differential plug problem...........
Thread Starter
Instructor
Joined: Jan 2005
Posts: 129
Likes: 0
From: Huntington Beach CA
differential plug problem...........
Okay, I thought that draining the diff oil and putting fresh in would be a simple job, perfect whilst I wait for some new calipers to arrive...
I remove the plug, suck out all the old oil, put some new oil and additive in and go to tighten the plug back up... this is where the problems start. The plug will only go in three or four turns before it gets stuck. I don't want to force it as an aluminium diff could cross thread easily. I've cleaned the thread on both the diff and plug but it still doesn't want to go in!
Has anyone else seen/had this? I'm not sure what to do, I'm going to get a new drain plug and see if this is the problem but if it isn't are there any recomendations? I'm beginning to go insane.... I've only had this car 2 months and I beginning to think it doesn't appreciate all this hard work and money I'm spending on it!
1980 C3, 4sp Manual
I remove the plug, suck out all the old oil, put some new oil and additive in and go to tighten the plug back up... this is where the problems start. The plug will only go in three or four turns before it gets stuck. I don't want to force it as an aluminium diff could cross thread easily. I've cleaned the thread on both the diff and plug but it still doesn't want to go in!
Has anyone else seen/had this? I'm not sure what to do, I'm going to get a new drain plug and see if this is the problem but if it isn't are there any recomendations? I'm beginning to go insane.... I've only had this car 2 months and I beginning to think it doesn't appreciate all this hard work and money I'm spending on it!
1980 C3, 4sp Manual
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
Originally Posted by more_cc's
Okay, I thought that draining the diff oil and putting fresh in would be a simple job, perfect whilst I wait for some new calipers to arrive...
I remove the plug, suck out all the old oil, put some new oil and additive in and go to tighten the plug back up... this is where the problems start. The plug will only go in three or four turns before it gets stuck. I don't want to force it as an aluminium diff could cross thread easily. I've cleaned the thread on both the diff and plug but it still doesn't want to go in!
Has anyone else seen/had this? I'm not sure what to do, I'm going to get a new drain plug and see if this is the problem but if it isn't are there any recomendations? I'm beginning to go insane.... I've only had this car 2 months and I beginning to think it doesn't appreciate all this hard work and money I'm spending on it!
1980 C3, 4sp Manual
I remove the plug, suck out all the old oil, put some new oil and additive in and go to tighten the plug back up... this is where the problems start. The plug will only go in three or four turns before it gets stuck. I don't want to force it as an aluminium diff could cross thread easily. I've cleaned the thread on both the diff and plug but it still doesn't want to go in!
Has anyone else seen/had this? I'm not sure what to do, I'm going to get a new drain plug and see if this is the problem but if it isn't are there any recomendations? I'm beginning to go insane.... I've only had this car 2 months and I beginning to think it doesn't appreciate all this hard work and money I'm spending on it!
1980 C3, 4sp Manual
Le Mans Master
Joined: Oct 2004
Posts: 5,269
Likes: 54
From: Orlando Florida
St. Jude Donor '05
same here.... 4 turns is enough 
there's no pressure inside the differential so you don't need to tighten it more.... in the unlikely case that it leaks at the plug, get some thread sealer or RTV and put that on the threads....
there's no pressure inside the differential so you don't need to tighten it more.... in the unlikely case that it leaks at the plug, get some thread sealer or RTV and put that on the threads....
Pro
Joined: Nov 2001
Posts: 684
Likes: 0
From: Winnipeg Manitoba
I had the same problem on my 1980 - I refilled the diff and then tryed to thread the plug in about 3-4 turns and then it stopped. I believe that the diff hole is some what conical in shape thats why it will only srew in about 3-4 turns.
Race Director
Joined: Jul 2004
Posts: 12,672
Likes: 329
From: Scottsdale Arizona
Mine does go in all the way to the shoulder (didn't count the number of turns) but I also don't think that it had ever been removed before.
Redbad is right though. There isn't any pressure in the diff so I wouldn't worry too much about it. Check it after driving for a while and if there isn't any leakage, I'd leave it alone.
Redbad is right though. There isn't any pressure in the diff so I wouldn't worry too much about it. Check it after driving for a while and if there isn't any leakage, I'd leave it alone.
Drifting
Joined: Jan 2000
Posts: 1,612
Likes: 0
From: Phoenix Arizona
Originally Posted by Richard Cooper
My 81 is the same way, it only goes in a few turns. Been that way since I got the car 8 years ago. It does not leak and therefore causes no problem. Don't worry about it.
Same problem with mine....... no leaks!!!
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Burning Brakes
Joined: Nov 2004
Posts: 1,028
Likes: 0
From: San Antonio Texas
Originally Posted by Bob Turner
Same problem with mine....... no leaks!!!
i have the same problem with my 79. had a "slight" leak perhaps due to my reluctance to overtighten and the difficulty of getting a socket or wrench in that cramped space. put teflon tape on threads and that completely stopped the leak.
Safety Car
Joined: Jan 2004
Posts: 4,776
Likes: 142
From: North of Atlanta GA
St. Jude Donor '05
I have the same problem, I just try it a few times and with a little finese it goes in correctly, not sure how many turns but I can feel it when it's threading right, once it does I can tighten it with no worries.
