On the last two test drives I've had a reallly nasty vibration above 60 mph in 3rd or in OD....at first I thought I had beaten up on my u-joints pretty badly and they were starting to complain... jacked the car up in the driveway to see if I could replicate the test without the test drive...
Before start up I crawled under and checked the position of my shift rods, and checked the driveline and rear....drive line and u-joints still tight...rearend has about 1/2" of back forth play in it...

Fire it up and ran it to 4000rpm, 1st-smooth, 2nd slight roughness, 3rd the cars vibrating pretty good, OD- I could probably do without the feeling of driving over as washboard...

Left it jacked up and running in 3rd noise and vibrations coming from tranny and/or bellhousing.... got back in and stabbed the clutch and the vibration spooled down to nothing....returned as soon as I let the clutch out...

Looks like I'll be pulling my tranny and bellhousing, inspecting the clutch (it was in nice shape when Thor and I dropped the new engine in...). I have an Iron Cased A-833OD that I just picked up in really nice shape that I might rebearing and install (at least the case will be stronger...).

I was hoping to be shook down for a test and tune and be at Woodburn...



-D.Idiot

Sounds like the trans.....thats no fun.

Changing to the iron OD is a 2 hour deal?

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Yeah....Im the one who destroyed this rare, vintage automobile.....

I'll probably put a new BR and Tailshaft seal in it and reseal the side plate, and see what happens...

Hopefully a 3 hour ordeal...
1 hour to pull the old tranny
1 hour to put the new tranny in and change yoke on driveline (this one uses a 29/30 spline yoke not the 25/26 spline version
1 hour to drink some Amber Ale to cope with being sore from tranny swap aerobics...

I'll have to autopsy this one to see what happened (chipped a tooth maybe?)

More soon,

-D.Idiot

Looks like when I get another chance to crawl under the car again I'll check the driveline again, my buddy asked if I checked the driveline phasing (making sure the u-joints are still properly indexed and not slightly twisted)...I do have another driveline from an 8 1/4" equipped Dart Sport I could put together and see if that was the case (if not I'll have it prepped and ready for the Beater Valiant's swap to an 8 1/4" rear).

If it is the tranny, I'm trying to figure out a way to put a driveline yoke in the rear of the tranny so I can spool the tranny up to the 4K rpm and see if it really is the problem or not...and not have it 'puke' out the end and go skipping off down the street....

Hmmm....

-D.Idiot

.............and that might be the most optimistic possibility. Stand back kids.....and keep your garbage can lid held high.


In reality the yoke is unlikely to move out of the tailshaft......gyroscopicly speaking....

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Any chance the driveshaft lost a weight?

It's funny because this driveline is clean no dents and it never got a counter balance weight at the factory...

I figure tomorrow night I'll pull the driveline and see where we go from there...

I gotta go dumpster diving in my garage for my other driveline... I put it away for a rainy day...it got buried and now we are getting thunderstorms... Hmmmm...

-D.idiot

I just got the driveshaft out to compare with my only other 8 1/4" driveshaft....

The 1973 Dart drive shaft seems to be on the level...that means when indexed the drive u-joint fork is completely level with the rear axle u-joint fork.... The one under the duster seems to be off about 1/2" a bubble width using a level or close to a few degrees if using measurements off a level surface....

Neither drive line is the rubber isolated type, they are solid welded from the factory...

I'm going to knock in some U-joints and try the 1973 version and see if the vibration goes away... if so...I'll need to have the other one dismantled and re fabbed/realigned for the BV when I retrofit it out.

I'm not pulling down the axle twisting torque that the big blocks have, but I wonder if having quality tires and a fair torque band would have contributed to a slight driveline twist...

Will know more after Saturday morning....

-D.idiot

Ran the engine up to rpms with only a yoke in the tranny...no vibration like the one encountered on the drive. Other driveline and new u-joints, the thing runs much smoother, but there is still some 'racket' from the exhaust pipes vibrating against what ever is around them....

I'm thinking I'm gonna need a professional driveline as the 'stock' one may not be up to the task of taking that wallop of torque all the time...

Changed out the breakin oil, it looked fine. while under the car I noticed that the bolts for the "ear" for the engine and tranny bellhousing had all loosened up...after retightening, hopefully that will take care of some of the rattling....

Jeez...

-D.Idiot

certainly won't hurt anything to tighten the bolts I got a truck once for cheap becausethey said the motor was junk but come to find out it was the clutch that was destroyed and only half of the bellhousing bolts were in it

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Nothing beats a slant six
1987 D150

On the driveline paint a straight line full length, if it is twisting you can see it (trick big boys use)

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Part of Tyrde-Browne Racing