78 Diff oil

[C1CKS]

Hi guys just joined, any idea what's the best diff oil for a 78 vette?

 

[Rich]

Hi Colin.

A very warm welcome and thank you for joining the Club.

I will have to defer to those far more knowledgeable than me to answer your question. Someone will no doubt be along soon.

 

[kentvette]

Ideally, GM's own! But, a good 80w gear oil will do. I use Millers Classic 85w Mineral Gear oil in mine.

The key thing is the GM limited slip additive, which you must add. You can buy that from a number of places, but I use Corvette Kingdom. For a refill of the diff, the consensus now is two bottles of additive and then add the diff oil to fill.

There is no drain hole on a '78 diff, so if changing (which is recommended) you'll need to pump it out with something like a hand drill driven pump.

 

[Chuffer]

Welcome to the jovial world of CCCUK . As Kentvette said , do a full drain and oil change then you have a new starting point you know about . If you can`t get a hand driven pump a heavy duty syringe with a neoprene tube might do it but you will need plenty of pulling power ! The LSD additive is crucial as Kentvette says and you must find a quiet car park or other area asap after the refill and do 8 to 10 figure of eight turns to get the LSD lubed up properly . Happy C3 motoring and post us all some pics .

 

[Corvetteville]

NEW Hand Electric Drill Drive Self Priming Pump Transfer Pumps Oil Fluid Water | eBay

Install and start the rig. Observe whether a certain amount of fluid is sucked into the pump within 15 to 20 seconds in the oil inlet pipe. If not, check whether the oil inlet pipe is correctly installed on the oil inlet pump.

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One of these

 

[C1CKS]

Ideally, GM's own! But, a good 80w gear oil will do. I use Millers Classic 85w Mineral Gear oil in mine.

The key thing is the GM limited slip additive, which you must add. You can buy that from a number of places, but I use Corvette Kingdom. For a refill of the diff, the consensus now is two bottles of additive and then add the diff oil to fill.

There is no drain hole on a '78 diff, so if changing (which is recommended) you'll need to pump it out with something like a hand drill driven pump.

Cheers i have the additive but was unsure about the oil as i read some say 75w and others 85w so cheers for the heads up

 

[C1CKS]

Welcome to the jovial world of CCCUK . As Kentvette said , do a full drain and oil change then you have a new starting point you know about . If you can`t get a hand driven pump a heavy duty syringe with a neoprene tube might do it but you will need plenty of pulling power ! The LSD additive is crucial as Kentvette says and you must find a quiet car park or other area asap after the refill and do 8 to 10 figure of eight turns to get the LSD lubed up properly . Happy C3 motoring and post us all some pics .

Cheers Chuffer, i will post some pics soon, just about to take the body off so be a while before i can do any figure 8's ☺

 

[johng]

If your taking the body off, then how about starting a thread showing us what you are doing. Now that I've got my car back together again I wish I had created a single thread showing what I had done, it would have been useful to re-visit to remind myself of exactly what I did! More importantly, I'm sure several of us would enjoy reading it.

 

[C1CKS]

If your taking the body off, then how about starting a thread showing us what you are doing. Now that I've got my car back together again I wish I had created a single thread showing what I had done, it would have been useful to re-visit to remind myself of exactly what I did! More importantly, I'm sure several of us would enjoy reading it.

Will do, just waiting for a space in my shop so i can have room for the body and i will then start posting some pics ☺