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Discussion Starter #1
Was in a discussion this morning about a guy who did a tube front end on a back half car.
Front what I hear, the tail shaft of the transmission is approximately 3" higher than the rear end yoke.
The driveshaft is on a 5* angle.
Anyone see a problem with this?
If it matters, this is a 69/70 Nova, ladder bar suspension, big block car that was running 8.8's.
 

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Discussion Starter #3
This wasn't a trick question this guy was just concerned with what he saw and asked me to post this question.

So you don't foresee any issues with u-joint failures or pinion angle?
 

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7.86 @ 8800DA 3365lb 275s
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there was a pretty lengthy discussion about this subject in the "sheffield race cars" thread in TOBT and as stated in there a lot of chassis cars have the tail housing above the pinion centerline. if the engine is set right the tail housing lands where it lands.
 

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7.86 @ 8800DA 3365lb 275s
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This wasn't a trick question this guy was just concerned with what he saw and asked me to post this question.

So you don't foresee any issues with u-joint failures or pinion angle?
wasnt really taking it as a trick question it's just that there were close to 100 views of the thread and no response. this to me is one of those types of questions that people avoid responding to because it can bring out a bunch of comments from "guy's in the know" that just know the answer, they cant really say why someone is "wrong" but they just know they are. it's not uncommon for the driveshaft to go down hill to the pinion.
 

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I've always been told that as long as both u joints are not on an angle you are fine. So if you set pinion angle so that under load there is no angle at the pinion, then the angle coming out of the trans is fine as long as its not extreme.
 

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I've always been told that as long as both u joints are not on an angle you are fine. So if you set pinion angle so that under load there is no angle at the pinion, then the angle coming out of the trans is fine as long as its not extreme.
Don't agree, IMHO idea is the u-joints are parallel under load
I don't have the link but there is a great video I saw a while ago that explains the concept. If the u-joints are not parallel there is a speed change thru the driveshaft

IMHO pinion angle is not referenced to the ground, it is referenced to the output shaft of the tranny
 

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Discussion Starter #10
Thanks for the replies.

In my mind, I was thinking if the driveshaft is on a harder angle, it would wear out the u-joints quickly or even cause some binding up and cause failure.
I was under the impression that you wanted as close to a straight line between the tailshaft and the pinion as possible.

Hey Mario, how ya been?
 

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7.86 @ 8800DA 3365lb 275s
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so if you get the engine set in place and the ride height of the car where you want it what do you do? the engine needs to be set in a certain place and where the tail housing is where it is as long its inline with the pinion the rest doesn't really matter. why do people think the u-joint being at an angle will wear them out overly fast? thats what they are designed to do, if there is binding then thats obviously to much of an angle. the angle at the tranny really isn't a huge issue as long as pinion angle is close even pinion angle is far less important then most think...

i think alot of guy's think within the box to much, they have been told that "the optimum setting is A and B" well just because "A and B" are optimum doesnt mean every other option is wrong and gonna cause catastrophic failure immediately....ok, maybe your driveshaft will need to be rebuilt at 500 runs instead of 505....life is full of overthinkers, this recovering overthinker included.
 

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Discussion Starter #12
I think a lot of the way I think, is due to my job where I need to make sure things line up properly so I take this home with me.

There is some other issues to this guys car, that I don't want to get into, but if the above issues don't seem to be a concern, then it is what it is.

Thanks again for your input.
 

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7.86 @ 8800DA 3365lb 275s
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I think a lot of the way I think, is due to my job where I need to make sure things line up properly so I take this home with me.

There is some other issues to this guys car, that I don't want to get into, but if the above issues don't seem to be a concern, then it is what it is.

Thanks again for your input.
i don't think it's a case of lining up properly or not if the engine is in right it's gonna be what its gonna be. saying your used to things lining up properly is to say his isn't lined up properly. if the engine is in right then the tail shaft is in the proper location
 

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Discussion Starter #16
i don't think it's a case of lining up properly or not if the engine is in right it's gonna be what its gonna be. saying your used to things lining up properly is to say his isn't lined up properly. if the engine is in right then the tail shaft is in the proper location
Well there is a question to as if the motor is in the right location and I'll leave it at that.....
Thanks
 

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Pinion angle is the relationship of pinion shaft to driveshaft. Ultimately the front u-joint and rear should have the same working angles but with suspension setups they can't be and the amount varies by suspension type. There should always be some negative pinion angle at rest and not go positive on launch.

This video explains what can happen when things are incorrect:

https://video.search.yahoo.com/vide...sabv&sigt=10vllihem&age=0&fr=yfp-t-442-s&tt=b
 

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I've always been told that as long as both u joints are not on an angle you are fine. So if you set pinion angle so that under load there is no angle at the pinion, then the angle coming out of the trans is fine as long as its not extreme.
Oh no, that is NO DOUBT wrong. You want both of them operating at the same degree (but opposite). Such as, if the angle of the front one is running down....the angle of the back one needs to run up . After setting both at the same angle.....then you add the amount of pinion angle you want.
 

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Yeap still got the same Camaro I had when you were building your T-Bird years ago. Does this mean we're old????
I know I am getting there, depending on the company I may have gotten there. LOL

Hard to beleive it was 2007 when I finished the T-Bird, now 7 years old. Seems like yesterday
 

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5* of downward shaft angle is good, it will keep the ujoints from crossing zero, just adjust the pinion angle to accomodate for it and all is good. Most people over read pinion angle, yes it effects stock ford 88 cars, becuase it changes the angles of the arm, and it really effects leaf springs cars with preload and snubbers etc. But mostly, as long as pinion angle is where it needs to be, just move the housing and keep pinion angle the same, and the suspension adjustment make the change, not the pinion angle itslef. and for the record I have had to adjust a few transmission cross members over the years to get the proper driveline angles to keep the car happy, if the unjoints cross center or 0, it'll whip the rear end like a jump rope violently.
 
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