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| | | | Joined: May 2020 Posts: 12 'Bolter | | 'Bolter Joined: May 2020 Posts: 12 | Hello all,
Eventually I would like to diesel swap my '66 C60H (doesn't have the original motor in it anyway), which is going to require different gearing. Right now I have the very tall 7.17 ratio gears (2-speed, other ratio is 9.something) according to my tag in the cab.
This is an air brake, cast spoke truck, with what I believe is the 17,000# or 17,800# Eaton axle (how to identify?) Am I better off getting a different axle? Unfortunately I just spent some good money putting new brake parts on this one, but if a new axle is my best option, so be it. I'd love to keep the 2-speed set up for originality's sake if I can.
Thanks! | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Check with rear end rebuilders. There are lots of modern trucks with Dayton wheels air and diesel ratios, so look around at dead box trucks, etc. before you spend money on your rear end.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: Jan 2008 Posts: 4,961 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,961 | Two speeds are getting hard to find for mid range trucks. Most of them use automatics. And spoke are very rare also. The rear rear of a tandem will work, but then you will need a 10 speed transmission. Single speed rear rear are every where and go for little more than scrap. In fact with today's scrap price, I an going to start hauling off. https://photos.app.goo.gl/NfrhhzxXcq7amnSV6 | | | | | Joined: Feb 2019 Posts: 87 'Bolter | | 'Bolter Joined: Feb 2019 Posts: 87 | Once you identify what rear end you have you can use this site to find gears. www.heavytruckparts.net type in your axle info. If it's not listed a simple phone call to them will probably find exactly what you're looking for. If it's a 3rd member like my 17221 rear is you maybe better off finding the whole 3rd member and swapping it. Pulling one of your axles out and verifying the spline count is something you'll have to do just to be sure. For my axle code there are two different splines 16 and the other 30-something. I have the 16 spline.
Last edited by Pvmt-Pndr; 04/11/2022 12:22 PM.
| | | | | Joined: Apr 2003 Posts: 942 'Bolter | | 'Bolter Joined: Apr 2003 Posts: 942 | Sounds like an interesting truck. Post some pictures if you can.
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