Spicer Shifter Fork Stud

[FloridaCliff]

Discovered something interesting on my spicer this weekend.

There are two studs in the top of the transmission that the shifting forks pivot on.

It looks as if they are torqued into the top and then the forks and there associated spacers and etc are attached with a nut, then a cotter pin goes through the top of the bolt and nut.

I was traveling this weekend and after about an hour on the road, all of a sudden when I up shifted I was stuck in third.  Long story short, the stud had backed out of the top of the transmission and was cocked over.  Threaded back in as tight as I could, continued on my way.

After taking a good look at it at my destination, I was able to see that the stud had been replaced once.
I also noticed that the 1-2 stud had a small bolt that went through a hole in the bottom of the stud in the transmission.  The 3-4 stud had the hole in the transmission case but not in the stud.

Question, Is the small bolt and hole standard or is this something someone thought up?

I am going to pull the stud for the 3-4 tommorrow and drill the hole and install the bolt, but curious.

As a side note I had noticed it seemed harder to hit 3rd gear on my last outing, the shifting fork  looked fine sitting there, but pulling on it showed the problem.

Cliff

[plyonsMC9]

Any luck with this yet Cliff?  If not, anybody out there have any ideas for our fellow bus-nut on his tranny?

Hope this helps,
Phil

[tekebird]

got a part number

[FloridaCliff]

Phil, Thanks

Let me rephrase my question:

I have a GMC with a V-Drive and four speed spicer transmission, on the studs that the shifter forks sit on the transmission, is there a small bolt on the bottom that retains the stud from unwinding itself?

The bolt is not shown in my parts manual!

Regardless, I am putting it back, but trying to find out if this was a homebrew fix, spicer update or not, mainly because it worked good on the shifter stud that it is was used on properly.

So, If you have one of these, a quick look will answer my question!

Thanks

Cliff

[Ncbob]

Obviously, Cliff I cannot add any wisdom to your dilemma..but if you have a Parts Manual for that old relic  it should show you every standard part designed for the shifter mechanism.

I don't know how explicit the GM Maintenance Manuals are for information in this area either but I know MCI's books are a bit shallow as far as detailed information is concerned.

No doubt one of the other 4905 owners will come in and offer enough information to solve your problem.  A little lock-tite wouldn't hurt either.

Bob

[Jerry Liebler]

Cliff,
    I have an earlier version of the same trans (my bus is a 1968)  and it has no bolts locking the studs.  Also my parts manual doesn't show any.  The stud part number is: 2425856.  There are bushings on the studs in the holes of the  levers the bushing Part number is: 2425857.  I've had mine hang up due to worn bushings allowing interference between the 1-2 lever and the 3-4 lever.
Regards
Jerry 4107 1120

[FloridaCliff]

Jerry,

Thanks for the information and feedback.

It will be interesting to see if any other GMC owners have this setup. 

Cliff

[FloridaCliff]

Well, I was lucky and punched out the pin that the PO or someone had put in there to hold the stud in with.

I found that when the transmission was rebuilt or replaced the correct spacer washer was not used.

I replaced the spacer with the correct size and reassembled with my new bolt/pin stud retention and it shifts as smooth as a baby's (you know what)   

I also noticed when I had the 3-4 shift fork off that the lower spacer on the 1-2 was also too small.  It didn't show it in the book, but the way it hit the shifting rod led me too believe that.  I made a new spacer and installed it.  Shifted better than ever, even though the 1-2 was really never a problem.

Anyway, if you have a spicer you may want to check this out.  It just might save you a little trouble out on the road.

Cliff

[larryh]

I just printed the two pages out and there is no lock pin on the studs that I can see in exploded view or the parts break down HTH

LarryH