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I lowered my front end a bit to correct some ride height issues. I ended up getting some vibration on my drive and it looks like I am not getting enough engagement on my DriveShaft yoke to the trans.
little engagement
I had an 1 1/4" inside the seal while I had a 2 1/8" outside the seal. I understand that is not enough engagement, and I think I am going to have PST build me a new shaft. My question is how much yoke should be inside the seal on a 4L80?
Also, since I won't be needing my old shaft, is there a market for used drive shafts. I don't hardly want anything for it just curious. Thanks for your help.
Looks like it's not fully engaged into the bushing.
If the Output Shaft is fully splined, You can run a pretty long yolk.
You can just install a longer yolk if you want, Sonnax yolks are very nice & balanced......Of coarse if your yolk is out of balance & the shaft was balanced to compensate, You will need to re-balance the shaft.
I would NOT be happy with that much of the short yoke hanging out of the back of the trans. I recently swapped to a similar one and I will be watching it closely when i install it. Does your output shaft have the oring??
I would NOT be happy with that much of the short yoke hanging out of the back of the trans. I recently swapped to a similar one and I will be watching it closely when i install it. Does your output shaft have the oring??
Yes sir there is a seal there at the tail of the trans. I think that might be what you are referring to, bit not sure.
Like was stated earlier, some output shafts are fully splined, so it would be easy for you to swap to a longer yoke if thats what you had. If you have the half splined one with o ring you may could still do that but may be required to cut the longer yoke down so that it doesnt over-engage the splines on the output shaft. Regardless, I would be figuring this out bc that's not enough engagement for me to be happy.
Like was stated earlier, some output shafts are fully splined, so it would be easy for you to swap to a longer yoke if thats what you had. If you have the half splined one with o ring you may could still do that but may be required to cut the longer yoke down so that it doesnt over-engage the splines on the output shaft. Regardless, I would be figuring this out bc that's not enough engagement for me to be happy.
Yeah I think I am going to bite the bullet and get a new one. anything I should know prior to calling pst or another company? I used Dennys measuring sheet to take all of my measurements.
I would verify you have the oring output shaft (can google for pics) then show them your engagement measurement pic. You can ebay search yokes and get a good idea of whats available. Its very common in fbody swaps to have to cut yokes down. What I would do it get a longer yoke, remeasure your current one at maximum engagement (the spot in the suspension cycle where the most yoke is in the trans, get that figure, then measure how far back the oring is, and figure out how much to cut off where at maximum engagement you are right against the oring (which is the end of the splines).
I would verify you have the oring output shaft (can google for pics) then show them your engagement measurement pic. You can ebay search yokes and get a good idea of whats available. Its very common in fbody swaps to have to cut yokes down. What I would do it get a longer yoke, remeasure your current one at maximum engagement (the spot in the suspension cycle where the most yoke is in the trans, get that figure, then measure how far back the oring is, and figure out how much to cut off where at maximum engagement you are right against the oring (which is the end of the splines).
Sounds like a good way to damage a transmission from the driveshaft being too long.
I would do it the right way and use a counterbored yoke.
Sounds like a good way to damage a transmission from the driveshaft being too long.
I would do it the right way and use a counterbored yoke.
No actually jake its not. He HAS a short counterbored yoke currently from the looks of it. While he may be able to find a longer one (I dont know what ALL is available and dont care), the long yokes Ive seen I thought were fully splined and way too long for this application. Measuring maximum engagement to the oring and making sure your yoke goes to that point and no further creates a yoke that is perfect. Im sorry in your effort to argue you fail to see that.
80e on top, 60e on bottom, both forged PST yokes
Counter bore for the oring. Now if his is like that, imagine how LITTLE splines he has engaged in its current configuration, and that counterbore aint doing jack ****.
Based on this thread ( https://ls1tech.com/forums/conversio...tion-help.html ) he has a maximum of 3.25" of engagement possible. Based on the recess of the splines and his picture above he is using 1 to 1.25 inch of that. Doesn't seem like enough. If the total spline area on the yoke is 3 and maybe 3/8ths, do they make one exactly 5"? That I have no clue, but if they didnt and made a 6 inch one he could cut an inch off of it.
No actually jake its not. He HAS a short counterbored yoke currently from the looks of it. While he may be able to find a longer one (I dont know what ALL is available and dont care), the long yokes Ive seen I thought were fully splined and way too long for this application. Measuring maximum engagement to the oring and making sure your yoke goes to that point and no further creates a yoke that is perfect. Im sorry in your effort to argue you fail to see that.
80e on top, 60e on bottom, both forged PST yokes
Counter bore for the oring. Now if his is like that, imagine how LITTLE splines he has engaged in its current configuration, and that counterbore aint doing jack ****.
My response isn't based off what some internet thread said.
It's based off years of experience. Not just my own but thousands of customers too.
A cut off yoke or a non counterbored one will bottom out BEFORE it even gets to the oring.
Your advice will cause damage.
I wouldn't base my measurements off the oring location.
We machine output shafts to prevent this issue, that's the ideal scenario. However a real counterbored yoke is the solution in this case.
A non-counterbored yoke cut to the correct length will work. Correct meaning short enough it won't hit the output shaft where it isn't splined. Not saying that's the best way but again I said I don't know every single yoke that's available. You're experience is notable, but your urge to argue and always be right overshadows it. Go back to your hole, we aren't impressed and you've actually added nothing of value here, except to pat yourself on the back, which is typical in most of your responses.
A non-counterbored yoke cut to the correct length will work. Correct meaning short enough it won't hit the output shaft where it isn't splined. Not saying that's the best way but again I said I don't know every single yoke that's available. You're experience is notable, but your urge to argue and always be right overshadows it. Go back to your hole, we aren't impressed and you've actually added nothing of value here, except to pat yourself on the back, which is typical in most of your responses.
You gave advice that would cause transmission failure. I corrected it. The point isn't to argue, it's to save some poor guy/gal the trouble of a ruined transmission. I don't really care if anyone is impressed.
08-04-2017, 10:30 PM
4L80E Yoke Engagement 
