Early Ford V-8 Club Forum

EFV-8 Club Forum / General Ford Discussion / differential

Reply to Discussion | New Discussion << previous || next >>

Posted By Discussion Topic: differential -- page: 1 2     fparsons 03-25-2011 @ 9:04 AM reply profile send p.m. Member Posts: 11 Joined: Oct 2009 want to replace my 4:11 rear end gear set with a 3:78 gear set ...need to know if anyone has input on how to adapt the 10 spline drive shaft to the 3:78 6 spline drive shaft .... supereal 03-25-2011 @ 10:25 AM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 There are couplers available to adapt the 6x10 spline parts. You will find them on page 64 of the C&G catalog. www.cgfordparts.com 37RAGTOPMAN 03-25-2011 @ 11:45 AM reply profile send p.m. Senior Posts: 1961 Joined: Oct 2009 I think you have the hollow drive shaft and are going to change from 10 spline to 6 spline, this requires welding of the adapter,you should have a drive shaft shop do this for you,or a machinest with a lathe and welding experience, I was lucky a friend of mine had a solid 6 spline drive shaft with the correct torque tube to go with it,I did just not want to have welded adapter in the drive train, I went with the 354-1, and I love it,,,!! faster,better fuel milage etc, less engine-fan noise, this is my 3 cents worth,37RAGTOPMAN MOXIE 03-25-2011 @ 4:25 PM reply profile send p.m. New Member Posts: 102 Joined: Oct 2009 Just replace the 4:11 in my 35 coupe with 3:54. Not sure why you are going with 3:78 but to each their own. It was a job finding a good driveshop that would make the changes necessary to the end of the drive shaft for the new 6 spline female coupler but I did. It meant staying there all day over seeing him but he got it done. He was wanting to take short cuts in doing the job. That's why I stayed. If you take it to a regular machine shop they will not do it. When they hear the word driveshaft they have a fear of getting sue if the shaft were to break or something like that. Again we have a guy that does nothing but drive shafts so he did it for me. The 3:54 gives you plenty of speed and very little hurt to the pull strength. In fact, except for the extra speed, I can tell no difference in driving. That's why if you are going to do it might as well go all the way and get the most speed at the lowest engine RPM you can find. And that would be 3:54. ford38v8 03-25-2011 @ 7:18 PM reply profile send p.m. Senior Posts: 2762 Joined: Oct 2009 Moxie, as you say, to each their own. I pulled out a perfectly good 4.44 and replaced it with a 3.78. The 4.44 is the best you can get if all you do is drive in parades or drive up hill backwards in San Francisco. Your 3.54 is perfect for Kansas and Nebraska, but not if you drive out west. My 3.78 is a great compromise between high speed driving and mountain ranges. On the one hand, I can drive all day long at 75 mph, or I can pull the Sierras/Cascades/Rockies in high gear. The driving backwards up hills in SF? I had to do that while doing multiple takes in a movie. I was to come down a hill just in front of a cable car coming out of the fog at night. About a dozen takes, and the whole scene wound up on the cutting room floor anyway. It was fun to see what happens behind the cameras, and to meet the actors, but I sure wouldn't give up my day job. Alan supereal 03-25-2011 @ 7:54 PM reply profile send p.m. Senior Posts: 6819 Joined: Oct 2009 We do lots of driveshafts of all kinds in our machine shop. It does require the correct equipment and the skill plus experience to do it properly. We do the fabrication and welding in a long bed lathe, and weld with a special technique to avoid warping the pieces. There are many places that claim to be competent, but none that actually perform this work successfully, that I know of, that fear legal repercussions. If anyone tells you that, it is likely they just don't know how to do it. JM 03-26-2011 @ 8:31 PM reply profile send p.m. Senior Posts: 822 Joined: Oct 2009 To answer your question more information is required from you. What year car or differential are you talking about? Which type drive shaft do you have? Closed vs. open? Solid vs. hollow inner shaft. Also, on your 3.78 gear se t, does the pinion gear have 6 or 10 splines? JM fparsons 03-28-2011 @ 11:14 AM reply profile send p.m. Member Posts: 11 Joined: Oct 2009 Thanks for the timely advice ...I have a 3:78 so thought I would give it a shot ...seems the 3:54 would be great, but since I have the 3:78 in good shape I will use it until I come across a 3:54 in my area ... fparsons 03-28-2011 @ 11:15 AM reply profile send p.m. Member Posts: 11 Joined: Oct 2009 Thanks ... fparsons 03-28-2011 @ 11:16 AM reply profile send p.m. Member Posts: 11 Joined: Oct 2009 3:54 would be my first choice, but I have a good 3:78 so will go with it ...thanks for the advice ....

<< previous || next >>

PAGE: 1 2

NOTE: YOU MUST BE A REGISTERED USER AND BE LOGGED IN TO POST (and reply to) messages in this forum. If you are a first time user, please click the CREATE A NEW ACCOUNT in the masthead above to register and Log In. After that, all you do is LOG IN to enjoy using this site.

DISCLAIMER: The V-8 Club does no independent testing of any of the opinions, thoughts or suggestions presented in the website on the Forum, in the Tech Tips section, or any section. A reader should consider the website to be a forum wherein differing solutions to a particular set of circumstances may be discussed. Ultimately, the selection of an item for an individual's vehicle must be based upon the independent study of the vehicle owner in consultation with people in the hobby and restoration experts.

EFV-8 Club Forum Home | Back to Home Page | Contact the Webmaster

Copyright © 2009 - EFV-8.org
Powered by < CF FORUM > v.2.1