LS65Speed Posted April 1, 2015 Share Posted April 1, 2015 Hello All I am working on a 4 Speed equipped M.C. and am wondering if someone here can answer a couple of questions? #1 What is the length of a drive shaft for a Muncie equipped M.C. when measured from U-Joint center Line to U Joint centerline? #2 Are the Th400 shafts and Th350 shafts from Monte Carlos the same length as the Muncie shafts from Monte Carlos? #3 Are M.C driveshafts (particularly the Muncie equipped M.C. ) shafts different length(s) than the Muncie equipped Chevelle shafts? Thanks for the help! Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 1, 2015 Share Posted April 1, 2015 a Chevelle shaft and Monte shaft should be the same length, from the firewall back they are the same dimensions I can measure my 4 speed shaft tomorrow night Quote Link to comment Share on other sites More sharing options...
LS65Speed Posted April 1, 2015 Author Share Posted April 1, 2015 That would be great...is the car a stick or an automatic? Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 1, 2015 Share Posted April 1, 2015 I can measure my 4 speed shaft tomorrow night Quote Link to comment Share on other sites More sharing options...
LS65Speed Posted April 1, 2015 Author Share Posted April 1, 2015 YES YES YES! That is exactly what I need. I think the shaft in this car is TOO short. I see in your profile that you work in aviation support work. I used to work as a propulsion test engineer at PWA. Moved on to other things later on but never lost my interest in things that fly. Thanks again! Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 1, 2015 Share Posted April 1, 2015 I run the ground equipment dept, or should say I am the ground equipment dept and work line service for our FBO, and maintain our fuel farm too why do you think it's too short? can you slide it forward enough to install/remove it with the weight on the axle? Quote Link to comment Share on other sites More sharing options...
Murphy Posted April 1, 2015 Share Posted April 1, 2015 I will throw this out there, when I did my TH350 conversion to a Muncie M20, I'm using the same driveshaft. I had the large round vibration dampner removed (mounted at the front of the driveshaft) and then had all the weights removed and then rebalance. Unfortunatly I don't have a photo of the driveshaft prior to removing the dampner but I'm sure someone else does. Also, I'm certain that Sam is correct that the Chevelle and MC shafts are the same, I was told they're the same on multiple occasions........... I found a pic of my original driveshaft, from a SBC350 with a TH350 trans........... Quote Link to comment Share on other sites More sharing options...
ripleydale Posted April 1, 2015 Share Posted April 1, 2015 I'm with Murphy. When I did a conversion from a Turbo 350 to a Muncie about 30 years ago, I'm sure I used the same drive shaft with no changes. Quote Link to comment Share on other sites More sharing options...
LS65Speed Posted April 1, 2015 Author Share Posted April 1, 2015 For Murphy Interesting PIC I have two cars so I will try to keep this clear. One car is a 1972. I have had the car since early 1973 and it never had that balancer on the shaft. It was originally a 350 CI TH350 car. I have seen those balancers on GM products but it seems to me they were on the "land yacht" models like the big station wagons and possibly Caddies / Pontiac "B" body. Never saw that balancer on a Chevelle or an MC. For Sam I think it is too short because the U-Joint in the front Yoke is a fair distance back from the trans. Before we get carried away some background you need. The car has a Richmond 5 Speed which is exactly the same bell housing to tail shaft length as a Muncie. I say exactly meaning to within small fractions of an inch. It is not dead nuts EXACT but it is VERY VERY close. I said Muncie earlier to avoid a bunch of discussion about "maybe it is the Richmond..........." from folks who are unaware of the lengths of a Richmond and a Muncie. Now having said that and made my confession. The Richmond uses a TH 400 yoke and the TH400 yoke comes in at least three lengths. One is quite long, visibly longer than the other two versions even when viewed from "all the way across the room". That long yoke is in the Richmond now and it extends a fair distance down the splines on the output shaft. I once compared to to a short TH 400 yoke as far as penetration into the tail housing. It goes plenty deep enough even considering the fact that I think the drive shaft itself is too short. The extra length of that long yoke allows the short drive shaft to work but the penalty for all this is that there is a gap between the end of the tail housing and the drive shaft. This is what makes me think the shaft in this car is of another origin other than being from a Muncie equipped M.C. The front universal joint is a fair distance back from what I have seen on factory cars (stick or automatic equipped) . I am wondering if that yoke and the u-Joint spinning around about a inch further behind the tail housing than normal might induce vibration. Remember the splines of that long yoke extend plenty far into the tail housing. I have already checked that. This is why I need your center to center distance of a known 4 Speed drive shaft to determine if the drive shaft in my car is too short. If it is to short I will get a longer shaft (proper length for a Muncie equipped M.C.) and use a shorter yoke. I have a short one right here in my storage area. First however I need to know the length of a stock 4 Speed shaft. The drive shaft in the car now works. It might be vibrating a bit but that might just be a need for a rebalance OR it might be because that U-Joint is a further distance back from the tail housing than normal. If the drive shaft in the car is indeed too short I will find and rebalance a correct length shaft rather than fool with the shaft that is in the car now. Hope this is not too long and boring and I certainly hope it clarifies why I am digging into this issue. Quote Link to comment Share on other sites More sharing options...
