Muncie Help Leak After Rebuild
11-06-2017, 06:13 AM
#1
Melting Slicks
Thread Starter
Muncie Help Leak After Rebuild
Had my '65 Muncie 1325 case rebuilt by a guy that advertises in NCRS. After the installing the trans, it immediately started leaking from the bearing retainer. Out comes the trans again and the rebuilder said the retainer bearing screws were to short. The case was also bushed .
Trans goes back in and the bearing retainer area starts to leak again. Rebuilder seems to be mystified. WTF did this guy do or miss?
Want to hold this guys feet to the fire since I paid him well for the rebuild. Is there a certain sealer that should be used on the bearing retainer gasket or what else could be causing it to leak? Thanks
Trans goes back in and the bearing retainer area starts to leak again. Rebuilder seems to be mystified. WTF did this guy do or miss?
Want to hold this guys feet to the fire since I paid him well for the rebuild. Is there a certain sealer that should be used on the bearing retainer gasket or what else could be causing it to leak? Thanks
11-06-2017, 06:21 AM
#2
Race Director
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St. Jude Donor '07
where is it leaking from; the front snout or the retainer to the case?
there is no shaft seal in a Muncie, the lube just drains back into the case through a passage and a hole. so, I can only think of 2 things, the trans is overfilled or the gasket is wrong (drain-back hole covered). OR, maybe it has the wrong bearing retainer....
no special sealer needed, RTV will work
Bill
there is no shaft seal in a Muncie, the lube just drains back into the case through a passage and a hole. so, I can only think of 2 things, the trans is overfilled or the gasket is wrong (drain-back hole covered). OR, maybe it has the wrong bearing retainer....
no special sealer needed, RTV will work
Bill
Last edited by wmf62; 11-06-2017 at 06:39 AM.
11-06-2017, 07:14 AM
#3
Race Director
Or is it leaking from the countershaft bore in the front of the case? It's concealed by the bellhousing when installed and a leak between the transmission and bellhousing can't really be distinguished as to which is the culprit without moving the transmission back. Although once moved back he should have been able to determine which it is. If it's leaking inside the bellhousing and coming out at the inspection plate then yeah, it's something up with the bearing retainer.
There's a gasket between the bearing retainer and case to keep any lube that gets past the bearing and slinger (if one is present) and allow the drainback at the bottom to function. But nothing in terms of a tight seal from the bearing forward as Bill said.
There's a gasket between the bearing retainer and case to keep any lube that gets past the bearing and slinger (if one is present) and allow the drainback at the bottom to function. But nothing in terms of a tight seal from the bearing forward as Bill said.
11-06-2017, 07:19 AM
#4
Tech Contributor
good points on possibly causes, also the gland nut could be chewed up from a pipe wrench or on backward, it works like an oil slinger against the retainer surface. Sealer should be used on the retainer bolts.
11-06-2017, 08:20 AM
#5
Burning Brakes
Or is it leaking from the countershaft bore in the front of the case? It's concealed by the bellhousing when installed and a leak between the transmission and bellhousing can't really be distinguished as to which is the culprit without moving the transmission back. Although once moved back he should have been able to determine which it is. If it's leaking inside the bellhousing and coming out at the inspection plate then yeah, it's something up with the bearing retainer.
There's a gasket between the bearing retainer and case to keep any lube that gets past the bearing and slinger (if one is present) and allow the drainback at the bottom to function. But nothing in terms of a tight seal from the bearing forward as Bill said.
There's a gasket between the bearing retainer and case to keep any lube that gets past the bearing and slinger (if one is present) and allow the drainback at the bottom to function. But nothing in terms of a tight seal from the bearing forward as Bill said.
11-06-2017, 08:24 AM
#6
Race Director
More good tips - the washer face of the gland nut should be forward towards the engine. And the retainer bolt holes in the case are drilled through.
11-06-2017, 08:28 AM
#7
Le Mans Master
Muncie's use two different thickness gaskets for the front bearing retainer. If you use the thin one when a thick one is needed, it will leak like crazy. My bet is it has the wrong gasket.
11-06-2017, 02:09 PM
#8
Melting Slicks
Thread Starter
Trans is not out. It is dripping down from what looks to be the bearing retainer area and forms a drip/leak at the bottom front of the trans. Assume it is leaking from the bearing retainer again. Will I be able to tell if I pull the inspection cover?
11-06-2017, 03:04 PM
#9
Race Director
It's just pretty hard to believe it's the bearing retainer as it has a weep hole in the bottom of the tube section that would dump any fluid into the back of the bellhousing (unless it's installed upside down). About the only way the bearing retainer can leak fluid that comes down the front of the transmission is if the gasket is completely gone between it and trans case or something. Even if lube is coming out a bolt hole under the bolt head - it would probably run down the inside of the bell housing.
