Just want to know what some of you guys paid for having the differential flushed.I got quoted $90 from a tranny shop.

Sound correct?

 

No...
just get a new gasket 10$ and about to quarts or so (not sure) of gear oil and 30 min-45min of your time. about 17-22$ its super easy. unbolt.let it leak out. then put on new gasket seal it and bolt it all up, then there is a port on the side of diff. taking of buy a 3/4 drive. fill it till the top of the port whole and put back on the plug or whatever its called and your done.



P.s. the gear oil is the nastyiest smell in the whole world.. so Dont get to much on yah

 

Yeah the is STENCH IS MOST FOUL!!!
OTHER OPTION IS TO stick in a suction hose & suck out old fluid & insert new!

 

yeah,
I wish i knew they had that tool when i did my flush..Ii was at schucks the other day and walked past those, Then i just kicked my self in the @$$. What ever it cost's get it because the smeal is horrible.

 

Cars been over 25,000 miles since it was done by previous owner...Does it need be done asap?

 

The differential cover bolts can be really tight. I had to use a pneumatic wrench on all of them and still one of the bolts went round. Thankfully I had the whole rear axle off the car and I had plenty of room to work on it. So be careful. Don't round out them bolts!

BTW: Pretty much all the bolts are supposed to be metric on our cars. (At least according to the manuals) But, are the cover bolts metric or inch sized? I had so much paint, rustprotection gunk and crap on the bolts, that even after cleaning them I could not tell 100% surely whether they were metric or not.

 

dang... mine wasn't that bad.

 

If it's not been done before, I'd replace the rear wheel bearings and seals

 

A diff flush? I didn't know they did such a thing. I change the rear fluid every year; although I honestly haven't changed it since I had to put on a junkyard axle to replace my busted 3.73/posi/disc axle.

You don't even need a gasket, a tube of ultra copper or blue RTV will work fine too.

And actually... I'd suggest leaving the axleshaft seals/bearings alone unless the seals are leaking and the bearings are torn up. You'd have to remove the pinion shaft lock bolt, which is a super thin 7 or 8 mm bolt. Guess what; the head of that bolt likes to snap off after years of torture, and you're stuck with the pinion shaft locked in. You can't get a drill bit aimed at the bolt hole either since it's below the edge of the diff casing.

So you might wind up in a nightmare just b/c you wanted to change seals/bearings that were fine.

 

One trick you can try with a stuck bolt is get a propane torch and heat it up until it's red then pour some cold water on it. Not exactly sure how it works but it's like magic. That bolt will come right off. Just make sure nothing flamable is around.

 

I was thinknig of changing all the seals in the 94 firebird rear end I bought for my car that's sitting downstairs before installing it, I take it this isn't the wisest choice?

 

Yes, that is a common trick. What happens is that the heat makes the metal expand. When you pour water or ice on the bolt, the bolt cools rapidly and shrinks faster than metal around it. That causes there to be some space between the threads of the bolt and the threads in the bolt hole. That also tears the bolt loose from the bolthole and it spins with relative ease. The other reason it works is that the bolt and the material around it can be made of different things. They therefore have different heat expansion ratios and the space between the threads changes due to heat expansion.

The problem is that metal conducts heat very well. That's why it's very hard to heat a bolt that is embedded in a large mass of metal. The energy used to heat the bolt escapes to the metal around it.

 

yeah it can also expland and shirnk all the other surounding metal also .. so pay attieon.

 

Yep. If your not careful, you could end up warping things.