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Muncie transmission - oil change

  
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Muncie transmission - oil change

 
chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 12/12/13
11:56 AM

Hi!

I want to change the oil in my Muncie. Can you tell me which fluid and how much of it will be needed to do it?
I don't have a drain plug, just a fill plug... what's the best way to get the old oil completely out of the transmission?

Maybe 75w90 or 80w90 gear oil? Syntetic or not?

Chris  

4zpeed 4zpeed
Enthusiast | Posts: 368 | Joined: 04/13
Posted: 12/12/13
12:47 PM

Hi Chris,

I always just used straight 90, others may use something different. If you have a turkey baster and a piece of vacuum hose that works good for removal, it will also help if the oil is a bit on the warm side. Good luck.

Grin  
Poncho huggen gear snatchen posi piro.

tuffnuff tuffnuff
Moderator | Posts: 2567 | Joined: 12/09
Posted: 12/12/13
01:59 PM

+1
Northern Tools has a Well-Bilt oil extractor for $9.99

http://www2.northerntool.com/fuel-transfer-lubrication/oil-extractors.htm

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 12/12/13
02:20 PM

I'll try to get such a tool where I live, thanks.
So would synthetic or mineral oil be better?  

shyrgfuh3 shyrgfuh3
Enthusiast | Posts: 462 | Joined: 11/13
Posted: 12/12/13
05:39 PM

hello chris;


you might be able to get a little $5.00 US, gas hand pump from the auto store. if it doesn't work you are only out 5 bucks. get your trans warm first do the oil flows more easily.


I might use regular 75/90 GL4 in your cold weather but if you want synthetic which might shift a little better try something like the one below.


I think it takes 1.5 us quarts.


REDLINE Synthetic Manual Transmission Lubricants

GEAR AND SYNCHRONIZER WEAR PROTECTION
Most manufacturers of manual transmissions and
transaxles recommend an 80W or 90W GL-4 lubricant.
GL-5 gears oils which are required in hypoid differentials
are not used in most synchromesh transmissions
because the chemicals used to provide the extreme
pressure protection can be corrosive to synchronizers,
which are commonly made of brass or bronze. Typically,
the use of a GL-5 lubricant in a synchromesh
transmission will shorten the synchronizer life by one
half. The extreme pressure requirements of spur gears
and helical gears found in transmissions are not nearly
as great as found in rear-wheel drive differentials. A
GL-4 lubricant provides adequate protection for most
manual transmissions, unless a unique design
consideration requires the extra protection of a GL-5.
The reason that many manufacturers have made
recommendations of motor oils or ATFs is that petroleum
80W gear oils frequently do not shift well at low
temperatures. Motor oils and ATFs are much more fluid
at lower temperatures and they are not corrosive toward
synchros, but they provide very poor gear protection.
These lubricants provide almost no extreme-pressure
protection. In addition, petroleum multigrade motor oils
and ATFs have very poor shear stability. The shearing
action by a manual transmission on thickeners is much
worse than in an engine or automatic transmission.
Within 5,000 miles the thickeners can be rendered
ineffective and the transmission will be operating on a
much reduced level of protection, as shown in the graph
below. In hot weather these transmissions will whine
and rattle because of poor vibration dampening and
metal contact. Red Line MTL and MT-90 provide the
excellent gear protection of a GL-4 gear oil in a synthetic
lubricant which spans hot and cold temperatures and will
not shear or oxidize with use.

