4 Speed Muncie M20 - QUESTION
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Joined: May 2016
Posts: 54
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From: Pewaukee Wisconsin
4 Speed Muncie M20 - QUESTION
Since I recently purchased this car I wanted to replace the standard transmission fluid however I only see 1 drain / fill plug and it is mounted relatively low on the transmission wall. I am sure I can remove the plug however I have no idea how I would fill it again? Perhaps I have to suck the old fluid out with a pump and pump in the new oil? Is this correct? Just one plug on the 4 speed manual transmission? 1969. Muncie M20.
Now that I've type it up it seems like my only option. Suck it out and pump on the new lube.
Thanks.
Now that I've type it up it seems like my only option. Suck it out and pump on the new lube.
Thanks.
Safety Car
Joined: Sep 2007
Posts: 4,458
Likes: 331
From: Indy Indiana
the 70 and up trannys have a drain plug as well as a fill plug.. so yes you have to pump out the old with a turkey baster ( or something similar ) and re-fill to the side fill plug level. same is true for the rear end housing/pumpkin.
some folks have actually drilled and tapped a drain plug hole into their 69 and older case.. if you do a search on this forum you might find a thread stating how.
some folks have actually drilled and tapped a drain plug hole into their 69 and older case.. if you do a search on this forum you might find a thread stating how.
Safety Car
Joined: Dec 1999
Posts: 3,605
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From: PA
Regards,
Stan Falenski
Racer
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From: carpentersville ill.
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
Suck it up, Buttercup! (I always wanted to say that).
get a good pump, one that looks like a grease gun, not some plastic piece of crap like the red on HF sells. you can suck it out with that and refill it as well. make sure it's one that the hose won't fall off of...BTDT
get a good pump, one that looks like a grease gun, not some plastic piece of crap like the red on HF sells. you can suck it out with that and refill it as well. make sure it's one that the hose won't fall off of...BTDT
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Thread Starter
Advanced
Joined: May 2016
Posts: 54
Likes: 3
From: Pewaukee Wisconsin
And now for the BAD NEWS: Try as I might....I can't get the plug removed from the transmission to save my life. I am going to keep putting penetrating oil on it for a few more days to see if I can get it. As of right now, I have the flats rounded over (not good), I applied heat a few times for 1 minute (Fire extinguisher close at hand).
My guess is that I will have to take it to the experts - someone with a lift and perhaps an impact wrench. Why did they use a 4 sided bolt? Standard sockets don't fit so I was forced to use the open end wrench. I have a impact, but not the right socket and I am not sure the impact is the way to go? I am not even sure there is enough room for an impact wrench??
Any suggestions?
By the way, I replaced the oil in the differential (Royal Purple and possi additive) and it looked pretty old! Even more reason to change the transmission fluid! Now I have to get that drain plug out!
My guess is that I will have to take it to the experts - someone with a lift and perhaps an impact wrench. Why did they use a 4 sided bolt? Standard sockets don't fit so I was forced to use the open end wrench. I have a impact, but not the right socket and I am not sure the impact is the way to go? I am not even sure there is enough room for an impact wrench??
Any suggestions?
By the way, I replaced the oil in the differential (Royal Purple and possi additive) and it looked pretty old! Even more reason to change the transmission fluid! Now I have to get that drain plug out!
Since I recently purchased this car I wanted to replace the standard transmission fluid however I only see 1 drain / fill plug and it is mounted relatively low on the transmission wall. I am sure I can remove the plug however I have no idea how I would fill it again? Perhaps I have to suck the old fluid out with a pump and pump in the new oil? Is this correct? Just one plug on the 4 speed manual transmission? 1969. Muncie M20.
Now that I've type it up it seems like my only option. Suck it out and pump on the new lube.
Thanks.
Now that I've type it up it seems like my only option. Suck it out and pump on the new lube.
Thanks.
Last edited by DN5014; Jun 10, 2016 at 01:40 AM.
Safety Car
Joined: Dec 1999
Posts: 3,605
Likes: 839
From: PA
The change was made around October 1969 as that is when we see all versions of the Muncie start showing up with the 661 case and two plugs. Is it possible that a 660 case with one plug stayed in inventory until November? Absolutely... This was a production line environment and there would have been no reason not use an"old" transmission from inventory in this instance.
Would be interesting to find out if you have a 660 or 661 case and what the assembly date is.
Regards,
Stan
Burning Brakes
Joined: Apr 2008
Posts: 1,222
Likes: 93
From: shelbyville West Michigan
they used 4 sided because it is a pipe plug. the threads are tapered and someone reamed it in too tight. if you can't get it with a pipe wrench, you'll have to drill it out and use an e-z out on it...good luck.
Team Owner
Joined: May 2001
Posts: 87,375
Likes: 1,593
From: Western NY
Try warming up the tranny case a little with a torch. That should allow you to remove the plug.