shawn Posted July 18, 2013 Share Posted July 18, 2013 well i put the spring-over that was in my '86 long box into the '91 shortbox and there seems to be a new drive-line vibration. its not bad, but i definitely feel something is there and it shows abit in the rear view mirror. both truck are 5 speeds and there is no t-case drop. a friend suggested shims and low and behold another friend has a new set to spare. my question is does anyone have experience of this kind of thing and do you, dear c.c. member, think it will solve my vibe. all input greatly appreciated. Link to comment Share on other sites More sharing options...
HOrnbrod Posted July 18, 2013 Share Posted July 18, 2013 Axle shims are used to correct excess pinion operating angle caused after a lift. Go to the Tom Woods site, get and angle finder at Lowes or elsewhere, and measure the angle. No way anyone can recommend what degree shims you need until we know that. http://4xshaft.com/techinfo.asp Link to comment Share on other sites More sharing options...
Biotex Posted July 18, 2013 Share Posted July 18, 2013 If you do go with shims, use only steel ones and IMO it is best to tack weld them in a couple of places. They have been know to get loose, crack and fall out. It is well documented. Link to comment Share on other sites More sharing options...
shawn Posted July 18, 2013 Author Share Posted July 18, 2013 uuuuugh. i picked the wrong day to fail geometry :( with a straight shaft ( no double cardan), i don't see how any of the angles would have changed. only difference is the t-case sits about 5.5 " higher than it was. i've read alot but at this point I'm not even sure if the housing should be rotated backward or forward ....... ive also seen posts that suggest 1 degree per inch of lift. from what i gather, in this set-up the pinions should be parallel regardless of the hieght difference. Link to comment Share on other sites More sharing options...
shawn Posted July 18, 2013 Author Share Posted July 18, 2013 i should have added in my original post that i do have the chevy drop shackles on. they are the 2 hole kind and are set on the lower-amount -of -lift setting, so in that configuration they are about 1" longer than stock. Link to comment Share on other sites More sharing options...
Biotex Posted July 18, 2013 Share Posted July 18, 2013 The 1/2" lift shackles will raise the pinion up. Could be your vibration. Link to comment Share on other sites More sharing options...
shawn Posted September 22, 2013 Author Share Posted September 22, 2013 in the end a 1.5" t-case drop solved pretty-much all of it. the slip yoke wasn't in far enough. the drop brought it in quite abit but could probably use an inch longer driveshaft too. (or thereabouts). Link to comment Share on other sites More sharing options...
Eagle Posted September 22, 2013 Share Posted September 22, 2013 Use a YJ slip yoke. It's longer, and it also allows a better range of operating angle. And it's much cheaper than a new driveshaft. Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 22, 2013 Share Posted September 22, 2013 The YJ slip yoke is 5/8" longer, that's all. But maybe that's enough for you. There are much longer yokes available if not. Link to comment Share on other sites More sharing options...
shawn Posted September 22, 2013 Author Share Posted September 22, 2013 Eagle, that's an awesome tip! that might be just the little bit extra that I'm missing now. and Hornbrod, i may be coming to you for ideas if i need a bit more. thanks guys. Link to comment Share on other sites More sharing options...
HOrnbrod Posted September 22, 2013 Share Posted September 22, 2013 YJ Slip Yoke GM Long Slip Yoke (Ebay) Link to comment Share on other sites More sharing options...
a4xnut Posted March 1, 2014 Share Posted March 1, 2014 21 September 2013 - 09:30 PM The YJ slip yoke is 5/8" longer, that's all. But maybe that's enough for you. There are much longer yokes available if not. YJ Slip Yoke From where I sit, the one labelled "MJ" appears to be longer than the "YJ" one. Link to comment Share on other sites More sharing options...
Incommando Posted March 2, 2014 Share Posted March 2, 2014 YJ Slip Yoke GM Long Slip Yoke (Ebay) What would be a good vehicle source for that GM slip yoke? Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 2, 2014 Share Posted March 2, 2014 HERE is one source. The ones using the 1310 u-joints that is. Link to comment Share on other sites More sharing options...
92tanMJ Posted March 3, 2014 Share Posted March 3, 2014 in the end a 1.5" t-case drop solved pretty-much all of it. the slip yoke wasn't in far enough. the drop brought it in quite abit but could probably use an inch longer driveshaft too. (or thereabouts). That's an awfully large tcase drop imo...More than one inch is pretty hard on the motor mounts and I have heard, never seen, but heard of people with 2" drops with their mechanical fans hitting the radiator. Noob question.. How is a longer slip yoke going to help with vibration? Aren't the vibrations caused by the angles of the joints? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now