Are you in a position to get under the car, unbolt the transmission and transmission mount, install a couple dowels in the lower transmission to bellhousing mount holes, support the engine with a jack under the bellhousing and slide the transmission back about 1/2 to 3/4 inch. I don't think you will even have to touch the driveshaft, shifter or clutch linkage to do that. You should be able to see with a bright light if the lube trail is coming from the countershaft hole or up higher at the bearing retainer.
Are you in a position to get under the car, unbolt the transmission and transmission mount, install a couple dowels in the lower transmission to bellhousing mount holes, support the engine with a jack under the bellhousing and slide the transmission back about 1/2 to 3/4 inch. I don't think you will even have to touch the driveshaft, shifter or clutch linkage to do that. You should be able to see with a bright light if the lube trail is coming from the countershaft hole or up higher at the bearing retainer.
Last edited by DansYellow66; 11-06-2017 at 03:05 PM.
11-06-2017, 04:36 PM
#10
Le Mans Master
I would hope the guy that rebuilt this trans. is smart enough to know to check it and use the correct gasket. If he didn't, I would be suspect of everything he did to that transmission.
11-06-2017, 09:28 PM
#11
Former Vendor
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
Are you sure the main shaft is not leaking instead of the bearing retainer? It's common for this shaft to wear in the main case and leak. It's not something I like to do because I like to fix these issues before we install.... But as a precautionary measure we'll put silicone black RTV around the end of the shaft before we install the tranny.
If the shaft is not solid to the case it will leak oil (and give the appearance that the leak is from the front retainer) this should be checked before the rebuild. If it's loose then the case needs to be re-bushed before the shaft is inserted into the trans. While it's an old rodder fix, and not the correct fix.... putting silicone sealer on the outer area of the shaft may keep you from leaking. Once you bolt the tranny down to the bellhousing the sealant is pressed against the bellhousing will seal up...
It won't change the clearance gap that is causing the leak and it won't solve the issue over the long run.... but it will work for a temp fix..
IMHO,
Willcox
If the shaft is not solid to the case it will leak oil (and give the appearance that the leak is from the front retainer) this should be checked before the rebuild. If it's loose then the case needs to be re-bushed before the shaft is inserted into the trans. While it's an old rodder fix, and not the correct fix.... putting silicone sealer on the outer area of the shaft may keep you from leaking. Once you bolt the tranny down to the bellhousing the sealant is pressed against the bellhousing will seal up...
It won't change the clearance gap that is causing the leak and it won't solve the issue over the long run.... but it will work for a temp fix..
IMHO,
Willcox
Last edited by Willcox Corvette; 11-06-2017 at 10:03 PM.
11-06-2017, 09:34 PM
#12
Team Owner
Dollars to doughnuts its the cross shaft. A common Muncie problem. Short of putting a bushing in the hole or buying a new case the RTV fix is the stopgap. It can last for years on lightly driven cars.
11-06-2017, 09:40 PM
#13
Le Mans Master
Sorry. If you read the original post, the case has been bushed. I'm still betting that the wrong gasket was used on the retainer. How many Muncies have you rebuilt?
Last edited by 1snake; 11-06-2017 at 09:41 PM.
11-06-2017, 09:46 PM
#14
Melting Slicks
Thread Starter
I had it re-bushed when rebuilt so I would't have any issues but I will check everything at this point.
11-06-2017, 09:47 PM
#15
Melting Slicks
Thread Starter
The guy that built this trans has been doing them for 30 years. Maybe it is time for him to do something else!
11-06-2017, 09:49 PM
#16
Team Owner
Based on the leaky rebuild I wouldn't count on any bushing job by the same shop.
We gonna go with the 40 years experience again...seems to be the stock answer ?
Last edited by Frankie the Fink; 11-06-2017 at 09:53 PM.
11-06-2017, 09:53 PM
#17
Le Mans Master
, I'm sure you know that there are two different thickness retainer gaskets and using the wrong one will cause the exact problem the OP has. 
11-06-2017, 09:55 PM
#18
Melting Slicks
Thread Starter
The rebuilder sent the case out to a machine shop that does the case bushing so I think that part may be ok.
11-06-2017, 10:01 PM
#19
Team Owner
Easy enough to check out....it was a suggestion...
I've had the situation occur on two of my Muncies...
Hope you find the issue and its an easy fix
11-06-2017, 10:02 PM
#20
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St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15
I've been doing this since 1974... so I'm kind of past the 40 yr barrier and I'm not sure if this counts or not... but my money is on the cross shaft as well. They will make you think the front cover is leaking, but there is no seal in the front cover and the only reason it would leak would be a tranny over-filled.
I've seen so many tranny shops build transmissions and even after re-bushed.. they leak...
If we pull a tranny for a clutch job, or for any other reason, we silicone the shaft as a preventative measure.... I don't like it but I also don't like doing work twice because of a tranny shop mistake or the shaft leaked.
Willcox
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