pinion angle or driveline?
04-25-2009, 01:02 PM
#232
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Join Date: Sep 2008
Location: Connecticut
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I believe that is your problem. I have never seen that much play. As an example, I have a brand new slip yoke and it was very hard to install given how tight the fit is to the tranny tail shaft. What bushing are you talking about? The only thing in the tranny that touches the yoke is the seal?
Replace that slip yoke and I think your problem will be fixed unless it is the tailshaft with the problem or the driveshaft is too short. Out of curiosity, if you remove the straps at the diff end, how far forward can you move the driveshaft? In other words, what is the measurement between the rear universal and the diff yoke cup with the driveshaft all the way forward and the car at ride height?
Replace that slip yoke and I think your problem will be fixed unless it is the tailshaft with the problem or the driveshaft is too short. Out of curiosity, if you remove the straps at the diff end, how far forward can you move the driveshaft? In other words, what is the measurement between the rear universal and the diff yoke cup with the driveshaft all the way forward and the car at ride height?
04-25-2009, 01:11 PM
#233
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-Snakes
There is indeed a bushing inside the trans that supports the slip yoke. I replaced it when I rebuilt the trans. After installing the new bushing the slip yoke could not be installed in the trans as it was too tight attempting to install the DS would have damaged something. I had to hone the bushing a few thou to get the slip yoke to slide in. It slides in now with fair effort (its not easy) until it reaches about 2/3rds down and then it slides on easier.
There is 1.7" between the end of the tail shaft (aluminum part) and the face of the slip yoke (just after tube)
-Gun
There is indeed a bushing inside the trans that supports the slip yoke. I replaced it when I rebuilt the trans. After installing the new bushing the slip yoke could not be installed in the trans as it was too tight attempting to install the DS would have damaged something. I had to hone the bushing a few thou to get the slip yoke to slide in. It slides in now with fair effort (its not easy) until it reaches about 2/3rds down and then it slides on easier.
There is 1.7" between the end of the tail shaft (aluminum part) and the face of the slip yoke (just after tube)
-Gun
04-25-2009, 02:37 PM
#234
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Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
there's some portrusion of the shaft so it's not really possible to tell how far further you actually could shove it in.
i have a rubber boot there and the yoke just about hits it. When I remove the shaft (or install) I have to push the DS as far as possible into the T5 to actually be able to remove it. not all needed but a good bit
i have a rubber boot there and the yoke just about hits it. When I remove the shaft (or install) I have to push the DS as far as possible into the T5 to actually be able to remove it. not all needed but a good bit
04-25-2009, 04:16 PM
#236
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Join Date: Sep 2008
Location: Connecticut
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Geez, you learn something new all the time! I never knew there was a bushing in the tranny.
Anyway, your slip yoke seems really loose and I could see that being a problem at speed. You're almost out of other options at this point, so that may be the issue. While 1 1/2" is more than the recommended 1", it doesn't seem like that would create such a significant vibration.
Anyway, your slip yoke seems really loose and I could see that being a problem at speed. You're almost out of other options at this point, so that may be the issue. While 1 1/2" is more than the recommended 1", it doesn't seem like that would create such a significant vibration.
04-25-2009, 06:27 PM
#237
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Jamming the yoke in all the way and then flexing it doesn't show much improvement maybe just a barely noticeable amount.
I could pick up a slip yoke test fit it in the tail shaft and if it doesn't make an improvement say it was the wrong one and return it.
Where is Scott?? I want him to get video of his T5 tailshaft/yoke flex....or at least give me an idea how it compares.
-Gun
I could pick up a slip yoke test fit it in the tail shaft and if it doesn't make an improvement say it was the wrong one and return it.
Where is Scott?? I want him to get video of his T5 tailshaft/yoke flex....or at least give me an idea how it compares.
-Gun
04-30-2009, 03:55 PM
#238
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latest adventure
Hey
So my latest adventure landed me at Dyanpack dyanmometers they are in the business of selling these dynos and I know some people that helped me get free analysis from them.
