| Slant Six Forum https://www.slantsix.org/forum/ |
|
| rear u-joint angle https://www.slantsix.org/forum/viewtopic.php?t=36601 |
Page 1 of 1 |
| Author: | gato [ Tue Aug 04, 2009 11:59 am ] |
| Post subject: | rear u-joint angle |
my A108 van has had the rear u-joint angle measured to be about 11* positive. i'm told it should be approx 2-3* negative. it starts to vibrate at about 65MPH. it all looks like stock positioning. what is movable to adjust this angle? D~~~! |
|
| Author: | Reed [ Tue Aug 04, 2009 12:56 pm ] |
| Post subject: | |
Only was to adjust that is to shim the rear axle. However, I would check things like the tranny mount and u-joints first. |
|
| Author: | Aggressive Ted [ Tue Aug 04, 2009 3:06 pm ] |
| Post subject: | |
You can buy 1 to 7 degree shims to put under the rear axle. It is not hard, loosen the rear U-Bolts around the axle housing and slide in the shim, then re-tighten. I run mine with a slight nose down, but level on the rear is fine too. You just don't want the nose parallel with the drive shaft or at a positive angle. When you apply torque the nose twists up as the rear of the vehicle squats. They make a bumper stop for racers to keep the wind up from happening, which bolts on the rear end above the rear U-Joint. $60 at Summit Racing.com Most all auto parts stores carry axle shims. |
|
| Author: | gato [ Tue Aug 04, 2009 8:35 pm ] |
| Post subject: | |
just b4 the road trip i got lucky enuff to run into a friend that shimmed me back a couple degrees. that's why the vibe doesn't come in til 65. in all honesty, it worked as a guide as to when i was going too fast. i mean, it is an A108! it looks like those shimms let my drivers side rear wheel drift forward about 1/2". seems the locator pins arent deep enuff. can they be extended? or replaced with longer pins? D~~~! |
|
| Author: | Aggressive Ted [ Wed Aug 05, 2009 10:35 am ] |
| Post subject: | |
You can replace the stock pin with a longer bolt and ream out the shim and shock mount plate to fit the new bolt. That will keep everything centered. |
|
| Author: | emsvitil [ Wed Aug 05, 2009 5:43 pm ] |
| Post subject: | |
How can the angle be that bad to start with? Did it originally have a CV joint at the tranny side? When you have a CV joint on the tranny side, the rear u-joint needs to point at the tranny CV(within 1-2 degrees). Which 10 degrees sounds like it's doing. |
|
| Author: | gato [ Wed Aug 05, 2009 10:30 pm ] |
| Post subject: | |
the front joint, in stock form, was something called a "ball and trunion", ibelieve. it was a disaster. whoever designed that thing should be hung by the balls till they r a falsetto! i did have it changed to a conventional u-joint, many years ago. i never heard anything about the rear joint angle till last month. D~~~! |
|
| Author: | gato [ Sun Nov 01, 2009 5:56 pm ] |
| Post subject: | |
is there anything special in the hardness of the locator pins? i finally got the out 2day. my local parts stores has reffered me to an alignment specialist to get axle shims. i think i can get it all back togetherrite this time. then just a leaking inner axle seal and i think i can leave "the road trip from hell" behind me. . . . . D~~~! |
|
| Author: | gato [ Sat Nov 07, 2009 9:40 am ] |
| Post subject: | |
how much sag can i expect of my rear leaf springs? could this be a factor? i think they may be the original springs. it seems there r no shims made with an angle as big as i need. it's been suggested to have my spring perches repositioned on the axle housing. i want to be sure it's not something simple b4 going such a drastic route. could the factory really have sent A vans out with such a negative angle? D~~~! |
|
| Author: | GTS225 [ Sat Nov 07, 2009 10:20 am ] |
| Post subject: | |
I know squat about the "A" vans, but here's a couple Q's that should be asked/answered. Does the "A" vans come originally with a two-piece drive shaft? What type drive shaft is in your van? (I'm speculating here....) If there's supposed to be a two-piece shaft in there, and someone at some time converted yours to a one-piece, then it very well could be the problem. Roger |
|
| Author: | gato [ Sun Nov 08, 2009 2:53 pm ] |
| Post subject: | |
to the best of my knowledge, it's always been a 1 piece shaft. there has never been any signs of any sort of center support bracket. originally it had a front u joint of the sort called a "ball and trunion". i think that was it. i did have it converted to a conventional cross type u joint many years ago. a regular cross in the rear also. the conversion may have place the front joint a few inches farther rearward of the transmission. i doubt that could account for 11* positive tho. D~~~! |
|
| Page 1 of 1 | All times are UTC-08:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|