The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > Heavy Haulers

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 06-08-2017, 10:07 AM   #1
sweetk30
Registered User
 
sweetk30's Avatar
 
Join Date: May 2012
Location: horseheads,ny rust belt
Posts: 2,794
2 speed rear ?

what is the split inside for the ratio ?

and can you run a 2 speed rear in a auto truck ?
__________________
77-k30lb BIG truck build .
87-k30lb budget beater build .
85-k30lb the plow machine build .
85-c10sb summer fun toy .
-----------------------------
HOLLEY SNIPER efi = worst case of p.i.t.a i ever had .

EDELBROCK pro flo 4 = best deal going so far . love my setup works great.
sweetk30 is offline   Reply With Quote
Old 06-08-2017, 12:59 PM   #2
b454rat
Senior Member
 
Join Date: May 2004
Location: Binghamton, NY
Posts: 3,454
Re: 2 speed rear ?

I don't think you can, since you need to let off to shift, same as driving a stick. Think it would be a pain too lol...
__________________
2000 GMC CCSB 454/4L80 6” lift SAS
1999 Chevy CCSB 454/NV4500 6” lift
1999 GMC Yukon 350/4L60 4" SAS
b454rat is offline   Reply With Quote
Old 06-08-2017, 10:21 PM   #3
rkn463
Registered User
 
rkn463's Avatar
 
Join Date: Jan 2012
Location: Iredell, Texas
Posts: 582
Re: 2 speed rear ?

Quote:
Originally Posted by sweetk30 View Post
what is the split inside for the ratio ?
I'm not sure I understand the question. But I'll take a stab at what I think...

If you check out the first post in this link: http://67-72chevytrucks.com/vboard/s...d.php?t=729084 you will see a graphic showing gear ratios. Basically if you divide the "big number" by the "little number" on any of them it works out to about 1.35, that would be the ratio difference that the planetary gears are adding. The tooth count on that same graphic shows the the ring and pinion defines the little number. This means that the high gear is the actual ratio and the planetary gears supply a lower gear (bigger number). I don't think I articulated that very well, I hope it makes sense. One last bit of info, I don't know how many different types of two speed diffs they may have offered.

Quote:
Originally Posted by sweetk30 View Post
and can you run a 2 speed rear in a auto truck ?
Having driven a two speed rear I'm pretty sure that if you started off in low range and got up to speed you could hit the switch for high range and then let off the gas and then right back on and it would shift just like you can do with the manual. However unless you are trying to get something really heavy moving you wouldn't need it. The downshift could be done but would be a challenge unless you came to a stop and shifted the trans to neutral before shifting the rear.

-Richard
__________________
I may have too many Chevys... Is that possible?
68 c50 pickup build: http://67-72chevytrucks.com/vboard/s...d.php?t=704713
rkn463 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 06:00 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com