We did lots of high speed testing from 75 to 88mph in an attempt to locate the vibration. I stuck my vid cam under the car and we ran er up. as speed increased you could see the vibration in the yoke right were it went into the tailshaft. It was nice and clear line but became fuzzy as vibration built up. You hear the vibration in the video and see the oil drop on the end of the tailshaft as well as the talshaft its self begin to vibrate at very high frequency.
Another great thing I found is that oil is indeed leaking from the tailshaft seal but much faster than I had imagined. I figured it was a drop or 2 per day as there was never any on the cement were it gets parked..well it only leaks when its spinning and it about 1 drop every 5 to 8 seconds. And it leaks before the vibration gets bad.....THIS IS GREAT NEWS at least I found something wrong.
Remember the video I showed of the flex in the slipyoke. I showed that same video to Bruce at modern driveline and he said it was leaking oil because it was worn and too much play....I never mentioned an oil leak to him but he noticed it some how or predicted it as its not obvious in the video.
These dynos bolt onto the axles and rear wheels are removed.. SO I KNOW 100% its not a wheel balance issue. as there were no wheels turning during the experiment.
Of course I did a power run to see what she was doing I long suspected that I was getting about 220 RWHP based on guesses
Max torque was 250Ftlbs at 3786 rpm
Max Hp was 211 at 4800 rpm and rapidly climbing but I didnt want to push it past 4800 all numbers are RWHP
Will post pics in a while
time to order new slipyoke and checks trans oil level (at least its still leaking out)
-Gun
So my latest adventure landed me at Dyanpack dyanmometers they are in the business of selling these dynos and I know some people that helped me get free analysis from them.
We did lots of high speed testing from 75 to 88mph in an attempt to locate the vibration. I stuck my vid cam under the car and we ran er up. as speed increased you could see the vibration in the yoke right were it went into the tailshaft. It was nice and clear line but became fuzzy as vibration built up. You hear the vibration in the video and see the oil drop on the end of the tailshaft as well as the talshaft its self begin to vibrate at very high frequency.
Another great thing I found is that oil is indeed leaking from the tailshaft seal but much faster than I had imagined. I figured it was a drop or 2 per day as there was never any on the cement were it gets parked..well it only leaks when its spinning and it about 1 drop every 5 to 8 seconds. And it leaks before the vibration gets bad.....THIS IS GREAT NEWS at least I found something wrong.
Remember the video I showed of the flex in the slipyoke. I showed that same video to Bruce at modern driveline and he said it was leaking oil because it was worn and too much play....I never mentioned an oil leak to him but he noticed it some how or predicted it as its not obvious in the video.
These dynos bolt onto the axles and rear wheels are removed.. SO I KNOW 100% its not a wheel balance issue. as there were no wheels turning during the experiment.
Of course I did a power run to see what she was doing I long suspected that I was getting about 220 RWHP based on guesses
Max torque was 250Ftlbs at 3786 rpm
Max Hp was 211 at 4800 rpm and rapidly climbing but I didnt want to push it past 4800 all numbers are RWHP
Will post pics in a while
time to order new slipyoke and checks trans oil level (at least its still leaking out)
-Gun
Last edited by Gun Jam; 04-30-2009 at 03:57 PM.
05-01-2009, 12:32 AM
#240
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Yeah I really have my fingers crossed that this does the trick....A simple fix I hope it works.
Here is the link to the vibration video...I didnt have the camera in best location and it was a bit dark for optimal video quality but you can hear the vibration and the best way to see it is by the oil drop on the tailshaft...Its not visually obvious because its such a high frequency, watch for blurriness of the tailshaft and that oil drop.
http://www.3rflying.com/slipyokedyno.mp4
here is a pic of the dyno graph..
-Gun
Here is the link to the vibration video...I didnt have the camera in best location and it was a bit dark for optimal video quality but you can hear the vibration and the best way to see it is by the oil drop on the tailshaft...Its not visually obvious because its such a high frequency, watch for blurriness of the tailshaft and that oil drop.
http://www.3rflying.com/slipyokedyno.mp4
here is a pic of the dyno graph..
-Gun