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| | | | Joined: Nov 2007 Posts: 39 'Bolter | | 'Bolter Joined: Nov 2007 Posts: 39 | Has anyone ever installed the 3.55 ring and pinion in a late thirties axle? I understand it's necessary to use a '40 to '53 carrier - are there any other concerns that anyone knows of? I've heard the the torque tube shaft may be a different length, but I don't know if that will be a factor.
Rob | | | | | Joined: Jan 2000 Posts: 2,074 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 2,074 | Rob-Roy, Great looking little truck btw. I would think Mr. Patrick himself would have ALL the answers for you, may try to give him a call. And tell him Jim from Turlock CA sent you.
Sorry I've never installed that piece but hang on here and I'm sure the bolters will be giving you good info.
Regards
Jim
| | | | | Joined: Sep 2001 Posts: 29,270 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,270 |
Follow Jim's advice.
Patrick is a great Guy. If you have not bought the parts yet, tell Patrick that you were hoping for the 1938 Stovebolter discount.
| | | | | Joined: Aug 2005 Posts: 278 'Bolter | | 'Bolter Joined: Aug 2005 Posts: 278 | I looked at doing the same thing with my 39. I spoke to Patrick about it. He is indeed a great guy and believed it could be done but appeared uncertain about the details. I had a 41 differential available and started comparing it with my 39 and found at least two issues.
1. Axle housing has the differential opening shifted ½” to the left on the 41. This is reflected in the different lengths of the 41 axles (the left is shorter than the right). On the 39, they are the same length. If you used the 41 pumpkin in the 39, your torque tube would be off center by ½”.
2. Propeller shaft and torque tube were different lengths. You would need to modify toque tube and propeller shaft and use different u-joints.
Given these and other difficulties, I have for now, not attempted the conversion. It would seem to make more sense to swap in a complete modified 40-46 differential. This would still require modification of the torque tube/propeller shaft. I could not easily do this with the 41 I had. It is from a ½ ton and my 39 is a ¾ ton. They have different axle housing diameter and spring placement. I would also like to hear from anyone who succeeded in the conversion and the issues they addressed. There are probably other things that I have over looked.
Last edited by Donf; 07/11/2009 4:06 PM.
| | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | 1940 was the first year in trucks to use a Hypoid rear end. Patrick's gear set is a Hypoid design and will only work in 40-54 diffs.
FYI, Hypoid means the pinion makes contact below the center line of the ring gear.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Jan 2000 Posts: 2,074 'Bolter | | 'Bolter Joined: Jan 2000 Posts: 2,074 | I ran a complete 54 passenger rear end 3:55s for a while in my 46, needs a few mods but not difficult.
If you need 6 lugs, just stick the 54 torque tube into a '48 and back passenger car axle.
Last edited by JiMerit; 07/11/2009 11:55 PM.
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