Torque??or Something Wrong?

[raharr3]

I have a 1967 170 three speed and when i down shift it pulls to the left and when i give it gas it pulls to the right. Detroit locker in the back Dana44s all around. What would cause this reaction?
Thanks you all in advance.

By the way the 170 will be gone soon replaced with a 302 and three speed replaced with C4.

 

[Broncobowsher]

I am going to guess suspension. Does it have a lift or anything. Check all the bushings, including the rear leef spring bushings.

mixing of lift parts like drag link drop brackets, drop pitman arms, different springs, etc. can have an influence on what you are describing as well. At one time I had the track bar corrected for my lift befrore I did the steering, took a half turn of the wheel between the gas and the brakes.

 

[raharr3]

The rig has no lift of any kind. YET;D

 

[RT]

Is the tire pressure in the back the same on both sides ??

The locker in my pickup would toss me around sometimes too.

 

[raharr3]

I will check the pressure after work.

Would different tread type tires cause the pulling to be more obvious? The two back tries are of different tread types is why i ask.

 

[carnage351]

I had that problem on my 85 bronco when a tie rod went out. If you checked the tie rod with the truck on the ground it seemed fine. I finally jacked up the truck and could tell it was bad. To check them jack up the truck and see if there is any play in them or have a friend turn the wheel lock to lock while you watch the drag link and the tie rods for play.

If it was just doing this under braking, i would say check and make sure that all the brakes (if it is still 4 wheel drum) are adjusted right.

Hope this helps, tires can also do some of this too, it may be a combination of things.

 

[RT]

I might measure the rolling radius too.

The two tires might say they are the same size but the actual size may be different.

 

[Broncobowsher]

With a Detroit, both rear tires must match. that is Right rear = Left rear. Same tire, same tread, same wear.

The locker acts as a spool that unlocks the faster tire and drives the slower tire in a turn. 2 different back tires is like the rear axle is always in a turn, just slightly.

When accelerating, the taller (slower turning) tire is driven and the smaller tire doesn't do anything until the big tire breaks loose (doubtful with the 170) and matches the speed of the smaller tire.

The detroit word the opposite when decelerating. The faster (smaller) tire drives the engine and the slower tire freewheels.

Sounds like the left tire is taller. Swap rear tire side to side and see if it reverses, that is pull left when on the gas.

 

[76Broncofromhell]

Detroits get upset very easily if the tire pressure/ wear are not exactly even. Check that and get back to us. It doesn't do it at a constant speed right?

 

[raharr3]

Correct, at a constant speed everything is good it is just when I give it gas and when i let the engine slow me down when I let up on the clutch after down shifting.

Ow ya btw this is only around town in 2wheel drive.