if you adjusted your pinion angle, come in!

[Fabman]

I've got a stock drive shaft. If I measure the angle that the pinion flange is pointing to the ground, is that the amount of negative angle I have?

What I can give you is theory...I am a stock car guy, not a Mustang expert.
You have to take the theory and apply it to your mechanical apparatus....but once you understand the theory, you know where to go and the limits of the machine will tell you how to do it.
Now then, what you basically want is for the flange on the pinion and the flange on the transmission to face each other exactly. One up, one down. The problem is, when you hit the gas, things move....arms flex, bushings compress/stretch.....so you need to start with the pinion facing the transmission, but slightly lower so that when everything moves under power, you end up with those flanges perfectly parallel. The exact amount depends on many variables. i.e.: how much power you make, how much traction you have, how much suspension moves etc. 1 or 2 degrees is probably plenty. That's not 2 degrees from vertical or from parallel with the ground, that's 1 or 2 degrees as compared to the front flange.....does that make sense?

 

[AnotherS197GT]

Yeah. So if I were to measure my drive shaft yoke at the trans and its angle is 3* and I measure the pinion yoke and its 1*, that would be -2*. If the trans angle is 1* and the pinion is 3*, that would be +2*?

By shortening the UCA, that would pull the pinion flange up, bringing its angle closer to zero. By lengthening it, I would be pushing the flange down and moving the angle farther from zero. Right?

So I need to move my LCA up a hole, check the angle and go test for hop?

 

[Fabman]

Yeah. So if I were to measure my drive shaft yoke at the trans and its angle is 3* and I measure the pinion yoke and its 1*, that would be -2*. If the trans angle is 1* and the pinion is 3*, that would be +2*?

By shortening the UCA, that would pull the pinion flange up, bringing its angle closer to zero. By lengthening it, I would be pushing the flange down and moving the angle farther from zero. Right?

So I need to move my LCA up a hole, check the angle and go test for hop?

Now you're cooking...

 

[Fabman]

Hang on....it's easy to get confused here....it depends on how you are measuring and from what plane. You want the flanges to face eachother perfectly, then lower the pinion. The amount depends...especially with a stock drive shaft....I dont think they are as fussy as the after market ones.....you just definitley dont want it pointing up past zero as compared to the trans flange. Does that make sense?

 

[AnotherS197GT]

Suspension sucks lol.


Where should I measure then? And do I subtract the pinion flange from the trans, or the trans from the pinion? I did read that having a positive angle would starve bearings in the rear of oil.

 

[Fabman]

Suspension sucks lol.


Where should I measure then? And do I subtract the pinion flange from the trans, or the trans from the pinion? I did read that having a positive angle would starve bearings in the rear of oil.

I gotta run....this has been explained 50 times in this thread. Go back and look. Suspention rocks....it makes it easy to beat guys that dont get it and you can do if for cheap....I'm out for now. have fun.

 

[AnotherS197GT]

Alright, I've got it all figured out I think. Hopefully I can find the time to work on it this weekend. I've got one more question for you... The more parallel my LCAs are, the less the axle is pushed to the ground, correct? The means more wheel spin, right?


Thanks for all the help dude.

 

[Fabman]

Alright, I've got it all figured out I think. Hopefully I can find the time to work on it this weekend. I've got one more question for you... The more parallel my LCAs are, the less the axle is pushed to the ground, correct? The means more wheel spin, right?


Thanks for all the help dude.

Yes, but there is a balance. If the top arm isnt pointed down at least some amount it aint ever gonna be pretty.
Get that thing pointed down, flatten out the lowers and get your wheel hop gone. Then you can experiment with the lowers.

I'm, still waiting for my MS paint lessons....

 

[AnotherS197GT]

Go to start, all programs, accessories, and click on paint. Depending on your version of windows, you'll have a bunch of preselected shapes. Choose what shape you want, then click and drag to make the shape whatever size you want. There are line tools as well. The pencil tool allows you to free hand draw, and so does the paint brush. The paint can will allow you to fill drawings with color. For perfectly proportionate shapes and straight lines, hold the shift key while you are making the shape. There are 2 different cut tools I think. Their icons are dotted lines. One is a square shape, and the other is freehand.

I can't think of anything else, but shoot me a pm if you have any questions. It's nowhere near as complicated as suspension, you should be alright haha

 

[gil_t2]

Yeah. So if I were to measure my drive shaft yoke at the trans and its angle is 3* and I measure the pinion yoke and its 1*, that would be -2*. If the trans angle is 1* and the pinion is 3*, that would be +2*?

By shortening the UCA, that would pull the pinion flange up, bringing its angle closer to zero. By lengthening it, I would be pushing the flange down and moving the angle farther from zero. Right?

So I need to move my LCA up a hole, check the angle and go test for hop?