DIRECTIONS FOR USE
Red Line MTL may be used in transmissions which
recommend 75W, 80W, or 85W GL-4 gear oils, or SAE
30 or 5W/10W30 motor oils. If a 90W GL-4 or SAE 40,
10W40, or 15W40 is required, MT-90 may be used. If the
transmission or transaxle requires an SAE 90 GL-5 gear
oil, then Red Line 75W90NS or 75W140NS Gear Oil
may be used. In transmissions which recommend Dexron
or Mercon fluids we recommend our D4 ATF which is
very similar to the MTL, being a GL-4 Gear Oil also. The
D4 ATF will provide better low-temperature shiftability,
and the MTL would provide better wear protection for
racing use. MTL is not designed for use in rear-wheel
drive differentials. Those generally require a GL-5 lubricant
such as Red Line 75W90 Gear Oil. It is not necessary
to flush the transmission before replacing with MTL.
Remove the drain plug and drain while warm. Seal
compatibility has been designed to be similar to petroleum
lubricants, and leakage should be no greater than
any other oil of comparable viscosity. Being formulated
with extremely stable synthetic basestocks, MTL and
MT-90 will last much longer than conventional petroleum
lubricants. However, we do not recommend extended
drain intervals, since without a filtration system, there is
no way to remove metal shavings other than draining the
lubricant. The regular maintenance intervals are also
recommended to insure that the proper level of the fluid
is maintained.


Red Line Oil's MTL and MT-90 are designed to provide excellent protection and improved shiftability for manual transmissions and transaxles, having cured the problem of hard shifting in thousands of transmissions with shifting troubles. How? They have the appropriate coefficient of friction for most manual transmission synchronizers (many gear oils, engine oils, and ATFs are too slippery for proper synchro engagement). And, the wide viscosity of MTL and MT-90 allow proper shifting over the entire temperature range which the transmission will experience. The synthetic base oils used have a very high viscosity index which provides relatively constant viscosity as temperature changes. MTL is a low 70W at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise. MT-90 is a thicker 75W90 version of MTL. The shear stability and oxidation stability of these products are excellent, thus the physical characteristics of Red Line MTL and MT-90 will change little with use.

MTL
MT-90

The MT-90 is a 75W90 GL-4 Gear Oil that’s slightly heavier than MTL. Provides excellent protection of gears and synchronizers and its balanced slipperiness provides a perfect coefficient of friction, allowing easier shifting.


RED LINE SYNTHETIC OIL CORP.
6100 Egret Court
Benicia, CA 94510
(707) 745-6100
www.redlineoil.com  

tuffnuff tuffnuff
Moderator | Posts: 2567 | Joined: 12/09
Posted: 12/12/13
05:40 PM

I would stay with 90 weight oil, as per originally used.
Going synthetic might produce leaks.,. it's your call.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 12/12/13
06:06 PM

If nineral is good enough I'll use it. I don't think it's very expensive so I might start to change it more often (every 2 years?!)

I could fine a Castrol EP 80W, it's the only mineral based oil from Castrol that I can get. API GL-4 is written on the bottle. Is this okay or should I search for the 90 weight?

Edit:
There is also a 85/90 mineral based from Liqui Moly with the same specification.
Is for my climate a lower or higher number better? I don't drive a lot when it's really cold outside and the car is parked in my heated garage.  

shyrgfuh3 shyrgfuh3
Enthusiast | Posts: 462 | Joined: 11/13
Posted: 12/12/13
06:18 PM

If nineral is good enough I'll use it.


thats what they were designed for so yes it is.


xxxxx


I don't think it's very expensive so I might start to change it more often (every 2 years?!)


Some people run it for 60 k miles. i think if you want to be overly cautious you might go every 15 - 20k us miles.


xxxxx


I could fine a Castrol EP 80W, it's the only mineral based oil from Castrol that I can get. API GL-4 is written on the bottle. Is this okay or should I search for the 90 weight?

Edit:
There is also a 85/90 mineral based from Liqui Moly with the same specification.
Is for my climate a lower or higher number better? I don't drive a lot when it's really cold outside and the car is parked in my heated garage.


since you drive when its cold and you might drag race it a bit more i would go 85/90.  

