. I was wondering if maybe one of the vendors had a heavy duty cover at a fair price.

Is it alright to get RTV in the gear Oil.

What kinda gear oil should I use?

I am pretty sure I have the limited slip in the back, how can I be sure, what the hell is friction modifier??????

Any other sage advice would be definitely appreciated.

GREASEMONKEY72

RTV sealent wont hurt the gear oil, common gear oil is 80-90w, im not sure if theres a preference for jeeps though

im not sure about the limited slip without taking the cover off

offroadnut36

Friction modifier helps the grip on the clutches in the limited slip. You have to put it in with the lube, or your LS will pretty much be useless.

SHO_91

You add friction modifiers to the tranny oil of a manual gearbox, when you can't throw the car into gear, when the engine is running. Reason is (most of the time) the synchronizers not engaging because of too slippery oil. I would try to keep RTV out of any oil, if possible, especially (manual) transmissions, because it clumps up and could prevent the bearings from being properly lubed. However, there is special sealant for transmissions/gear boxes, an anaerobic sealer. RTV is frowned upon at transmission shops.

SeriousOffroad

Order up a new cover from Dan Fredrickson on this forum, Dan owns Ruff Stuff. You won't find a better value for your dollar.

jeepride

Ijust installed a ruff stuff on my 8.25 rearend no more leaking rubber plug plus this thing is heavy duty

Bustedback

RTV on the diff cover is a standard practice from the factory. The friction modifier is for the limited slip diff in the rearend. Never seen anybody recomend putting it in a transmission before, worked for Chrysler for a while and it was never intended for the manual transmission as far as I know.

1990cherokee

i just did gears in my 8.25 and dana 30 i am know running 70/90 synthetic

djb383

I installed a Felpro diff cover gasket with a very light coat of copper RTV. The key to a good seal is DON'T crank the cover bolts down too tight. Just past snug is plenty good. You won't get any RTV in the gear oil if you apply a thin coat along with a cover gasket.

To tell if you have a LSD, raise the axle (both wheels off ground) and rotate one wheel by hand. If the opposite wheel turns the same direction, you have a LSD. If the opposite wheel turns the opposite direction, you have an open diff.

I believe 80W90 gear oil is for general use in the 8.25 and 80W140 is recommended for trailer towing.

The LSD additive/friction modifier DOES NOT increase the clutch friction, it decreases the friction of the clutches so they don't chatter/make noise when they slip during a tight turn.

GREASEMONKEY72

i forgot about that trick

Metmknice

Especially if you have LSD/locker you will want to run at least 75w-110. I prefer Amsoil SevereGear.. And YES YOU CAN run the "friction modifier" with full syn fluid.

djb383

Hummm, the Amsoil site doesn't say you should/must use thicker/heavier 75W110 gear oil in a traction enhanced diff.

http://www.amsoil.com/storefront/svt.aspx

SeriousOffroad

Lockers do not require a friction modifier.

DesertFox4x4

gasket and a thin layer of rtv i use either ultra black or gms (gm factory silicone, im a gm mechanic have tons of the crap) jus give it a chance to set up a bit before u put in the the gear oil. and as mentioned above friction modifier reduces friction to stop the clutches in the lsd from sticking and releasing causeing them to chatter. never heard of it in a trans and never seen a manual trans not shift cause the fluid was too slipery. syncros engauge by teeth on the blocking ring into the hub nothing to really slip to not engage unless teeth on blocking ring missing.

SHO_91

My bad, this is a differential thread, sorry.
I wouldn't recommend friction modifiers over the right manual transaxle fluid in the first place either, but it does help with shifting problems. All else I said is standard procedure in a trans shop (RTV, and such).