How much shold I be charged to have the differental fluid changed in my 73 vette? There is a clunking noise made after highway driving when making a right turn off the exit ramp. Thanks

It's not that hard to do yourself, but I wouldn't think more than 30 bucks to have it done. Just be sure the additive is included!

Have to agree that changing the fluid is not hard nor expensive to do yourself...BUT you will need to suck it out
since you do not have a drain plug...not a big deal

BUT I really have my doubts that you can get it done for 30 bucks... IF you are paying a mechanic for his time plus the cost of the fluid and the additive...

Labor rates in shops are only slightly less around here then what Cardiac Surgeons charge...and slightly more then what a good (read crooked) Lawyer charges ... no offense to any of you Lawyers ...we all know only Honest Lawyers would own a C3 lol


Bob

Do it yourself and save,the only problem is you can never get all the old grease out,unless you take the rear cover off.buy one of those cheap syphon guns down at the local parts house,suck out as much as you can.I put TWO small bottles of G.M. anti slip additive in first then fill it to the bottom of the fill plug hole with posi lube,run it like that for a month or so,then drain it out and do the whole thing again .that should solve the problem,it worked for me.after that once a year should be good.the G.M. additive cleans the clutch plates,when they get "gunked up"they wont slip like they are supposed to,they lock together,and then when you make a turn they finally brake apart causing that clunk noise.once the additive gets them cleaned off,it should be fine.after you get the grease changed take your car out for a ride,get it warmed up good find a big parking lot and do a bunch of figure eights ,half a dozen one way then half a dozen the other,that should help brake the clutches loose.after that the noise should be gone

Thanks guys for the info, my chevy dealer is going to charge me about $75.

LS4,

Ron is on the money. I just changed mine (71k miles) & it came out like tar. I will definitely be doing this in 1k miles & once more for good measure.

Anthony

Bob Griffiths said: since you do not have a drain plug...not a big deal

with a drill bit and a tap and die set you can have a drain plug..

makes it much much easier to keep your gear oil fresh

Corvette Central and others sell a Drain plug add on kit for the Diff. It includes everything.

I am aware that I can just drill and tap in a plug in the
rear... But was not aware someone sold complete kits... seems to me everyone has a drill and a tap & die set in the garage... So I just wonder just how many of these kits are sold...

But to be completely honest it really is not a hard or time consuming job to reach for the siphon gun and suck it out...

Bob Griffiths

Bob Griffiths said: I am aware that I can just drill and tap in a plug in the rear... But was not aware someone sold complete kits... seems to me everyone has a drill and a tap & die set in the garage... So I just wonder just how many of these kits are sold... But to be completely honest it really is not a hard or time consuming job to reach for the siphon gun and suck it out... Bob Griffiths

well the kit has a plug, a bit, the tap, all properly sized and some kind fo tool to align the bit.

as for whether its better to siphon or drain.. drain.. everytime.

with the siphon you will NOT get everything out.

I like to screw out the drain plug and then spray copious amounts of brake parts cleaner into the fill hole

this all runs out the drain hole and is much more likely to bring any small metal flakes out with it.

I have even flushed one with water, use air compressor to blow it out and then use a hair dryer for about an hour to dry off the insides, followed that up with brake parts cleaner and then let sit for a few hours, then fill. ive had great results doing this.