ST400: Shift into gear and KA THUNK

Ug, I can't win for losing. It's taken me 7 months to go from a non-running rats nest from the junkyard to a car that runs and drives. Yesterday I finally get my rubber fuel line replaced so that the car can move forward and back without someone walking the gas can back and forth with the car :laugh:

Anyway, tonight I go out to take it for a spin (actually a back and forth) and as soon as I shifted it out of park I feel a huge BAM and for a second it sounds like gears gnashing. My idle is high, probably 1500, but I've dropped cars into gear higher than that with no problems. Once I have it in R or D it does fine and goes back and forth, but when I first drop it in R or from N into D, real heathly BAM. Going from R to D, if I do it quickly, no bam, but from park or neutral after a while BAM.

Fluid is full and healthy looking.

Any thoughts? o No:

 

Get that idle dropped down to a more reasonable speed, 7-800 RPM would be good.
It will be a lot happier.

 

Joe, check your u-joints, pinion bearing and backlash in your diff!! Chances are that there is play in there some where. My best is u-joints are dry after sitting in the slavage yard. You would be better off if you replaced them instead of just trying to grease them. The needle bearing in the u-joints do not like dryness and will, essentially, disintegrate with a load applied.

HTH

 

Great thoughts! I haven't put grease anywhere on the car and I know it needs it, so I will have to check the driveline and evaluate the components.

 

Update: I have no problem going into drive with no thunk, but reverse gets me a thunk.

I went looking under the hood, and I my fan shroud had broken :ball: :ball: :ball:

I'm thinking the fan shroud catches when I put the car into reverse. I should know tomorrow when I remove the shroud.

 

Have you checked all mounts engine and trans.? I had a cracked bell housing on a buick once which also created a noise like this also.

Bill

 

Mystery is solved!

Found out what my noise was. When the car was put in reverse, when the driveline changed geometry, my cracked fan shroud would get pulled into the fan. So bad fan shroud :ball: but good motor. :TU:

 

Maybe, the car is almost 41 years old.

 

Check your mounts ...

 

A little JB Weld (after I check the mounts and get to the bottom of this) and the shroud should be good as new :laugh:

(I have the chunk that flew out).

 

Just as a follow up (don't mean to drag this to the top) it did turn out to be bad motors mounts.

Just wanted to add that note in case anyone else has a clunk.