808muscle

Made another adjustment to the UCA Saturday before racing. Still have the vibes and my 60ft is the worst its ever been with DRs. I am over this DS. Its coming out, hello stocker. For whatever reason two different shafts and same results. What a waste of my time. I know many of you guys have had great success and even gotten better ETs. I never once had a better ET or 60ft.
Went to swap my wheels at the end of the night and 4 of my studs are fubar. Anybody change them out? I read some old threads where it looks like its fairly simple.

tx_zstang

Is the pinion end of the rear end angled up or down in relation to the rest of the rear end housing? the pinion end should be slightly down.
I'm running a Shaftmasters w/o issues.

808muscle

It's angled down. I have change the setting more than a dozen times. It's coming out. Im over it.

wrokon

Trying to help my son fix vibration on his 05/V6/Auto after transmission rebuild. The shop that had the rebuild done (they farm it out to a tranny shop they have used for some years - swear by them) found that the shaft-to-differential (pinion?) u-joint was worn, and causing vibration at speed (50+ mph - feels like a nice back massager in the bottom of the car).

I have tried wiggling that u-joint with my hand while under the car, but it barely seems able, if at all, to move side-to-side/up-down - just a bit of rotational play, a degree or 2, that seems to me to be normal mechanical slack that should be taken up once the car is in motion. Is their diagnosis correct? My son swears there was not any such vibration before the rebuild, and I am wondering if the re-installation of the transmission/driveshaft is at fault. I did see where one of the rear flange bolts and the hole it is in seem to have been marked with fresh white paint, presumably to reattach the shaft back there where it was before.


The kicker is that this is the "bad" type driveshaft that does not have replaceable u-joints, so the $25 part replacement becomes a $550 part replacement, plus almost $100 labor.

I have done some moderately involved car work in my younger days like replacing a 3-sp tranny with 4-spd in a 64 Fairlane, so figured "how hard can this be?". So, refusing to give Ford any more money for their bad design decsion, I got a shaft from Shaftmasters (they really need a better name ;-) ), and was puzzled by the "instruction sheet" that states the "Factory OEM pinion angle must be maintained at zero degrees".

A bit of web searching the last couple days led me to this thread, amongst others, and I think I know what that means now: the rear differential/axle assembly has to be lined up with the back of the driveshaft parallel to the ground with the suspension loaded - is that it?

Anyway, all the stuff I am seeing talks about adjusting the pinion to get the right alignment by somehow rotating the front of the differential up/down, but seems to assume an adjustable rear suspension as with after-market suspensions. Is the STOCK rear suspension adjustable (if needed), and if so, how?

Or am I totally off-base about what is involved here?

TIA,
W

wrokon

Forgot to mention: the object of this exercise is to make this car fit for sale, and be done with - not interested in sinking any more money in that is absolutely necessary (disgusted with Ford's abandonment of responsibility for the transmission - 50K miles in 7 years, not being raced, it should have held up better - instrument panel gauges going crazy - $270 to some guy in Missouri who specializes in fixing that f'up; $550 "u-joint replacement") - 'nuff said.

808muscle

To adjust your pinion angle you need an adjustable UCA ie upper control arm. That will enable you to point your pumpkin up or down depending on your needs. You can get one for $125/150 or so.

Is your car lowered at all? If stock then you shouldnt have to adjust the PA. Do you currently have a stock DS in there? If your getting vibrations with a stock DS then IMO you got other issues going on. 50 mph is kinda low to be getting DS vibes. Most people get the vibration in the 60-80 mph range.

wrokon

Thanks for the response.

The shop that had the tranny rebuild done is claiming the rear u-joint is the source of the vibes.

This is straight stock 05/V6/Auto, and I just got a new DS to match from Shaftmasters. We really do not want to put any more money into it than the almost $3200 just spent for tranny rebuild + DS. The goal is to get it up to snuff with minimum effort, and no more costs to sell ASAP. We ain't racing it, and are not setting it up for anyone else to.

I guess we will try to put the new DS in tomorrow, and see how it rides after that. Shaftmasters' site claims no change to stock PA is needed, so that is why the instructions that actually came with it shook me a bit.

808muscle

My suspension is not lowered and I had vibration, lots of vibration. Even after installing a UCA and a second DS I still had vibration.
I understand what your goals are here. Good luck and follow the install instructions to a T. Make sure you clean all the old locktite out real good. That can cause vibration itself. There is a great DIY writeup you can follow.
https://mustangforums.com/forum/2005...ll-w-pics.html

wrokon

Thanks! That appears to be a helpful tutorial you linked (although one of its links is broken, for the replacement pinion flange kit - "forums.bradbarnett.net could not be found", but I do not need that anyway), and it seems that installation on a GT with manual tranny needed a pinion flange adapter plate that I did not get with the DS - not needed for v6/auto, right?

The comment about leftover loctite causing vibrations has me wondering if the shop that removed/replaced the tranny/DS missed that bit. Maybe it would help my current setup if I just redid the DS R+R with a thorough cleaning?

Hope springs eternal

wrokon

Just to follow up. A rainy weekend killed my ambition, and the need to get the car right, led me to take it back to the shop where they did the transmission R&R. After some frank discussion and explanation of their u-joint diagnosis, I decided to have them install the driveshaft. The proof was in the result: the vibration is totally gone, and the ride is as solid as it should be - now my son wants to keep that dang 'Stang, and probably will take out a loan on it (just finished paying it off!) to pay off the credit card bills for the tranny and driveshaft.

All's well, ending well (I hope).

Thanks for the info in your responses, 808! Race on, dude!