pinion angle or driveline?
08-22-2011, 05:29 AM
#281
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
hi all, well i still haev vibrations at 80+, but I spent so much time on checking the angles simply because the rearend I got was welded up incorrectly (4 down instead of 4 up). I actually had the pinion pointing down upon install. well I cut the the thingies that sit on the leaf spring and I was never sure I got it right. Well all parts of the rear are rebuilt or new including the T5 (rebuilt). so that's why I'm still chasing angles.
What I found though is that when I jack up the rear axle and starts spinning tyres with a dialgauge under the driveshaft at front and back the whole driveshaft goes up and down every half turn by about half millimeter (or was it even a full one). I'm not sure what causes this ... and i'm pretty sure that the up down motion in front is 90 degrees off the up/down motion in the back. so as you ruen the shaft it goes up/down but the front in different motion than the back.
No idea how much is normal ... .~:-(
Gun: you mentioned somewhere how to replace that tial bushing..... do you still have instructions for that? I might just give it a try and replace that ... ?! or next time I'll just measure with dialgauge how much I can move this thing
What I found though is that when I jack up the rear axle and starts spinning tyres with a dialgauge under the driveshaft at front and back the whole driveshaft goes up and down every half turn by about half millimeter (or was it even a full one). I'm not sure what causes this ... and i'm pretty sure that the up down motion in front is 90 degrees off the up/down motion in the back. so as you ruen the shaft it goes up/down but the front in different motion than the back.
No idea how much is normal ... .~:-(
Gun: you mentioned somewhere how to replace that tial bushing..... do you still have instructions for that? I might just give it a try and replace that ... ?! or next time I'll just measure with dialgauge how much I can move this thing
Last edited by kalli; 08-22-2011 at 05:34 AM.
08-22-2011, 06:27 AM
#282
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
Norm
08-22-2011, 06:50 AM
#283
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
well I always ended up measuring different angles. Well I found a good page on how to measure them exactly and I'll come back with numbers then. I always reoved DS and measured at front of yoke or bottom of yoke tec. It's only now I understand that it has to be measured at the cap ...
http://www.classicchevy5speed.com/fi...roc_111606.pdf
http://www.classicchevy5speed.com/fi...roc_111606.pdf
08-22-2011, 10:29 AM
#285
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Thread Starter
Join Date: Dec 2005
Location: Hills of California
Posts: 5,208
Kalli I would simply install the new TS bushing by tapping in with a socket once that was done I found it was always impossible to install the DS because the TS bushing was so tight. I would then simply use a 3 pad brake cylinder hone on a drill and oil. hone the inside evenly from front to back and back to front checking often the fit.
Once the slip yoke slides in with moderate effort you are ready... It should slide in smooth but require a bit of twisting and pushing.
Once the slip yoke slides in with moderate effort you are ready... It should slide in smooth but require a bit of twisting and pushing.
08-22-2011, 11:31 AM
#286
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
Kalli I would simply install the new TS bushing by tapping in with a socket once that was done I found it was always impossible to install the DS because the TS bushing was so tight. I would then simply use a 3 pad brake cylinder hone on a drill and oil. hone the inside evenly from front to back and back to front checking often the fit.
Once the slip yoke slides in with moderate effort you are ready... It should slide in smooth but require a bit of twisting and pushing.
Once the slip yoke slides in with moderate effort you are ready... It should slide in smooth but require a bit of twisting and pushing.
08-22-2011, 07:16 PM
#287
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Join Date: Dec 2005
Location: Hills of California
Posts: 5,208
I believe there was notch at the bottom of the bushing that ran the full length...it was about 1/4 wide and 1/8" deep. I guess its purpose is to allow for oil to flow freely to the oil seal and slip yoke...I used a hack saw (one where the blade sticks out past the handle) I guess like a key hole hack saw. I cut the old bearing in half above this notch then grabbed one edge of the cut with pliers and rolled it up and it just fell out.
06-14-2014, 07:55 AM
#288
5th Gear Member
Join Date: Aug 2004
Location: ABQ, NM, USA
Posts: 2,593
So here is an update after 4 months of driving it around. (READ for answers)
The issue is pretty much non existent and I cant remember the last time it vibrated. At the start of this thread it was an almost daily occurrence. I have had the car at or above 90 in the last month or so and it was fine nothing really noticeable.
