4 Speed Input Shaft Question...

[elevenssc]

Should there be any play (left/right and up/down) at the end of the input shaft on a 4 speed trans?  I've got about 1/16" play (left/right) on mine.  My gut is telling me that this is not right but I want to ask.  If it ts not normal, what is the fix?  Is is as easy as replacing the input shaft bearing? (I say "easy" not knowing what this might involve)

Here's some background onfo...
Every 4th or 5th time I would take the car out, coasting up to a stop sign or stop light, I would push the clutch in and I'd get a nasty vibration.  Engine RPM at about 1200 to 1500.  The vibration would come from the clutch area because the solution to stop the vibration was to let the clutch out.  I was thinking that the pilot bearing or throw out bearing was the culprit.  Having separated the engine and tranny, the throw out bearing looks to be just fine.  I have not inspected the pilot bushing yet, but the trans input shaft play has me concerned.

The vibration I'm trying to describe is similar to what would happen if a small shaft "warbels" around the inside of a larger hole.  Since my input shaft does have some play in it, something could be mis-aligned.

Thanks for reading and thanks for your input.  Please let me know if any more info is needed.

[Changin Gears]

1/16" play is normal.  Really sounds like the pilot bushing.

[elevenssc]

Cool!

Not being that familiar with the 4-speed set up...do I need to pay attention to getting the clutch centered when I re-assemble things or is it pretty much self centering?  (I have a rear main oil leak I need to fix "while it is out" )

[Changin Gears]

You do need to align the clutch with an alignment tool or old input shaft.  I would suggest using the roller pilot bearing that was recently on another thread here.

[elevenssc]

Just curious, is there machining needed to make clearance for the roller pilot bearing or it a drop in?

[Changin Gears]

I've had mixed results insalling the bushing, you are supposed to use a burnishing tool. 

However the needle bearing one is easy to install. They are about $10.

[73EStroker]

If the tranny has been in for a long time then spend the $100 or so and replace all the bearings and the seals. The shaft will "flop" around a bit if the tranny is on the floor and you are moving the input shaft. What holds that in line is the main input bearing and the pilot bushing. Hard to tell what is wrong with the tranny on the floor unless you dismantle for a look around. You will see a wear strip in the bearing race when you remove it if the bearing is shot. Also synchro replacement is a lot better than banging the dog teeth of your gear couplers. Cheap insurance, replace them if the tranny is apart.

[Chryco Psycho]

the way to check the front brg is to measure the play in  & out there should be virtually no play if there is then you should replace the brg  , there is always side to side play . The brg is not easily replaced , you will need to remover the main shaft & gears & drop the counter shaft down to get the pinion out to replace the front brg , of you are doing this replace all the brgs

[Aussie Challenger]

Keep in mind that the spigot bearing supports one end of the input shaft, so if it is missing the input shaft will be free to move around and will do damage to the gearbox. You can use the original bush readily available or the bearing from a late model, but don't use both.

[elevenssc]

Thanks for all the great info.  There is no play in & out of the trans, so I think the trans is just fine.

I do have another question regarding the roller pilot bearing though...

I just got off the phone with Mancini Racing.  Evidently, (at least from my conversation) there are different versions of the 4-speed offered for 1970?  I needed to know which 4-speed I have, and depending upon which one I have, I may need to machine the input shaft to accept the roller pilot bearing...I'm confused.

I'm not that familiar with the 4-speed options that were put behind 340's for 1970.  If there are different models of 4-speeds, what are the different models, and how can I tell the difference?
Is the roller pilot bearing a "drop in" or is machining needed?

Thanks again...

[Aussie Challenger]

The only machining that I know of is if the back of the crank is not drilled out, then you need to drill a clearance hole so that the end of the input shaft will go into it, The bearing just slots into the back of the crank.
All A833 have 23 spline input shafts except for the Hemi/440 6pak which has 18 splines but this doesn't effect the spigot. The front bearing cover has 3 different sizes and you need to match to the bellhousing.

  Check out this site, very informative.....   
      http://www.slantsix.org/articles/4-speeds/ODA833fourspeed1.htm

[Changin Gears]

Sounds like Mancini thought you were talking about the through-out bearing. 

For the pilot bearing the trans type does not matter.  The needle bearing will fit them all. 

Since you are already running a stick shift, no machining for either bearing type will be required.

[elevenssc]

Thanks a bunch everyone!  You've given me all the info that I should need going forward.

This site rocks!!!