Automotive Help

[100Coogn]

Vehicle is a 1972 Ford pick up.  F-150 I believe.
Engine 300 straight six.
Transmission 4 speed manual. (hydraulic)

Problem is at 40 mph you can feel a shimmy and stick shakes around terribly.  U-Joints have already been changed.  What's odd is that it will do it while the truck is at a stop and in neutral.  Everything is smooth while the clutch is pushed in, but as soon as the clutch is released the gear shift begins shaking.  That is while it's in neutral.
The motor & transmission are not the original.
The motor is an 80's model and the transmission is a 90's.
Lol, sounds like a Johnny Cash song.
Sorry about the sketchy details of the truck.  I won't know the exact specs on things, until I see it.

Thanks for any help.

Coogan

[Tracerfi]

the truck is 40 years old that may be one of the problems other than that thats all i can tell you sorry 

[smoe]

Probably motor/transmission mounts.

[SilverZ06]

Probably motor/transmission mounts.

yep, sounds like bad mounts

[100Coogn]

I'm leaning towards throw out bearing, or warped fly wheel.

 Coogan

[Masherbrum]

Mounts are shot.   

[TomD]

Had one similar experience when making an engine change over from 6cyl to 8cyl in a customers Mustang about 25 years ago. Some Ford engines are internally balanced, and some externally. Note, this is not unique to Ford, just saying.. The problem arises when the bolt pattern is the same making it possible to bolt the wrong flywheel on. It's possible you may have a situation like this. Here is a link to a site which may be helpful in enabling to make that determination.

http://www.rowand.net/shop/tech/fordflywheeslandflexplates.htm

Hope you find this useful

[100Coogn]

Thanks TomD for your response.  Pretty good link there.  Appreciate your time looking that up.

Coogan

[CAP1]

Vehicle is a 1972 Ford pick up.  F-150 I believe.
Engine 300 straight six.
Transmission 4 speed manual. (hydraulic)

Problem is at 40 mph you can feel a shimmy and stick shakes around terribly.  U-Joints have already been changed.  What's odd is that it will do it while the truck is at a stop and in neutral.  Everything is smooth while the clutch is pushed in, but as soon as the clutch is released the gear shift begins shaking.  That is while it's in neutral.
The motor & transmission are not the original.
The motor is an 80's model and the transmission is a 90's.
Lol, sounds like a Johnny Cash song.
Sorry about the sketchy details of the truck.  I won't know the exact specs on things, until I see it.

Thanks for any help.

Coogan

if the transmission is from a 90's ford, it's got a hydraulic clutch release bearing, and a top mount internal linkage shifter.

it almost sounds like something's out of balance, or coming loose. by what you describe, i think the very first thing i'd check would be bellhousing bolts.

[TomD]

Thanks TomD for your response.  Pretty good link there.  Appreciate your time looking that up.

Coogan

Any time Coogan. Good luck sir.

[100Coogn]

cc:  Will check bell housing bolts and all the mounts.  Thanks again.  Just was curious as to what I'm getting myself into.

Coogan  

[morfiend]

I'm leaning towards throw out bearing, or warped fly wheel.

 Coogan

  This would be what I'd suspect first as well!  You could have a worn input shaft if the trowout bering is real bad but I'd think you could hear that.  Also as Cap said it has a hydraulic clutch release and they are known to fail so a small leak could also be part of the problem.

  I also would inspect both tranny and motor mounts,all you need is a good pry bar to check those!


  

[uptown]

the truck is 40 years old that may be one of the problems other than that thats all i can tell you sorry 

aren't you 15?

[RngFndr]

Interesting.. While in Neutral, let the clutch out, the whole Trans and engine start shaking, or JUST the shifter stick???

Remember the 300/6 is an externally balanced engine.. Requires a specific flywheel, balanced for the engine, and Pressure plate as well.. Although many Fords have the same Crank Flange pattern, so the wrong Flywheel will bolt in place easily.. And that will cause this problem.. But it should be shaking ALL the time if that was the cause..

If it is just the stick, then it might be bent shaft in the transmission..

Hmmmm???

[CAP1]

Interesting.. While in Neutral, let the clutch out, the whole Trans and engine start shaking, or JUST the shifter stick???

 i think you're the only other one that noted that it happens in neutral. that's what makes me lean towards bell bolts, loose/missing pressure plate bolt or srping, or possibly a fialed throughtout bearing. if it were anything at all to do with engine balance, it would be all the time. there could be internal transmission problems too, now that i think of it....those wouldn't be evident unless the tranny was being spun, which would happen any time that the clutch pedal is released....even in neutral.