65pmdgto1 65pmdgto1
Enthusiast | Posts: 504 | Joined: 12/07
Posted: 12/12/13
08:26 PM

Every Muncie I've had, except one, and there have been a few had a drain plug on the lower passenger side. I had one without the drain and my son had one too without it. I always just drilled and taped the case for an 1/8" pipe plug in the factory boss even in the car after you suck out as much as possible. Sucking in out you won't be getting the fine metal out of the transmission. When I got a car with a Muncie or Borg in it I would drain the transmission and fill it with ATF and drive it for 20-30 minutes come home and drain that then refill with good old smelly 90 weight. Guys I knew would mix a pint of STP a pint of ATF and the rest 90 weight which was supposed to make 'em shift better. I never really noticed any difference but they liked it. As I remember they take about 2 1/2 quarts. I really miss that old Muncie gear groan and the noise they make in reverse was kind annoying, ie straight cut gears for reverse.
I guess I've learned to like my OD auto shifters.  

65pmdgto1 65pmdgto1
Enthusiast | Posts: 504 | Joined: 12/07
Posted: 12/12/13
08:28 PM

Sorry duplicated again when it said could not post. So I wait a few minutes and hit post again and it's there twice.??????????????  

chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 12/13/13
06:21 AM

I was in the shop to see what I can get now.. they don't have the 85w90 any more, I have to take 80 or 80w90, both mineral based. I think the 80w90 would be the better choice, correct?

It's a Castrol Manual EP 80w-90 and price is about $15 for one litre.  

tuffnuff tuffnuff
Moderator | Posts: 2567 | Joined: 12/09
Posted: 12/13/13
11:38 AM

Chris, that 80w90 will work great in your M-21.,. you'll probably need 1 1/2 litre, if you get all the old gear oil out.

Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

chrisaustria chrisaustria
User | Posts: 187 | Joined: 01/13
Posted: 12/14/13
12:10 AM

Thank you very much. I'll get the 80w90. Maybe I have a M20.. I could find an article about the drain plugs.. seems like only M22 had them, so I probably don't have a M22. Now I have to find out if it's a M20 or 21.. but both will use the same oil I guess so it's not that important.

I'll get some pump and try to get as much out as possible. Maybe I'll change it twice so the fresh oil will combine with the rest of the old oil and it will be cleaner.. I have to buy at least 4 litres so I have enough to do it twice.  

65pmdgto1 65pmdgto1
Enthusiast | Posts: 504 | Joined: 12/07
Posted: 12/14/13
08:30 AM

M-20 or M21 some had that drain plugs some didn't. I think if it was a replacement case the plug wasn't taped.
M-20 will have a 256 low gear and the M-21 will be 2.20 low gear.....  

4zpeed 4zpeed
Enthusiast | Posts: 368 | Joined: 04/13
Posted: 12/15/13
01:14 AM

Hi Chris,

In late 1969, all Muncie 4-speeds got both a fill and drain plug, before that only the M22 had a drain plug. So granted the guts have not been changed more than likely you have a M20 or M21 and it is fairly easy to tell between the two as the difference between 3rd and 4th gear with the M21 is minimal.

Here are a few links for identification but the only sure way to know what ratio you have without taking it out or looking inside is jack it up and spin the motor while observing the driveshaft rotation.

People that like the M21 say that it seems like the M20 has the effect of falling on its face when the shift is made from 3rd to 4th gear, on the other hand people that prefer the M20 say that it seems like the M21 is missing a gear because when the shift from 3rd to 4th occurs there's no noticeable difference.

The M21's ratios are more suited to keeping the RPM range in a power band, thus you notice the close knit gears.

It is essential to confirm if your utilizing a close or wide ratio Muncie when contemplating things such as rear gears or cam selection, hope this helps.    

      Year                 1st   2nd  3rd   4th  Rev
1963 - 1965   M20  2.56 1.91 1.48 1.00 3.16
1966 - 1974   M20  2.52 1.88 1.46 1.00 3.11
1963 - 1974   M21  2.20 1.64 1.28 1.00 2.27
1967 - 1974   M22  2.20 1.64 1.28 1.00 2.27


http://www.5speeds.com/muncie2.htm
http://www.myss396.com/ChevelleInfo/Transmissions/Muncies.html


Grin  
Poncho huggen gear snatchen posi piro.

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