When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
What is everyone’s tool of choice to suck the old differential fluid out, so I do t have to take off the entire case? Is there one at harbor freight that will get the job done?
yes, the HF suction seems to do well for me (still working for PS fluid etc..)..i put a coat hanger to guide hose to get near the bottom best i could..
drive it around to warm up prior..don't forget whale oil
I use an electric pump that I originally purchased to change oil in my chevy powered boat. I use it to suck the oil from my 4-stroke powered jet ski also. It has battery terminal clips for 12v power source and I purchased at Walmart years ago.
Reason I’m asking is in that I’m working on the car that’s been sitting the last 15 years. At low speed when making turns, the rear axles will “shimmy” or have a rub-like sound. You can even see it visually. I don’t know if just changing the fluid will help or not, but it was my first guess.
The two bottles of additive should help the posi chatter. After you’ve changed out the fluid, find a large parking lot and do a series of slow, tight figure eights to ensure the posi clutch plates move relative to each other and pick up the fresh fluid.
Reason I’m asking is in that I’m working on the car that’s been sitting the last 15 years. At low speed when making turns, the rear axles will “shimmy” or have a rub-like sound. You can even see it visually. I don’t know if just changing the fluid will help or not, but it was my first guess.
My thoughts, if your VISUALLY seeing "shimmy", it will need more attention than gear oil & additive. Do more checking first, , IMHO, ,
I heard somewhere else to drain it, and rinse with kerosene/diesel a few times to flush everything out??
I think the draining fluid will flush out any metal shavings. I never had any problem with mine. If concerned, I guess one could do as you suggest or run a magnet up into the newly tapped hole.
The Sta Lube gear oil pump works well for this operation. Reverse the plastic tubing to the bottom of the pump body to remove gear oil, then back to normal when adding new fluid. https://www.pelicanparts.com/More_In....htm?pn=SL4344
John
I took my C3 to a Jiffy Lube and let them Vacuum out the old and replace it with new. By the way, I watched them the whole time to be sure I got what I was paying for. It was inexpensive and I did not smell like 90 weight for days afterwards.
Now I do it at home with a large Liquid vacuum that sucks it dry. I still hate the smell of that stuff...
If the Corvette sat for that long then you might need to replace the Rear Wheel Bearings and rebuild the Trailing Arms while you are at it. My C3 would steer from the rear as the bearings got really bad. It is dangerous to have bad bushings and bearings back there.
Van Steel used to offer a Million Mile Warranty on their rebuilt trailing arms. I am confident they will both last a while longer. They do Excellent work there at Van Steel's in Florida.
A magnet on a extending handle would check for any ferrous bits on the bottom of the differential.
If you find any metal shavings then you might consider flushing the differential out to get all the junk out. Kerosene when warm is a great solvent and will cut any sludge type deposits if there are any and it is still a good lubricant.
Changing Differential Fluid
