Newbie service
Thread Starter
Intermediate
Joined: Jun 2016
Posts: 39
Likes: 1
From: Old England
Newbie service
Hi gang. Well my L48 has now got new paint, so that should make it go faster. And so I'd better change the oil and filter. But not going to start another oil thread, it's getting dino 20-50 will 1200 ish ZDDP.
But what oil filter? I dunno what all these anti suck back valves and stuff mean! So any advice would be appreciated please.
I've had a couple of slight clunks from the back when I've pulled away, so I don't think there's any harm in changing the diff oil... what spec should I put in there, and any LSD additive...?
Please tell me what to do and thanks a lot in anticipation of some help and advice!
But what oil filter? I dunno what all these anti suck back valves and stuff mean! So any advice would be appreciated please.
I've had a couple of slight clunks from the back when I've pulled away, so I don't think there's any harm in changing the diff oil... what spec should I put in there, and any LSD additive...?
Please tell me what to do and thanks a lot in anticipation of some help and advice!
Thread Starter
Intermediate
Joined: Jun 2016
Posts: 39
Likes: 1
From: Old England
I know, that would be easy, Mike!
I hope this information maybe in the manual, but it's in the glove box, in the car which is 100 miles away, getting painted. Weather forecast for next week is dry, so I wanted to get this stuff sorted out asap, order things in advance, get it done, rather than be tempted to use the vehicle when it really needs an oil change etc.
The backstory is a little dull...
I hope this information maybe in the manual, but it's in the glove box, in the car which is 100 miles away, getting painted. Weather forecast for next week is dry, so I wanted to get this stuff sorted out asap, order things in advance, get it done, rather than be tempted to use the vehicle when it really needs an oil change etc.
The backstory is a little dull...
Intermediate
Joined: May 2016
Posts: 47
Likes: 10
From: Aberdeen, Scotland
Can't help you with the oil filter but have you checked the bushing at the front of the diff with regards to the rear end clunking.
Just had to do mine as i was getting clunking from the rear end when easing on and off the throttle.
The bottom bush was fine but when i stuck my hand up to check the upper bush (which you can't see) the rubber was non-existent.
If its a manual, you can also check by having someone put it in reverse and bring the clutch up to the biting point as if you were about to move. Does the front of the diff move when you do this? Should be solid and not move. If there's any movement it will clunk when driving.
Took about 30 mins to replace on a ramp.
Cheapest and simplest fix so worth checking it first. Pic below is for a 73.
Just had to do mine as i was getting clunking from the rear end when easing on and off the throttle.
The bottom bush was fine but when i stuck my hand up to check the upper bush (which you can't see) the rubber was non-existent.
If its a manual, you can also check by having someone put it in reverse and bring the clutch up to the biting point as if you were about to move. Does the front of the diff move when you do this? Should be solid and not move. If there's any movement it will clunk when driving.
Took about 30 mins to replace on a ramp.
Cheapest and simplest fix so worth checking it first. Pic below is for a 73.
Last edited by vaux_2; May 18, 2017 at 07:53 AM.
Team Owner
Joined: Sep 2006
Posts: 31,214
Likes: 4,301
From: Westminster Maryland
Hi EH,
Here's a link to a copy of the 78 Owners Manual.
Lot's of service and maintenance information within it.
https://www.gmheritagecenter.com/doc...t-Corvette.pdf
Regards,
Alan
Here's a link to a copy of the 78 Owners Manual.
Lot's of service and maintenance information within it.
https://www.gmheritagecenter.com/doc...t-Corvette.pdf
Regards,
Alan
Last edited by Alan 71; May 18, 2017 at 09:01 AM.
Le Mans Master
Joined: Mar 2001
Posts: 5,738
Likes: 644
From: Lincoln, CA
Don't worry about the anti drain valves because out filters are installed upside down.
They always have oil in them. I like the Wix filters. I use a high pressure version because I have my Filter bypass blocked.
As for the rear yes on the additive, and correct gear oil.
They always have oil in them. I like the Wix filters. I use a high pressure version because I have my Filter bypass blocked.
As for the rear yes on the additive, and correct gear oil.
Racer
Joined: Jan 2005
Posts: 434
Likes: 47
From: Lake in the Hills IL
I just bought the GM diff lube and posi additive off Amazon w/ free 2 day shipping and got them yesterday. I bought 2 bottles of the lube and 1 posi based on some threads from here. Need to get a little sucker/baster type deal to get it out of the diff. Prob. hit up Harbor Freight as I heard they had them for fairly cheap.
Mine has been chattery feeling/sounding after driving around for >20-30 min. for a year or 2 now. Hopefully that does the trick with that issue. Know I prob. need to do the rear trailing arms/bearings soon too, but that's pretty expensive.
Mine has been chattery feeling/sounding after driving around for >20-30 min. for a year or 2 now. Hopefully that does the trick with that issue. Know I prob. need to do the rear trailing arms/bearings soon too, but that's pretty expensive.
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Thread Starter
Intermediate
Joined: Jun 2016
Posts: 39
Likes: 1
From: Old England
Thanks guys, thanks to you all for your help and advice
(...and here's a pic of our nice and tidy Vette)
Last edited by English Howie; May 30, 2017 at 06:23 AM. Reason: Adding a picture