John S Posted April 2, 2015 Share Posted April 2, 2015 I have a 1970 Monte with 350 and M20 Muncie 4 spd. Driveshaft length from centerline of front u-joint to centerline of rear u-joint is 56 inches. John S Quote Link to comment Share on other sites More sharing options...
LS65Speed Posted April 2, 2015 Author Share Posted April 2, 2015 I have a 1970 Monte with 350 and M20 Muncie 4 spd. Driveshaft length from centerline of front u-joint to centerline of rear u-joint is 56 inches. John S Thank you John !!!! I am in Roswell GA, we should meet some time! I have some parts to sell and I am always looking for parts like the 4 Speed driveshaft. I will measure tomorrow and report back. Can you help me find some sources like a 3.08 12 bolt and some of this miscellaneous small items that are hard to find? M.C. specific parts are getting harder and harder to find so I am always looking for folks in this "section" of the car hobby. Quote Link to comment Share on other sites More sharing options...
John S Posted April 3, 2015 Share Posted April 3, 2015 I'm open to that, not that far away. Don't have many parts sources other than the places I hear of from others on the forum. Hope your driveshaft works. John S Quote Link to comment Share on other sites More sharing options...
LS65Speed Posted April 3, 2015 Author Share Posted April 3, 2015 I'm open to that, not that far away. Don't have many parts sources other than the places I hear of from others on the forum. Hope your driveshaft works. John S Maybe one of those shows at Summit? We will see. Honey Do list got in the way of measuring the drive shaft on Thursday. Honey Do got in the way of doing anything BUT the Honey Do list now that I look back at Thursday. I was beat by the time we finished dinner and not about to take the D-shat out. Going to get the numbers on that length today and report back later. Ray Quote Link to comment Share on other sites More sharing options...
LS65Speed Posted April 3, 2015 Author Share Posted April 3, 2015 John Went out and measured it with it still in the car. 54 Inches. Chevelle shaft? Maybe. Hmmmm? I wonder what the effect of this is on driveline vibes? The car doesn't shake or shudder violently but there are some harmonics at certain speeds. I considered balancing that shaft some time ago but now I am glad I looked into the length issue before I spent money. The yoke in there now extends 3 inches out of the trans before the flange for the U-Joint flares out. Ya wonder how people get the combinations of parts they get. This setup works, I have driven the car several thousand miles but I am not one to beat on my machinery so I guess it will work the way it is at least in normal use. I think this is another thing to add to the list, find a 56 inch tube. I am thinking that short yoke I have on the shelf with the 56 inch shaft is the right way to do this. Anyone have a 56 inch tube anywhere? See what I mean about finding parts? There is a big yard south of Charlotte that allows you to walk and find parts. Not sure if you can remove stuff yourself but they do allow you to walk around from what I have heard. Might need to research who they are and plan a trip. Quote Link to comment Share on other sites More sharing options...
John S Posted April 3, 2015 Share Posted April 3, 2015 I have put my Monte in a couple of Summit shows. Quote Link to comment Share on other sites More sharing options...
LS65Speed Posted April 3, 2015 Author Share Posted April 3, 2015 I have put my Monte in a couple of Summit shows. I have put my Monte in a couple of Summit shows. Ok maybe we can work something out for the ned Summit show? Any thoughts on a source for a d-shaft? Quote Link to comment Share on other sites More sharing options...
LS65Speed Posted April 3, 2015 Author Share Posted April 3, 2015 John Looked at your profile and your pics. The cars are almost TWINS!!!! When looked at from the outside they are the same triple black with Rally wheels. Different mechanicals but thy would look good parked side by side! Ray Quote Link to comment Share on other sites More sharing options...
John S Posted April 4, 2015 Share Posted April 4, 2015 Ray There is a place in Griffin, old car yard, Johnson Auto Salvage that will allow you to walk out in their yard for $2. I was there once did not see any first gens but saw a mid 70's. Was looking for tilt column at one time I got in contact with Desert Valley Auto Parts in AZ once. They had one but for a column shift. Maybe find a longer one and cut it down? Also Mark at Driveline Service of Atlanta in Forest Park may be able to help you. They rebuilt my rear end for the Monte. Hard to find 45 yr. old parts. Most went to crusher. Maybe ebay? John S Quote Link to comment Share on other sites More sharing options...
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