Driveline angles revisited

RnrdTheFox · Feb 7, 2006

I've posed this question before, and got different responses, so I will ask again. I was talking to a guy today locally that swears I have too acute of an angle. He has me a little freaked out right now. I'm about to put the body back on the frame, so nows the time to get this stuff right.

The angle at the CV measures about 25* right now. I was told that this was ok by other folks, and that it could handle that angle. it doesn't bind when you roll it. I know that if I drop it too much, that the intake will rock back into the firewall, or the front yoke will start to point up too much.

I'm running a 3 1/2" suspension, AODE.

Help????! ?:?

broncnaz · Feb 7, 2006

You can shim the rear axle to get a better angle see the pinion anlge tech article to the left. I cant see your setup being all that bad as its only 1 1/2" longer than stock. but you need to check your pinion angle I just checked mine with a 2.5in lift it was 20 degrees with the pinion being at 11 degrees so I could stand to shim the axle a little although I havent seen any ujoint problems in the 8 years or so that I've had the lift on. Although I suppose I go through them a little faster than before its just hard to really tell.

RnrdTheFox · Feb 7, 2006

broncnaz said:
You can shim the rear axle to get a better angle see the pinion anlge tech article to the left. I cant see your setup being all that bad as its only 1 1/2" longer than stock. but you need to check your pinion angle I just checked mine with a 2.5in lift it was 20 degrees with the pinion being at 11 degrees so I could stand to shim the axle a little although I havent seen any ujoint problems in the 8 years or so that I've had the lift on. Although I suppose I go through them a little faster than before its just hard to really tell.

I know I have to correct the pinion angle with shims. I think I'm probably going to have to clean it up with about 6 degree shims. The angle at the CV joint end is what I'm wondering about. The guy was telling me the angle at the CV joint was too much at 25 degrees.

I guess my real issue is twofold. It's going to be a daily driver and I'm wondering if it's going to have vibrations due to the CV joint operating outside of it's recommended range. And then going through Ujoints every few months.

Does anyone know what the stock angle is at the CV? And also the operating angle range of stock CV joints?

thanks.

slyjki · Feb 7, 2006

jack it up by the bumber until flexed out turn the driveshaft to see if you have any bindage atall if not you are good to go.

broncnaz · Feb 7, 2006

The angle at the CV joint is irrelavant so to speak what you are looking for is the angle of the driveshaft measured off the tube vs the rear axle pinion yoke. CV joints are designed so they can be a few more degrees off than a standard driveshaft and live a long life.
Heres some stock specs
engine angle 4 3/4 degrees
rear driveshaft to horizontal 16 1/2 degree - 19 1/2 degree depending on GVW
rear pinion angle 13 1/4 degrees.
of couse the closer you can get the angle the longer your ujoints and CV will last. I would say that most people have no vibration problems with setups similar to yours I know a couple of guys that had similar setups except they had 5.5in lifts and they had no problems with vibrations but did wear out ujoints fairly fast.
Not real sure on the recommeded operating angle of the CV but It shouldnt be a problem as it is for street driving and while offroad your speeds are slow at full flex the angle may get steeper but the driveshaft also tends to get longer which counter acts the angle to a degree.
You might want to do a search on CV joints to get the answers your looking for. I've been on this forum for a while and it's a issue that doesnt come up all that often so it would lead me to believe its not that big of a problem on our rigs. but its worth checking out could save a few ujoints.

RnrdTheFox · Feb 8, 2006

broncnaz said:
The angle at the CV joint is irrelavant so to speak what you are looking for is the angle of the driveshaft measured off the tube vs the rear axle pinion yoke. CV joints are designed so they can be a few more degrees off than a standard driveshaft and live a long life.
Heres some stock specs
engine angle 4 3/4 degrees
rear driveshaft to horizontal 16 1/2 degree - 19 1/2 degree depending on GVW
rear pinion angle 13 1/4 degrees.
of couse the closer you can get the angle the longer your ujoints and CV will last. I would say that most people have no vibration problems with setups similar to yours I know a couple of guys that had similar setups except they had 5.5in lifts and they had no problems with vibrations but did wear out ujoints fairly fast.
Not real sure on the recommeded operating angle of the CV but It shouldnt be a problem as it is for street driving and while offroad your speeds are slow at full flex the angle may get steeper but the driveshaft also tends to get longer which counter acts the angle to a degree.
You might want to do a search on CV joints to get the answers your looking for. I've been on this forum for a while and it's a issue that doesnt come up all that often so it would lead me to believe its not that big of a problem on our rigs. but its worth checking out could save a few ujoints.

Thanks. That's the kinda details I was looking for. My gut tells me you are correct. I've been surfing the web and found the following articles. Only one of them get's into the operating range of the CV joint, and it's very limited. It says that "A stock Spicer double cardan CV joint can be run successfully at about 22 degrees". I just wonder what "successfully" really means. I'm just trying to get to a space where I don't have a vibration driving down the highway at 70 mph, and get a resonable life from the ujoints. I deal with a shorter life on ujoints even to achieve the first requirement %)

http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml#Double-Cardan-Measurement

http://www.4x4wire.com/toyota/tech/driveline/

http://www.pirate4x4.com/tech/billavista/PR-shaft/index.html

RnrdTheFox · Feb 8, 2006

I spent most of my morning calling different driveline shops both locally and around the country. All but one, said things should be fine. The one that did say it would not work, didn't seem to be that "educated" in what I was asking.

Two of the others said the "operating range" for a stock Spicer CV joint was up to 26 degrees and that they had seen them work just fine beyond that. All said the rear pinion needs to be zero'ed out without question, if I didn't want vibrations and failing Ujoints.

Driveline angles revisited

RnrdTheFox

Sr. Member

broncnaz

Bronco Guru

RnrdTheFox

Sr. Member

slyjki

Sr. Member

broncnaz

Bronco Guru

RnrdTheFox

Sr. Member

RnrdTheFox

Sr. Member

Similar threads