Figure Eights After Changing Rear End Lube
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Le Mans Master
Joined: Dec 2006
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Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
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From: Great Plains Iowa
Burning Brakes
Joined: Mar 2013
Posts: 1,018
Likes: 582
From: West Monroe Louisiana
2023 C3 of the Year Finalist - Unmodified
I really hate to enter this, but this is my own personal experience.
After setting up for over 20 years and a 3 year restoration I got my 73
back on the road again. I started having a popping from the rear end when I
creeped ahead from a stop. Ordered the additive and got new gear oil,
but I thought I would just try the figure 8's first.
Sure enough after doing them, the popping stopped and hasn't returned
again.
So there it is for what it's worth.
Donnie
After setting up for over 20 years and a 3 year restoration I got my 73
back on the road again. I started having a popping from the rear end when I
creeped ahead from a stop. Ordered the additive and got new gear oil,
but I thought I would just try the figure 8's first.
Sure enough after doing them, the popping stopped and hasn't returned
again.
So there it is for what it's worth.
Donnie
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Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
I really hate to enter this, but this is my own personal experience.
After setting up for over 20 years and a 3 year restoration I got my 73
back on the road again. I started having a popping from the rear end when I
creeped ahead from a stop. Ordered the additive and got new gear oil,
but I thought I would just try the figure 8's first.
Sure enough after doing them, the popping stopped and hasn't returned
again.
So there it is for what it's worth.
Donnie
After setting up for over 20 years and a 3 year restoration I got my 73
back on the road again. I started having a popping from the rear end when I
creeped ahead from a stop. Ordered the additive and got new gear oil,
but I thought I would just try the figure 8's first.
Sure enough after doing them, the popping stopped and hasn't returned
again.
So there it is for what it's worth.
Donnie
I've changed the rear end and gear oil in my '69 3 times in the 36 years I've owned it. Never once did I use the GM additive, I always used the gear oil with the additive already in it. Never once did I have any popping or clunking or whatever supposedly happens.
Race Director
Joined: May 2005
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From: Millington Illinois
St. Jude Donor '08-'09
Does that make sense to you?
Last edited by 63mako; Aug 19, 2015 at 12:18 PM.
Le Mans Master
Joined: Jan 2006
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From: Butler Pa
Drifting
Joined: Jul 2002
Posts: 1,995
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From: Garland Texas
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
If you drain gear lube with modifier out and install new fluid with modifier why would you even need to work it in? I don't quite understand your question. If the clutches aren't popping from lack of modifier in the old lube, you don't need to work in the new lube. Because there ain't no problem.
If the clutches are popping with the old lube it's because of lack of friction modifier on the clutches. That's why they are popping. They are sticking to each other. The lube with friction modifier needs to be worked into the clutches. Hence figure 8's.
Really? On a 90 degree turn in town the outer wheel is going to rotate a dozen times more than the inner wheel. How big are the streets in your town?
If the clutches are popping with the old lube it's because of lack of friction modifier on the clutches. That's why they are popping. They are sticking to each other. The lube with friction modifier needs to be worked into the clutches. Hence figure 8's.
Really? On a 90 degree turn in town the outer wheel is going to rotate a dozen times more than the inner wheel. How big are the streets in your town?
Exactly what he posted here. If the clutches are grabbing then do some circles to work in the new fluid instead of driving for days or weeks before it stops grabbing.WTF is so hard about driving to the closest parking lot and doing a few circles in each direction....
The better question of the day is why aren't these idiotically stupid threads belong in C3 General with a poll attached where they belong?
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
WTF is so hard about driving to the closest parking lot and doing a few circles in each direction....
Because the job has already been done by the time you get to the parking lot.
But my question was "What happens if you DON'T do figure eights?
Thread Starter
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
WTF is so hard about driving to the closest parking lot and doing a few circles in each direction....
Because the "working it in" job has already been done by the time you get to the parking lot.
But my question was "What happens if you DON'T do figure eights?
Melting Slicks
Joined: Mar 2008
Posts: 2,989
Likes: 198
From: Meriden CT
63 Mako already answered your question, that should be enough, but look at it from a "professional" point of view. Say you did a rebuild and didn't bother to do the figure eights. Customer picks up the car all happy but comes back five minutes later asking WTF did you do to my car, whats all these noises? I'd rather take the car for a figure eight test drive than deal with a pissed off customer who may not ever come back, or talk trash about your shop.
Last edited by SH-60B; Aug 19, 2015 at 04:24 PM.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
BTW, this thread is taxing, and I wish it would die as well.
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,754
From: Charlotte NC
100%Those that KNOW....KNOW to do this step...so any chance of potential damage is lessened....and mentioned by 63 Mako and tracdogg2.
I am NEITHER cheap or lazy.....and regardless of the type of rebuild to a differential. I personally do the road test to 'break-in' the ring gear (if replaced) and or get the clutches lubed so there is no problem. I will do whatever it takes so I do not have to re-visit a repair.
Nobody is perfect. I KNOW I have been wrong and ADMITTED IT...that I WAS WRONG.....but at some point....this HAS to sink in and make sense. If not...than this is ridiculous...much like trying to lead a horse to water that does not want to drink.
DUB
