So I bought an 85 pickup last year and slowly been rebuilding about everything in it. Built a 22R block from an 87 w/261 cam, 4.88 motives with a Spartan for the rear. Long story short, I finally get around to the front axle rebuild 18 months later and what drains out of the diff looks very much like broken down grease and nothing like gear oil. I just pulled the plug lastnight not the diff yet but has anyone ever seen this, am I gonna have to look for a new diff housing to build or will it be ok?

 

Sounds like your diff oil has been contaminated with water.

If you want to you can pull it apart and clean everything. Then reassemble and full with some 75W90, and replace the diff breather. Or just fill it with cheap gear oil, run it for a while, then flush and replace with good gear oil.

 

I've got new gears and setup kit just wondering if everything else will be ok to build.

 

I presume since you said it was an 85, that it is solid axle front.

As previous post said, it could be contaminated with water, or you may have bad outer axle seals, causing grease from knuckle area to get in and mix a bit. Usually if its water mixed, it'll be cloudy, since water and oil dont mix. If its grease from knuckle, its usually dark and not milky. Thats my experience anyway. If its an IFS, well, then I dont know....

 

Have'nt had a chance to pull the 3rd yet but it was so thick that 3 days later it still has not settled to the corners of the drain pan. Black like moleases but thick as grease. Hopefully I'll be able to get the rear together tonight and pull the front apart to inspect it. Thanx.

 

if you pull everything apart for the full rebuild and clean it all out you will be fine. Just make sure you clean ALL the parts and the inside of the housing and 3rd member. Grease is just another lube. So it is better then sawdust or banana peels. People do crazy things to try and cover up noises or clunks or grinding.. Plus, it was in the front. So it won't be as big of a deal compared to if it was run in the rear.

 

The last front 3rd I pulled apart had bearings welded to the pinion and spun damage in the carrier so bad the whole 3rd was junk so I'm a little nervous to pull this one.

 

Well hopefully it turns out okay! Did ya get any chance to pull it off yet? Got any pics? Getting any? LoL

 

I'll be able to pull it saturday morning.

Never posted a pic and this was all I had an the computer @ work. Will definantly get the camera out to the shop tonight.

 

Snapped a pic at lunch but the camera isn't the best.

This is what drained out of the front of the 85, I suppose it could be knuckle grease but it seems like somebody pumped it full.

 

I would verify that the knuckles are still full of grease, if they are empty, then that may have contributed to your pan of "stuff". Otherwise, it does look like someone may have been trying to cover up something in the diff. Bad bearings, broken teeth, who knows? Or they may have not known to put in gear OIL.... I have seen folks fill the knuckle area with gear oil because there is a plug on the knuckle itself. So people presume fill plug and figure oil goes there...

What does it smell like? To me, gear oil is much more stanky than grease. Even burnt grease can be rank though...

 

thanks rokblok for mentioning the plug on the knuckle, what is that there for

 

Doesn't smell like gear oil at all and im thinking that if the oil was contaminated by grease it would settle flat in the pan, but it's been sitting for days and still all globbed up like grease? Ten min here ten min there, progress is moving about as fast as that grease. hopefully i can get the rear buttoned up tonite and start stripping the front down.

 

From what I have been told, by some old school Toy technicians, it was to allow grease to be inserted into the knuckle for the Birfield joint. It was to prevent from always having to disassemble the bearings to pack the Birf. A few shots of grease kept it lubed. But like I said, most people put gear oil in the knuckle because of that plug. Which will leak out of the bottom of the knuckle(felt/wipe seal area) because those seals were not designed to seal IN oil, they were designed to keep contaminants(dust, dirt, water, etc) OUT... And since the grease that is INSIDE the knuckle shouldn't ever get hot enough to become viscous(runny), it wont leak past the felt/wipe seals. If you have oil coming out of those areas(bottom of the knuckle), then you have two options, one someone has filled it full of gear oil, two-the axle seal is leaking and diluting the grease making it runny and leak...

 

Now, I have seen some brands of "fix-it-alls" have a chemical reaction to the oil, which basically means, it thickens it up to muffle noise.... Just like oil "stop-leak" thickens the engine oil so it cant seep out, well, it also swells seals and gaskets, but anyway....

 

Thanks for the help and I'll update with my findings as soon as it's all apart.
p.s. the felts were leaking but not as bad as the last one i disected.

 

I got the 3rd out last night and I've got no idea. It sure looks like grease to me, full from knuckle to knuckle.





And this is as far as I got by 1am.