You have this back wards, shorting the UCA pulls the pinion DOWN, you have the basics but you must always keep in mind where your pivot points are. All so setting the pinion angle is different on a 2 piece vs a 1 piece driveshaft. When you check the angle at the trans flange, that should be a neg figure,( back of the trans points down towards the back of the car) The front of the pinion points down, remember the pivot point is your axle. With a 1 piece DS you are looking to set a 2 degree difference between the center line of the pinion and the center line of the trans.

 

[Fabman]

You have this back wards, shorting the UCA pulls the pinion DOWN

That is correct....glad you caught that.

 

[AnotherS197GT]

Ok, thanks for catching my mistake. I was reading through here last night and I found a video for setting the pinion angle on the stock 2 piece. You measure on the rear half of the drive shaft to find whats equivalent to the trans flange angle, then measure on the pinion flange. Adjust until at the proper angle.

Is it OK to load the suspension by placing jack stands on the axle tubes, or will that fuck with my readings? I planned on throwing some cinderblocks under the rear tires if not.

 

[AnotherS197GT]

Center hole, 2-3* of angle. Smooth as butter.

 

[Fabman]

Center hole, 2-3* of angle. Smooth as butter.

 

[AnotherS197GT]

Thanks for all your help!

Now I just need to track down this weird squeaking noise from my rear end. Last weekend I installed these to help bring down my clunk:
http://www.umiperformance.com/catalog/index.php?main_page=product_info&cPath=12_131&products_id=341

Now the car is making a moaning/squeaking noise. It seems to happen most often turning turns, but does during acceleration sometimes. I removed the mount, put the spacers in, the put the arm back in the mount and torqued it while off the car. I then put the mount back in, loaded the suspension and torqued the bolt on the diff.

Do you think because I torqued the upper bolt off the car, thats binding my bushing?

 

[Fabman]

Thanks for all your help!

Now I just need to track down this weird squeaking noise from my rear end. Last weekend I installed these to help bring down my clunk:
http://www.umiperformance.com/catalog/index.php?main_page=product_info&cPath=12_131&products_id=341

Now the car is making a moaning/squeaking noise. It seems to happen most often turning turns, but does during acceleration sometimes. I removed the mount, put the spacers in, the put the arm back in the mount and torqued it while off the car. I then put the mount back in, loaded the suspension and torqued the bolt on the diff.

Do you think because I torqued the upper bolt off the car, thats binding my bushing?

I'm not familiar with this issue....I'm sure someone here is...lots of smart people on this site.

 

[rojizostang]

doesn't the stock drive shaft have a cv joint at the back? (i don't have mine anymore)

if so, the pinion angle shouldn't really matter. the dss drive shaft that i have has a cv joint at the rear, and this negates the necessity of adjusting the pinion angle.

 

[CandyRedGT]

Since my 2008 GT was T-boned BADDDDD by a HIT & RUN....*^%$#%^&^%$%^&%$# SOB...in April while i was driving it..........we will be re-setting the pinion angle...after the replacement axle housing/Dyno Tech drive shaft... and BMR control arms are installed..........I was hit in the drivers door and 1/4 panel....it even broke the axle housing!!! So far....my insurance has agreed to pay for new BMR control arms....Moser axles, Detrioit Tue Trac...etc exactly what i had when i was hit!! I need to read up on what all i've missed in this thread!! Thanks guys, Joe

 

[Whiskey11]

Got a question for the people more in the know than I about this nonsense. Currently I have what I would like to call the 2 piece clunk if I am not smooth on acceleration and shifting between 1st and 2nd. 3rd and up don't seem to have the issue. I can really produce the issue if I let off the gas at high RPM in 1st gear. It was enough that my father noticed it today when he took my car to the dealership to have the battery replaced (under warranty somehow! ).

Tomorrow I plan on taking my car and retorquing all of the bolts from the watts link and lowering springs install in hopes of chasing a different noise out of the rear (a squeak) and I plan on doing the same up front. I've got some noise from the rod ends in the endlinks up front.

Anyway, my question is:
Does pinion angle effect the amount of play between the gear teeth in the diff at all? I ask because if I jack up the back of the car and rotate the rear wheel there is about a 15º of rotation before I get the resistance from the differential in both the forward and reverse direction. I didn't think there would be quite that much play in the system but I only have a slight bearing whine and no noise from the gears at all. I would hope they are installed correctly as it was a factory option for the 3.55's. That said, my rear lower and upper control arms are BONE STOCK, the rear end is a factory installed 3.55 rear diff that came with the car.

Car has 26,800 miles and some of that is autocross miles which is a lot of on/off throttle applications in second gear.

Is this something an adjustable UCA will fix if I adjust the pinion angle again? It did it stock so I'm guessing not.

And before anyone says it, I can't install a 1 piece driveshaft with my class rules for autocross so I'm stuck with this shitty 2 piece unit.

Thanks in advance.

 

[gil_t2]

Answer is No, If you have stock 2 piece DS, I would check the center bearing.