6 spline or 10 spline rear end

F

Ford1933

Senior Member
Is the 37 Ford rear end a 6 spline or a 10 spline. I am looking at buying an open drive shaft adapter from Speedway.

Thanks
Mick
 
This won't help much, but it could be either. Some '37's were built with 6 spline pinions, but most were built with 10 spline. Also, there is no way of telling if someone changed it from the original unless you know for a fact that it's never been changed.
 
my understanding is it could be either,and to be safe you need to look. Others can be more precise with when the change occurred.
 
Seems like the 4.11's are 10-spline with a tapered/tubular driveshaft, and the 3.78's are 6-spline with a straight/solid driveshaft with center bearing and a
grease fitting on the torque tube? This subject was discussed at great length on the "old" Ford Barn, which is "out there somewhere"?

As per later posts below, the above post is incorrect/incomplete in that a 1937 with 3.78 could be either 6-spline or 10-spline, although it is apparently true that a 6-spline will have the solid driveshaft with center bearing and therefore would
also have a lube fitting for the center bearing on the torque tube. IF no lube fitting, one could "assume" that it is a 10-spline with the hollow driveshaft...
except that assuming is probably not a good idea...
 
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Richard (EV8G) said:
Seems like the 4.11's are 10-spline with a tapered/tubular driveshaft, and the 3.78's are 6-spline with a straight/solid driveshaft with center bearing and a
grease fitting on the torque tube? This subject was discussed at great length on the "old" Ford Barn, which is "out there somewhere"?
Click to expand...

Richard, 3.78's came in 10 spline as well as 6, and 3.54's also came in 6/10 spline. I've only found 4.11's in 10 spline but as sure as I'm sitting here typing this, someone probably has an original set of 4.11's with 6 spline :confused:. JM
 
i think its pretty safe to say any 6 splined one will have a centre bearing and a grese fitting on the torque tube given the solid driveshaft.
 
Also, get you open drive kit from these guys, great guys, excellent product, made in the USA.

www.hotrodworks.com

Speedway used to buy these kits from hotrodworks, then they cut them out of the loop and started knocking them off in china.:mad:
 
JM 35 Sedan said:
Richard, 3.78's came in 10 spline as well as 6, and 3.54's also came in 6/10 spline. I've only found 4.11's in 10 spline but as sure as I'm sitting here typing this, someone probably has an original set of 4.11's with 6 spline :confused:. JM
Click to expand...

You are correct that there are/were 3.78's with 10-spline (part number 68-4209-B) and the hollow driveshaft. There are/were also 3.78's with 6-spline (part number 68-4209-A and the solid driveshaft. There is also listed #48-4209-D with 4.11 ratio and 6-spline, but (even though it has a 48 number prefix) which is specified for 38-48 and so would not have been available for 1937,
except that nothing is 100% certain, as you say. #48-4209-E with
3.54 ratio is also listed with 6-spline, again for 38-48, same story.

IF a 1937 (confirmed to be original equipment-but who knows?) rear has a lube fitting on the torque tube, it would/should/probably be a 6-spline with the solid driveshaft and center bearing, and most likely a 3.78 ratio. As the man said, probably need to take it apart to be
sure...
 
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