# m20 leak



## iron_goat (2 mo ago)

My 67 came in today. Got under the car after a few times around the block and noticed a leak from thentail, where the yoke goes in. It shifts, it's stiff but it's working. there is an audible clunk from under the car when getting on the gas.


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## RMTZ67 (Mar 12, 2011)

There is a rear seal, pretty easy fix. I would be checking fluid in trans and diff along with u joints.


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## Bopman (7 mo ago)

X2 on above and also check engine and transmission mounts as one of these could be your clunk you are talking about when you get on gas.


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## geeteeohguy (Feb 2, 2008)

As crusty as that looks, check the U joints and everything else under the car. Also check the slop in the rear end by turning the driveshaft and feeling the yoke at the diff.

The way your oil and seal look, my bet is that the rear bushing is also worn out, and possibly the front yoke. The rear bushing can be removed in-car easily with a TH350 rear bushing tool. Put the new bushing in the freezer for an hour or so and then drive it in. You check the yoke with a straight edge or your eye. Any 'saddle' along its length, and it's time for a replacement, or you'll tear up your new bushing and seal. No fear....once completed, good for another 100,000+ miles. 
I have never seen blacker oil in a Muncie, and I've seen a lot of Muncie's. That needs to be changed before more driving is done. Check the rear lube, too.


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## lust4speed (Jul 5, 2019)

Before you take things apart, grab the universal joint and push/pull up and down and see how much movement you have. Should be a fair indicator of the shape the bushing is in.


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## iron_goat (2 mo ago)

The m20 is getting swapped with an m22w from Midwest Muncie. There's a 455 block with an ohio 4340 stroker crank in my garage waiting to be built that will end up in the car. 
The M20 will get rebuilt and probably repurposed for my 76 formula. 
Thanks all for your help.


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