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I need some help. I had someone else install my trans an 4 link I have had some vibration when you let off the gas. The drive shaft runs good an true. I'm not a drive line person but now I'm thinking my angles are off. Trans is down 8 degrees rear is up 6 degrees this is setting at ride height. With the shaft in it is going down hill towards the trans 3 degrees. Dose that make sense to anybody?
Your trans yoke must be lower than your rear pinion. I think I'd raise the trans but make sure the intake is level. you could lower the angle of the rear a bit. You may have to re figure your entire drive line.
It is will this be a major problem
Like Charlie said, get the intake manifold level first which should leave the transmission about 3 degrees down.....then lower the pinion to about 3 degrees up....
Ok, thanks
The engine/trans and pinion should be set at the same angle. Anything more than 3 degrees would be unusual.
How are you measuring the angles? Also measure the angle of the driveshaft.
Off the yoke face an trans input face
If you are measuring angles relative to the ground level----you are doing it wrong--it should be the angle of the drive shaft relative to the angle of the trans tailshaft and pinion c/l----the shorter lengths in most hot rods make the angles more than longer drive shafts in modern stuff--------
Ok, I got my trans down bout 2.8 deg pinion up 3.0 deg another question my drive shaft at the rear and center is about .014 runout at the trans it hard to tell. My in an out clearance is 1.125 slip but I can take the drive shaft and move it up and down or back an forth till it's plum off the indicator I got + or - .04 on my indicator. I'm sure you should have some but is that normal?
Are you saying that with a dial indicator on driveshaft you're getting 0.014" runout at the back, 0.014" at the center, but able to drive it off scale, exceeding 0.040" at the transmission end? If my understanding is right, and if you have your u-joints properly seated in the rear yoke it sounds to me like you may have a bad pinion bearing, and at the front end maybe a bad output shaft bearing. That said, you may have a driveshaft that's bent or has a yoke installed funky. Have you had your driveshaft checked at a good shop, like Inland Empire if you have one near by? If not look for the place that services big trucks and they generally do car & jeep shafts, too.
I had the shaft checked by the people that made it they said it was good but I didn't see it my self. I don't think it's pinion bearing. It was biult by someone I know very well it only has bout 500 miles on it. The drive shaft was worse than that at the back I turned it 180* to get it within .014"as for the trans bearing I will have to get it checked
Are you sure you've got the right front yoke for your transmission output shaft? Could be the tooth count is right, but the ID of the yoke is a little large and you're only getting partial engagement of the splines? Just thinking out loud here. With the driveshaft out can you wiggle the transmission output shaft?
The shaft coming out of the trans will move around about .050"
Seems to me that the output shaft bearing shouldn't have that kind of play in it, but then I'm not a tranny expert by any means. Maybe one of the other guys will jump in a bit later and offer some solid advice.Quote:
Originally Posted by 39 Chevy
Sounds like you need a new tail shaft housing bushing--------
How did you measure the run out??? and was the high/low spots at the same rotational point of the shaft????If for instance, they lined up exactly with the u joint cross---then you probably don't have the bearing cups seated properly--could be bend housing or snap rings not seated----
It's hard to get a good measurement because it's loose I thank it may be the bushing like you said. Is there anything wrong with making the bushing longer for more support. Also is brass or bronze?
The good tailshaft bushings should be sintered bronze, similar to the material that the good valve guides are made of.... Jerry probably knows the real name of the stuff......
good valve guide are manganese bronze .color looks yellow bronze . and phosphor bronze. color red bronze ... Sintered bronze or oil lite bronze cast bronze SAE 841 is ok for a tail shaft bushing porous can fill with oil . would not work for a valve guide .wirst pin bushing in Rods is AMPCO 18 mosty trade name aluminum bronze ... Valve seats are 25 alloy alloy 3
Ok thanks I have some aluminum bronze , how bout the length can I make it longer?
Why would you not simply buy an OEM replacement??Quote:
Originally Posted by 39 Chevy
No reason not to really, I guess it's just the thought of doing it myself
you can make one but by the time you cut it and press it in then hone to fit .your wasting a good chunk of bronze . there will be wast. alot of the trans bushing are roll flat steel butt locked ground and diped they are cheap but last if you make one you will need a oil groove maybe a X oiling groove keep that aluminum bronze some what wet /cool and happy if it get hot and dry... bad deal
Not sure what the advantage of being longer would be..... the proper fit and most of the support comes from the ID and splines on the input shaft fitting the trans output shaft correctly.... If it were a 5 or 6 speed road racer with lots and lots of shifts per lap the extra support of a longer bushing might help stabilize things a bit, but on a street car I doubt there would be any gain....
For Pat: in the sprint car days on methanol, probably just seeing what we wanted to see, but sintered bronze guides seemed to hold lube better on the valves. This was back in the late 70's, we played with a lot of different valve guide materials trying to run the valves tight in the guides without seizing them!!!! As with many things, modern technology and alloys seems to have all but eliminated that problem??????
i have some race engine on alcohol G Reeds bbc is nasty ..and some others and there just plane old manganese bronze guilds .SAE 841 is alloyed impregnated with SAE 30 oil it ok for door hinge bushing pilot bushing water pumps .motor bushing . alloy 936 SAE modified 64 machines better the 932 . all guildes i use are iron or special mix of nickel bronze . manganese bronze hi zinc bronze. some phosphors bronze for valve guides . coating on valve stem what valve is made of. honing for the right clearance and abit of luck helps i never been a big fan of drying up the stems much on all out race stuff . nothing is harded on guides then the old air cooled harley davidson engines
Thanks, sounds like I will be better of just to buy one and be done.
Thanke for the help fellows this is a good place for info.
since you are dealing with drive line problems, you probably ought to use the proper tools to change that bushing----or take a chance on killing off the tail housing
Ok I'm back I got the tail housing off I need to know how much clerance it should be between the shaft an bushing. Right now the bushing is .006 bigger than the shaft.
Are you measuring the I.D. with the bushing already pressed in? That's the measurement that counts.
Yes, i measured it with the bushing pressed in
6 thousandths is acceptable for that size shaft. Oil it and install it.