Replacing the tailshaft bushing alone did not solve the problem
Replacing both the tailshaft busing and slipyoke made big improvement but I still noticed a vibration once and a while... Well apparently after letting the bushing and the yoke run a bit that went away too because I haven't noticed any issues from it for some time now (3 months at least daily driving)
Im am okay with the performance now but Im not done with this thread quite yet I plan sometime soon to acquire a 3" aluminum high speed balanced drive shaft from Denny's someday in the near(ish) future.
Of course Ill post the results here as well.
So in short the issue was mostly if not nearly (98% +) solved at least at speeds below 100 by the following:
1) replace tail shaft bushing
2) Replace silpyoke
3) Tailshaft busing will be too tight after install to insert slipyoke so use a brake cylinder hone on bushing until slipyoke can be installed with moderate effort with grease on slipyoke.
-Gun
The issue is pretty much non existent and I cant remember the last time it vibrated. At the start of this thread it was an almost daily occurrence. I have had the car at or above 90 in the last month or so and it was fine nothing really noticeable.
Replacing the tailshaft bushing alone did not solve the problem
Replacing both the tailshaft busing and slipyoke made big improvement but I still noticed a vibration once and a while... Well apparently after letting the bushing and the yoke run a bit that went away too because I haven't noticed any issues from it for some time now (3 months at least daily driving)
Im am okay with the performance now but Im not done with this thread quite yet I plan sometime soon to acquire a 3" aluminum high speed balanced drive shaft from Denny's someday in the near(ish) future.
Of course Ill post the results here as well.
So in short the issue was mostly if not nearly (98% +) solved at least at speeds below 100 by the following:
1) replace tail shaft bushing
2) Replace silpyoke
3) Tailshaft busing will be too tight after install to insert slipyoke so use a brake cylinder hone on bushing until slipyoke can be installed with moderate effort with grease on slipyoke.
-Gun
It seems that most cars have the tranny pointing down and our stangs also have the diff pointing down, which is not the 'equal and opposite' directions that are preferred.
My current setup would naturally have them around 2* pointing down, equal and not opposite. Does this even matter at all?
06-14-2014, 10:29 AM
#289
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Thread Starter
Join Date: Dec 2005
Location: Hills of California
Posts: 5,208
I left what I think was a 3* or 4* degree shim in the rear....whatever I last tried.
I guess the moral of the story is these cars are old skool and they ran great without any magic from the factory. If something is wrong and you end up having do weird things like measure pinion angles and you did nothing that would drastically change any operating angles but you've ended up resorting to magic to fix something like a vibration...maybe you should start all the way back to basics and make sure is not just a worn out yoke....Nothing on these cars should be as complicated as the above.
But really the last piece to this thread will be the addition of an Aluminum drive line. That I still plan to do and I think it would improve high speed smoothness further although its pretty well dialed in now.
-Gun
I guess the moral of the story is these cars are old skool and they ran great without any magic from the factory. If something is wrong and you end up having do weird things like measure pinion angles and you did nothing that would drastically change any operating angles but you've ended up resorting to magic to fix something like a vibration...maybe you should start all the way back to basics and make sure is not just a worn out yoke....Nothing on these cars should be as complicated as the above.
But really the last piece to this thread will be the addition of an Aluminum drive line. That I still plan to do and I think it would improve high speed smoothness further although its pretty well dialed in now.
-Gun
06-14-2014, 03:46 PM
#290
5th Gear Member
Join Date: Aug 2004
Location: ABQ, NM, USA
Posts: 2,593
Well my yoke does not move like in your video. Most I can see is the seal lip around the shaft deflect a bit, so it must not be more than .001" or so. As for engagement, it is about 1/2" from bottoming in, or I can only slide it 1/2" forward before it stops if I disconnected it from the rear yoke.
I did notice that my left rear tire does not spin as true and the right with the car up in the air in first at idle. Bad wheel or axle?
I did notice that my left rear tire does not spin as true and the right with the car up in the air in first at idle. Bad wheel or axle?
Last edited by 69mach1377; 06-14-2014 at 03:52 PM.