kalli

i'm carrying this problem around since I installed T5 and rearaxle. it's gettign better with modifications I already made. was really horrible at start, but the tyres were balanced and in the meantime I changed wheels and balanced them again (did that myself) and the result is the same. Since I know the angles are off (from measuring) I'll have to do that anyway. I am sure it will improve, however I'm not sure if it's 100% cured after that.
But we'll see tonight

kalli

i cannot possibly drop the engine :-( I have only half inch to oil pan and less than 1/8 of an ich between steering link and starter (when tyres are straight).
i have no idea why this is so close in my car ... no way i can drop the engine half inch

kalli

this might show it better:


as said, can't drop engine further as I'd hit the steering linkage with starter or oilpan.
Anyone any idea why this is so tight in my car? i know that people did drop their engine in 65s ... what's wrong here? is my steering linkage wrong?
the only idea is to bolt the steering linkage from the bottom. But I guess that's probably all tapered, so that's a no-go ...

Kalli

eZ

Have you tried putting some washers in the tranny crossmember? raising it just a touch? every little bit helps

kalli

Hi Ez ... I'll definetly try that next. I figured that I have the wrong steering likage (from a 6cyl). see other post. so that's not gonna change in the next two months.
There's no room in trans tunnel for lifting it. Worst case scenario I'll make some ... *g*
I'll check on that option again, however I feel thats not an option yet as if I raise the back, my starter will hit the draglink (center link). There's no room for any further down .... but I'll measure it up again while turning wheels ...

TexasAxMan

I think you have that backward, raising the tranny tailshaft should increase the clearance of the starter. Or am I missing something?

cprstreetmachines

You got the idea. Engine down or tail up. Pointing down 6 in the rear is a bit excessive. You were also right. If the decel makes it worse, the pinion thrusting down is making it farther out of range. iirc that is 6 cyl steering of the top of my head. All V8's had a single out put a the idler. Finding out if it's working angle or frequency vibration will help you figure it out. The reason you have "equal but/and opposite" is so the frequency coming from each u-joint is the same, and meet in the middle of the drive shaft, which equals no vibration. Overall length has a lot to do with what you can get away with. Working angle being the other, and you get that. Have you tried shimming the pinion up yet to 6 ? Measure your drive shaft angle when you do this if you haven't already. You cannot get a working angle without the angle of the drive shaft. You want to make sure moving the pinion angle up will not cause a horrid working angle. That will depend on the pinion to tail shaft height. I can't remember right now, but think the pinion is a good bit lower and you should be fine.

Offset pinion is normal. That helps vibration and u-joint life. Most manufactures do/did it. If you want to measure how far off it is drop a plumb bob at the front and rear rocker pinch welds. Snap a line that goes thru those marks pas the tail shaft, and past the pinion. Then drop a line from then, and measure side to side on your snap lines.

Mustang Al.

Hi Monster Billy. I was wondering did you figure out where your vibration was coming from. I have a 67Coupe ,347, C4 auto which has taken me 3 yrs to restore. I have had it once up the road and it vibrates like a washing machine, coming from the new balanced tailshaft with new joints both ends, new diff as well.. I found some wear in the extensioin hsg bush but i think its more than that. You have swapped the whole rearend it seems to fix your problem. I have had mine on jack stands with the wheels off with little change of vibration so thats the wheels eliminated. Tailshaft runout is 30 thou.
Any clues would be great
Al.

dodgestang

How about a non-standard look at the problem.

Do you have a non-low profile tire/rim combo you can put on and take the car for a spin and confirm you have the same problem.

The reason I ask....I have two cars with similar issues (in so far as the faster I go once I get it up there they start to sound like they have a driveline vibration). Both cars are EXTREMELY different in both suspension and driveline setups (exotic 3 link, 410 stroker, auto and stock style, 351w, t5). The only thing similar between the 2 is low profile tires.

Gun Jam

dont you guys see what he is talking about?

The pinion angle looks off to me on the horizontal plane not the vertical plane.

The left axle looks like its closer to the front than the right axle look how its kinked the yoke


Kalli I would measure from a known center point under the car to the U bolts that hold the axle to the leaf spring. Or any clever method of determining if the rear end is level on the horizontal plane in the car or the transmission is off center or something like that.