694spd
Well-Known Member
I reinstalled my drive shaft and it appears that it's a little short. I had the slip yoke replaced when I had it balanced. This is the original shaft to the car.
Is my drive shaft too short?
- Thread starter 694spd
- Start date
-
rustycowll69
Well-Known Member
it looks too short to me. But I've seen the results of having a too short driveshaft saw off the back half of a transmission, twice. TF Patty made a mobile out of some of the more recognizable shards of the trans and driveshaft left. It also had a sign integrated with it that asked, "are you sure your driveshaft is long enough?"
440DART1970
1970 Dart 446ci Swinger
Follow
Looks are one thing, how far that yoke is in the trans tail is the other.
694spd
Well-Known Member
I just came up with this before picture taken when I first bought the car. Same shaft, different slip yoke, but I have no reason to believe they were any differences between the two. The one difference is that I changed the leaf springs out with a pair that I bought at a swap meet. They were a new set that the seller bought from Mancini's for his A-body. I'm now thinking that the front segments are not 20" long. Maybe more like 21-22" long?
Here also is a pic of the new leaf springs. I could never find the part number stamped on it listed anywhere.
Here also is a pic of the new leaf springs. I could never find the part number stamped on it listed anywhere.
Treblig
Well-Known Member
the before pic has a much longer rubber boot, the new pic has a short boot that exposes more yoke??
Treblig
Treblig
d55dave
Well-Known Member
You cannot tell simply by the picture as you have no idea how long that new slip yoke is. The only way to know is to unbolt the rear u joint and push the shaft all the way forward. With the car weight on the rear suspension (not with the differential hanging on the springs.......is it hanging in the pic?) The shaft should slide forward 1", or have 1" to slide back to seat the u joint.
Don't skip over good advice. Read post#5. Only 4 fasteners hold the drive shaft in. That's less than five minutes worth of work to determine how much the slip yoke engages the splines on the output shaft. THAT'S what's important. Not how much of the slip yoke is sticking out.
That said, the locating pin on the new springs does look to be in a different location. Put a tape measure on it.
That said, the locating pin on the new springs does look to be in a different location. Put a tape measure on it.
Not that it would make much of a difference with your driveshaft question but according to the part numbers on those leaf springs you picked up, the right side of your car will sit higher than the other since the arch on the right side is higher (different leaf spring placement compared to the left side).
694spd
Well-Known Member
When the picture was taken I had the jack stands under the axle so the weight was on the suspension. The car is back on the tires for now as I'm doing work under the hood for now. I will get it back up on the stands in a couple of days to check how much slip yoke engagement I have on the trans output shaft. I do recall that the output shaft stuck out just a little past the end of the tail shaft seal boot.
The springs have more arch than the stock one changing the rear end height pulling on the shaft rearwards a litte.
Also when installing the springs it is possible to have the rear end slightly moved backwards by the installer. It is a small amount of play in the locating pin and hole.
Small things keep adding up.
Even though the yoke is for the transmission, I have gotten different length yokes.
Again, see how much is actually inside the transmission!
694spd
Well-Known Member
I still have the original slip yoke that was replaced. My next move when I get the car back on the stands will be to pull the shaft back out and compare the two slip yokes.
I tracked the leaf springs part number to a 2005 MP catalog. "P4510268-9" are listed as A-Body XHD OEM Style Springs. Not much else info is given. I have to believe that the front segment is 20" but I will try to get a measurement when I pull the shaft back out.
I tracked the leaf springs part number to a 2005 MP catalog. "P4510268-9" are listed as A-Body XHD OEM Style Springs. Not much else info is given. I have to believe that the front segment is 20" but I will try to get a measurement when I pull the shaft back out.
Front segment is 20" on those.
jos51700
Green Bearing thread connoisseur
Call your friendly local drive shaft shop. When they made a new shaft for my dart, they had about two measurements that were simple as pie and they knew where it needed to be.
And yes, that absolutely is the result of taller springs
And yes, that absolutely is the result of taller springs
rustycowll69
Well-Known Member
this question reminds me of my wife asking, "do these pants make my butt look big?". If you have to ask, you kinda already know the answer, hahaha
dtmlevatan
Long time lurker
That's what she said ...lol
I heard my driveshafts a little to short all of my life! I can't help it if I'm hung like a light switch! But on a serious note. It appear to be about a inch short. But it depends how much of your yoke splines are in gauged with your output shaft? I say splines because the first inch or so of the yoke does not have splines. Remember it is a slip yoke because it is constantly changing with the suspension motion, acceleration, braking and hit pot holes. You damn sure do not want that driveshaft to fall out while you are in motion!
Mine looks similar. I thought was short, but inserted it all the way and pulled back an inch and measured. This is what I got from the drive shaft place. There was 1-1/8" of tail shaft hanging out also.
Last edited:
TrailBeast
AKA Mopars4us on Youtube
The amount of spline engagement isn't the only consideration.
How much of the yoke is in the tail shaft bushing is a pretty big deal, but on the OP's pic it looks like it's at a max acceptable distance if that is a standard length yoke.
I have also seen shorter ones like Rumble mentioned.
How much of the yoke is in the tail shaft bushing is a pretty big deal, but on the OP's pic it looks like it's at a max acceptable distance if that is a standard length yoke.
I have also seen shorter ones like Rumble mentioned.
With new springs, and a stock shaft its likely nothing to worry about.
rustycowll69
Well-Known Member
your top picture is misleading in comparison with his pic, because you have the short, flat rear seal, and OP has the extended "double" seal.
-
